A sliding shoe wear amount real-time monitoring device and an axial plunger pump

Abstract

A kind of sliding shoe wear amount real-time monitoring device and axial piston pump, with the increase of use length, sliding shoe thickness gradually decreases, return disc drives permanent magnet gradually close to the magnetic sensor in disc, so that magnetic sensor can monitor the change of magnetic field and send corresponding electrical signal to controller, controller judges whether the thickness of sliding shoe reaches critical value based on the received electrical signal, therefore provide a kind of non-contact monitoring sliding shoe thickness technical scheme, realize indirect measurement of sliding shoe wear amount in axial piston pump, effectively solve the problem that prior art cannot monitor sliding shoe wear amount in real time in the process of axial piston pump operation, reduce downtime inspection time, reduce operating cost, and then according to wear monitoring data, scientific preventive maintenance plan is formulated, guarantee the continuity and stability of production.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of wear monitoring, in particular to a real-time monitoring device for wear amount of a sliding shoe of an axial piston pump. BACKGROUND

[0002] The axial piston pump is an important hydraulic power source, and the sliding shoe is a key sealing element and transmission mechanism in the axial piston pump. The sliding shoe will be worn in long-term use, and if the sliding shoe is excessively worn, the performance of the pump will be reduced or even fail. Since the sliding shoe is compact and has a small gap with the swash plate, direct measurement is not convenient, and installing a sensor on the sliding shoe will damage the performance of the sliding shoe. SUMMARY

[0003] The present application aims to provide a real-time monitoring device for wear amount of a sliding shoe of an axial piston pump, which is used to monitor the wear amount of the sliding shoe during operation of the piston pump and reduce the situation of shutdown inspection.

[0004] To achieve the above-mentioned purpose, the present application provides the following technical scheme:

[0005] A real-time monitoring device for wear amount of a sliding shoe is used for an axial piston pump,

[0006] A disc is detachably installed on the swash plate, and at least one magnetic sensor is arranged in the disc;

[0007] A return disc is provided with a plurality of sliding shoes arranged in a uniform circumferential array, and the return disc presses one end of the sliding shoe to the disc under the elastic force of a center spring, and the other end of the sliding shoe is arranged in the return disc and used to connect a piston;

[0008] At least one permanent magnet is arranged in the disc between two adjacent sliding shoes, the return disc gradually approaches the disc as the sliding shoe is worn and thinned, the permanent magnet gradually approaches the magnetic sensor, and the magnetic sensor is in different magnetic fields; and

[0009] A controller is used to receive an electric signal output by the magnetic sensor in different magnetic field strengths, and judge whether the thickness of the sliding shoe reaches a critical value based on the electric signal.

[0010] Further, a plurality of magnetic sensors are arranged in the disc in a uniform circumferential array around the axis of the disc.

[0011] Further, an annular groove is arranged in the disc coaxially with the axis of the disc, and a plurality of magnetic sensors are arranged in the annular groove.

[0012] Further, the sliding shoe comprises a wear part and a connecting part connected with each other, the radial dimension of the wear part is larger than that of the connecting part, the connecting part is arranged in the return disc, and the return disc is pressed against the wear part so as to press the wear part against the disc.

[0013] Further, a plurality of permanent magnets are arranged on one end of the return disc towards the disc, the permanent magnets are arranged between two adjacent sliding shoes, and each permanent magnet is arranged in a uniform circumferential array around the axis of the return disc.

[0014] Further, the critical thickness of the wear part is larger than the thickness of the permanent magnet.

[0015] Further, the wear resistance of the disc is higher than that of the wear part.

[0016] Further, the swash plate is provided with a mounting groove, the disc is arranged in the mounting groove, and a limiting mechanism is arranged between the disc and the swash plate.

[0017] Further, the limiting mechanism comprises a positioning convex part arranged on the side wall of the mounting groove and a positioning groove arranged on the outer vertical surface of the disc, and the positioning groove and the positioning convex part are matched with each other.

[0018] An axial plunger pump comprises the sliding shoe wear amount real-time monitoring device as described above.

[0019] The beneficial effects of the present application are as follows:

[0020] 1. The sliding shoe wear amount real-time monitoring device provided by the present application can monitor the thickness of the sliding shoe in a non-contact manner, indirectly measure the wear amount of the sliding shoe in the axial plunger pump, effectively solve the problem that the existing technology cannot monitor the wear amount of the sliding shoe in real time during the operation of the axial plunger pump, reduce the downtime inspection time, reduce the operation cost, and then develop a scientific preventive maintenance plan according to the wear monitoring data, and ensure the continuity and stability of production.

[0021] 2. The sliding shoe wear amount real-time monitoring device provided by the present application is detachably arranged on the swash plate, and the sliding shoe abuts against the disc, so that the swash plate is not directly in frictional contact with the sliding shoe, the swash plate is prevented from being abraded, and the swash plate is protected, when the disc is worn, only the disc needs to be replaced or repaired, and the replacement and repair costs are reduced.

