CN104854422A - Dielectric sensor arrangement and method for swashplate angular position detection - Google Patents

Abstract

Swashplate angle sensing arrangement for a variable displacement pump 10 a nonrotating swashplate 12 and a rotating pump 10 barrel 14 includes a dielectric sensor in a swashplate angle sensing arrangement 50. The arrangement includes a sensing probe 52 coupled to the casing 16, a sensor target 54 coupled to the swashplate 12, and a controller 48 configured to direct an alternating current through the sensing probe 52 to establish an impedance between the probe 52 and the target 54, and to determine voltage across the probe 52. The controller 48 is further adapted to determine the angle of the swashplate 12 relative to the casing 16 based on the determined voltage.

Description

The dielectric sensors arrangement detected for swash plate angle position and method

Technical field

This patent openly relates in general to a kind of method and apparatus for monitoring variable displacement hydraulic pump, relates more specifically to a kind of method and arrangement of the angle for monitoring swash plate.

Background technology

Variable delivery pump is used in many dissimilar hydraulic systems usually.Some vehicles generally include and are driven with the hydraulic pump producing flow of pressurized fluid by the engine in vehicle or motor.Pressure fluid can be used for any object in multiple object during the operation of vehicle.Such as, machine can use pressure fluid around the work implement in building site propel machine or mobile apparatus.

Variable delivery pump is usually from reservoir suction operation fluid such as such as oil, and convection cell acting is with the pressure increasing fluid.Pump can comprise the pumping element of the pressure increasing fluid, such as such as a series of piston.Pump also can comprise by to-and-fro movement driven plunger to increase the variable-angle swash plate of the pressure of fluid.

The pump comprising variable-angle swash plate also can comprise the angle changing swash plate also changes pump capacity thus mechanism with the length of stroke changing piston.Pump capacity can be reduced with the length of stroke shortening piston by the angle changing swash plate.Alternatively, the angle by changing swash plate can increase pump capacity with the length of stroke increasing piston.

The amount of the pressure fluid required by variable delivery pump can be changed according to the concrete operations condition of the system or vehicle that depend on pump.In vehicle application, such as, the total efficiency of vehicle can be improved with the requirement of mating vehicle by change pump capacity.If the pressure fluid that vehicle needs is less, then the angle of swash plate can be changed to the length of stroke reducing piston.On the contrary, if the pressure fluid that vehicle needs is more, then the angle of swash plate can be changed to the length of stroke increasing piston.

Vehicle or system can comprise monitoring operation requirements and the operation of control pump to mate the control system of this requirement.In order to effectively make the output of pump mate with the requirement of vehicle or system, such as, control system monitors the current output of pump by the angle sensing swash plate.If control system can determine the angle of swash plate exactly, then control system can estimate the current output of pump exactly.Then, control system can regulate the angle of swash plate to mate the requirement of vehicle.

Variable delivery pump can comprise the sensor of the angle of monitoring swash plate.Swash plate sensor can based on any principle in some different principle.Such as, sensor can based on mechanical, optical, electrical, magnetic or Hall effect principle.But; usually the known sensor based on these principles is inapplicable in variable delivery pump, can cause the remarkable increase of the total cost of pump, may be not fully sane to stand the demand operated; or the impact of system interference can be subject to, such as be subject to the impact of the iron-bearing materials in pump fluid.

Such as, the swash plate angle sensor of the type manufactured by Rexroth is based on the combination of the electric principle and magnetic principle that are called as Hall effect.This sensor utilizes and is attached to swash plate and the permanent magnet extended in the outside of pump case.Hall effect semi-conductor chip is arranged between permanent magnet.By guiding electric current by semi-conductor chip and measuring the voltage at the chip two ends of gained, the angle of swash plate can be determined.But, between pump case and the magnet being projected into outside pump case, obtain effective sealing be difficulty and costliness.In addition, any magnetic material of sensor proximity can the operation of disturb sensor.The United States Patent (USP) 6,848,888 authorizing the people such as Du attempts to overcome some shortcoming of the hall effect sensor of prior art.

Wish how are metal fragment, cavitation and various noise in the working fluid of no matter temperature variation, significant system vibration, frequently pressure surge, pump, and pump discharge measures arrangement will provide reliable information under severe working environment.Manufacture and the operation of also wishing this type of arrangement are economical.

