US20070212247A1

US20070212247A1 - Method of generation of surgeless flow of the working fluid and a device for its implementation

Info

Publication number: US20070212247A1
Application number: US11/379,671
Authority: US
Inventors: Alexander Stroganov; Yury Volkov; Sergey Ryadnov
Original assignee: Individual
Current assignee: Individual
Priority date: 2006-03-08
Filing date: 2006-04-21
Publication date: 2007-09-13

Abstract

The invention refers to mechanical engineering and can be used for reducing the level of vibrations and noise caused by pulsations of the fluid flow generated by a rotor sliding-vane machine. A method of generating a surgeless fluid flow by rotating the rotor of the rotor sliding-vane machine, separating the fluid in the transfer cavities from the inlet cavity by the vanes, transference the transfer cavities to the outlet cavity of the machine, merging them with the outlet cavity followed by the fluid displacement characterized by that the volumes of the transfer cavities and fluid pressure in them are varied in the process of the transference so that the mentioned pressures are substantially equalized with the outlet pressure by the moment when the transfer cavities are merged with the outlet cavity. A rotor sliding-vane machine with a working chamber in the annular groove on the face of the rotor comprising vanes in the vane chambers and force chambers of variable volume. The machine comprises means of variation of the volume of the force chambers and fluid pressure in them, and means of adjusting the degree of the working fluid pressure changes in the force chambers.

Description

The invention refers to mechanical engineering and can be used for substantial reduction of level of the working fluid flow pulsations and of caused by them vibrations and noise in rotor sliding-vane pumps and hydromotors operating at high pressure.

BACKGROUND OF THE INVENTION

There is known a method of generation of a surgeless flow of the working fluid using a rotor sliding-vane machine consisting in the following: vanes sliding at the rotation of the rotor along the internal surface of the housing separate the transferred portions of the working fluid in transfer cavities from the inlet cavity in the housing of the machine with inlet pressure, transfer the mentioned transferred portions of the working fluid to the outlet cavity in the housing of the machine with the outlet pressure substantially unequal to the inlet pressure, after that transfer cavities are merged with the outlet cavity and the transferred portions are displaced into the outlet cavity.
The described method of generation of surgeless flow of the working fluid implies two variants of hydromechanical transformation of power in rotor sliding-vane machines. In the first variant mechanical power is supplied to the rotor shaft generating at rotation a flow of the working fluid from the inlet cavity with low pressure to the outlet cavity with higher pressure. In this case the rotor machine is working as a pump and transforms mechanical power into hydraulic one.
In the second variant the working fluid with higher pressure is delivered to the inlet cavity of the rotor sliding-vane machine and causes rotation of the rotor thereby transforming hydraulic power into mechanical one. In this case the machine is working as a hydromotor.
Hereinafter we shall describe the method of generation of surgeless flow of the working fluid with transformation of the mechanical power to hydraulic power as the basic variant, i.e. we shall describe a rotor sliding-vane machine working as a pump keeping in mind that all the described effects are also true for a hydromotor differing by the opposite sign of the pressure drop between the inlet and outlet cavities. For the rotor machine working as a pump the inlet cavity shall be called a suction cavity and the outlet cavity—a pumping cavity. The area of the transfer of the transferred portions from the inlet cavity to the outlet cavity shall be called forward transfer area.
The existing rotor sliding-vane machines implementing this method are subdivided into two main types depending on the working chamber configuration.
In the rotor machines of the first type the working chamber is bounded by the internal cylindrical surface of the housing and external cylindrical surface of the rotor. The vanes in such machines are generally located with a possibility of radial movement relative to the rotor (<<Pump handbook>> Igor J. Karassik, Joseph P. Messina, Paul Cooper, Charles C. Heald. McGraw-Hill Copyright 2001, 1986, 1976, section 3.8). The surfaces of the housing and of the rotor forming the working chamber in such machines have different curvature. Therefore the uniformity of the flow, i.e. constant speed of suction and pumping can be provided at their certain position relative to each other only. Displacement adjustment by changing the distance between the cylindrical surfaces of the rotor and of the housing leads to kinematic nonuniformity of delivery. The displacement hereinafter means the volume of the working fluid transferred by the rotor machine from the inlet duct to the outlet duct per one turn of the rotor.
In the rotor machines of the second type the working chamber is bounded by the face surface of the rotor and the internal face surface of the cover plates of the housing located opposite to it. The machines of this type provide for different kinds of movement of the vanes relative to the rotor: axial movement (U.S. Pat. No. 570,584), radial movement (U.S. Pat. No. 894,391), and rotation of the vanes (U.S. Pat. No. 1,096,804 and U.S. Pat. No. 2,341,710). For any kind of the vanes movement the cavities where the vanes are located shall be hereinafter referred to as the vane chambers. Flat face surfaces of the rotor and of the housing forming the working chamber provide a uniform delivery at any distance between them, i.e. at any displacement.
Allocation of the working chamber in the annular groove at the face of the rotor of pumps (U.S. Pat. No. 1,096,804, U.S. Pat. No. 3,315,164, U.S. Pat. No. 6,547,546 and RU2175731) provides for rotor radial unloading and rigid fixing of the vanes in the working chamber. The main sealings between reciprocally rotating parts in such a pump are transposed to the face surfaces of that part of the rotor where the annular groove is made and hereinafter referred to as the working part of the rotor, and to the corresponding face surfaces of the cover plate of the housing abutting the mentioned annular groove and hereinafter referred to as the working cover plate of the housing. The mentioned sealing face surfaces of the rotor and of the housing can be made flat. Therefore, technological, thermal and other clearances between flat sealing surfaces are easily taken up by forward oncoming movement of one sealing surface towards the other due to the pressing of the working part of the rotor to the working cover plate of the housing.
In the majority of the known rotor sliding-vane machines part of fluid is transferred back from the outlet cavity to the inlet cavity in the cavities in the rotor and in the cavities formed between the rotor and the housing. Hereinafter these cavities shall be referred to as the backward transfer cavities, and portions of the working fluid contained in them—backward transferred portions. The area of the transfer of the backward transferred portions of the working fluid contained in the backward transfer cavities from the outlet cavity to the inlet cavity is hereinafter referred to as the backward transfer area.
We consider the device described in RU 2175731 to be the closest analog of the device implementing the method described above.
The mentioned patent describes a pump with a housing comprising working and supporting cover plates called in the patent “the cover plates of the housing”. The face of the rotor located opposite the working cover plate of the housing has a cylindrical annular groove going through vane chambers called “openings in the rotor” in the patent with the vanes called in the patent “displacers”. The surfaces of the rotor's face, which are located at the opposite sides from the annular groove, contact with a possibility of sliding along the faces of the sealing elements, which are located opposite them and mounted in the slots on the working cover plate of the housing. The pump includes a backward transfer limiter, the patent calls “partition”, separating suction cavity from pumping cavity. Suction cavity connected to the inlet port is called in the patent “inlet opening”, while the pumping cavity connected to the outlet port is called in the patent “outlet opening”. The surfaces of the backward transfer limiter being in sliding contact with the rotor means of backward transfer insulation, are called in the patent “internal surfaces of cylindrical annular groove”. Backward transfer limiter is fastened to the working cover plate of the housing. The pump contains a vanes drive mechanism the patent calls “mechanism setting axial arrangement of the displacers relative each other”. The element of the housing being in sliding insulating contact with the vanes so that the distance between it and the rotor determines the displacement of the machine is hereinafter referred to as the forward transfer limiter. The forward transfer limiter in this pump is formed by a part of internal surface of the working cover plate. For an adjustable embodiment of the machine the patent calls the forward transfer limiter “an insulating element movable in axial direction”. The second face of the rotor contacts with the supporting cover plate of the housing.
The described method and the rotor machines where it is implemented have a significant disadvantage that is flow pulsations at significant pressure drops between the inlet and the outlet. It is caused by the fact that the fluid comes into the transfer cavity from the suction cavity at the inlet pressure. Then the transferred portion is transferred in the closed transfer cavity. In the machines with the working chamber made in the annular groove mentioned above the transfer cavities are formed by the sections inside the annular groove between two adjacent vanes and by the cavities inside the rotor connected to the working chamber, for example by the vane chambers. If the means of insulation remove the inter-leakage of the working fluid between the pumping and suction cavities via the forward transfer area (this is one of the conditions to achieve high volumetric efficiency) then the pressure of the transferred portion of fluid during the transfer does not reach the outlet pressure.
As a result when the transfer cavity merges with the pumping cavity there is a big difference between the pressure of the transferred portion of fluid and the pressure of the fluid in the pumping cavity. Due to compressibility of the working fluid there periodically appear counter flows of fluid decompression from the pumping cavity to the transfer cavity balancing the pressures and causing periodical pulsations of the flow rate and pressure in the pumping area and pressure line. Total mass of decompressing transfer of fluid brought to the transfer cavity by such a decompression flow depends on the compressibility of the fluid and the pressure difference to be balanced.
Different working fluids have different constant of compressibility therefore the value of the pressure drop where the mentioned decompression effects start to appear is different. For common industrial oils with the compressibility factor of about 0.001 MPa⁻¹the mentioned decompression effects start to appear at pressure drops of several MPa.
At the outlet pressures of tens MPa the total mass of decompression transfer can amount to several percent of the mass of the transferred portion of fluid. It should be noted that at the significant volumes of the backward transferred portions of the working fluid transferred back from the pumping area to the suction area there can also arise the corresponding pressure pulsations in the suction line of the pump caused in this case by decompression expansion of the fluid from the backward transfer cavities to the inlet cavity. The frequency of pulsations is determined by the frequency of the decompression flows origination. The level of decompression pulsations depends on many factors, for example on pressure drop, quality of insulation means, speed of the rotor rotation, proportion of the transferred volumes with the volumes of the cavities being under the outlet pressure and their hydrodynamic characteristics.
In positive displacement pumps with good insulation means at high pumping pressures these pulsations can reach significant values becoming the main reason causing noise and vibration in hydraulic systems that often lead to rejection of the hydraulic drive in favor of the electric drive.
We should also mention such consequence of the mentioned effect as the decrease of the total hydromechanical efficiency at high pumping pressures. In fact to displace total mass of decompression transfer brought by the counter decompression flow from the pumping cavity to the transfer cavity back to the pumping cavity, the displacer should make additional work spending additional part of the power supplied to the drive of the pump. This additional power is not transferred to the pressure line as it is transformed by counter decompression flows into the heating of the working fluid, vibrations of the hydrosystem, sound waves in pumping and suction ducts and acoustic noise.
As the volumetric efficiency of the pumps is increased due to improvement of the quality of the sealing elements the power losses on the leakages of the working fluid are decreased, and the power of the decompression flows increases and at maximum displacement of the pump and pumping pressures of tens MPa it can reach several percent of the power transferred to the load. In the majority of the pumps with variable displacement the delivery to the pressure line is decreased by simultaneous reduction of the volumes of the transferred portions and increase of volumes of the back transferred portions. It is evident that at high pumping pressures and small delivery to the load power losses on decompression in such pumps can even exceed useful power delivered to the load.
Application of passive means of smoothing over decompression pressure pulsations, for example throttle channels on the surface of the forward transfer limiter (patent EB00374731) may decrease the amplitude of pressure pulsations increasing their duration and thereby decrease a share of the power losses for noise and vibrations in hydrosystem increasing the losses on heating the fluid. But the total level of power losses on decompression can not be decreased by such passive means.
At high speeds of the rotor rotation the impulse of pressure decompression arising at merging the transferred volume to the pumping area have steep front edges. As a result there are generated high-frequency acoustic oscillations in the pressure line. The capacity of the pressure line in this case shall be considered as a distributed characteristic and mere increase of this capacity does not always lead to the corresponding decrease of the high-frequency components of decompression pulsations and noise and vibration connected with it.

SUMMARY OF THE INVENTION

The objective of the present invention is to decrease the level of pulsations of the flow of the working fluid caused by decompression in rotor sliding-vane machines and to decrease thereby the power losses for noise and vibrations generation in hydraulic system and for heating of the working fluid.
The present invention achieves this objective by the following method: surgeless flow of the working fluid is generated by means of rotating the rotor of rotor sliding-vane machine, filling with the fluid at inlet pressure the inlet cavity of the machine and connected to the inlet cavity transfer cavities in the rotor and between the vanes separated from the outlet cavity of the machine with outlet pressure substantially unequal to the inlet pressure, separating of the transferred portions of the working fluid from the inlet cavity in the transfer cavities by the vanes, connecting transfer cavities to the outlet cavity, displacing the working fluid into the outlet cavity of the machine. Each transfer cavity corresponds to its individual range of angles of the rotor rotation within which the said transfer cavity is separated from the inlet and outlet cavities. During the transference of the transfer cavities the pressures of the transferred portions of the working fluid in them is varied by variation of the volumes of the transfer cavities so that the mentioned pressures are substantially equalized with the outlet pressure by the moment of merging of the transfer cavities with the outlet cavity.
In rotor sliding-vane machine working as a pump the pressure in the outlet cavity also referred to as the pumping cavity exceeds the pressure in the inlet cavity also referred to as the suction cavity. Therefore the invention provides for reduction of volumes of the transfer cavities of the pump during their transference from the suction cavity to the pumping cavity of the pump and for corresponding increase of the pressure in the transferred portions. In a machine working as a hydromotor the pressure in the outlet cavity is lower than the pressure in the inlet cavity. Therefore the invention provides for the increase of volumes of the transfer cavities of the hydromotor during their transfer from the inlet cavity to the outlet cavity of the hydromotor and for corresponding decrease of the pressure in the transferred portions. Hereinafter we shall describe the method of generation of a surgeless flow of the working fluid in rotor sliding-vane machine working as a pumps as the basic variant. The described solutions are also applicable for a hydromotor modified in accordance with the opposite sign of the pressure drop between the inlet and outlet cavities.
Variation of the working fluid pressure in the transferred portions by variation of the volumes of the transfer cavities so that the mentioned pressures are significantly equalized with the outlet pressure by the moment of merging the mentioned transfer cavities with the outlet cavity removes the origin of decompression flows between the transfer cavities and the outlet cavity at the moments of merging described above. Thereby the pulsations caused by these decompression flows are removed and the uniformity of the flow of the working fluid is improved.
To implement the method of generation of surgeless flow of the working fluid a device is offered with a housing with inlet and outlet ports comprising a working cover plate with a forward transfer limiter and a backward transfer limiter made on it. The device comprises a rotor with vane chambers in the working part and an annular groove made on the working face surface of the working part of the rotor and connected to the vane chambers with the vanes kinematically connected to the vanes drive mechanism mounted on the housing. The working cover plate of the housing is in sliding insulating contact with the working face surface of the working part of the rotor and forms a working chamber in the annular groove. Rotor means of backward transfer insulation being in sliding insulating contact with the backward transfer limiter as well as rotor means of forward transfer insulation being in sliding insulating contact with the forward transfer limiter and comprising vanes separate from each other: the inlet cavity hydraulically connected to the inlet port, the outlet cavity hydraulically connected to the outlet port, and at least one transfer cavity including an inter-vane cavity bounded by the surfaces of the annular groove, forward transfer limiter and two adjacent vanes. Each transfer cavity corresponds to its individual range of angles of the rotor rotation within which the mentioned transfer cavity is separated from the inlet and outlet cavities.
To reduce the level of pulsations of the working fluid flow each transfer cavity comprises at least one force chamber connected to the inter-vane cavity contained in the mentioned transfer cavity, and each force chamber is kinematically connected to the means of the volumes variation with a possibility to change a proportion between the volume of the force chamber at the angle of the rotor rotation at which it is connected to the inlet cavity and the volume of the same force chamber at another angle of the rotor rotation at which it is connected to the outlet cavity.

