FR2702250A1 - Hydraulic machine or motor with pistons and back pressure. - Google Patents

Abstract

A hydraulic piston machine comprises an annular cam disc (3), secured to the housing; a cylinder block (10) consisting of a rotor rotating relative to the disc (3); multiple bores (11) radial with respect to the axis of rotation of the cylinder block (10); and pistons (12) slidable in the bores (11) and bearing on the disc (3). A chamber (30) of the housing is respectively stressed by the pressure of the fluid flowing from the machine, or by an external pressure.

Description

HYDRAULIC PISTON AND BACK PRESSURE MACHINE OR MOTOR

  The present invention relates to a machine or

  hydraulic piston lifter, in particular to a radial piston machine comprising an annular cam disc, secured to the casing; a block cylinder produced in the form of a rotary body mounted for rotation about an axis, relative to the

  cam disc; a large number of bores arranged radially-

  ment relative to the axis of rotation of the cylinder block; and pistons which are slidably housed inside the bores and bear on the cam disc, the bearing surface of the cam disc being located in a chamber of the casing.

  Machines of this kind are known from the de-

  patent application DE-A-39 19 456 These machines are distinguished by a compact and inexpensive type of construction, as well as

  by their ability to develop and support strong pres-

  In such radial piston machines, the pistons

  tones fulfill the functions of repression and sealing-

  and, as a rule, rollers transmit to

  so-called pistons the forces developed by the cam disc,

  in order to generate a torque If a counter

  hydraulic pressure is established on the discharge side, for example when the inlet and discharge are connected by a regulating valve, or when hydraulic motors are installed in series, this results in poor mechanical efficiency and, in particular, poor starting performance This is due to the reactive power The pistons operating in back pressure generate this power

  reactive and degrade performance.

  The object of the invention is to increase the low yield

  ment supplied in back-pressure mode by the piston machine of the type in question, in particular to guarantee starting

  safe in piston machines installed in series.

  According to the invention, this object is achieved by

  the fact that the housing of the housing is respectively stressed

  té-e by the pressure of the fluid flowing from the machine Grâ-

  this when the casing chamber is stressed by the pressure of the flowing working fluid, the pistons considered make

  pressure balancing and cannot, by cons

  sequent, generate no reactive power making the

difficult marrage.

  A particularly advantageous improvement of the invention is characterized in that the housing of the housing is stressed by an external pressure. This characteristic has the effect of ensuring that the pressure forces acting on the housing are limited, and that the system of sealing of the shaft be free of forces from

pressure.

  According to other characteristics peculiar to the

note:

  the cylinder block preferably has, on its two sides

  these extremes, sealing surfaces to ensure watertight

  the housing of the housing, delimited radially outwards by the cam disc, vis-à-vis the internal housing of the housing which is located on the shaft side, the housing of the housing, delimited by the cam, by the pressure of the fluid flowing from the machine, or by an external pressure; advantageously, the sealing surfaces are located radially outside the control holes;

  the housing of the housing, located on the shaft side, can be

  munication with leaking oil connection

  preferably the two working fluid connections

  provide, by means of a non-return check valve

  rusty, with the housing chamber delimited by the disc

  with cams, the piloting of the non-return valves being respective-

  ment ensured by the upper inlet pressure;

  the unlockable non-return valves can be

  ciously formed by a circuit selector-reverser; the valves and their associated control channels can be conveniently integrated into the housing; and preferably, the solicitation of the casing chamber by

  pressure is provided respectively by a piston valve

  three-way tone, controlled by the pressure of the flowing working fluid, the casing chamber being respectively stressed, in this switching position of the valve

  piston, by the pressure of the flowing working fluid.

  The invention will now be described in more detail,

  by way of non-limiting examples, with regard to the

  attached sins in which: Figure 1 is an axial longitudinal section of a radial piston machine; Figure 2 is, in its left half, a section along the line I Ia-I Ia of Figure 1 and, in its right half, a section along the line I Ib-I Ib of Figure 1; and FIG. 3 is a connection diagram of a drive unit comprising two machines or piston engines

installed in series.

  In Figure 1, one of the housing halves is

  signed by 1 and the other half of the housing is marked with 2.