Summary of the invention

According to an aspect of the present invention, provide a kind of swash plate angle for variable delivery pump sensing arrangement, this variable delivery pump has the housing of the non-rotating swash plate comprising the rotation pivotable be suitable for relative to pump barrel.Swash plate limits the swash plate angle of the plane relative to the rotation being substantially perpendicular to pump barrel.Swash plate angle sensing arrangement comprises the sensing probe being connected to housing, the sensor target being connected to swash plate and controller.Controller is configured to guide alternating current by sensing probe, to form impedance and determine to sense the voltage at probe two ends between sensing probe and sensor target.Controller is also suitable for based on the angle of determined voltage determination swash plate relative to housing.

According on the other hand, the invention provides a kind of variable delivery pump, this variable delivery pump have housing, be arranged on housing in and be suitable for the cylinder that rotates around rotation, and to be arranged in housing and the non-rotating swash plate be suitable for relative to axis pivotable.Described pump also comprise be connected to swash plate sensor target, be connected to housing and near the sensing probe of sensor target and controller.Controller is configured to guide current crosses sensing probe, and to form impedance and determine to sense the voltage at probe two ends between sensing probe and sensor target, controller is also suitable for based on the angle of determined voltage determination swash plate relative to housing.

According to another aspect, the invention provides a kind of method for monitoring the position of non-rotating swash plate in variable delivery pump be configured to relative to axis pivotable, described pump is included in the cylinder that can rotate around described axis in housing.Described method comprises the sensor target that provides and be connected to swash plate and provides and is connected to housing and near the sensing probe of sensor target.Described method is further comprising the steps of: guide alternating current cross over sensing probe with sensing probe and sensor target between set up impedance, determine sense probe two ends voltage and based on the angle of determined voltage determination swash plate relative to housing.

Accompanying drawing explanation

Fig. 1 is a schematic diagram being used from the swash plate angle sensing arrangement of the angle position of the swash plate of monitoring in variable delivery pump, and this variable delivery pump illustrates with diagram side profile sectional view in the figure.

Fig. 2 is the diagrammatic end view of the valve plate of the pump that the II-II along the line of Fig. 1 intercepts.

Fig. 3 is the schematic diagram of the swash plate angle sensing arrangement of Fig. 1.

Fig. 4 is the view of the sensing probe that in Fig. 3, IV-IV along the line intercepts.

Fig. 5 is the diagram of the dielectric property of the parts of the swash plate angle sensing arrangement of Fig. 3.

Fig. 6 is the diagram of the equivalent dielectric analysis circuit of the arrangement of Fig. 3.

Fig. 7 is the chart of the correlativity of measured voltage and swash plate angle in the exemplary embodiment according to swash plate angle sensing arrangement of the present invention.

Embodiment

The present invention relates to a kind of method, system and arrangement for controlling variable displacement hydraulic pump 10.More specifically, the present invention relates to a kind of method of the angle position for monitoring the wobbler 12 in variable delivery pump 10, system and arrangement.Described method and arrangement are suitable for the variable displacement hydraulic pump of various physical configuration, and can be realized almost any control that the system of variable delivery pump is housed by software and controller.

The exemplary embodiment of variable delivery pump 10 has been shown in Fig. 1.As shown in the figure, pump 10 comprises and being arranged in housing 16 with the cylinder 14 rotated around cylinder axis 18.The a series of chamber 20, Fig. 1 of cylinder 14 restriction shows two in described chamber 20.Chamber 20 equidistantly separates around cylinder axis 18 with circular array usually.Each chamber 20 comprises outlet port 22.Cylinder 14 passes through the pressure of compressed gas cylinder barrel spring 26 and cylinder 14 therein tightly against valve plate 24.As best seen in figure 2, valve plate 24 comprises inhalation port 28 and discharge port 30, and the importance of these two ports will be described below.