LIST OF DRAWINGS

The essence of the offered invention is explained by the graphs and drawings of the device realizing the method described above. The figures present:
FIG. 1—graphs of variation of the volume of the transfer cavity and pressure of the working fluid in it at constant mass of the transferred portion of the working fluid depending on the angular travel φ of the transfer cavity within the range from the angle of its detachment from the inlet cavity φ_detach.to the angle of its merging with the outlet cavity φ_merg.;
FIG. 2—graphs of the outlet pressure pulsations caused by decompression flow at merging the transfer cavities with the outlet cavity in case of no leakages and compensating flows;
FIG. 3—schematic representation of implementing the method of variation of the volumes of the transfer cavities in rotor sliding-vane machine with force chambers of variable length: fragment of circular development in forward transfer area;
FIG. 4—schematic representation of implementation of the method of variation of the volumes of the transfer cavities in rotor sliding-vane machine with force chambers of variable length and with a supporting part of the rotor: fragment of circular development in forward transfer area;
FIG. 5—graphs of variation of the volume of the transfer cavity and the pressure of the working fluid in it depending on the angular travel of the transfer cavity within the range from φ_detach.to φ_merg.at adjustment of the total amplitude of variation of the volumes of the transfer cavities depending on the outlet pressure if there are no leakages and compensating flows;
FIG. 6—schematic representation of adjusting the total amplitude of variation of the volumes of the transfer cavities depending on the difference between the reference pressure and the pressure in the transfer cavity at the reference angle using a differential double-acting hydrocylinder and a control valve;
FIG. 7—graphs of the compensatory-comparative flow rate and of the variation of the volume of the transfer cavity, change of mass and pressure of the working fluid in it depending on the angular travel of the transfer cavity within the range from φ_detach.to φ_merg.at adjustment of the total amplitude of variation of the volumes of the transfer cavities depending on the difference between the reference pressure and the pressure in the transfer cavity at the reference angle;
FIG. 8—graphs of variation of the volume of the transfer cavity, change the mass and pressure of the working fluid in it depending on the angular travel of the transfer cavity within the range from φ_detach.to φ_merg.illustrating the variation of the shift angle and reference angle when the leakages rate from the transfer cavity is changed;
FIG. 9—graphs of variation of the volume of the transfer cavity, change of mass and pressure of the working fluid in it and fluid flow rate between the transfer and outlet cavities depending on the angular travel of the transfer cavity within the range from φ_detach.to φ_merg.at adjustment of the total angle of changing the pressure of the working fluid depending on outlet pressure by means of variation of the merging angle φ_merg.;
FIG. 10—graphs of variation of the volume of the transfer cavity, change of mass and pressure of the working fluid in it and fluid flow rate between the transfer and inlet cavities depending on the angular travel of the transfer cavity within the range from φ _detach. 0 to φ_mergingat adjustment of the total angle of changing the pressure of the working fluid in transfer cavities depending on outlet pressure by means of variation of the detachment angle φ_detach.;
FIG. 11—a graph of the secondary kinematic nonuniformity of the delivery caused by sine-like variation of the volume of the transfer cavities (delivery jumps of the first and the second type do not fall in the same time interval);
FIG. 12—a graph of the secondary kinematic nonuniformity of the delivery caused by sine-like variation of volume of transfer cavities (delivery jumps of the first and second type fall in the same time interval);
FIG. 13—graphs of the outlet pressure pulsations caused by decompression and of the secondary outlet pressure pulsations caused by kinematic nonuniformity of the delivery at zero volume of the outlet duct;
FIG. 14—graphs of the secondary outlet pressure pulsations caused by secondary kinematic nonuniformity of the delivery at small volume of the outlet duct;
FIG. 15—schematic representation of the method of compensation of secondary kinematic nonuniformity of the delivery using a compensating hydraulic duct between the outlet cavity and the transfer cavity closest to it;
FIG. 16—graphs of variation of the volume of the transfer cavity, change of mass and pressure of the working fluid in it and compensating flow rate depending on the angular travel of the transfer cavity within the range from φ_detach.to φ_merg.at generation of the compensating flow between the outlet cavity and the transfer cavity closest to it;
FIG. 17—graphs of residual secondary kinematic nonuniformity of the delivery if there is a compensating flow between the outlet cavity and the transfer cavity separated from the outlet cavity by one vane;
FIG. 18—graphs of secondary pulsation of the outlet pressure if there is a compensating flow between the outlet cavity and the transfer cavity separated from the outlet cavity by one vane for zero volume of the outlet duct;
FIG. 19—schematic representation of the method of compensation of secondary kinematic nonuniformity of the delivery using a compensating hydraulic duct between the outlet cavity and the transfer cavity separated from the outlet cavity by two vanes, wherein said duct contains a compensating cavity;
FIG. 20—graphs of variation of the volume of the transfer cavity, change of mass and pressure of the working fluid in it and compensating flow rate depending on the angular travel of the transfer cavity within the range from φ_detach.to φ_merg.at generation of the compensating flow between the outlet cavity and the transfer cavity separated from the outlet cavity by at least two vanes;
FIG. 21—rotor sliding-vane machine with force chambers of variable volume between the working part of the rotor and supporting part of the rotor supported by rotatory thrust block in the form of a rolling bearing: cross section across the plane passing through the backward and forward transfer limiters (a) and a sectional view along the plane passing through the inlet and outlet ports (b);
FIG. 22—rotor sliding-vane machine with force chambers of variable volume between the working part of the rotor and supporting part of the rotor sliding along the supporting cover plate of the housing: a sectional view along the plane passing through the inlet and outlet ports;
FIG. 23 a—rotor sliding-vane machine with working and supporting cover plates of the housing joined into an operational unit of the housing located between the working and supporting parts of the rotor, and with pivoted vanes and force chambers of variable volume between the supporting part of the rotor and the rotor linking element: a sectional view along the plane passing through the inlet and outlet ports;
FIG. 23 b—rotor sliding-vane machine with working and supporting cover plates of the housing joined into an operational unit of the housing located between the working and supporting parts of the rotor, and with pivoted vanes and force chambers of variable volume between the supporting part of the rotor and the rotor linking element: a sectional view along the plane parallel to the working face surface of the rotor and passing through the annular groove;
FIG. 23 c—rotor sliding-vane machine with working and supporting cover plates of the housing joined into an operational unit of the housing located between the working and supporting parts of the rotor, and with pivoted vanes and force chambers of variable volume between the supporting part of the rotor and the rotor linking element: fragment of the circular development along the annular groove;
FIG. 24—schematic representation of the tilt angle variator of the supporting cover plate of the housing;
FIG. 25—embodiment of a control valve in the form of a control sliding valve selector with stator windows of the slide valve on the supporting cover plate of the housing and a selector switch of stator windows of the slide valve;
FIG. 26—schematic representation of the means of the total angle adjustment by variation of the φ_merg.comprising normally closed bypass duct between the outlet cavity and transfer cavity and containing a valve of the total angle adjustment in the form of a back-pressure valve;
FIG. 27—schematic representation of the means of the total angle adjustment by variation of the φ_detach.comprising lockable bypass duct between the inlet cavity and transfer cavity and containing a valve of the total angle adjustment;
FIG. 28—embodiment of the valve of the total angle adjustment in the form of piston-like sliding valve selector of bypass channels;
FIG. 29—rotor sliding-vane machine with force chambers of variable volume between the working part of the rotor and supporting part of the rotor sliding along the supporting cover plate of the housing—cut out quarter of the rotor and housing: a view from the side of the working part of the rotor;
FIG. 30—rotor sliding-vane machine with force chambers of variable volume between the working part of the rotor and supporting part of the rotor sliding along the supporting cover plate of the housing: circular development of the machine along the annular groove, suction area, forward transfer area, pumping area and backward transfer area are marked;
FIG. 31—rotor sliding-vane machine with force chambers of variable volume between the working part of the rotor and supporting part of the rotor sliding along the supporting cover plate of the housing—cut out part of the rotor and housing: a view from the side of the supporting part of the rotor;
FIG. 32—rotor sliding-vane machine with force chambers of variable volume between the working part of the rotor and supporting part of the rotor sliding along the supporting cover plate of the housing—cut out half of the housing: a view from the side of the working part of the rotor, working and supporting parts of the rotor are not depicted;
FIG. 33—rotor sliding-vane machine with force chambers of variable volume between the working part of the rotor and supporting part of the rotor sliding along the supporting cover plate of the housing—cut out half of the housing: a view from the side of the working part of the rotor, part of the supporting cover plate of the housing is not depicted;
FIG. 34—rotor sliding-vane machine with force chambers of variable volume between the working part of the rotor and supporting part of the rotor sliding along the supporting cover plate of the housing: circular development of the machine along the annular groove and schematic representation of the means of adjusting the total amplitude of variation of the volumes of the transfer cavities, compensating hydraulic duct and means of adjusting the total angle for backward transfer cavities in the form of a back restriction bypass channel with a back-pressure valve.