  A cam disc 3 is interposed between the two halves of the casing These two halves are joined with the cam disc,

  by means of fixing screws 4, to form a uniform assembly

  rigid shutter A shaft 5 is mounted in half 1 of the housing

  ter, by means of a ball bearing 6 One end 8 of the shaft, located on the casing side, is produced in the form of a

  splined shaft with multiple shims and door, via

  re of a corresponding recess 9, a rotor 10 connected to the rear

  bre by concordance of shapes, by means of a washer and a screw The rotor 10 is designed as a cylinder block and has bores 11 (Figure 2) uniformly distributed around its periphery, which are used to receive pistons 12 In their external radial region, the pistons 12 are provided with a recess intended to receive a lining shell 13 and a cylindrical roller 14 The rollers 14 are supported

  against a cam track 17 of disc 3 In the region ra-

  lower dial of each piston, the latter comprises, in a circumferential groove 12 c, a segment 20 fulfilling the function of a sealing element By means of bores 21 extending axially, the piston chambers formed by the bores 11 are in interactive connection with control holes 22, 23 also extending in the axial direction and formed in a fixed control socket

  24 integrated in half 2 of the housing The control socket

  of 24 delimits peripheral control chambers 25, 26

  which communicate, respectively, with non-il-

  lustrous in detail and assigned to the tank and the source of

  pressurized fluid, or with the connection of another machine

  ne with radial pistons, installed in series Depending on the position of the chambers II with pistons relative to the control holes 22, 23, the latter are connected either to the source of pressurized fluid, or respectively to the reservoir or to the connection other machine with radial pistons, which imposes on the rotor 10 a torque that said rotor passes through to the outside, via the shaft connection

  grooved with multiple shims, on the respective drive shaft 5

or exit.

  A chamber 30 of the casing, radially delimited by the

  disc 3 with cams as well as by external surface areas

  la, 2a of the casing, is radially delimited towards the inside, on one, i Qa of the end faces of the rotor, by a support body 31 secured to the casing, provided with a sealing surface 31 a and having a radially embedded sealing ring 32; and said chamber is delimited, on the opposite extreme face l Ob, by the control socket 24

  designed with axial sliding faculty The force conferred

  The tightness results from the pressure of the working fluid.

  range which acts on annular surfaces 25 a, 26 a cham-

  control 25, 26 of the control sleeve 24, and which presses said surfaces against the end face l Ob of the rotor, the opposite end face i Da of said rotor coming simultaneously

  apply tightly against the waterproof surface-

  ment 31 has support body 31 Chambers 33, 9, 34 axial-

  internally, in mutual communication by fluid, are connected to a leakage oil connection or channel 36, provided in part 2 of the casing By means of channel 36, the leakage oil present in the chambers 33, 9, 34 is returned, without any pressure, to the reservoir not shown, so that no significant overpressure can develop in these chambers, and the shaft sealing system is therefore not subjected to any increased pressure By

  via a distribution device 40, the cham-

  bre of the narrowly delimited casing is respectively sol-

  licit by the pressure A or B of the working fluid, acting on the outlet side It follows, for sure, that the pistons 12 are the subject of pressure balancing during their stroke

  retrograde, and that they are thus not exposed to any counter

  pressure causing reactive power The distribution device is produced in the form of a

  three-way, control channels 48 a, 49 a being in common

  communication with the peripheral control chambers 25, 26.

  A channel 43 a, leading to the chamber 30 of the casing, has a branching channel 43 b gaining a pressure chamber 50

  in which the control socket 24 must be added

  nally biased towards the rotor 10, by its end face 24 a, under the effect of the pressure transferred to the casing chamber On the bushing side and on the casing side, the pressure chamber 50 is sealed by means of a

  end piece 53 having two sealing rings 51 and 52.

  When, according to Figure 3, two hy-

  hydraulics 41, 42 are installed in series, it is ensured that

  these two engines are exposed to the same difference in pressure

  between entry and exit (assuming reports

  identical drive ports) If, for example, a different

  pressure bar of 100 bar acting on the pistons is necessary to generate a determined torque, the working fluid is supplied to the hydraulic motor 41, in one of the directions of rotation, under a working pressure of 200 bar In the hydraulic motor 42 connected to the hydraulic motor 41 via a working conduit 43, a pressure of 100 bar is established when the output of said motor is in communication, by means of a con-

  duit 44, with the tank subjected to atmospheric pressure

  that the distribution device 40 transmits, to the chamber

  of the crankcase of the hydraulic motor 41, the working pressure

  prevailing in the work channel 43 The in-

  pouring takes place when, via the working conduit

  vail 44, the working fluid is supplied to the hydraulic motor

  that 42, in the opposite direction of rotation, under a pressure of less than 200 bar In this case, via the