Turn back to Fig. 1, pump 10 also comprises a series of piston 32 and has the swash plate 12 of drive surfaces 36.A piston 32 is slidably disposed in each room 20.An each end in piston 32 is arranged towards outlet port 22, and another end arranges towards the drive surfaces 36 of swash plate 12 and is biased to and engages with the drive surfaces 36 of swash plate 12.Piston 32 is come against swash plate 12 by fixed air gap device or positive force hold-down mechanism such as such as spring (not shown) usually.For the purposes of the present invention, fixed air gap device or positive force hold-down mechanism will be called as spring.

In an illustrated embodiment, each piston 32 is connected to slide block 38.Each piston 32 comprises joint such as routine as directed ball-and-socket joint 40 with the connecting portion 38 of corresponding slide block 38, and each slide block 38 is arranged between corresponding piston 32 and swash plate 12.Each joint 40 allows the relative movement between swash plate 12 and corresponding piston 32.

Swash plate 12 can to have a certain degree setting relative to housing 16.For the purposes of the present invention, angle α measures from the line z vertically drawn from cylinder axis 18.But, person of skill in the art will appreciate that, different reference point can be used to measure swash plate angle.

Axle 42 is connected to cylinder 14 by any suitable mechanism.The rotation of axle 42 causes cylinder 14 around the corresponding rotation of cylinder axis 18.Axle 42 can such as, by suitable (being schematically shown) power source 44 such as engine, internal combustion engine drive.But person of skill in the art will appreciate that, axle 42 can by the power source 44 such as such as electrical motor driven of other types.

Cylinder 14 rotates with constant angular velocity omega.When cylinder 14 rotates, the combination of the power of the spring (not shown) in the angled drive surfaces 36 of swash plate 12 and each chamber 20 will drive the to-and-fro movement in each chamber 20 of each piston 32.Therefore, what each piston 32 was periodically crossed in the inhalation port 28 of valve plate 24 and discharge port 30 is each.The inclined angle alpha of swash plate 12 makes piston 32 experience the oscillatory displacement of turnover cylinder 14, thus hydraulic fluid is pumped into the inhalation port 28 into low-pressure port, and hydraulic fluid is pumped out the discharge port 30 into high pressure port.

Swash plate 12 controls the length of stroke of each piston 32 and the rate of displacement of pump 10 relative to the angle α of housing 16.Increase swash plate angle α and will cause the larger length of stroke of each piston 32.On the contrary, reduce swash plate angle α and will cause the length of stroke of the reduction of each piston 32.The Fluid Volume of predefined level is pressurized to during the increase of the length of stroke of each piston 32 can be increased in each rotation of cylinder 14.The Fluid Volume of predefined level is pressurized to during the reduction of the length of stroke of each piston 32 can be reduced in each rotation of cylinder 14.In one embodiment, the rotating range of swash plate 12 can be limited in the approximately negative least displacement position of 20 ° and the maximum displacement position of approximately positive 20 °.

The inclined angle alpha of swash plate 12 can be controlled by any suitable angle control mechanism 46, and usually based on blowdown presssure and/or the requirement of discharging flow rate.Such as, the inclined angle alpha of swash plate 12 controls by hydraulic control, and in the mode of another example, this hydraulic control architectures can comprise one or more power piston (not shown).This type of mechanism, at such as United States Patent (USP) 6,375,433 and 6,623, is disclosed in 247, and because of them by those skilled in the art is familiar with, thus will be not described further in the present invention.But person of skill in the art will appreciate that, the actuator of mechanism's such as such as solenoid-activated of another type or servo control mechanism may be used for the angle α changing swash plate 12.In order to instruction is supplied to angle control mechanism 46, controller 48 can be provided.

Controller 48 can comprise the electronic control module with microprocessor and storer.As known to persons skilled in the art, storer is operably connected to microprocessor and store sets of instructions and variable.What be associated with a part for microprocessor and electronic control module can be other known circuits various such as such as feed circuit, signal modulation circuits and solenoid driver circuitry etc.

Controller 48 can be programmed to the operation based on different input parameter control pumps 10.Such as, in the machine, controller 48 can the motion of monitoring utensil or the required movement of machine itself to determine the demand of pressure fluid.Such as, when controller 48 determines that pressure fluid demand exceedes the current output of pump 10, controller 34 can adjusting angle control gear 46 to increase the angle α of swash plate 12, thus increase the discharge capacity of pump 10.