DETAILED DESCRIPTION OF THE INVENTION

FIG. 1 presents two families of graphs: (a)—dependence of the volume of the transfer cavity on its angular travel and (b)—dependence of pressure of the transferred portion of the working fluid in the transfer cavity on its angular travel φ within the range of the angles of the rotor rotation φ_totalfrom the angle of detachment of the transfer cavity from the inlet cavity φ_detach.to the angle of its merging with the outlet cavity φ_merg.. Hereinafter the angles and the corresponding angular travels are understood as the angles of the rotor rotation around the axis of its rotation. The graphs are given for different types of dependence of the volume of the transfer cavity on its angular travel, namely: for the case of constant volume of the transfer cavity (curves 1 a, 1 b), for the case of decrease the volume of the transfer cavity providing for equalizing the pressure in it with the outlet pressure ( curves 2 a, 2 b), and for the cases of insufficient ( curves 3 a, 3 b) and excessive (curves 4 a, 4 b) decrease of the volume of the transfer cavity. All graphs are given for a machine working as an ideal pump, i.e. assuming that there is no change of mass of the transferred portions due to leakages.
The family of graphs in FIG. 2 depicts a time base of the outlet pressure with decompression pulsations for different extents of decreasing the volume of transfer cavities. All graphs are given for the same machine and for the same conditions as for FIG. 1. Curves on the graphs correspond to: curve 5—constant volume of the transfer cavity; curve 6—variation of volume of the transfer cavity providing pressures equalizing; curve 7—insufficient variation of volume of the transfer cavity; curve 8—excessive variation of volume of the transfer cavity.
FIG. 3 schematically presents a variation of volumes of the transfer cavities in rotor sliding-vane machine comprising housing 1, rotor with vane chambers 3 made in working part 2 of the rotor and comprising vanes 4 being in sliding insulating contact with forward transfer limiter 5 made on the housing and separating inter-vane cavities 8 from inlet 6 and outlet 7 cavities. Each transfer cavity 9 comprises inter-vane cavity 8 and force chamber 10 connected to it and made in the rotor similar to hydrocylinder while variation of the volume of transfer cavities 9 is realized by means of cyclical variation of the volume of force chambers 10 at the rotor rotation. The mentioned cyclical variation of the volumes of force chambers 10 can be realized, for example, by means of kinematic connection of movable walls 11 of force chambers 10 with cam mechanism 12 mounted on housing 1. The preferred embodiment (FIG. 4) has supporting part of the rotor 13 mounted with a possibility to rotate synchronously with working part of the rotor 2 and make tilts relative to it so that mutual tilt of the axes of rotation of supporting 13 and working 2 parts of the rotor causes cyclical variation of the volumes of mentioned force chambers 10 at the rotor rotation.
Variation of the transfer cavity volume by means of varying the force chamber volume at the rotor rotation can be supplemented by variation of the inter-vane cavity volume done by varying the extent of protrusion of the vanes sliding along the forward transfer limiter and separating this transfer cavity from the inlet and outlet cavities of the rotor.
Reduction of volume of closed transfer cavities of the pump to achieve the pressure equal to the pumping pressure required to make some work for compression of the working fluid and therefore requiring certain power consumption. This power spent on compression of the fluid is transferred to the pressure line in greater or smaller extent depending on the proportion of the volumes of transfer cavities and volumes of the backward transfer cavities and can be used in load at expansion of the compressed fluid. The mentioned proportion depends on the structure of the pump, and for a pump with variable displacement it also depends on the current displacement of the pump. The other part of the power spent on compression is proportional to the share of the working fluid returned in the backward transfer cavities through backward transfer area from the outlet cavity to the inlet cavity. The preferred embodiment of the invention provides for such a variation of volumes of the backward transfer cavities that the pressure in them becomes substantially equal to the inlet pressure by the moment of merging of the mentioned backward transfer cavities with the inlet cavity. For the pump mode where the outlet pressure exceeds the inlet pressure closed backward transfer cavities in backward transfer area are enlarged providing a decrease of pressure of the working fluid to the value of the inlet pressure. In this case the working fluid confined in closed backward transfer cavities makes a work expanding. So this other part of the power spent on the working fluid compression returns to the drive of the pump.
For the mode of a hydromotor increase of the volume of transfer cavities at their movement from inlet to outlet cavity allows recovering potential power saved in the compressed working fluid at its expansion.
Adjustment of the Extent of Pressure Variation of the Transferred Portions of the Working Fluid.
At the given composition of the working fluid and constant temperature the pressure Pi(φ) of the transferred portion of the working fluid is determined by its density ρ(φ). The density ρ(φ) is determined by the volume of the transfer cavity Vi(φ) and the mass Mi(φ) of the transferred portion of the working fluid in it. At the moment of detachment of the transfer cavity from the inlet cavity its volume Vi(φ_detach.i) and mass of the working fluid in it Mi(φ_detach.i) are determined by displacement of the machine. Change of mass Mi(φ) of the working fluid in the transfer cavity at its angular travel within the mentioned range of angles of the rotor rotation φ_totali from the angle of detachment of the transfer cavity from the inlet cavity φ_detach.i to the angle of merging with the outlet cavity φ_merg.i results from the working fluid migration with flow rate DRi(φ) into i transfer cavity due to leakages from it and inflow into it from the cavities with higher pressure. At the given characteristics of the means of insulation of rotor sliding-vane machine change of the mass dMi(φ) of the transferred portion of the working fluid depends on the difference between the outlet and inlet pressure dP, and on the rotor rotation speed ω. At transference of the transfer cavity from the inlet cavity to the outlet cavity its volume Vi(φ) is varied in accordance with the chosen dependence of the variable part of volume of the transfer cavity Ai(φ) on its angular travel: Vi(φ)=Vi(φ_detach.i)+Ai(φ). From the point of view of the present invention a significant characteristic of the dependence Ai(φ) is the extent of variation of the volume of the transfer cavity at given angle range φ_totali hereinafter referred to as a total amplitude of variation of the volume of the transfer cavity:
A _total =Ai(φ_merg. i)−Ai(φ_detach. i)=Vi(φ_merg. i)−Vi(φ_detach. i).
To achieve the pressure Pi(φ_merg.i) in the transfer cavity by the moment of its merging with the outlet cavity equal to the outlet pressure P_out, the adjustment of extent of the pressure variation of the transferred portion of the working fluid resulting from the variation of volume of the transfer cavity depending on the difference between the outlet and inlet pressure dP, on displacement of the machine, on the speed of the rotor rotation ω and on change of mass of the working fluid dMi in the transfer cavity is provided. The invention provides for two methods of such adjustment.
The first method, preferable in terms of the level of uniformity of generated flow at big changes of difference between the inlet and outlet pressures, provides that at the given range of angles φ_totali the adjustment is performed by changing the total amplitude Atotal of the variation of volume of the transfer cavity by changing the dependence Ai(φ). This method is hereinafter referred to as the method of the total amplitude adjustment.
The second method being cost-wise preferable provides that at the given dependence Ai(φ) the adjustment is performed by changing the range φ_totali of angles of the rotor rotation from φ_detach.i to φ_merg.i within which the transfer cavity is separated from the inlet and outlet cavities by means of changing φ_merg.i or by means of changing φ_detach.i. This method is hereinafter referred to as the method of total angle adjustment.
Both methods of adjustment are considered in detail below.
Method of the Total Amplitude Adjustment
The invention provides that in dependence on displacement of the rotor machine, on difference between the inlet and outlet pressures dP, and on change of mass of the working fluid in the transfer cavity dM the total amplitude of variation of volume of the transfer cavity Atotal is changed.
If the displacement of the machine increases the total amplitude Atotal is also increased, if the displacement of the machine decreases the total amplitude is decreased, for example, by means of kinematical connection between the forward transfer limiter and supporting part of the rotor that is made with a possibility to vary the tilt angle of the axis of its rotation relative to the axis of rotation of the working part of the rotor, or with another drive mechanism of movable walls of force chambers.
When the magnitude of the difference dP between the outlet and inlet pressures is increased the total amplitude Atotal is also increased, and when the difference is decreased the amplitude is also decreased. Curve 9 a in FIG. 5 describing the variation of volume Vi of the transfer cavity, and 9 b describing the change of pressure Pi in it correspond to greater pressure drop dP, while curves 10 a and 10 b—to smaller dP. Adjustment of Atotal depending on dP can be made, for example, using pressure sensors and electric drive.
For more precise equalizing of pressure Pi in transfer cavities with the outlet pressure Pout, especially at variable speed of the rotor rotation or at variable temperature and viscosity of the working fluid, the invention provides for total amplitude Atotal adjustment depending on difference between the reference pressure P_ref(Pin, Pout) equal to the chosen value between inlet Pin and outlet Pout pressures, and pressure Pi(φ_refi) in the transfer cavities at the chosen angles of the rotor rotation equal to the reference angles φ_refi. The mentioned reference angles φ_refi are chosen within the range from detachment angle φ_detach.i to merging angle φ_merg.i, namely: φ_refi is chosen equal to the angle shifted by the chosen angle of shift φ_shiftrelative to the angle at which i transfer cavity merges with the outlet cavity, i.e. φ_refi=φ_merg.i−φ_shift.
One skilled in the art can find that at the given dependence of the volume of the transfer cavity on the angle of the rotor rotation Vi(φ) at the given speed of the rotor rotation and given rate of leakages through the means of insulation of the chosen transfer cavity there is an unique correspondence between the pressure Pi(φ_refi) in the mentioned transfer cavity at the angle of the rotor rotation equal to the reference angle φ_refi for this cavity and the pressure in it Pi(φ_merg.i) at the angle of the rotor rotation at which this transfer cavity merges with the outlet cavity.
Therefore, in the pump mode at given outlet pressure Pout there is determined a value of reference pressure P_ref(Pout), providing equalizing of the transferred portion pressure Pi with the outlet pressure Pout by the moment when the transfer cavity merges with the outlet cavity. If at reference angles the pressure in the transfer cavities of the pump Pi(φ_refi) is below the reference pressure P_ref(Pout) then the total amplitude of variation of volumes of the transfer cavities Atotal is increased, but if it is above the reference pressure the total amplitude is decreased. In the hydromotor mode instead of the outlet pressure Pout the inlet pressure Pin is used as well as the inverse relationship of the total amplitude Atotal on correlation between P_ref(Pout) and Pi(φ_refi), i.e. if at the reference angles the pressure in the transfer cavities of the hydromotor Pi(φ_refi) is below the reference pressure P_ref(Pin) then the total amplitude of variation of volumes in transfer cavities Atotal is decreased, while if it exceeds the reference pressure the amplitude is increased.
Adjustment of total amplitude Atotal depending on the difference between the reference pressure P_ref(Pout) and the pressure in the transfer cavity at the reference angle Pi(φ_refi) can be done, for example, using pressure sensors and electric drive. In the preferred embodiment of the invention a hydraulic actuator is used, for example a differential double-acting hydrocylinder. In this case (FIG. 6) adjustment of total amplitude Atotal is done by moving piston 14 of differential double-acting hydrocylinder 15, while piston 14 is under the reference pressure from the first side looking into first cavity 16 of hydrocylinder 15 and under the outlet pressure (for a hydromotor—under the inlet pressure) from the second side looking into second cavity 17 of hydrocylinder 15. Hydraulic connection of first cavity 16 of hydrocylinder 15 with transfer cavities 9 is provided by unlocking control valve 18 at the angles of the rotor rotation equal to the angles of unlocking φ_unlock., and locking control valve 18 at the angles of the rotor rotation equal to the reference angles φ_ref. When first cavity 16 of hydrocylinder 15 is connected via valve 18 to transfer cavities 9, and if there is a difference between the reference pressure and the pressure in the transfer cavities the working fluid flows between cavity 16 and transfer cavities 9 and piston 14 travels. Transformation of piston 14 travel into the change of total amplitude Atotal is realized by kinematical connection of piston 14 to the mentioned supporting part of the rotor made with a possibility of changing the tilt angle of the rotation axis, or to another drive mechanism of movable walls of the force chambers.
Proportion of the outlet (for a hydromotor—inlet) pressure to the said value of the reference pressure providing equalization of the pressure of the transferred portion with the outlet pressure by the moment when the transfer cavity merges with the outlet cavity, is determined by proportion of the areas of the first and the second side of piston 14 and by the value of external forces acting upon piston 14, for example, from the side of means of tilting the supporting part of the rotor.
If the pressure in transfer cavities of the pump at the reference angles Pi(φ_refi) is less than the reference pressure P_ref(Pout) then the fluid flows from first cavity 16 of hydrocylinder 15 to transfer cavities 9, and piston 14 moves from the second side to the first one that leads to the increase of total amplitude of variation of volumes of the transfer cavities Atotal. If the pressure in transfer cavities of the pump at the reference angles Pi(φ_refi) exceeds the reference pressure P_ref(Pout) then the fluid flows from transfer cavities 9 to the first cavity 16 of hydrocylinder 15, and piston 14 moves from the first side to the second one leading to the decrease of total amplitude of variation of volumes in transfer cavities Atotal. Equality of the mentioned pressures Pi(φ_refi) and P_ref(Pout) corresponds to the equilibrium point of piston 14.
The described flows of fluid between the first cavity of hydrocylinder 15 and transfer cavities 9 hereinafter referred to as compensatory-comparative flows, lead both to the change of total amplitude Atotal and to the change of mass of the working fluid in transfer cavities that also leads to the change of pressure in them. At insufficient pressure in the transfer cavity Pi(φ_ref)<P_ref(P_out) compensatory-comparative flow goes from the first cavity of hydrocylinder to the transfer cavity (curve 11 a, FIG. 7) increasing the mass of the working fluid and the pressure in the transfer cavity (curves 11 b and 11 d). At an excessive pressure in the transfer cavity Pi(φ_ref)>P_ref(P_out) compensatory-comparative flow goes from the transfer cavity into the first cavity of the mentioned hydrocylinder (curve 12 a) decreasing the mass of the working fluid and pressure in the transfer cavity (curves 12 b and 12 d). The family of curves 13 a-13 d illustrates the processes in the transfer cavity in the steady working mode at P _out 0.
At rapid change of the outlet pressure from P _out 0 to P _out 1 or to P _out 2 the change of mass of the working fluid in transfer cavities due to compensatory-comparative flows allows to compensate the inertia of the total amplitude adjustment that is considered to be an additional advantage of such method of adjustment. Transitions from curve 13 c to curves 11 c or 12 c in FIG. 7 correspondingly reveal the changes of A_totaldue to the transfer by the compensatory-comparative flow (curves 11 a or 12 a) of the part of the working fluid from first cavity 16 of hydrocylinder 15 to transfer cavity 9. It can be seen that curve 11 c shifted after a single transfer of the mass from the first cavity of hydrocylinder lies above curve 14 c, i.e. total amplitude A′_total 1 did not reach the value of total amplitude A _total 1 corresponding to the equilibrium position of piston 14 at pressure P _out 1. Curve 11 b shows the change of mass dMi in the transfer cavity at Pi(φ_ref)<P_ref(P_out 0). Due to the increased mass the change of pressure in the transfer cavity Pi(φ_ref) does not follow the curve 11-1 d corresponding to insufficient total amplitude A′_totalat constant mass of the transferred portion, but follows the curve 11 d providing better approximation to curve 14 d corresponding to equilibrium total amplitude A _total 1, and therefore a better equalizing of the pressure in the transfer cavity Pi(φ_ref) with the outlet pressure P _out 1 by the moment of merging. Similarly, curve 12 c lies below curve 15 c, i.e. total amplitude A′_total 2 after a single mass transfer from transfer cavity to the hydrocylinder has not reached the value of total amplitude A _total 2, corresponding to equilibrium position of piston 14 at pressure P _out 2. But due to smaller mass (curve 12 b) the change of pressure in the transfer cavity Pi(φ_ref) follows the curve 12 d providing for better approximation to curve 15 d and therefore for better balancing the pressure in the transfer cavity Pi(φ_ref) with the outlet pressure P _out 2 by the moment of merging.
For even more accurate balancing the pressures Pi in the transfer cavities with the outlet pressure P out the invention provides for adjustment of total amplitude A_totalof variation of volumes of the transfer cavities depending on the amplitude and phase of pulsations of the outlet pressure. For the pump mode at which the outlet pressure exceeds the inlet pressure it is made as follows: if the moments of merging transfer cavities with the outlet cavity match with the positive-going fronts of pressure pulsations (curve 8 FIG. 2) then A_totalis decreased, but if the mentioned moments match with the negative-going fronts of pressure pulsations (curves 5, 7) then A_totalis increased. For the mode of a hydromotor at which the outlet pressure is less than the inlet pressure A_totalis on the contrary increased at positive-going fronts in the mentioned moments of time and is decreased at the negative-going fronts. If the amplitude of pulsations of the outlet pressure is increased the variation rate of the mentioned total amplitude is increased.
Adjustment of total amplitude A_totaldepending on the amplitude and phase of pulsations of the outlet pressure can be done, for example, using pressure pulsations sensors, phase detector and electric drive.
The preferred embodiment of the invention provides for the use of the described method of the total amplitude adjustment depending on the difference between the reference pressure and pressure in the transfer cavity at the reference angle, while reference angles are varied depending on the amplitude and phase of pulsations of the outlet pressure.
In the mode of a pump outlet pressure exceeds the inlet pressure and if the moments of merging the transfer cavity with the outlet cavity match with the positive-going fronts of pressure pulsations indicative of the excessive value of the total amplitude then the value of the shift angle is decreased and thereby the reference angle is approached to the angle of merging of this cavity with the outlet cavity. Thereby, the pressure in transfer cavities at the reference angles becomes higher than the reference pressure and total amplitude decreases. If the mentioned moments of time match with the negative-going fronts of pressure pulsations then the value of the shift angle is increased approaching the reference angle to the angle of detachment of the transfer cavity from the inlet cavity, as a result the pressure in transfer cavities at the reference angles becomes lower than the reference pressure, and total amplitude increases. In the mode of a hydromotor, on the contrary, the inlet pressure exceeds outlet pressure and if the moments of the transfer cavity merging with the outlet cavity match with the positive-going fronts of pressure pulsations then the value of the shift angle is increased and thus the value of the reference angle is approached to the angle of detachment of this transfer cavity from the outlet cavity. But if the mentioned moments match with the negative-going fronts of pressures pulsations then the value of the shift angle is decreased and thus the reference angle is approached to the angle of merging of this cavity with the outlet cavity. The shift angle can be adjusted, for example, by changing the moments of locking and unlocking control valve 18. When the amplitude of pulsations of the outlet pressure is increased the extent of variation of the shift angle is also increased.