  distribution device 40, the housing of the motor housing

  hydraulic tor 42 is stressed by the prevailing pressure

  in the work channel 43 The drive unit,

  taking two hydraulic motors 41, 42 and being able to be ac-

  operated in both directions of rotation, has a

  distribution tif 40 consisting of a 45-fold distributor

  three tracks, hydraulically actuated and having two

  switching positions a, b In the switching position

  tion a of the distributor 45, the chamber 30 of the motor housing

  hydraulic 41 is connected, via section

  conduits 43 a, 46 a, to the working conduit 43 connecting the two hydraulic motors, and the chamber 30 of the casing of the

  hydraulic motor 42 communicates with the tank via the

  pipe section 46 b In the position of com-

  mutation b of the four-way distributor 45, the chamber 30 of the hydraulic motor housing 42 is connected to the working conduit 43 and the chamber of the hydraulic motor housing 41 is connected to the reservoir In one of the directions of rotation, in which the working fluid is supplied to the hydraulic motor 41 via a working conduit 47, and in which the working fluid returns again to the reservoir from the hydraulic motor 42, via the conduit

  44, the distributor 45 moves to the position of com

  mutation following pressure solicitation, takes place

  rant via a control duct 48 In the other direction of rotation, in which the working fluid flows into the hydraulic motor 42 by traversing the working duct 44, and returns from the hydraulic motor 41 to the reservoir via the working duct 47, the distributor passes to the switching position b via

of a control duct 49.

  When the drive unit is only used for one direction of rotation, it can naturally be dispensed with from the distribution device. In this case, the

  casing is directly connected to the outlet of the hydrau-

  lique, without interposition of a distributor, more specifically by means of a channel extending in the corresponding housing part The distributor 45 is used only for the transmission of pressure and therefore requires only small nominal diameter, so that it can be integrated in a simple way in the pumping casing, with the control channels which are associated with it In this case, it is produced in the form of a corresponding three-way distributor

  in Figure 1, because it controls only the chamber 30 of the car-

  ter of one of the motors, in which it is integrated.

  It goes without saying that many modifications can

  be made to the invention as described and shown

without departing from its framework.

Claims (9)

R E V E N D I C A T I O N S -   1 Hydraulic piston machine or motor, in particular radial piston machine comprising an annular disc (3) with cams, secured to the casing; a cylinder block (10) produced in the form of a rotary body mounted for rotation about an axis, with respect to the cam disc (3); a large number of bores (11) arranged radially with respect to the axis of rotation of the cylinder block; and pistons (12) which are slidably housed inside the bores and bear on the cam disc (3), the bearing surface of the cam disc being located in a chamber (30) of the housing, machine characterized by the fact that the chamber (30) of the housing is   respectively stressed by the pressure of the flowing fluid machine.   2 Hydraulic piston machine or motor, in particular radial piston machine comprising an annular disc (3) with cams, secured to the casing; a cylinder block (10) produced in the form of a rotary body mounted for rotation, around   an axis, relative to the cam disc (3); a big name-   bre of bores (11) arranged radially with respect to the axis of rotation of the cylinder block; and pistons (12) which are slidably housed inside the bores and bear on the cam disc (3), the bearing surface of the cam disc being located in a chamber (30) of the housing, machine characterized by the fact that the chamber (30) of the housing is   stressed by external pressure.   3 Machine according to claims 1 or 2, character-   laughed at by the fact that the cylinder block (1) has, on its two end faces, sealing surfaces (10 a,   l Ob) to seal the casing chamber, remove   limited radially outwards by the disc (3)   mes, opposite the interior chamber (9, 33, 34) of the car-   ter which is located on the shaft side, the casing chamber, delimi-   ted by the cam disc, being stressed by pressure   of fluid flowing from the machine, or by ex pressure   later. 4 Machine according to claim 3, characterized in that the sealing surfaces (10 a, l Ob) are   radially outside the control holes (22, 23).   5 Machine according to claim 4, characterized in that the chamber (9, 33, 34) of the housing, located on the shaft side, is in communication with a leakage oil fitting (36).   6 Machine according to claim 5 combined with the re-   vendication 1, characterized by the fact that the two working fluid connections communicate, via an unlockable non-return valve, with the chamber of the casing   delimited by the cam disc, the control of the non-return valves   Dash being provided respectively by the higher pressure arrival.   7 machine according to claim 6, characterized by   the fact that the unlockable non-return valves are   més by a selector-reverser of circuit.   8 Machine according to claims 6 and 7, character-   laughed at by the fact that the valves and their control channels   associated are integrated in the casing.   9 Machine according to any one of claims   previous, characterized in that the solicitation   of the chamber (30) of the housing by a pressure is respected   This is ensured by a three-way piston valve, controlled   Ded by the pressure of the flowing working fluid, the cham-   bre (30) of the housing being respectively urged, in this switching position of the piston valve, by the   working fluid pressure flowing.