Controller 48 of the present invention can have any conventional design comprising and be configured to perform the hardware and software calculated, and sends and receive proper signal to perform disclosed logic.Controller 48 can comprise one or more controller unit, and can be configured to only perform disclosed strategy, or strategy disclosed in performing and other process (not shown) of machine.Controller 48 has any suitable structure, and can comprise processor (not shown) and memory member (not shown).Processor can be microprocessor as known in the art or other processors.In certain embodiments, processor can be made up of multiple processor.In one example, controller 48 comprises digital processing unit system, this digital processing unit system comprise have data input and control export microcontroller circuit, thus according to store on a computer-readable medium computer-readable instruction operation.Usually, processor will have associated with it long-term (non-volatile) storer being used for stored program instruction and short-term (volatibility) storer for the result of (or being obtained by process) in store operands and processing procedure.

Processor can perform the instruction of the angle α for generating swash plate angle signal and control swash plate 12, all methods as described herein.This type of instruction can be read into or be incorporated in computer-readable medium such as memory member, or is provided to the outside of processor.In alternative embodiments, hard-wired circuit can be used to replace software instruction or to combine to realize swash plate angle method with software instruction.Therefore, embodiment is not limited to any specific combination of hardware circuit and software.

Term used herein " computer-readable medium " refers to and participates in providing any medium of instruction for performing or the combination of medium to processor.This type of medium can take many forms, includes but not limited to non-volatile media, Volatile media and transmission medium.Such as, non-volatile media comprises CD or disk.Volatile media comprises dynamic storage.Transmission medium comprises concentric cable, copper cash and optical fiber.

The common form of computer-readable medium comprises such as floppy disk, flexible disk, hard disk, tape or any other magnetic medium, CD-ROM, any other optical medium, punched card, paper tape, any other has the physical medium of sectional hole patterns, RAM, PROM and EPROM, FLASH-EPROM, any other memory chip or chuck, or any other medium that computing machine or processor can read.

Memory member can comprise any form of computer-readable media as above.Memory member can comprise multi-memory element.

Controller 48 can be encapsulated in single shell.In alternative embodiments, controller 48 can comprise the multiple parts be operably connected and be encapsulated in multiple shell.Controller 48 can be the integral part of control panel, and can be fixedly connected to terminal box (not shown).In another embodiment, controller 48 can be fixedly attached to prime mover, generator and/or machine frame (not shown).In other embodiments another, controller 48 can be arranged in multiple position be operably connected, and comprises and is fixedly attached to framework, prime mover, generator, terminal box and/or is long-rangely attached to machine (not shown).

Controller 48 can be configured to generate pump angle signal according to such as desired POF or desired pump output pressure.In one embodiment, pump angle signal can be the signal that the angle α of swash plate 12 revised by order swash plate angle control gear 46.

In order to determine and control the flow rate of self-pumping 10, be necessary to identify the angle α with the swash plate 12 of control pump exactly.According to the present invention, the swash plate angle sensing arrangement 50 of dielectric sensors form can engage with pump 10 the angle α sensing swash plate 12, such as shown in figures 1 and 3.In an illustrated embodiment, swash plate angle sensing arrangement 50 comprise sensing probe 52 and sensor target 54 together with the fluid media (medium) 56 be arranged in pump case 16.It will be understood by those skilled in the art that sensing probe 52 and sensor target 54 roughly should set size for pump 10, and utilize exercisable material under the condition of work applicatory of the design for pump 10.

In shown arrangement 50, sensing probe 52 connects the inside of pump case 16 and is exposed to the inside of pump case 16.Sensing probe 52 plays conductor, and can have any design suitably.Only by way of example, with reference to Fig. 3 and Fig. 4, the electrode 58 that sensing probe 52 can be current-carrying part or be arranged in steel pump case 16, wherein electrode 58 and pump case 16 separate by non-conductive section or insulator 60.Electrode 58 can have any design suitably, and can be such as conductive metal wire.Similarly, insulator 60 can have any design suitably formed by nonmagnetic substance, only such as plastics, teflon or plexiglas by way of example.Such as, insulator 60 can have round-shaped and can comprise the central opening 62 that wire electrode 58 extends through.Insulator 60 can be arranged on and directly be sealed in the opening 64 in pump case 16, or is surrounded by other conductive layer 66, as shown in Figure 3 and Figure 4.Sensing probe 52 can pass through any suitable arrangement such as such as securing member, and the (not shown) such as such as screw are fixed to housing 16.Those skilled in the art will recognize that and can utilize alternative sensing probe design.