If the leakages are equal for all transfer cavities then the shift angles are chosen equal for all the cavities. But if different transfer cavities have different rate of leakages then the choice of different values of the shift angles for different transfer cavities allows to compensate spread of leakages. Total amplitude of variation of volume of transfer cavities (FIG. 8, curve 16 a) is chosen corresponding to the average rate of leakages (curve 16 c). At equal shift angles compensatory-comparative flows equalize the pressures in the transfer cavities at φ=φ_ref=φ_merg.−φ_shift, but by the moment of merging with the outlet cavity the difference in leakages still leads to the spread of pressures in the transfer cavities (curves 17 b, 18 b) and residual pulsations of different signs. To compensate different rate of leakages the shift angles for different transfer cavities are chosen different. In the mode of a pump for that transfer cavity (curves 18 c, 18 d) which rate of leakages exceeds the average level for all transfer cavities (curve 16 c), (is chosen) shift angle φ _shift 2 should exceed average shift angle φ _shift 0. For the cavity (curves 17 c, 17 d) where the rate of leakages is less than the average level for all transfer cavities, shift angle φ _shift 1 should be less than average shift angle φ _shift 0 allowing to compensate the spread of leakages. As for the cavity which rate of leakages exceeds the average one (curve 18 c) shift angle φ _shift 2 is larger, at reference angle φ _ref 2=φ _merg. 2−φ _shift 2 the pressure in it Pi(φ_ref 2) is lower than reference pressure P_ref(P_out 0). Therefore compensatory-comparative flow will go from first cavity 16 of hydrocylinder 15 to this transfer cavity decreasing the mass of the working fluid in cavity 16 and increasing the mass and the pressure of the working fluid in the mentioned transfer cavity (curve 18 c), compensating the loss of the working fluid caused by high rate of leakages from it. For the cavity where the rate of leakages is below the average (curve 17 c), there is chosen a smaller shift angle φ _shift 1 therefore at reference angle φ _ref 1=φ _merg. 1−φ _shift 1 pressure in it Pi(φ_ref 1) shall be higher than reference pressure P_ref(P_out 0). Therefore compensatory-comparative flow shall go from this transfer cavity to cavity 16 decreasing the mass and the pressure of the working fluid in the mentioned transfer cavity with low rate of leakages (curve 17 c) and increasing the mass of the working fluid in first cavity 16 of hydrocylinder 15 thus compensating the losses of the working fluid taken by compensatory-comparative flows out of it to the transfer cavities with high rate of leakages. In a hydromotor mode the inverse dependence of the shift angle on the rate of leakages is applied. The rate of leakages can be detected, for example, by measuring pressure in the transfer cavities. The preferred embodiment provides that for each transfer cavity pulsations of the outlet pressure are detected at the moments of its merging with the outlet cavity while the reference angle for this transfer cavity is chosen depending on pulsations amplitude and phase as described above.
Method of the Total Angle Adjustment.
The invention also provides for a method of adjustment of the extent of variation of pressure in the transfer cavities by means of total angle adjustment, i.e. by adjustment of the angle range φ_total=φ_merg.−φ_detach.within which the transfer cavity is separated from the inlet cavity and from the outlet cavity, and variation of volume of the transfer cavity leads to the change of pressure in it. Total amplitude of variation of volumes of the transfer cavities Atotal at this method of adjustment is chosen corresponding to the maximum difference between the inlet and outlet pressure dP and maximum displacement. The corresponding changes of volume of the transfer cavity and pressure of the working fluid in it are shown in FIG. 9 ( curves 19 a, 19 b). At maximum pressure drop dP and displacement the total angle φ_totalis also maximal. When dP or displacement is changed total angle φ_totalis also changed, namely: when dP or displacement is decreased φ_totalis decreased, when these characteristics are increased the total angle is increased.
There are provided for two variants of the total angle φ_totaladjustment.
In the first variant φ_merg.is changed by connecting the transfer cavity with the outlet cavity ahead of time, at the moment when the pressure in the transfer cavity becomes equal to the outlet pressure. As a result of the ahead of time connection further change of pressure of the working fluid in the transfer cavity stops (curves 20 b, 21 b FIG. 9). The mentioned connection of the transfer cavity with the outlet cavity ahead of time can be done by shifting the vane separating the mentioned transfer cavity from the outlet cavity or by connecting the transfer cavity with the outlet cavity through a normally closed bypass duct. In the latter case starting from the moment of unlocking bypass duct a part of fluid is displaced out of the transfer cavity via the bypass duct to the outlet cavity (curves 20 c,d, 21 c,d FIG. 9) (for a hydromotor—out of the outlet cavity to the transfer cavity). Bypass duct is unlocked, for example, using a pressure sensor and electrically controlled valve. The preferred embodiment of the invention provides for the use of a back-pressure valve in the bypass duct that is opened when the sign of the pressure difference between the ends of the bypass duct is changed.
In the second embodiment total amplitude Atotal is also chosen at maximum (curves 22 a, 22 b FIG. 10), i.e. corresponding to the maximum values of dP and the displacement of the machine, when dP or displacement of the machine is changed φ_detach.is changed by the delayed detachment of the transfer cavity from the inlet cavity. The variation of φ_detach.can be done as follows: when the transfer cavity being transferred from the inlet cavity to the outlet cavity the transfer cavity remains connected to the inlet cavity within the chosen angular travel (curves 23 b-d, 24 b-d). The mentioned delay can be realized by changing the character of movement of the vane leading to the delayed detachment of the transfer cavity from the inlet cavity by this vane, or by connecting the transfer cavity with the inlet cavity via the lockable bypass duct. In the latter case up to the moment of the bypass duct locking a part of the fluid is displaced out of the transfer cavity (curves 23 c,d and 24 c,d FIG. 10) via the bypass duct to the inlet cavity (for a hydromotor—out of the inlet cavity to the transfer cavity), not to the outlet cavity. Therefore the second method of total angle adjustment is preferable for the machines which displacement has to be adjusted to zero. The bypass duct is locked, for example, using a pressure sensor and electrically controlled valve. The preferred embodiment of the invention provides for adjustment of φ_detach.depending on the amplitude and phase of the pressure pulsations in the outlet cavity. For the pump mode, when the outlet pressure exceeds the inlet pressure this is realized as follows: if the moments of transfer cavities merging with the outlet cavity match with the positive-going fronts of pressure pulsations (curve 8 FIG. 2) then φ_detach.is increased, i.e. the mentioned delay is increased, but if the mentioned moments of time match with the negative-going fronts of pressure pulsations (curves 5, 7) then φ_detach.is decreased. For the mode of a hydromotor, when the outlet pressure is less than the inlet pressure φ_detach.is on the contrary increased at negative-going fronts at the mentioned moments of time and is decreased at the positive-going fronts.
In both embodiments the resistance of the bypass duct is chosen so that the fluid flow along the bypass duct described above results in no pressure drop between the ends of the bypass duct significant from the point of view of the objective of the invention.
In order to equalize the pressure of the working fluid in backward transfer cavities to the inlet pressure by the moment when the backward transfer cavities merge with the inlet cavity there are provided similar solutions for adjustment of the range of angles of the rotor rotation at which current backward transfer cavity is separated from the outlet and inlet cavities. If the total amplitude Atotal is constant, the mentioned range of angles of the rotor rotation for each backward transfer cavity is increased at the increase of the difference between the outlet and inlet pressure and is decreased at the decrease of the mentioned difference. If the total amplitude Atotal is increased when the displacement is being increased then maximum value of the mentioned range of angles of the rotor rotation corresponds to minimum displacement, and when the displacement is increased the mentioned range of angles of rotation of the rotor is decreased.
Sinusoidal Law of Variation of Volumes of the Transfer Cavities
In the cost-wise preferable embodiment of the invention it is provided that the volumes of transfer cavities are varied depending on the angular travel of transfer cavities in accordance with the sinusoidal law. The angular travel of each i transfer cavity means the angle φ_imeasured in the direction of the rotor rotation from that position of the rotor at which this transfer cavity is equidistant from the inlet and outlet cavities. Sinusoidal law or Sine function is understood here as such a dependence of the variable part of the volume of the transfer cavity Ai(φ_i) on its angular travel that provides for the absolute value a₁exceeding absolute value of all other expansion coefficients a_kand b_kat expansion in Fourier series: $Ai (φ_{i}) = Ai (0) + \sum_{k} (a_{k} \sin (k φ_{i}) + b_{k} \cos (k φ_{i})) .$
One of the embodiments of the invention provides for the use a sinusoidal angular dependence of lengths of the segments of straight lines passing through the center of the circle limited by this and another coplanar circle of larger diameter with a center shifted by the value that is significantly smaller than the radius of the first circle to change the volumes in transfer cavities.
The use of cylindrical surface of the housing with an axis parallel and shifted relative to the axis of the rotor rotation for sinusoidal variation of volumes of transfer cavities allows for changing the extent of variation of volumes of transfer cavities by varying the mentioned shift of axes similar to adjustment of displacement of radial piston or radial sliding-vane pumps. The invention provides for the use of the mentioned shifted cylindrical surface of the housing as a guiding cam surface of the drive mechanism of movable walls of force chambers.
Another embodiment provides for the use of sinusoidal angular dependence of lengths of the line segments limited on the cylindrical surface by the plane perpendicular to the axis of the cylinder and by the plane tilted towards the mentioned surface at a small angle.
The use of the face surface of the housing tilted at a small non-zero angle relative to the plane perpendicular to the axis of the rotor rotation for sinusoidal variation of volumes of transfer cavities allows for changing the extent of variation of volumes of transfer cavities by changing the mentioned tilt angle similar to adjustment of displacement of axial-piston pumps. The invention provides for the use of the mentioned tilted face surface of the housing as a guiding cam surface of the drive mechanism of movable walls of force chambers.
The preferred embodiment of the invention (FIG. 4) providing for the use of supporting part of the rotor 13 mounted with a possibility to rotate synchronously with working part of the rotor 2 and to make tilts relative to it, while mutual tilt of the axes of rotation of supporting 13 and working 2 parts of the rotor in the plane passing through inlet 6 and outlet 7 cavity provides for cyclical variation of volumes of force chambers 10 in accordance with the sinusoidal law.
Sinusoidal law of variation of volumes of transfer cavities of variable volume generates secondary kinematic nonuniformity of the delivery of rotor sliding-vane machine due to cyclically changing total volume of the mentioned cavities connected to the outlet cavity and to the inlet cavity (FIG. 4). The mentioned nonuniformity of delivery has sharp jumping changes of delivery in the outlet cavity of two types (curve 25 FIG. 11). The jumps of the first type <<a>> take place in the outlet cavity at the moments when the transfer cavities merge with the outlet cavity. The jumps of the second type <<b>> take place in the outlet cavity at the moments when backward transfer cavities are detached from the outlet cavity. If the mentioned detachment of the backward transfer cavities from the outlet cavity occurs at the same time with the transfer cavities merging with the outlet cavity then delivery jumps of the second type coincide with the jumps of the first type, as a result the total amplitude of the delivery jumps increases (curve 26 FIG. 12). For the pump the mentioned jumps lead to the increase of the delivery. In the intervals <<c>> between jumping increase of the delivery the delivery is gradually decreased.
FIG. 12 presents an example of secondary kinematic nonuniformity of the delivery of rotor sliding-vane pump with 13 vanes, with the volume of the transfer cavity of 7 cm³and sum of volumes of the outlet cavity, cavities in the rotor connected to it, channels in the housing, equal to 32 cm³, at the tilt angle of the supporting part of the rotor corresponding to the pumping pressure of 40 MPa and compressibility of the working fluid of 0.001 MPa⁻¹characteristic for hydraulic oils. At zero change of mass of the working fluid in transfer cavities the mentioned secondary kinematic nonuniformity has amplitude of about 2% of the pump delivery when the jumps of delivery of the first and second types coincide. If the jumps of delivery of the first and second types do not coincide, the amplitude of the secondary kinematic nonuniformity decreases (curve 25 FIG. 11). If the jumps of the second type fall on the middle between the jumps of the first type the amplitude of the secondary kinematic nonuniformity for the described pump is about 1%.
If the capacity of the pumping duct is close to zero, i.e. if the load with a zero inlet capacity, for example, a throttle, is located directly next to the outlet port of the pump, then at the mentioned total outlet capacity of 32 cm³the mentioned kinematic nonuniformity for both cases is transformed into the pressure pulsations (FIG. 13) correspondingly 1% (curve 27) or 0.2% (curve 28) of the pumping pressure. At the same conditions the initial pressure pulsations caused by decompression exceed 11% (curve 29). Therefore, sinusoidal variation of volumes of the transfer cavities providing pressure equalizing of the transferred portions with the pressure in the outlet cavity by the moment of their merging and complete annihilation of power losses on decompression leads to the decrease of pressure pulsations from 10 to 50 times significantly improving the uniformity of created working fluid flow.
When the capacity of the pumping duct is increased pressure pulsations caused by kinematic nonuniformity of delivery are decreased (FIG. 14). One can see that even at relatively small capacity of the pumping duct equal to 320 cm³, pressure pulsations are decreased from 1% (curve 27 FIG. 13) to 0.2% (curve 30 FIG. 14) and from 0.2% (curve 28 FIG. 13) to 0.05% (curve 31 FIG. 14) correspondingly providing good uniformity of created working fluid flow. At further increase of the pumping duct capacity the uniformity of the flow improves and pressure pulsations caused by secondary nonuniformity of the delivery is decreased to negligible values.
Compensatory Flow
To improve the uniformity of created flow of the working fluid at small capacity of the pumping duct the invention provides for compensation of the mentioned secondary nonuniformity of delivery by generating at least one compensatory flow of the working fluid between one of the transfer cavities and the outlet cavity via a compensatory duct.
To compensate the mentioned delivery jumps of the first type the invention provides for (FIG. 15) merging of the current transfer cavity 9 with outlet cavity 7 after detachment from inlet cavity 6 of at least one of the following transfer cavities, and at the moment of merging the mentioned current transfer cavity with the outlet cavity there is created first compensatory flow of the working fluid between the transfer cavity following the mentioned current cavity and the outlet cavity via first compensatory duct 19.
Generation of the compensatory flow with a simultaneous merging of the transfer cavity with the outlet cavity is realized, for example, using a sliding valve selector or a solenoid valve providing the connection of the compensatory duct with transfer cavities at certain angles of the rotor rotation φ_compens.corresponding to the moments of merging other transfer cavities with the outlet cavity.
FIG. 16 presents dependences of compensatory flow rate DRi(φ) (FIG. 16 a), change of mass in the transfer cavity DMi(φ) (FIG. 16 b), volume of the transfer cavity Vi(φ) (FIG. 16 c) and pressure of the transferred portion Pi(φ) (FIG. 16 d) on angular travel of the transfer cavity in case of no compensatory flow (curves 32 a-32 d) and in case of compensatory flow between the outlet cavity and the closest transfer cavity (curves 33 a-33 d).
In this case the difference of pressures between the ends of the compensatory duct changes step-wise simultaneously with a first type jump of delivery from the cavities of variable volume to the outlet cavity causing the corresponding jump of the compensatory flow rate of the working fluid from the outlet cavity via the compensatory duct (curve 33 a).
Hydraulic resistance of the compensatory duct is chosen so that the jump of the compensatory flow rate from the outlet cavity and the mentioned jump of delivery of the first type are equal and compensate each other. The value of the secondary kinematic nonuniformity of delivery is proportional to the speed of the rotor rotation. Therefore when the speed of the rotor rotation is increased hydraulic resistance of the compensatory duct is decreased, and vice versa. If at the change of displacement of the rotor sliding-vane machine total amplitude of variation of volumes of transfer cavities is changed then at the increase of displacement hydraulic resistance of the compensatory duct is decreased, and vice versa. If at the change of the difference between the outlet and inlet pressure dP there is changed the full range of angles within which the transfer cavity is separated from the inlet and outlet cavities then at the increase of dP hydraulic resistance of the compensatory duct in increased and vice versa.
It is also possible to compensate the jumps of delivery of the second type similarly. For this purpose at the moment of detachment of the current backward transfer cavity from the outlet cavity there is generated the second compensatory flow of the working fluid between one of the mentioned following transfer cavities and the outlet cavity via the second compensatory duct.
Generation of the compensatory flow between the outlet cavity and the transfer cavity leads to the change of mass of the working fluid in the transfer cavity (curve 33 b) leading to quicker decrease of pressure differences between the ends of the compensatory duct (curve 33 d) and decrease of the compensatory flow rate (curve 33 a). Increase of the mass of the fluid in the transfer cavity compared to the initial variant (transfer from curve 32 b to curve 33 b in FIG. 16) leads to the necessity to decrease A′total compared to the initial Atotal (transfer from curve 32 c to curve 33 c FIG. 16) in order to achieve the same Pout (see curves 32 d without compensatory flow and 33 d with a compensatory flow FIG. 16). Difference between the character of decline of the compensatory flow rate (curve 33 a depicts flow rate to the transfer cavity, and curve 34 FIG. 17—flow rate from the outlet cavity, they are equal in value and opposite in sign) and the character of decline of the secondary nonuniformity of delivery in the intervals between the jumps (curve 35, FIG. 17) determines the level of residual kinematic nonuniformity of delivery (curve 36 FIG. 17).
For the example of the pump described above made so that the jumps of delivery of the first and second type coincide, at the speed of the rotor rotation of 3000 rpm and hydraulic resistance of the compensatory duct of 0.5 MPa sec/cm³generation of the compensatory flow between the outlet cavity and transfer cavity closest to it reduces the level of kinematic nonuniformity of delivery from 2% (curve 35) to 0.3% (curve 36). The level of pressure pulsations even for the example with zero capacity of the outlet duct described above is decreased from 1% (curve 27) to 0.1% (curve 37 FIG. 18) which is regarded as nearly absolute uniformity of generated working fluid flow.
For deeper suppression of residual kinematic nonuniformity of delivery the invention provides for merging of current transfer cavity with the outlet cavity after detachment of at least two following transfer cavities (FIG. 19) from the inlet cavity, and compensatory flow of the working fluid is generated between the second one or following it of the following transfer cavities and the outlet cavity via compensatory duct 19 comprising compensatory cavity 20 of chosen capacity separated from outlet cavity 7 by a channel with chosen hydraulic resistance. FIG. 20 presents dependencies of the compensatory flow rate DRi(φ) out of the mentioned compensatory cavity to the transfer cavity (FIG. 20 a), of the compensatory flow rate DR_ac(φ) from outlet cavity 7 to compensatory cavity 20 (FIG. 20 b), change of mass in the transfer cavity DMi(φ) (FIG. 20 c), volume of the transfer cavity Vi(φ) (FIG. 20 d) and pressure in the transfer cavity Pi(φ) (FIG. 20 e) on angular travel of the transfer cavity for the case of no compensatory flow (curves 39 a-39 e) and for the case of compensatory flow (curves 40 a-40 e). One can see that more linear character of the compensating flow decline (curve 40 b) reproduces the character of decline of the secondary nonuniformity of delivery (curve 35, FIG. 17) better and more complete compensation of the secondary kinematic nonuniformity of delivery is possible in this case.
The higher the capacity of the compensatory cavity is the lower the level of the residual uncompensated nonuniformity, but the lower total amplitude A_totaland the higher level of dissipative power losses caused by the effect of decompression of the working fluid at merging of the mentioned compensatory cavity with the current transfer cavity (see the jump of the compensatory flow on curve 40 a and pressure jump on curve 40 e) and by the losses on hydraulic resistance of the compensatory duct are. The capacity of the compensatory duct comprising the capacity of the compensatory cavity V_acis chosen on the basis of the optimum proportion between the level of dissipative power losses and the level of residual uncompensated kinematic nonuniformity of delivery for a particular application. Resistance of the compensatory duct at the set capacity is chosen as described above.
For the example of the pump described above application of such a method with the capacity of 297 cm³and hydraulic resistance of 0.05755 MPa·sec/cm³provides a reduction of the outlet pressure pulsations to the values of 0.001% order (curve 38 FIG. 18), i.e. absolute uniformity of the flow even for the described above conditions of zero capacity of the outlet duct.
Device