Sensor target 54 is arranged on sensing probe 52 opposite, namely on swash plate 12.Sensor target 54 can pass through any suitable arrangement such as such as one or more securing member, and the (not shown) such as such as screw are fixed to swash plate 12.Sensor target 54 is arranged on swash plate 12 in certain position, and sensor target 54 is changed with the position of swash plate 12 relative to the position of sensing probe 54.Such as, sensor target 54 can be arranged along the edge of swash plate 12.

The same with sensing probe 52, sensor target 54 can have any design suitably.In one embodiment, similarly, sensor target 54 comprises the current-carrying part 68 surrounded by non-conductive section or insulator 70.

Swash plate angle sensing arrangement 50 also comprises controller 48.Although the controller 48 of swash plate angle sensing arrangement is illustrated as the controller 48 being configured to the angle controlling swash plate 12, is understandable that, one or more controller can be provided.

Controller 48 is configured to make the alternating current from power supply 72 be fed to sensing probe 52.By forming alternating current between the electrode 58 and the pump case 16 playing the electrode effect contacted with conductive layer 66 equally of sensing probe 52, when pump case 16 is metals, between electrode 58 and pump case 16, form impedance.The impedance formed will depend on both sensor targets 54 of the near surface being comprised in fluid media (medium) 56 between pump case 16 and electrode 58.In a word, fluid media (medium) 56 and sensor target 54 can be called as medium.Along with the angle α of swash plate 12 changes, the medium between electrode 58 and pump case 16 changes.Therefore, this change will cause the change of the boundary condition of current path and therefore causes the change of impedance.

Therefore, in an illustrated embodiment, the sensing non-conductive section of probe 52 or insulator 60 and fluid media (medium) 56 play placement dielectric effect between adjacent electrodes, and the combination being equivalent to capacitor and resistor can be considered to, the current-voltage behavior that this combination will copy for given application.The change of the geometric configuration of the spacing between housing 16, the change sensing the medium between probe 52 and sensor target 54 and/or above-mentioned parts will cause the change of the impedance of equivalent electrical circuit.

Impedance variation can change at leap resistor R _loutput terminal 74 place measure voltage V _out.Therefore, the angle α of swash plate angle sensing arrangement 50 pairs of swash plates 12 is responsive, makes the gained voltage V measured at output terminal 74 place be associated with sensing probe 52 _outsensor signal form the instruction of the angle position of swash plate 12 can be supplied to controller 48.Then, controller 48 can make at leap resistor R _loutput terminal 74 place measure voltage V _outassociate with the position of swash plate 12, and therefore associate with swash plate angle α, with based on measured voltage V _outdetermine the corresponding flow rate that pump exports or pressure, this information can be utilized to control further or change pump output.

The ultimate principle of dielectric sensing arrangement can be seen in Fig. 3 and Fig. 5 to Fig. 6.By the complex media of fluid media (medium) 56 and sensor target 54, sensing probe 52 and pump case 16 form the circuit (all using drawing reference numeral 50 to mark) that can be considered to the combination of the some independent capacitor be made up of three kinds of different materials.Therefore, these three kinds of materials are those materials in insulator 60, fluid media (medium) 56 and sensor target 54.

In one embodiment, because the dielectric of considered insulator 60, fluid media (medium) 56 and sensor target 54 is faulty, so replace constant so that loss to be described with plural number.Therefore, the dielectric property of described material represents with following equation, wherein, and _tit is the specific inductive capacity of sensor target 54; □ _iit is the specific inductive capacity of insulator 60; □ _othe specific inductive capacity of fluid media (medium) 56:

□ε _T＝ε _T’-”jε _T

□ε _I＝ε _I’-”jε _I

□ε _O＝ε _O’-”jε _O

Band is skimmed and the two amount of skimming of band depends on frequency.Therefore, by fixed part, for sense probe 52 Exact Equivalent Circuit only for being possible during single frequency in the region near relaxation frequency.

Ignore the sensing resistance of probe 52, the resistance of pump case 16 and other stray capacitances and inductance, swash plate angle sensing arrangement 50 can be represented by the equivalent electrical circuit being labeled as drawing reference numeral 50 in Fig. 6.Therefore, as shown in Figure 6, the equivalent electrical circuit of the embodiment of swash plate angle sensing arrangement 50 can be obtained, wherein, R ₁and R ₂the both interior resistance of sensor.At input sinusoidal voltage E _iunder the excitation of (j ω), by the electric current I (j ω) of loading resistor, the output voltage V at loading resistor two ends _ovoltage (that is, sensing the electrode 58 of probe 52 and the voltage at the steel sheel 16 two ends) V at (j ω) and electrode two ends _p(j ω) all can calculate by this equivalent electrical circuit as shown in Figure 6.

For an embodiment, such as, transport function is as follows:

$G_I\left(\mathrm{j\ω}\right)\≈\frac{\mathrm{j\ω}(R_1+R_2)+1}{\mathrm{j\ω}(R_L(R_1+R_2)+R_1{R}_2)C+R_L+R_1}---\left(1\right)$

$G_{\mathrm{Vo}}\left(\mathrm{j\ω}\right)\≈\frac{\mathrm{j\ω}{R}_L(R_1+R_2)C+R_L}{\mathrm{j\ω}(R_L(R_1+R_2)+R_1{R}_2)C+R_L+R_1}---\left(2\right)$

Parameter in transport function can around operating point with different frequencies by input data and export data identification.In order to obtain for impedance variation optimum sensitivity, Selecting parameter can be made transport function is optimised relative to the sensitivity of its parameter.Exemplarily, consider | G| ²=GG*, wherein G* is the complex conjugate of G.In order to the necessary condition obtaining the optimum sensitivity of each parameter of this situation is:

$\frac{\∂}{{\∂p}_j}\left(\frac{\∂}{{\∂q}_i}\left(G_{\mathrm{vo}}\left(\mathrm{j\ω}\right){G_{\mathrm{vo}}}^{*}\left(\mathrm{j\ω}\right)\right)\right)=0---\left(3\right)$

Wherein q _isensitive parameter, p _jrepresent design variable.

It should be appreciated by those skilled in the art that, gained relation between measured voltage and swash plate angle will depend on various factors, include but not limited to the presence or absence of the hydraulic fluid medium 56 sensed between probe 52 and sensor target 54, sense the respective material of probe 52, sensor target 54 and insulator 60, size and shape and their corresponding impedance.Illustrated in Fig. 7 voltage with for comprising the gained relation of the angle position of the swash plate 12 of the model of the embodiment of triangle sensor target 54.By this way, can optimization relative shape, size and material, to provide the curve of expectation, such as, such as provide the embodiment of the linear relation of voltage and swash plate angle.

Industrial applicibility

Disclosed swash plate angle sensing arrangement 50 utilizes dielectric to sense the principle of arrangement to determine the angle position of swash plate 12, and therefore determines the fluid stream of the variable delivery pump 10 be used in hydraulic system.The embodiment of disclosed arrangement can provide good system performance.

Swash plate angle sensing arrangement 50 and the embodiment utilizing this swash plate angle to sense the variable delivery pump 10 of arrangement 50 can provide the reliable determination of swash plate angle α.These embodiments can be very sane.These embodiments can be implemented by the packaging simplified, and can be in use very sane and solid.

How no matter be comprised in ferrite fragment in the fluid media (medium) 56 in pump 10, the embodiment of swash plate angle sensing arrangement 50 can provide reliably and accurately to be measured.Similarly, no matter how one or more disadvantageous operating conditions such as includes but not limited to dramatic temperature change, significant system vibration, frequently pressure surge, cavitation and various noise, and embodiment can provide this type of reliably and accurately to measure.