Device offered for implementation of the aforesaid method of generation of a surgeless flow of the working fluid comprises (FIG. 21-23, FIG. 29-34) housing 1 with inlet 24 and outlet 25 ports comprising working cover plate 21 with forward transfer limiter 5 and backward transfer limiter 22 on it. The device also comprises a rotor with vane chambers 3 made in working part 2 of the rotor, and annular groove 23 made on the working face surface of the rotor and connected to vane chambers 3 that contain vanes 4 kinematically connected to the vanes drive mechanism mounted on the housing. The rotor also includes force chambers 10 of variable volume. Working cover plate 21 of the housing is in sliding insulating contact with the working face surface of working part of the rotor 2 and forms a working chamber in annular groove 23. Rotor means of backward transfer insulation being in sliding insulating contact with backward transfer limiter 22, and rotor means of forward transfer insulation including vanes 4 being in sliding insulating contact with forward transfer limiter 5 separate from each other: inlet cavity 6 hydraulically connected to inlet port 24, outlet cavity 7 hydraulically connected to outlet port 25 and at least one transfer cavity 9. Each transfer cavity 9 is formed by inter-vane cavity 8, bounded by the surfaces of annular groove 23, forward transfer limiter 5 and two neighboring vanes 4, and at least one force chamber 10 connected to this inter-vane cavity 8. Each of the mentioned transfer cavities 9 corresponds its individual range of angles of the rotor rotation within which the mentioned transfer cavity 9 is separated from inlet 6 and outlet 7 cavities. The working fluid confined in the transfer cavities forms transferred portions of the working fluid. To implement the aforesaid method of generation of a surgeless flow of the working fluid the device comprises the means of variation of volumes made with a possibility to vary proportion between the volume of force chamber 10 at the angle of the rotor rotation at which it is connected to the inlet cavity and the volume of the same force chamber at another angle of the rotor rotation at which it is connected to the outlet cavity.
The invention provides for embodiments of the device suitable for use as a pump or as a hydromotor, and as a pumping-motor unit of hydromechanical transmission. In some embodiments the housing is fixed to the rack of the aggregate and the rotor rotates relative to the housing and the rack of the aggregate. In other embodiments the rotor can be fixed to the rack of the aggregate with the housing rotating relative to it. There is also another possible embodiment with the rotor and the housing rotating relative to the rack of the aggregate, for example, if the device is a unit of hydromechanical transmission. Hereinafter we shall consider relative rotation of the rotor and housing independently of the method of mounting of the device in the aggregate. In any case rotor or rotor unit means a unit with an annular groove in the face element and containing vanes making cyclical movements relative to the rotor at every turn of the rotor changing the extent of their protrusion to the annular groove. The housing or stator unit means the unit relative to which the location of the inlet and outlet ports does not change at reciprocal rotation of the rotor and housing.
The means of variation of volumes providing a possibility of changing the volume of the force chamber within the mentioned range of angular travel of the transfer cavity can be made, for example (FIG. 3), in the form of the mounted on housing 1 cam mechanism 12 being in sliding contact with the movable walls 11 of force chambers 10 of variable volume.
Device with Supporting Part of the Rotor
To implement the aforesaid method of sinusoidal variation of volumes of the transfer cavities the preferred embodiment of the invention (FIG. 4) provides for supporting part of the rotor 13 kinematically connected to working part of the rotor 2 by an assemblage of rotor elements comprising force chambers 10 of variable volume so that to rotate synchronously with the working part of the rotor with a possibility to make axial movements and tilts relative to it. Said movements of supporting part of the rotor 13 relative to working part of the rotor 2 lead to variation of volumes of force chambers 10. The means of variation of volume in this embodiment comprise the means of tilt of the rotation axis of supporting part of the rotor 13 relative to the axis of rotation of working part of the rotor 2. Tilt of the rotation axis of the supporting part of the rotor relative to the working part of the rotor at angle γ (FIG. 4) lying in the plane passing through the axis of rotation of the working part of the rotor and through inlet and outlet cavities causes sinusoidal variation of volumes of force chambers 10 at the rotation of the rotor. The amplitude of variation of the volumes is proportional to the tangent of the angle of reciprocal tilt of the said axes of rotation.
To adjust the variation of volumes of the force chambers the mentioned means of tilting comprise a tilt angle variator comprising a travelling element kinematically connected to the supporting part of the rotor so that the travel of the mentioned element leads to the change of the tilt angle of the axis of rotation of the supporting part of the rotor relative to the axis of rotation of the working part of the rotor.
The embodiment of the invention preferred from the point of view of volumetric efficiency at low speeds of the rotor rotation provides in this case (FIG. 21) that the means of tilt of the axis of rotation of supporting part of the rotor 13 comprise rotatory thrust block 26 with working part of the rotor 13 mounted on it. The rotatory thrust block is made, for example in the form of a rolling bearing.
To adjust total amplitude of variation of volumes of the transfer cavities the invention in this case provides for a tilt angle variator comprising a housing carrier 27 of rotatory thrust block 26 mounted with a possibility of tilt, i.e. a turn relative to working cover plate 21 of the housing around the axis parallel to the straight line passing through the axis of rotation of the working part of the rotor and through the forward and backward transfer limiters. Tilt angle variator comprises a travelling element in the form of piston 14 of differential hydrocylinder 15 kinematically connected to the housing carrier 27 of rotatory thrust block 26 so that the travel of piston 14 relative to hydrocylinder 15 causes rotation of carrier 27 around the mentioned axis and leads to the change of the tilt angle of the axis of rotation of supporting part of the rotor 13 relative to the axis of rotation of working part of the rotor 2.
To reduce the wear of the supporting part of the rotor at the tilt of its axis of rotation relative to the axis of rotation of the working part of the rotor the force chambers are kinematically connected to the supporting part of the rotor via load-bearing jointed elements made as sliding elements 29 with a flat surface being in sliding contact with the flat surface of supporting part of the rotor 13, and concave spherical surface being in sliding contact with convex spherical surface of movable walls 11 of force chambers 10.
The embodiment of the invention (FIG. 22) preferred from the point of view of reduction of the losses on friction and overcoming the tendency to cavitation at high speeds of the rotor rotation provides for the means of tilt of the axis of rotation of the supporting part of the rotor comprising supporting cover plate 30 of the housing being in sliding insulating contact with supporting part of the rotor 13. On supporting cover plate 30 there are made insulating dams 59 (FIG. 32) opposite the forward transfer limiter and backward transfer limiter 22 of working cover plate 21. To reduce the losses on friction there are made the supporting cavities 32 provided with the means of insulation between supporting cover plate 30 of the housing and supporting part of the rotor 13, in this case each transfer cavity 9 is connected to at least one supporting cavity 32. Supporting cavities 32 improve hydraulic balance of supporting part of the rotor 13 and reduce the losses on friction.
The invention provides for two types of architecture of the device for generation of surgeless flow of the working fluid comprising a supporting cover plate of the housing.
The first type of the architecture of the device corresponds to traditional configuration of rotor hydraulic machines with the rotor located between working 21 and supporting 30 cover plates of the housing linked by the linking element of the housing. The linking element can be traditionally made as a hollow body with a rotor located inside it. There is also an embodiment with a through opening in the rotor with the linking element of the housing passing through it.
In the devices corresponding to the second type of architecture (FIG. 23 a, b, c), supporting cover plate 30 of the housing and working cover plate 21 of the housing are combined forming operational unit 33 of the housing located between working 2 and supporting 13 parts of the rotor. Operational unit of the housing can be made as an integral part. In such an embodiment the role of the working cover plate is performed by the face surface of the operational unit that is in sliding insulating contact with the working face surface of the working part of the rotor, and the function of the supporting cover plate is performed by the opposite face surface of the operational unit being in sliding insulating contact with the surface of the supporting face of the supporting part of the rotor. For the second type of architecture the invention provides that the mentioned assemblage of rotor elements used to connect working 2 and supporting 13 parts of the rotor comprises rotor linking element 34. There are provided for two embodiments of the rotor linking element. In the first embodiment operational unit 33 of the housing has through opening 35 which rotor linking element 34 passes through. In the second embodiment the rotor linking element is made outside the operational unit of the housing mounted on the bearing element, like a shaft, passing via the through opening in the working or supporting part of the rotor. Force chambers 10 can be located both at the side of the working part of the rotor, and at the side of the supporting part of the rotor. The device has channels made for connection of supporting cavities 32 to inter-vane cavities 8. These channels can be made in linking element 34. The preferred embodiment provides for making channels 89 in operational unit 33 of the housing, including the channels in forward transfer limiter 5. To prevent the losses on fluid decompression at merging of channels 89 with transfer cavities 9, channels 89 are made so that the capacity of channel 89 makes a negligible share of the volume of transfer cavity 9.
In the devices in FIG. 22, 23 the mentioned supporting cavities are made on supporting part of the rotor 13 and separated by insulating dams 31. In particular embodiment the supporting part of the rotor is made similar to the working part of the rotor, i.e. also comprises the annular groove and the vanes located in vane chambers and locking the annular groove and separating it into separate inter-vane cavities, equivalent to the supporting cavities from the point of view of hydraulic balancing. In this case the mentioned insulating dams of the supporting cover plate opposite the forward and backward transfer limiters of the working cover plate are made as forward and backward transfer limiters, and in the annular groove there is formed the second working chamber between the supporting part of the rotor and the supporting cover plate of the housing. In case of such an embodiment the offered invention considers any of two mentioned parts of the rotor as working and the other is correspondingly considered to be the supporting part.
The invention also provides for such an embodiment (FIG. 25) where supporting cavities 32 are made in supporting cover plate 30.
Both mentioned types of architecture of the device with the supporting part of the rotor sliding along the supporting cover plate of the housing, and the variants of embodiment of the supporting cavities are described in details in the application RU 2005113098 of 26 Apr. 2005 <<Rotor sliding-vane machine>>.
No matter which of two types of architecture described above is implemented in the devices containing a supporting cover plate of the housing, the invention provides for adjustment of total amplitude of variation of volumes of the transfer cavities. For this purpose supporting cover plate 30 of the housing (FIG. 24) is mounted with a possibility of turn relative to working cover plate 21 of the housing around axis 36, parallel to the straight line passing through the forward and backward transfer limiters. Tilt angle variator comprises travelling element 28, kinematically connected to supporting cover plate 30 so that the travel of mentioned element 28 causes a turn of supporting cover plate 30 around the mentioned axis and leads to the change of the tilt angle of the axis of rotation of the supporting part of the rotor relative to the axis of rotation of the working part of the rotor.
Device Embodiments for Implementing the Methods of Total Amplitude Adjustment
To implement the aforesaid method of the total amplitude adjustment the tilt angle variator also comprises a converter of the parameters of the working fluid flow into the travel of the mentioned travelling element.
To implement the described above method of adjustment of the total amplitude of variation of the volumes depending on the difference between the outlet pressure and inlet pressure the mentioned variator of the tilt angle of the axis of rotation of the supporting part of the rotor comprises a converter of the difference of pressures between the inlet and outlet cavities into the travel of the travelling element which is kinematically connected to the supporting part of the rotor with a possibility to change the tilt angle of the axis of rotation of the supporting part of the rotor at the travel of the mentioned element. The mentioned converter is made, for example, using pressure sensors and an electric drive or using a calibrated spring and a piston of the hydrocylinder filled with the working fluid under the outlet pressure of the pump (for a hydromotor—under the inlet pressure).
To implement the aforesaid method of adjustment of total amplitude of variation of volumes of the transfer cavities depending on the difference between the reference pressure and the pressure in the transfer cavities at the reference angles, the invention provides for the mentioned tilt angle variator comprising a converter of the difference between the reference pressure and the pressure in the current transfer cavity at the reference angle into the travel of the travelling element kinematically connected to the supporting part of the rotor with a possibility to vary the tilt angle of the axis of rotation of the supporting part of the rotor at travel of the mentioned element. The reference pressure is equal to the chosen value between the inlet and outlet pressures and the reference angle is chosen within the range from the angle of detachment of the mentioned current transfer cavity from the inlet cavity to the angle of merging of the mentioned current transfer cavity with the outlet cavity.
The said converter can be made using pressure sensors and an electric drive. In the preferred embodiment the mentioned converter is made as a hydraulic actuator, for example, as a double-acting hydrocylinder made with a possibility of hydraulic connection to the transfer cavities via the control valve and hydraulically connected to the outlet cavity (for a hydromotor—to the inlet cavity). In one of the embodiments of the invention (FIG. 6) hydraulic actuator is made as differential double-acting hydrocylinder 15 with first cavity 16 connected to control valve 18, and second cavity 17 connected to outlet cavity 7. Control valve 18 is equipped with an electric drive, for example, a solenoid, and an electronic control system providing the opening of control valve 18 at the moments of time corresponding to the angles of the rotor rotation equal to the mentioned reference angles. The use of a solenoid valve with electronic control as a control valve that can be opened and closed in the moments of times specified for each transfer cavity provides maximum flexibility of the shift angles adjustment depending on the rate of leakages. But such valve should be opened and closed many times during one turn of the rotor so the operation speed of such a valve will restrict the possibilities of the shift angles adjustment at high speed of the rotor rotation.
In another embodiment of the invention (FIG. 25) the mentioned control valve is made as a control sliding valve selector with stator window of slide valve 38 on the first surface on the stator unit of the machine hydraulically connected to first cavity 16 of differential double-acting hydrocylinder 15, and rotor windows of slide valve 39, made on the second surface on the rotor unit of the machine so that each transfer cavity is hydraulically connected to one rotor window of slide valve. The mentioned first and second surfaces are in sliding insulating contact with each other with a possibility of hydraulic connection of each rotor window of slide valve to stator window of slide valve. Connection of the transfer cavity to the first cavity of differential double-acting hydrocylinder in this case occurs when the corresponding rotor window coincides with the stator window of the sliding valve selector. Shift angles in this case are set by mutual location of the slide valve windows on the rotor and stator units. To adjust shift angles at high speeds of the rotor rotation the invention provides for the use of a control sliding valve selector with an assemblage of stator slide valve windows 38 on the first surface on the stator unit of the machine made with a possibility of hydraulic connection of each rotor slide valve window 39 to any stator window of slide valve 38. Each stator window of slide valve 38 is hydraulically connected to selector switch 40 of the stator windows that is hydraulically connected to first cavity 16 of differential double-acting hydrocylinder 15. Depending on the speed of the rotor rotation, viscosity of the working fluid and other characteristics influencing the rate of leakages out of the transfer cavities there is chosen one of the stator slide valve windows that is hydraulically connected to first cavity 16 of hydrocylinder 15 via selector switch 40. Thereby there is chosen one shift angle from a set of the shift angles. The selector can be made, for example, as a solenoid distributing valve. In the machine shown in FIG. 25 rotor slide valve windows 39 are connected both to stator slide valve windows 38, and to supporting cavities 32 made in this case on supporting cover plate 30 of the housing.
To implement the aforesaid method of adjustment of the total amplitude of variation of volumes of the transfer cavities depending on the amplitude and phase of pulsations of the outlet pressure the invention provides for an embodiment with tilt angle variator comprising a converter of the amplitude and phase of pulsations of the outlet pressure into the travel of the travelling element kinematically connected to the supporting part of the rotor with a possibility to vary the tilt angle of the axis of rotation of the supporting part of the rotor at travel of the mentioned element. The mentioned converter can be made, for example, using pressure pulsations sensor, phase detector and electric drive. The section “Detailed description of the device and operation of one embodiment of the offered invention” further describes the preferred embodiment with the mentioned converter made two-stage and comprising two converters electrically connected to each other: the first—converter of the amplitude and phase of pulsations of the outlet pressure into a shift angle determining the reference angle for each transfer cavity, and the second—converter of the difference between the reference pressure and the pressure in the transfer cavity at the reference angle into the travel of the travelling element described above.
To adjust the displacement, i.e. volume of the working fluid transferred by the device from the inlet port to the outlet port per one turn of the rotor, and to change the total amplitude at the change of displacement the invention provides for a forward transfer limiter made movable in axial direction and equipped with the mechanism of variation of the extent of the forward transfer limiter protrusion to the annular groove, while the means of tilt of the axis of rotation of the supporting part of the rotor are made with a possibility to vary the tilt angle of the axis of rotation of the supporting part of the rotor when the axial location of the forward transfer limiter is changed.
Device with a Compensating Duct
To implement the aforesaid method of compensating the secondary kinematic nonuniformity of delivery by means of creating a compensatory flow of the working fluid between the transfer cavity and the outlet cavity the invention provides for the vanes being in sliding insulating contact with the forward transfer limiter are made so that at the same time at least two transfer cavities can be separated from the inlet and outlet cavities, and the outlet cavity is hydraulically connected to the compensating valve made with a possibility of hydraulic connection to the transfer cavities via the compensatory duct equipped with a compensating throttle.
The compensating valve can be made, for example as a solenoid valve electrically connected to the sensor of the angle of the rotor rotation. The preferred embodiment of the invention (FIG. 15) provides for the said compensating valve made as a sliding valve selector formed by distributing channel 41 in forward transfer limiter 5 and by vanes 4. At the rotation of the rotor the vanes periodically shut off distributing channel 41 connected to the current transfer cavity, and connect it to the following transfer cavity generating compensatory flow between this following transfer cavity and the outlet cavity. For the described embodiment with the supporting cover plate of the housing it is also provided that the sliding valve selector can be formed by the distributing channel made in the supporting cover plate of the housing with a possibility to be connected to the supporting cavities in the supporting part of the rotor, and means of insulation of the supporting cavities made on the supporting part of the rotor and being in sliding insulating contact with the supporting cover plate of the housing with a possibility to shut off the distributing channel at the rotation of the rotor.
To adjust hydraulic resistance of the compensatory duct compensating throttle 42 is provided with the means of change of its hydraulic resistance χ. To implement the aforesaid method of improving the accuracy of compensation of the secondary kinematic nonuniformity of delivery the invention provides for (FIG. 19) the mentioned compensatory duct comprising at least one compensating cavity 20 separated from outlet cavity 7 by at least one of the mentioned compensating throttle 42. Compensating cavity 20 can have the means of change of its capacity.
Embodiments of the Device for Implementation of the Methods of Total Angle Adjustment
To implement the method of total angle adjustment φ_totaldescribed above the invention provides that the device is equipped with the means of total angle adjustment that either comprise at least one bypass channel made with a possibility of hydraulic connection to the transfer cavities and equipped with a valve of total angle adjustment, or comprise the vanes mounted in the rotor with a possibility to vary the total angle. Below you can find the description of the embodiments of the means of total angle adjustment to implement both variants of the method of total angle adjustment described above.
To implement the aforesaid method of total angle adjustment by changing the angle of merging of the transfer cavity with the outlet cavity φ_merg.the valve of total angle adjustment is made with a possibility to be hydraulically connected to the outlet cavity. To adjust φ_merg.the invention provides for two embodiments of the mentioned valves. In the first embodiment (FIG. 26) valve of total angle adjustment 43 is made in forward restriction bypass channel 44 in the stator unit, while one end of channel 44 communicates to outlet cavity 7, and the other end of channel 44 enters the forward transfer area with a possibility to be connected to transfer cavities 9. Valve 43 is made with a possibility to unlock channel 44 when the sign of the pressures drop between two ends of channel 44 is changed. In the second variant of adjustment of φ_merg.the valves of total angle adjustment are made in the rotor. The preferred embodiment of the invention provides for the use of the vanes as movable elements of the valves of total angle adjustment. In this case each of these vanes is made so that when the sign of the pressures drop between two transfer cavities separated by this vane is changed the vane is shifted unlocking the transfer cavity where the pressure has exceeded the pressure in the outlet cavity. FIG. 4 presents a section of the rotor with axially movable vanes 4 mounted in vane chambers 3 and connected to the vanes drive mechanism with a possibility of axial backlash. To provide self-sealing of vane sealing ledges 45 sliding along forward transfer limiter 5, the cavity located in vane chamber 3 from the vane's side opposite sealing ledge 45 is connected via channel 46 to the transfer cavity 9 ahead of the said vane, that displaces the fluid out of it to the pumping cavity (in a hydromotor said cavity is connected to the transfer cavity behind the vane). While the pressure in transfer cavity 9 behind vane 4 being separated by the vane from outlet cavity 7 is less than the pressure in the outlet cavity, the force acting upon the opposite face of vane 4 exceeds the force acting upon sealing face 45, and vane 4 is pressed to forward transfer limiter 5. As soon as the pressure in transfer cavity 9 behind the vane starts to exceed the pressure in outlet cavity 7, vane 4 is forced from forward transfer limiter 5 and unlocks the mentioned transfer cavity. FIG. 23 a, b, c presents a section of the rotor with axially turning vanes 4 mounted in the vane chambers (3—
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y
eHo) and made with a possibility of bending elastic element 47 of vane 4 when the sign of the pressure drop changes. While the pressure in the transfer cavity 9 behind the vane 4, i.e. in the cavity separated from the outlet cavity of the pump by the vane, is less than the pressure in outlet cavity 7, elastic element 47 of vane 4 is acted upon by the force pressing it to the walls of vane chamber 3. As soon as the pressure in the transfer cavity 9 behind the vane 4 starts to exceed the pressure in outlet cavity 7, elastic element 47 of vane 4 is forced from the walls of vane chamber 3 and bends unlocking the mentioned transfer cavity 9 (the mode of hydromotor for this embodiment corresponds to the reverse direction of the rotor rotation and opposite sign of the pressure drop).
To implement the method of total angle adjustment by changing the angle of detachment of the transfer cavity from the inlet cavity φ_detach.the invention provides for two embodiments of the means of variation of the total angle. In the first embodiment (FIG. 27) valve of total angle adjustment 43 is made in forward restriction bypass channel 44 in the stator unit, while one end of channel 44 communicates to inlet cavity 6, and the other end of the channel 44 enters the forward transfer area with a possibility to be connected to transfer cavities 9. Valve 43 is made with a possibility to lock channel 44 at the angles of the rotor rotation equal to the detachment angles. In the preferred embodiment the mentioned valve is made with an electric drive electrically connected to the detector of the amplitude and phase of pressure pulsations in the outlet cavity. The use of the valve of total angle adjustment that can be electrically locked and unlocked in the periods set for each transfer cavity provides maximum flexibility of detachment angles φ_detach.adjustment depending on the pressure drop and speed of the rotor rotation. But such valve should be opened and closed many times during one turn of the rotor so the operation speed of such a valve will restrict the possibilities of the detachment angles adjustment at high speed of the rotor rotation. To adjust detachment angles at high speeds of the rotor rotation the invention provides for the use of a valve of total angle adjustment in the form of a sliding valve selector with a manifold of forward restriction bypass channels made in the housing of the machine (in forward transfer limiter, for example) with a possibility of hydraulic connection to the transfer cavities. Each bypass channel is hydraulically connected to the selector switch that is hydraulically connected to the inlet cavity. Angles of the rotor rotation at which different bypass channels are separated by rotor means of insulation, for example, by vanes, from the current transfer cavity, correspond to different angles of detachment of this transfer cavity from the inlet cavity. Depending on the pressure difference and speed of the rotor rotation there are chosen bypass channels that are hydraulically connected to the inlet cavity via the selector. Thereby one detachment angle is chosen out of the set of detachment angles. The selector switch can be made, for example, as a solenoid distributing valve electrically connected to the detector of the amplitude and phase of pressure pulsations in the outlet cavity. The cost-wise preferable embodiment of the invention (FIG. 28) for adjusting detachment angle depending on pressure difference provides for an embodiment of the selector as piston valve selector 48 with piston 49 influenced by the fluid under the outlet pressure from one side (for a hydromotor under the outlet pressure), and being under the pressure close to the inlet from the other side (for a hydromotor—to the outlet) and bears against calibrated spring 50. Position of the piston is determined by the balance between the pressure forces and elasticity force of the calibrated spring and changes depending on the pressure difference, changing the set of bypass channels 44 connected to inlet cavity 6, and thereby changing detachment angle.
In the second embodiment of means of variation of total angle for adjustment of φ_detach.the invention provides for vanes drive mechanism equipped with the means of variation of the angle of detachment of the transfer cavities from the inlet cavity by the vanes. The vanes drive mechanism allowing to vary detachment angles φ_detach.can be made, for example, as a cam mechanism (as in FIG. 29, FIG. 30) comprising mounted on housing 1 carrier 51 of guide slot 52 in which side lobes 53 of vanes 4 slide. Profile of the slot determines the character of the axial movement of the vanes at the rotor rotation. Vane drive mechanism controls cyclical movement of vanes 4 relative to working part 2 of the rotor at its rotation so that vanes 4 in suction area A axially move out of vane chambers 3 to annular groove 23 and in forward transfer area B shut off cross section of the working chamber separating the transfer cavities from the inlet cavity. One skilled in the art can find that slew of carrier 51 around the axis of rotation of the rotor will lead to the change of the angle of detachment of transfer cavities 9 from inlet cavity 6 by vanes 4. Means of variation of detachment angle for such vanes drive mechanism can be implemented, for example, using an electric drive of carrier 51 slewing electrically connected to the detector of the amplitude and phase of pressure pulsations in the outlet cavity.
To implement the method of total angle adjustment described above with regard to the backward transfer cavities the invention provides for the rotor means of backward transfer insulation being in sliding insulating contact with the backward transfer limiter separating at least one backward transfer cavity connected to at least one force chamber of variable volume from the inlet and outlet cavities. In this case each backward transfer cavity corresponds to its individual range of angles of rotation of the rotor within which the mentioned backward transfer cavity is separated from the inlet and outlet cavities, and the device has at least one back restriction bypass channel containing a valve of total angle adjustment of backward transfer. One end of back restriction bypass channel is connected to the inlet cavity, while the other end of the mentioned channel enters the backward transfer area with a possibility to be connected to the backward transfer cavities. The mentioned valve is made with a possibility to unlock the mentioned back restriction bypass channel when the sign of the pressure drop between two mentioned ends of the back restriction bypass channel changes.
Rotor means of backward transfer insulation comprise the sections of the internal side cylindrical surfaces of the annular groove being in sliding insulating contact with the backward transfer limiter. In one of the embodiments the mentioned means of insulation comprise sections of vanes surfaces being in sliding insulating contact with the backward transfer limiter. In the preferred embodiment the mentioned means of insulation comprise spots of the bottom of annular groove 64 (FIG. 29, 30) being in sliding insulating contact with backward transfer limiter 22.
Detailed Description of the Device and Operation of One Embodiment of the Offered Invention
To describe the design and operation of one embodiment of the offered invention in detail we shall dwell on the variant of configuration preferred from the point of view of reduction of losses on friction and tendency to cavitation at high speeds of the rotor rotation and intended to be used as a pump.
The device in the present embodiment of the invention (FIG. 22, FIG. 29-34) comprises two main units: the housing and the rotor mounted inside the housing with a possibility of rotation.
The rotor comprises working part 2 with vane chambers 3 and annular groove 23 of constant rectangular cross-section made on the working face surface and vanes 4 with through channels 46 installed with a possibility of axial movement in vane chambers 3 connected to annular groove 23.
Housing 1 is made with inlet 24 and outlet 25 ports and with face working 21 and supporting 30 cover plates each consisting of load-bearing element 54 and internal functional element 55, while anti-deformation chambers 56 connected to outlet port 25 are made between the mentioned load-bearing and functional elements, while suction 57 and pumping 58 distributing cavities divided by insulating dams 59 are made in the functional element of the supporting cover plate.
The working chamber of the device is bounded in radial direction by the internal surfaces of annular groove 23, and in axial direction by the internal surface of working cover plate 21 of housing 1 and by bottom 60 of annular groove 23. To consider the processes in the machine during the transfer of the working fluid there are marked out four areas (FIG. 30): suction area A, forward transfer area B, pumping area C and backward transfer area D.
Suction area A in the working chamber corresponds to the location of the inlet cavity (or suction cavity) 6 connected to inlet port 24, while the pumping area C in the working chamber corresponds to the location of the outlet cavity (pumping cavity) 7 connected to outlet port 25. Connection of the inlet and outlet cavities to the inlet and outlet ports correspondingly is made via channels 61 and 62 in working cover plate 21 of the housing, but in other embodiments of the present invention it can be also made via the channels in the rotor.
Forward transfer area B is located between suction A and pumping C areas in the working chamber. In this area the fluid contained in the working chamber between vanes 4 and in the rotor cavities connected to the working chamber is transferred from suction area A to pumping area C. In backward transfer area D part of the fluid from pumping area C is transferred back to suction area A.
Forward transfer limiter 5 is mounted on the working cover plate of the housing, and located in the working chamber in forward transfer area B and is in sliding contact with sealing ledges 45 of vanes 4 protruded to annular groove 23. Thereby a possibility to separate by vanes at least one transfer cavity 9 from inlet cavity 6 and from outlet cavity 7 is provided. Transfer cavity 9 includes inter-vane cavity 8 bounded in annular groove 23 by the surfaces of the forward transfer limiter and two neighboring vanes. Each of the mentioned transfer cavities has its individual range of angles of the rotor rotation within which the mentioned transfer cavity is separated from the inlet and outlet cavities.
The mentioned limiter 5 is made movable in axial direction. In case of its axial movement the area of the cross-section of the forward transfer area changes and therefore the displacement of the device also changes. To control its axial movement the device has a drive mechanism of the forward transfer limiter. In the device with the fixed displacement the mentioned forward transfer limiter can be made as flat insulating dam on the working cover plate of the housing.
Vanes drive mechanism 63 is made as a cam mechanism comprising a mounted on housing 1 carrier 51 of guide slot 52 in which side lobes 53 of vanes 4 slide. Profile of the slot determines the character of the axial movement of the vanes at the rotor rotation. Vanes drive mechanism controls cyclical movement of vanes 4 relative to working part 2 of the rotor at its rotation so that vanes 4 in suction area A axially move out of vane chambers 3 to annular groove 23 and in forward transfer area B shut off cross section of the working chamber, and in pumping area C move out of annular groove 23 to vane chambers 3 and open cross section of the working chamber in backward transfer area D.
The forward transfer limiter drive mechanism described above is kinematically connected to the vanes drive mechanism so that when the location of the forward transfer limiter relative to the bottom of the annular groove changes the extent of protrusion of the vanes into the annular groove in the forward transfer area also changes, allowing for keeping sliding insulating contact of the vanes sealing ledges with the forward transfer limiter.
Other embodiment of the present invention can have a different character of the vanes movement. Any character of the vanes movement relative to the rotor leading to cyclical changing of the extent of shutting off the cross section of the annular groove by the vane is admissible. For example, besides the designs with axial movement there may also be designs with radial, pivoting movement of the vanes, and their combination. Independent of the character of vanes movement in pumps with variable displacement the mentioned mechanism should be kinematically connected to axially movable forward transfer limiter in order to provide the change of the extent of protrusion of the vanes out of the vane chambers to the annular groove corresponding to the change of the area of cross section of the working chamber in forward transfer area.
Backward transfer limiter 22 is mounted on working cover plate 21 of the housing and located in the working chamber in backward transfer area D and is in sliding insulating contact with the rotor means of backward transfer insulation including the internal surfaces of annular groove 23 and bottom sealing ledges 64. This provides a possibility to separate at least one backward transfer cavity 66 limited by the surfaces of backward transfer limiter 22 and two neighboring bottom sealing ledges 64 and comprising force chamber 10 from inlet cavity 6 and outlet cavity 7. Each mentioned backward transfer cavity has its individual range of angles of the rotor rotation within which mentioned backward transfer cavity 66 is separated from inlet 6 and outlet 7 cavities.
In other embodiments of the present invention backward transfer limiter 22 is in sliding contact with the vanes and it is made movable in axial direction. Its relocation leads to the change of the displacement of the machine. In this case the vanes drive mechanism shall be kinematically connected to the axially movable backward transfer limiter to provide the change of the extent of protrusion of the vanes out of the vane chambers into the annular groove corresponding to the change of the cross sectional area of the working chamber in backward transfer area.
Besides, in this embodiment the rotor contains supporting part 13 with supporting cavities 32 made on its external face. The mentioned supporting cavities are insulated by flat surfaces of insulating dams 31 and peripheral face seals 67 due to the sliding insulating contact of the mentioned flat surfaces with flat insulating surfaces of supporting cover plate 30 of the housing.
The mentioned working and supporting parts of the rotor are mounted on bearings 68 on working 21 and supporting 30 cover plates of the housing correspondingly and connected to inlet shaft 69 by means of joints so that they rotate synchronously but have a possibility to make little axial movements and tilts relative to each other.
The rotor also has force chambers of variable volume 10 located between working part of the rotor 2 and supporting part of the rotor 13. The mentioned force chambers in the present embodiment of the device are formed by force cavities 70 made on the surfaces of working 2 and supporting 13 parts of the rotor looking at each other and cannular connectors 71 mounted with a possibility of sliding in the mentioned force cavities. Cannular connectors have sealing shoulders. Their form, location and dimensions are chosen so that to provide an insulation of force chambers within the whole range of axial movements and tilts of the supporting part of the rotor relative to the working part of the rotor.
Mentioned force chambers 70 in supporting part of the rotor 13 are connected via channels 72 to supporting cavities 32. Force cavities 70 in working part of the rotor 2 in the present embodiment of the device are made as an extension of vane chambers 3 and connected to the working chamber via channels 46 in the vanes. The force chambers have springs 73 to provide the sealing if there is no pressure.
The means of tilt of the rotation axis of the supporting part of the rotor relative to the rotation axis of the working part of the rotor in the present embodiment of the device comprise the mentioned supporting cover plate 30 of the housing and means of tilt of the supporting cover plate of the housing in their turn comprising tilt axis 36 fixed to housing 1 and holding supporting cover plate 30 of the housing with a possibility of rotation. They also comprise limiting thrust of the housing 74, fixing thrust of the housing 75, spring 76 and a tilt angle variator of the supporting cover plate of the housing relative to the working cover plate of the housing. Tilt axis 36 is located so that the moment of pressure forces of the working fluid acting upon supporting cover plate 30 of the housing from the side of supporting part of the rotor 13 is minimal. Limiting thrust of the housing 74 is made so that it could limit the tilt angle of the supporting cover plate of the housing. Fixing thrust of the housing 75 is made so that it could provide parallelism of the axes of rotation of supporting 13 and working 2 parts of the rotor at the abutment of supporting cover plate 30 of the housing to fixing thrust of the housing 75. Spring 76 provides tightening of the supporting cover plate of the housing to the fixing thrust of the housing at zero pumping pressure. Tilt angle variator comprises regulating thrust of the housing 77, mode switching valve 78, control valve 18, and a converter of the difference between the reference pressure and the pressure in the transfer cavity at the angle of the rotor rotation equal to the reference angle into the travel. Said converter is made in the form of differential double-acting hydrocylinder 15 mounted on supporting cover plate 30. First cavity 16 of hydrocylinder 15 is hydraulically connected either to control valve 18, or to outlet cavity 7 via mode switching valve 78. Control valve 18 is hydraulically connected to control channel 79 made in the supporting cover plate 30 of the housing so that one of its ends enters the surface of insulating dam 59 and communicates to supporting cavities 32 of supporting part of the rotor 13 in the forward transfer area. Second cavity 17 of hydrocylinder 15 is hydraulically connected either to damping channel 80 or to inlet cavity 6 via mode switching valve 78. Damping channel 80 is hydraulically connected to anti-deformation chamber 56 of supporting cover plate 30 of the housing connected to outlet cavity 7. The area of piston 14 looking into first cavity 16 is equal to S1, and the area of the piston looking into second cavity 17 is equal to S2 while S2<S1 (in the present embodiment of the device S2=0.5·S1). Rod 81 of piston 14 rests against regulating thrust of the housing 77 via sliding element 88 providing abutment of the surfaces at tilts. Mode switching valve 78 and control valve 18 are electrically connected to converter 82 of the amplitude and phase of pulsations into the shift angle. The mentioned converter comprises electrically connected sensor of the angle of the rotor rotation 83, fast-response sensor of pressure pulsations 84, and microcontroller 85 equipped with the timer and digital amplitude converter.
Angular size of the outlet cavity in the present embodiment of the device is chosen so that the moment of detachment of the current backward transfer cavity from the outlet cavity by the vane coincides with the moment of merging of the outlet cavity with one of the transfer cavities. Therefore to compensate the secondary kinematic nonuniformity of the delivery into the outlet cavity the considered device had one compensating channel 19 and a compensating sliding valve selector. The compensating sliding valve selector in the present embodiment of the device is made as distributing channel 41 that can be shut off by vanes 4 at the rotor rotation and made in forward transfer limiter 5. Distributing channel 41 is connected to compensating channel 19 containing compensating throttle 42 of variable hydraulic resistance. The means of variation of hydraulic resistance of compensating throttle 42 are not depicted in the drawings.
Backward transfer limiter 22 has back restriction bypass channel 86 containing valve of total angle adjustment 43 for backward transfer, while one of the ends of mentioned back restriction bypass channel 86 is connected to inlet cavity 6, and the other end of mentioned channel 86 communicates to one of backward transfer cavities 66, and mentioned valve 43 is made with a possibility to unlock mentioned back pressure restriction bypass channel 86 when the sign of the pressure drop between two mentioned ends of back pressure restriction bypass channel 86 changes.