Should be appreciated that aforementioned explanation provides disclosed system and the example of technology.But, it is contemplated that of the present invention other be embodied in can be different from aforementioned exemplary in details.Concrete example that reference equivalent discusses is intended to all references of the present invention or its example and in general not intended to be implies any restriction to scope of invention.Except as otherwise noted, otherwise be all intended to indicate those features not to be preferred about the distinctiveness of some feature and all language of derogatory, instead of this category feature is got rid of completely outside scope of the present invention.

Unless otherwise indicated herein or the obvious contradiction of context, otherwise describing term " " that in context of the present invention, (in the context particularly at following claims) uses, " one ", " being somebody's turn to do ", " at least one " and similar referring to odd number and plural number is contained by being construed as.Unless otherwise indicated herein or the obvious contradiction of context, otherwise the term " at least one " used before the list of one or more project (such as " in A and B at least one ") will be construed as two or more the combination (A and B) meaning an entry (A or B) or the listed project selected from listed project.

Unless otherwise indicated herein, otherwise the scope of value herein describe the shorthand method being only intended to be used as to refer to separately each independent value fallen within the scope of this, and each independent value is just incorporated in the present specification as coverlet is solely documented in herein.Unless otherwise indicated herein or in the obvious contradiction of context, otherwise all methods as herein described can any suitable order perform.

Therefore, the present invention includes all modifications and the equivalent of the theme enumerated in the appended claims that applicable law allows.In addition, unless otherwise indicated herein or in the obvious contradiction of context, otherwise its any combination of the said elements likely in modification be all included in invention.

Claims (10)

1. the sensing of the swash plate angle for variable delivery pump 10 arrangement 50, described variable delivery pump has housing 16, described housing 16 comprises the non-rotating swash plate 12 of rotation 18 pivotable be suitable for relative to pump barrel 14, described swash plate 12 limits the swash plate angle of the plane relative to the described rotation 18 being substantially perpendicular to described pump barrel 14, and described swash plate angle sensing arrangement 50 comprises:

Sensing probe 52, described sensing probe 52 is arranged in described housing 16;

Sensor target 54, described sensor target 54 is mounted to described swash plate 12; And

Controller 48, described controller 48 is configured to guide alternating current by described sensing probe 52, to form impedance and determine the voltage at described sensing probe 52 two ends between described sensing probe 52 and described sensor target 54, described controller 48 is also suitable for the described angle determining described swash plate 12 based on described determined voltage.

2. swash plate angle sensing arrangement 50 according to claim 1, also comprises the fluid media (medium) 56 be arranged between described sensing probe 52 and described sensor target 54.

3. swash plate angle sensing arrangement 50, the current-carrying part 58 that wherein said sensing probe 52 comprises the inside being exposed to described housing 16 and the non-conductive section 60 be arranged between described current-carrying part 58 and described housing 16 according to any one of claim 1 or 2.

4. swash plate angle sensing arrangement 50 according to claim 3, wherein said current-carrying part 58 comprises line.

5. the swash plate angle sensing arrangement 50 according to any one of claim 1-4, wherein said sensor target 54 comprises current-carrying part 68 and is arranged on the non-conductive section 70 between described current-carrying part 68 and described swash plate 12.

6. the swash plate angle sensing arrangement 50 according to any one of claim 1-5, wherein said controller 48 is configured to guide described alternating current between described sensing probe 52 and described housing 16.

7. the swash plate angle sensing arrangement 50 according to any one of claim 1-6, wherein said formed impedance changes with the described angle of described swash plate 12.

8. a variable delivery pump 10, it comprises:

Housing 16;

Cylinder 14, described cylinder 14 to be arranged in described housing 16 and to be suitable for rotating around rotation 18;

Non-rotating swash plate 12, described non-rotating swash plate 12 to be arranged in described housing 16 and to be suitable for relatively described axis 18 pivotable; And

Swash plate angle sensing arrangement 50 according to any one of claim 1-7.

9., for monitoring a method for the angle of the non-rotating swash plate 12 according to any one of claim 1-8, it comprises the following steps:

Alternating current is guided to cross over described sensing probe 52 to form impedance between described sensing probe 52 and described sensor target 54;

Determine the described voltage at described sensing probe 52 two ends; And

The described angle of described swash plate 12 is determined based on described determined voltage.

10. method according to claim 9, also comprises the described step of the described angle based on wobbler 12 described in described determined Angulation changes.