Let us consider the implementation of the method described above at the operation of the aforesaid device in the pump mode, and variation of pressure in transfer cavities and in backward transfer cavities. It is assumed that by the beginning of the consideration the outlet pressure in the outlet cavity of the pump, i.e. in pumping cavity, significantly exceeds the pressure in the inlet cavity of the pump, i.e. in suction cavity. To consider a complete cycle consisting of suction, forward transfer, pumping and backward transfer we shall follow the state of the working fluid in the cavities connected at the transference to the vane chamber of one chosen vane. The initial moment of consideration corresponds to the position of the chosen vane at the beginning of the suction area. The present pump operates as follows:
At the initial moment of the cycle equal to one turn of the rotor the chosen vane 4 is located on the border of backward transfer area and suction area.
When inlet shaft 69 is rotating the torque is transferred via joints 87 to working 2 and supporting 13 parts of the rotor causing their rotation relative to housing 1.
At the rotation of the rotor side lobe 53 of the vane 4 slides along the guide slot 52 of such a form that the vane moves out of vane chamber 3 in suction area A into annular groove 23. At the same time the working fluid via channel 46 in this vane fills up the space in vane chamber 3 vacated by the moving vane 4. Besides the fluid can come into vane chamber 3 of the chosen vane via channels 46 in other vanes, suction distributing cavity 57, supporting cavity 32, channel 72 and force chamber 10 decreasing the tendency of the pump for cavitation.
While the working fluid in the force chamber is under low or zero pressure the force cavities of the force chamber are drawn apart by springs 73. Protruded vane in forward transfer area B contacts with sliding by its sealing ledge 45 with forward transfer limiter 5 and detaches from the inlet cavity the inter-vane cavity 8 shut off by the sealing ledge of the previous vane 4 in front of in the direction of the rotor rotation. Insulating dam 31 of the supporting part of the rotor in forward transfer area has a sliding contact with flat insulating dam 59 of the supporting cover plate of the housing and detaches supporting cavity 32 shut off by the previous dam 31 in front of the direction of the rotor rotation from the distributing and inlet cavities. So the current transferred portion of the working fluid confined in the volumes of inter-vane cavity 8, channel in the vane 46, vane chamber 3, force chamber 10, channel 72 and supporting cavity 32 in supporting part of the rotor 13 jointly forming transfer cavity 9 is closed in forward transfer area.
At the rotor rotation the transferred portion of the working fluid moves in transfer cavity 9 from inlet cavity 6 to outlet cavity 7.
The tilt angle of the axis of rotation of supporting part of the rotor 13 relative to the axis of rotation of working part of the rotor 2 is determined by the position of piston 14 of differential double-acting hydrocylinder 15. In the operational mode, i.e. when pulsations are caused by the decompression flows only, and if there are no pulsating changes of load or pulsating leakages, first cavity 16 of hydrocylinder 15 is connected to control valve 18 via mode switching valve 78, while second cavity 17 is connected to the outlet cavity via mode switching valve 78 and damping channel 80. In the presence of decompression flows damping channel 80 and capacity of second cavity 17 smooth pressure pulsations in outlet cavity 7, therefore the pressure in second cavity 17 of hydrocylinder 15 is equal to the pressure in outlet cavity 7 averaged for the period of time determined by the capacity of second cavity 17 and by hydraulic resistance of damping channel 80. Piston 14 takes such a position that the difference of pressure forces acting upon the piston are balanced by the forces connected to the elasticity of spring 76 and with the described above moment of pressure forces of the working fluid acting upon supporting cover plate 30 of the housing from the side of supporting part of the rotor 13.
If the character of pressure pulsations in the outlet cavity is indicative of the pulsating change of load or of the pulsating leakages of great value due to destruction of the pump, i.e. if there is a component of great amplitude in the pulsations spectrum with the frequency below the frequency of decompression pulsations, then first cavity 16 of hydrocylinder 15 shall be connected to outlet cavity 7 via mode switching valve 78, and second cavity 17 of hydrocylinder 15 shall be connected to the inlet cavity via mode switching valve 78 to prevent appearance of vibration of supporting cover plate 30 of the housing. In this case piston 14 will move from first cavity 16 to second cavity 17 until the supporting cover plate abuts fixing thrust of the housing 75 and takes the fixed position at which the axis of rotation of supporting part of the rotor 13 is parallel to the axis of rotation of working part of the rotor 2.
At transference of the transferred portion the volume of force chamber 10 decreases in accordance with the sinusoidal law due to the tilt of the axis of rotation of supporting part of the rotor 13. The mentioned tilt angle is chosen so that the density and the pressure of the working fluid in the force chamber increase at current level of the change of mass of the working fluid in the transfer cavity caused by the leakages rate and the speed of the rotor rotation.
Due to the means of local pressures balancing as an manifold of channel 46 in vane 4, channel 72 in the supporting part of the rotor and channel in cannular connector 71 change of pressure in all mentioned cavities 8, 46, 3, 10, 72, 32 forming transfer cavity 9 that confines the chosen transferred portion of the working fluid is equal.
The reference angle at which transfer cavity 9 is connected to cavity 16 of hydrocylinder 15 via control valve 18 is determined by the shift angle by which the reference angle is different from the angle of the rotor rotation at which the chosen transfer cavity merges with the outlet cavity. The signals locking and unlocking control valve 18 and thereby determining the shift angle are produced by converter 82 of the phase and amplitude of the outlet pressure pulsations to the shift angle. Microcontroller 85 of converter 82 reads the signals from sensor of the angle of the rotor rotation 83 and from pressure pulsations sensor 84 and calculates the speed of the rotor rotation, moments of time corresponding to merging of transfer cavities with the outlet cavity, amplitude of pressure pulsations and their phase relative to the mentioned moments of merging, and unlocking characteristics, i.e. shift angles, reference angles or corresponding moments of time at which control valve 18 receives unlocking and locking signals. In the stationary regime the pulsations amplitude does not exceed the set acceptable level and the mentioned converter does not change the current unlocking characteristics. If a regime parameter, for example, load, displacement of the pump, leakages rate or speed of the rotor rotation, is changed leading to the pulsations amplitude exceeding the mentioned level then the converter changes the unlocking characteristics, namely, decreases the shift angle, if the phase of pulsations corresponds to excessive total amplitude of variation of volumes in transfer cavities, and increases the shift angle, if the phase of pulsations corresponds to insufficient total amplitude. When the speed of the rotor rotation is changed the mentioned converter will also change the interval between the unlocking and locking of the control valve.
When the rotor is turned by the angle equal to the angle of unlocking valve 18 at the chosen reference value for the chosen transfer cavity, mentioned converter 82 produces an unlocking signal resulting in the unlocking control channel 79 by control valve 18 providing the connection of transfer cavity 9 to first cavity 16 of differential double-acting hydrocylinder 15.
If the pressure of the transferred portion is less than the pressure in first cavity 16 of hydrocylinder 15 there appears a compensatory-comparative flow via control channel 79 from hydrocylinder 15 to transfer cavity 9 increasing the mass of the working fluid in the transferred portion. The pressure of the transferred portion increases and the pressure in first cavity 16 of hydrocylinder 15 decreases. Piston 14 of the mentioned hydrocylinder moves from second cavity 17 to first cavity 16 and causes the increase of the mentioned tilt angle of the axis of rotation of supporting part of the rotor 13 and total amplitude of variation of volumes in the transfer cavities.
If the pressure of the transferred portion exceeds the pressure in first cavity 16 of hydrocylinder 15 there appears a compensatory-comparative flow via control channel 79 to hydrocylinder 15 from transfer cavity 9 decreasing the mass of the working fluid in it. The pressure of the transferred portion decreases and the pressure in first cavity 16 of hydrocylinder 15 increases. Piston 14 of the mentioned hydrocylinder moves from first cavity 16 to second cavity 17 causing the decrease of the aforesaid tilt angle of the axis of rotation of supporting part of the rotor 13 and total amplitude of variation of volumes in the transfer cavities.
If the pressure of the transferred portion is equal to the pressure in the first cavity of differential double-acting hydrocylinder then there appears no flow of the working fluid between them and the piston does not move.
At the rotation of the rotor by the angle corresponding to the moment of merging of the previous transfer cavity with the outlet cavity, vane 4 separating the chosen transfer cavity from the previous one terminates shutting off distributing channel 41 of the compensating sliding valve selector connected to compensating channel 19. As a result there appears a compensating flow of the working fluid into considered transfer cavity 9 from outlet cavity 7. At the moment of appearance the compensatory flow has maximum rate as the difference of pressures between the inlet and transfer cavities at this moment is maximal. The pressure of the transferred portion increases due to the decrease of volume of the transfer cavity owing to decreasing the volume of the force chamber and due to the increase of the mass of the working fluid in the transferred portion owing to the compensatory flow. At the same time the compensatory flow rate goes down. In the stationary regime the pressure of the transferred portion equalizes with the pressure in outlet cavity 7 by the moment of merging of this transfer cavity with the outlet cavity. Therefore the compensatory flow rate decreases to zero by this moment.
At the end of the transference of the chosen transferred portion in forward transfer area to the outlet cavity preceding vane 4 moves from forward transfer limiter 5. At that preceding insulating dam 31 of supporting cavity 32 of the chosen transferred volume moves from insulating dam 59 to the area of pumping distributing cavity 58 of supporting cover plate 30 of the housing. Thereby, the chosen transfer cavity merges with the pumping cavity. The pressures of the working fluid in them are equalized so there are no decompression flows between them at the moment of merging. As a result the flow of the working fluid to the outlet cavity and to the pressure line is characterized by no pressure pulsations.
At the same moment converter 82 of phase and amplitude of pulsations of the outlet pressure into the shift angle captures the pressure in the outlet cavity. As there are no decompression flows and no pressure pulsations caused by them in the outlet cavity the amplitude of pulsations captured by the converter does not exceed the predetermined acceptable level and the mentioned converter does not change the current unlocking characteristics.
If one of such characteristics as load, rotation speed, pump displacement or leakages rate substantially changes it results in appearance of decompression flows and the corresponding pressure pulsations in the pumping cavity and the amplitude of pulsations exceeds the mentioned level. In this case if the phase of pulsations will correspond to the excessive total amplitude of variation of volumes in transfer cavities, i.e. if decompression flows go from the transfer cavity to the pumping cavity and the pressure in the pumping cavity at the moments of merging of transfer cavities with the outlet cavity grows step-wise (curve 8, FIG. 2), the mentioned converter shall reduce the shift angle. But if the phase of pulsations corresponds to insufficient total amplitude of variation of volumes, i.e. if the pressure in the pumping cavity at the mentioned moments of merging decreases step-wise (curve 7, FIG. 2) the mentioned converter shall increase the shift angle.
If due to uneven wear the leakages rates via the insulating surfaces of different transfer cavities becomes different causing the direction and value of the decompression flows at merging of different transfer cavities with the outlet cavity to be different, the converter 82 will change shift angles for different transfer cavities differently. For the cavity which merging with the pumping cavity causes a decompression flow directed to the pumping cavity followed by positive jump of the outlet pressure, mentioned converter 82 will decrease the shift angle relative to the average shift angle. As a result control valve 18 will open and the transfer cavity will merge with first cavity 16 of hydrocylinder 15 at later point, when the pressure of the transferred portion exceeds the pressure in first cavity 16 of hydrocylinder 15. The compensatory-comparative flow will go out of the transfer cavity into first cavity 16 of hydrocylinder 15 leading to the decrease of the mass of the working fluid in this transferred portion and to the decrease of decompression flow and caused by it positive pressure jump at merging this transfer cavity with the outlet cavity. For the cavity which merging with the pumping cavity causes a decompression flow directed out of the pumping cavity followed by negative jump of the outlet pressure, the mentioned converter will increase the shift angle relative the average shift angle. As a result control valve 18 will open and the mentioned transfer cavity will merge with first cavity 16 of hydrocylinder 15 at earlier point, when the pressure of the transferred portion is less than the pressure in first cavity 16 of hydrocylinder 15. The compensatory-comparative flow will go out of first cavity 16 of hydrocylinder 15 into transfer cavity 9 leading to the increase of the mass of the working fluid in this transferred portion and to the decrease of decompression flow and caused by it negative pressure jump at merging of this transfer cavity with the outlet cavity.
If uneven change of load or partial destruction of the elements of the pump causes pulsations of the outlet pressure with great amplitude and with the frequency significantly lower that the frequency of decompression pulsations at this speed of the rotor rotation then converter 82 will give out a switching signal to mode switching valve 78. In this case first cavity 16 of hydrocylinder 15 will be connected to outlet cavity 7, and second cavity 17 of hydrocylinder 15—to the inlet cavity. At the same time piston 14 will move from first cavity 16 to second cavity 17 until the supporting cover plate abuts at fixing thrust of the housing 75 and takes a fixed position at which the axis of rotation of supporting part of the rotor 13 is parallel to the axis of rotation of working part of the rotor 2.
Sinusoidal variation of volume of force chamber at the described merging transfer cavity 9 with pumping cavity 7 causes a delivery jump of the first type out of the transfer cavity to the outlet cavity. Due to the described above configuration of the outlet cavity merging of the considered transfer cavity with the outlet cavity coincides with the moment of detachment of one of backward transfer cavities 66 from the outlet cavity. Therefore the delivery jump of the second type is added to the delivery jump of the first type increasing its amplitude. But a compensatory flow from the outlet cavity to the following transfer cavity via compensating channel 19 appears at the same moment. Resistance of compensating throttle 42 is chosen so that the compensatory flow rate at this moment is equal to the value of the mentioned delivery jump from force chamber 10 to outlet cavity 7. Thereby, all the working fluid displaced out of force chamber 10 is sucked in into compensating channel 19. As a result a surgeless flow of the working fluid comes into outlet port 25 of the pump.
If the speed of the rotor rotation or the pump displacement changes the means of change of hydraulic resistance of compensating channel 19 change hydraulic resistance of compensating throttle 42. At that if the speed of the rotor rotation or the pump displacement increases the mentioned means decrease the resistance of compensating throttle 42, and if the speed of the rotor rotation or the pump displacement decreases the mentioned means increase the resistance of compensating throttle 42.
As the chosen vane passes the pumping area side lobe 53 of the vane slides along guide slot 52 of such a form that the vane in pumping area C moves out of annular groove 23 to vane chamber 3 displacing the working fluid via channel 46 into outlet cavity 7.
As the chosen vane passes pumping area C at first sinusoidal variation of volume of force chamber 10 causes gradual decrease of the delivery of this force chamber to outlet cavity 7 to zero and then the change of the sign of the mentioned delivery and gradual increase of suction from the outlet cavity to this force chamber. Several force chambers move in the pumping area at the same time. Some of them displace the working fluid to the pumping cavity and some suck in the working fluid from the pumping area. Total delivery of all these force chambers determines the character of the secondary kinematic nonuniformity of delivery into the pumping cavity (curve 35 FIG. 17) where the step increase of the delivery is followed by a gradual decrease. The character of the decrease of the compensatory flow (curve 33 a FIG. 16) described above is close to the character of the delivery from the force chambers. Therefore, practically all the working fluid displaced out of the force chamber is sucked into the compensating channel and a surgeless flow of the working fluid (curve 36 FIG. 17) comes into the outlet port of the pump not only at the moment of the jump but also between the jumps.
By the moment the chosen vane approaches the backward transfer area D (FIG. 30) it entirely comes into the vane chamber. Bottom sealing ledges 64 in annular groove 23 adjacent to the chosen vane from both sides relative to the direction of rotation of the rotor moving from pumping area to the backward transfer area are in sliding insulating contact with the surface of the backward transfer limiter and thus lock bottom cavity 65 in annular groove 23. Insulating dam 31 of supporting part of the rotor 13 in backward transfer area has a sliding contact with flat insulating dam 59 of the supporting cover plate of the housing and locks supporting cavity 32 from behind. From the front supporting cavity 32 is locked by the previous insulating dam 31. Thereby, in the backward transfer area current backward transferred portion of the working fluid becomes locked in backward transfer cavity 66 including the volumes of bottom unloading cavity 65, channel 46 in vane 4, vane chamber 3, force chamber 10, channel 72 and supporting cavity 32 in supporting part of the rotor 13. At that the suction from the outlet cavity to the force chamber stops leading to a positive jump of delivery of the second type to the outlet cavity. Due to the configuration of outlet cavity 7 described above the detachment of considered backward transfer cavity 66 from outlet cavity 7 coincides with the moment of merging one of the transfer cavities with the outlet cavity. Therefore the delivery jump of the second type is added to the delivery jump of the first type increasing its amplitude. As the total jump of delivery is completely compensated by the compensating flow as described above there is achieved a high uniformity of the generated flow of the working fluid in the outlet duct of the pump.
At the rotation of the rotor this backward transfer cavity 66 moves from outlet cavity 7 to inlet cavity 6.
Due to the tilt of the axis of rotation of the supporting part of the rotor the volume of force chamber of variable volume 10 increases in accordance with the sinusoidal law at transference of backward transfer cavity, therefore the density and pressure of the working fluid in the force chamber is decreased as its volume increases. At that expanding and increasing the volume of force chamber 10 the working fluid makes a useful work partially compensating the work spent on compression of the working fluid in the transfer cavity.
Due to the means of local pressures balancing as manifold of channel 46 in vane 4, channel 72 in the supporting part of the rotor and channel in cannular connector 71 the change of pressure in all mentioned cavities 65, 46, 3, 10, 72, 32 forming the backward transfer cavity is equal.
In the described pump of variable displacement the angular size of backward transfer area D is chosen equal to the angular size of forward transfer area B so that to provide the extent of expansion of the backward transfer cavities sufficient to decrease the pressure of backward transferred portions to the level of the inlet pressure at the decreasing of displacement of the pump down to zero when the volume of the transfer cavity at its merging with the pumping cavity becomes equal to the volume of the backward transfer cavity at the moment of its detachment from the pumping area. Therefore when the displacement of the pump is increased the range of angles of the rotor rotation within which the backward transfer cavity is separated from the outlet cavity and from the inlet cavity is decreased by early connection of the backward transfer cavity with the inlet cavity, as when the sign of the pressure drop between the ends of back restriction bypass channel 86 valve 43 opens and at further transference of backward transfer cavity 66 till the moment of its merging with suction cavity 6 the working fluid is sucked from suction cavity 6 to force chamber 10 which volume is increasing. Thereby, excessive variation of pressure in the backward transfer cavity that could lead to decompression or cavitation is prevented and there is achieved a uniformity of the generated working fluid flow in the suction line of the pump.
The considered operation of the device described above shows that offered in the present invention method of generation of surgeless flow of the working fluid and device for its implementation eliminate the origins of decompression pulsations and compensate the secondary kinematic nonuniformity of the delivery and provide the high level of uniformity of the generated working fluid flow and thus overcome such a significant disadvantage of the fluid power drive as vibrations and noise and correspondent power losses.

Claims

1. Method of generation of a surgeless flow of a working fluid including rotating a rotor of a rotor sliding-vane machine; filling an inlet cavity of the machine with the working fluid at inlet pressure; detaching the working fluid from the inlet cavity by vanes in transfer cavities separated from an outlet cavity with an outlet pressure substantially unequal to the inlet pressure; transferring the working fluid in the transfer cavities to the outlet cavity; merging the transfer cavities with the outlet cavity and displacing the working fluid to the outlet cavity of the machine, while each transfer cavity includes at least one chamber of variable volume and is separated from the inlet and outlet cavities within given range of the angles of the rotor rotation

wherein a pressure of the working fluid in the transfer cavities is being varied in the process of the said transference by variating volumes of the transfer cavities and said chambers of variable volume, so that the said pressures become substantially equal to the outlet pressure by the moment of merging the said transfer cavities with the outlet cavity.

2. The method according to claim 1 wherein at the increase of the difference between the inlet and outlet pressures the total amplitude of variation of the volumes of the transfer cavities is increased, while it is decreased at the decrease of the said difference.

3. The method according to claim 1 wherein pulsations of the outlet pressure are detected and if the moments of merging the transfer cavities with the outlet cavity match with the rising fronts of the outlet pressure pulsations then at the outlet pressure exceeding the inlet pressure total amplitude of variation of the volumes of the transfer cavities is decreased, while it is increased at the inlet pressure exceeding the outlet pressure, but if the said moments of time match with the falling fronts of the outlet pressure pulsations, then at the outlet pressure exceeding the inlet pressure the said total amplitude is increased while it is decreased at the inlet pressure exceeding the outlet pressure.

4. The method according to claim 1 wherein in case of the positive difference between the reference pressure equal to the chosen value between the inlet and outlet pressures and the pressure in the current transfer cavity at the angle of the rotor rotation equal to the reference angle chosen in the range from the angle of detachment of the said transfer cavity from the inlet cavity to the angle of merging the said transfer cavity to the outlet cavity, at the outlet pressure exceeding the inlet pressure total amplitude of variation of the volumes of the transfer cavities is increased, while it is decreased at the inlet pressure exceeding the outlet pressure, but if the said difference is negative, at the outlet pressure exceeding the inlet pressure said total amplitude is decreased, while it is increased at the inlet pressure exceeding the outlet pressure.

5. The method according to claim 4 wherein for each transfer cavity there are detected pulsations of the outlet pressure in the moments of its merging with the outlet cavity and, if the said moments match with the rising fronts of pulsations of the outlet pressure, then at the outlet pressure exceeding the inlet pressure the said reference angle for this transfer cavity is shifted closer to the angle of merging of the said transfer cavity to the outlet cavity, while at the inlet pressure exceeding the outlet pressure it is shifted closer to the angle of detachment of the said transfer cavity from the inlet cavity, but if the said moments match with the falling fronts of pulsations of the outlet pressure, then at the outlet pressure exceeding the inlet pressure the said reference angle for this transfer cavity is shifted closer to the angle of detachment of the said transfer cavity from the inlet cavity, while at the inlet pressure exceeding the outlet pressure it is shifted closer to the angle of merging of the said transfer cavity with the outlet cavity.

6. The method according to claim 1 wherein the said range of the rotor rotation angles is increased at increase of the difference between the outlet and inlet pressures and decreased at decrease of the said difference for each transfer cavity.

7. The method according to claim 6 wherein for each transfer cavity the said range of the rotor rotation angles is changed by variation of the angle of the rotor rotation at which the said transfer cavity merges with the outlet cavity.

8. The method according to claim 6 wherein for each transfer cavity the said range of the angles of the rotor rotation is changed by variation of the angle of the rotor rotation at which the said transfer cavity is detached from the inlet cavity.

9. The method according to claim 1 wherein the volumes of the transfer cavities are varied as a sine function of the angle of the transfer cavities travel.

10. The method according to claim 9 wherein the current transfer cavity is merged with the outlet cavity when at least one of the following transfer cavities is detached from the inlet cavity, while at the moment of merging the said current transfer cavity with the outlet cavity there is generated a compensating flow of the working fluid between one of the said following transfer cavities and the outlet cavity via a compensating hydraulic duct.

11. The method according to claim 10 wherein at the moment of detachment of the current backward transfer cavity from the outlet cavity there is created the second compensating flow of the working fluid between one of the said following transfer cavities and the outlet cavity via the second compensating hydraulic duct.

12. The method according to claim 10 or 11 wherein at increase of the rotor rotation speed hydraulic resistance of the said compensating hydraulic duct is decreased, while it is increased at decrease of the said speed.

13. The method according to claim 1 wherein the working fluid is detached from the outlet cavity in backward transfer cavities isolated from the inlet cavity, the working fluid is transferred in the backward transfer cavities to the inlet cavity and backward transfer cavities are merged with the inlet cavity, while each backward transfer cavity has its individual range of the rotor rotation angles within which the said backward transfer cavity is isolated from the outlet and inlet cavities, and in the process of the said transference the pressure of the working fluid in the backward transfer cavities is varied by variation of volumes of the backward transfer cavities so that the said pressures are substantially equalized with the inlet pressure by the moment the said backward transfer cavities merge with the inlet cavity.

14. The method according to claim 13 wherein the said range of the rotor rotation angles is increased at increase of the difference between the outlet and inlet pressures and decreased at decrease of the said difference for each backward transfer cavity.

15. The method according to claim 13 wherein for each backward transfer cavity the said range of the rotor rotation angles is decreased at increase of displacement of the rotor sliding-vane machine and it is increased at decrease of the said displacement.

16. The method according to claim 14 or 15 wherein for each backward transfer cavity the said range of the rotor rotation angles is changed by variation of the angle of the rotor rotation at which the said backward transfer cavity merges with the inlet cavity.

17. The method according to claim 14 or 15 wherein for each backward transfer cavity the said range of the rotor rotation angles is changed by variation of the angle of the rotor rotation at which the said backward transfer cavity detaches from the outlet cavity.

18. A device for generation of a surgeless flow of the working fluid comprising a housing with inlet and outlet ports including a working cover plate with a forward transfer limiter and a backward transfer limiter, a rotor with vane chambers in it's working part and with an annular groove made on a working face of a working part of the rotor and connected to the vane chambers with vanes which are kinematically connected to a vanes drive mechanism mounted on the housing, while the working cover plate of the housing is in sliding insulating contact with the working face surface of the working part of the rotor and forms a working chamber in the annular groove, while rotor means of backward transfer insulation being in sliding insulating contact with the backward transfer limiter as well as rotor means of forward transfer insulation being in sliding insulating contact with the forward transfer limiter including the vanes separate from each other inlet cavity hydraulically connected to the inlet port, outlet cavity hydraulically connected to the outlet port and at least one transfer cavity including an inter-vane cavity bounded by the surfaces of the annular groove, forward transfer limiter and two adjacent vanes, while each transfer cavity corresponds to its individual range of angles of the rotor rotation within which the said transfer cavity is separated from the inlet and outlet cavities, wherein each transfer cavity comprises at least one force chamber connected to the inter-vane cavity of the said transfer cavity, while the said force chamber is kinematically connected to the means of variation of the volumes with a possibility to change a proportion between the volume of the force chamber at the angle of the rotor rotation at which it is connected to the inlet cavity and the volume of the same force chamber at another angle of the rotor rotation at which it is connected to the outlet cavity.

19. The device according to claim 18 wherein the rotor is provided with a supporting part of the rotor made with a possibility to rotate synchronously with the working part of the rotor and to make axial movements and tilts relative to it causing the variation of the volumes of the said force chambers, while the means of variation of the volumes comprise means of tilting made with a possibility of tilting the rotation axis of the supporting part of the rotor relative to the rotation axis of the working part of the rotor.

20. The device according to claim 19 wherein the means of tilting comprise a rotatory thrust block with the supporting part of the rotor mounted on it.

21. The device according to claim 19 wherein the means of tilting comprise a supporting cover plate of the housing being in sliding insulating contact with the supporting part of the rotor.

22. The device according to claim 21 wherein the supporting cover plate of the housing and the working cover plate of the housing are joined forming an operational unit of the housing located between the working and supporting part of the rotor.

23. The device according to claim 19 wherein the means of tilting comprise a converter of the amplitude and phase of the outlet pressure pulsations into a travel of a travelling element kinematically connected to the supporting part of the rotor with a possibility to vary the tilt angle of rotation axis of the supporting part of the rotor by the travel of the said element.

24. The device according to claim 19 wherein the forward transfer limiter is made axially movable with a possibility to vary it's protrusion extent into the annular groove, while the said means of tilting are made with a possibility of variation of the tilt angle of rotation axis of the supporting part of the rotor at the variation of the axial position of the forward transfer limiter.

25. The device according to claim 19 wherein the said means of tilting comprise a converter of the pressure difference between the inlet and outlet cavities into a travel of the travelling element kinematically connected to the supporting part of the rotor with a possibility of variation of the tilt angle of rotation axis of the supporting part of the rotor by the travel of the said element.

26. The device according to claim 19, wherein the said means of tilting comprise a converter of the difference between the reference pressure equal to the chosen value between the inlet and outlet pressures, and the pressure in the current transfer cavity at the angle of the rotor rotation equal to the reference angle chosen within the range from the angle of detachment of the said transfer cavity from the inlet cavity to the angle of merging of the said transfer cavity with the outlet cavity into a travel of the travelling element kinematically connected to the supporting part of the rotor with a possibility of variation of the tilt angle of rotation axis of the supporting part of the rotor by the travel of the said element.

27. The device according to claim 26 wherein the said converter comprises a control valve and a hydraulic actuator made as a differential double-acting hydrocylinder and a travelling element is made as a piston between two cavities of the said hydrocylinder, while the hydrocylinder is mounted with a possibility of hydraulic connection of first cavity of the hydrocylinder to the transfer cavities via a control valve and hydraulic connection of second cavity of the hydrocylinder—to the outlet cavity.

28. The device according to claim 26 wherein the said converter comprises a control valve and a hydraulic actuator made as a differential double-acting hydrocylinder and a travelling element is made as a piston between two cavities of the said hydrocylinder, while the hydrocylinder is mounted with a possibility of hydraulic connection of first cavity of the hydrocylinder to the transfer cavities via the control valve and hydraulic connection of second cavity of the hydrocylinder—to the inlet cavity.

29. The device according to any of claims 27, 28 wherein the said means of tilting comprise means of opening and closing the control valve made with a possibility of variation of the moments of opening and closing the control valve depending on the amplitude and phase of the outlet pressure pulsations.

30. The device according to any of claims 27, 28 wherein the control valve is made as a sliding valve selector with a stator window made on the housing and hydraulically connected to the said converter and rotor windows made on the rotor with a possibility of hydraulic connection of each rotor window to the stator window while every transfer cavity is hydraulically connected to one rotor window.

31. The device according to any of claims 27, 28 wherein the control valve is made as a sliding valve selector with at least two stator windows made on the housing, a selector switch of stator windows made with a possibility of hydraulic connection of the said stator windows to the said converter and rotor windows made on the rotor with a possibility to connect each rotor window to each stator window, while every transfer cavity is hydraulically connected to one rotor window.

32. The device according to any of claims 18 wherein the outlet cavity is connected to one end of a channel the other end of which is made with a possibility to be connected to the transfer cavities, while the said channel has a valve made with a possibility to unlock the said channel.

33. The device according to any of claims 18 wherein the vane is mounted in the vane chamber with a possibility to isolate the transfer cavity from the outlet cavity at one sign of the pressure difference between the said cavities and not to isolate the said cavities from each other at opposite sign of the said pressure difference.

34. The device according to any of claims 18 wherein the vanes drive mechanism is made with a possibility of variating the angles of the rotor rotation at which the vanes detach the transfer cavities from the inlet cavity.

35. The device according to any of claims 18 wherein the inlet cavity is connected to one end of a channel the other end of which is made with a possibility to be connected to the transfer cavities, while the said channel has a valve made with a possibility to close the said channel.

36. The device according to any of claims 18 wherein the inlet cavity is connected to a selector switch hydraulically connected to at least two bypass channels made in the housing of the machine with a possibility of hydraulic connection to transfer cavities, while the said selector switch is made with a possibility to connect bypass channels with the inlet cavity and to disconnect bypass channels from the inlet cavity.

37. The device according to any of claims 18 wherein the rotor means of backward transfer insulation being in sliding insulating contact with the backward transfer limiter are made with a possibility to separate from the inlet and outlet cavities at least one backward transfer cavity comprising a force chamber while each backward transfer cavity corresponds to its individual range of the angles of the rotor rotation within which the said backward transfer cavity is separated from the inlet and outlet cavities, and the inlet cavity is connected to one end of a channel the other end of which is made with a possibility to be connected to the backward transfer cavities, while the said channel has a valve made with a possibility to unlock the said channel.

38. The device according to any of claims 18 wherein the rotor means of backward transfer insulation being in sliding insulating contact with the backward transfer limiter are made with a possibility to separate from inlet and outlet cavities at least one backward transfer cavity comprising a force chamber, while each backward transfer cavity corresponds to its individual range of the angles of the rotor rotation within which the said backward transfer cavity is separated from inlet and outlet cavities, and the outlet cavity is connected to one end of a channel the other end of which is made with a possibility to be connected to the backward transfer cavities, while the said channel has a valve made with a possibility to close the said channel.