[0022] 3. The sliding shoe wear amount real-time monitoring device provided by the application has high wear resistance of the disc, which is higher than that of the wear part of the sliding shoe, so that the disc is not worn before the wear part, and the magnetic sensor is not damaged. BRIEF DESCRIPTION OF DRAWINGS

[0023] In order to more clearly illustrate the technical solutions in the embodiments of the application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments or the prior art description. Obviously, the drawings in the following description only show some embodiments of the application, and for those skilled in the art, other drawings can also be obtained from these drawings without creative labor.

[0024] Figure 1 FIG. 1 is a schematic diagram of the sliding shoe wear amount real-time monitoring device of the application;

[0025] Figure 2 FIG. 2 is an exploded view of the sliding shoe wear amount real-time monitoring device of the application;

[0026] Figure 3 FIG. 3 is a schematic diagram of the return disc of the sliding shoe wear amount real-time monitoring device of the application;

[0027] Figure 4 FIG. 4 is a partial cross-sectional view of the disc of the sliding shoe wear amount real-time monitoring device of the application;

[0028] Figure 5 FIG. 5 is a schematic diagram of the working process of the sliding shoe wear amount real-time monitoring device of the application;

[0029] Figure 6 FIG. 6 is a schematic diagram of the axial piston pump of the application;

[0030] In the drawings, 10 is a disc; 101 is an annular groove; 102 is a positioning groove; 20 is a magnetic sensor; 30 is a return disc; 301 is a through hole; 40 is a sliding shoe; 401 is a wear part; 402 is a connecting part; and 50 is a permanent magnet. DETAILED DESCRIPTION

[0031] The application will be described in detail below. Figures 1-6 The application will be described in detail below.

[0032] The application provides a sliding shoe wear amount real-time monitoring device for an axial piston pump,

[0033] The disc 10 is detachably installed on the swash plate, and at least one magnetic sensor 20 is arranged in the disc 10. Further, the swash plate is provided with a mounting groove, the disc 10 is installed in the mounting groove, and a limiting mechanism is arranged between the disc 10 and the swash plate. Specifically, the limiting mechanism comprises a positioning convex part arranged on the side wall of the mounting groove and a positioning groove 102 arranged on the outer vertical surface of the disc 10, and the positioning groove 102 and the positioning convex part are matched with each other.

[0034] The return disc 30 is provided with a plurality of sliding shoes 40 arranged in a uniform circumferential array, and the return disc 30 is pressed against the disc 10 at one end of the sliding shoe 40 under the elastic force of the center spring, and the other end of the sliding shoe 40 is provided with a plunger for connection;

[0035] At least one permanent magnet 50 is arranged between two adjacent sliding shoes 40 on the disc 10, and the return disc 30 gradually approaches the disc 10 due to wear and thinning of the sliding shoe 40, so that the permanent magnet 50 gradually approaches the magnetic sensor 20, and the magnetic sensor 20 is in a magnetic field of different strengths; and

[0036] A controller is configured to receive an electrical signal output by the magnetic sensor 20 under different magnetic field strengths, and determine whether the thickness of the sliding shoe 40 reaches a critical value based on the electrical signal. The critical value is the minimum thickness of the sliding shoe 40 in normal use.

[0037] As the length of use increases, the thickness of the sliding shoe 40 gradually decreases, and the return disc 30 drives the permanent magnet 50 to gradually approach the magnetic sensor 20 arranged in the disc 10, so that the magnetic sensor 20 can monitor the change of the magnetic field and send a corresponding electrical signal to the controller, and the controller determines whether the thickness of the sliding shoe 40 reaches a critical value based on the received electrical signal. Therefore, the embodiment provides a non-contact monitoring technology for the thickness of the sliding shoe 40, realizes indirect measurement of the wear amount of the sliding shoe 40 in the axial plunger pump, effectively solves the problem that the prior art cannot monitor the wear amount of the sliding shoe 40 in real time during the operation of the axial plunger pump, reduces the downtime inspection time, reduces the operation cost, and further formulates a scientific preventive maintenance plan according to the wear monitoring data, thereby ensuring the continuity and stability of production.

[0038] In the embodiment, the disc 10 is provided with a plurality of magnetic sensors 20 arranged in a uniform circumferential array around the axis thereof. Further, the disc 10 is provided with an annular groove 101 coaxially arranged with the axis of the disc 10, and the annular groove 101 is provided with a plurality of magnetic sensors 20. Further, the disc includes a base and a cover, the base is provided with an annular groove, the magnetic sensor is installed in the annular groove, and one side of the base provided with the annular groove is provided with a plurality of positioning shafts, and the cover is provided with positioning holes matched with the positioning shafts, and the cover is quickly installed on the base through the cooperation of the positioning shafts and the positioning holes. In other embodiments, the base and the cover can also be provided with grooves matched with each other, and the space surrounded by the two grooves constitutes the annular groove. Further, the magnetic sensor 20 is a giant magnetoresistance sensor, and in other embodiments, the magnetic sensor 20 is a Hall sensor.

[0039] In this embodiment, the slipper 40 includes an interconnected wear portion 401 and a connecting portion 402, with the radial dimension of the wear portion 401 being larger than that of the connecting portion 402. The return plate 30 is provided with a through hole 301, and each connecting portion 402 passes through the corresponding through hole 301. The return plate 30 presses against the wear portion 401, thereby pressing the wear portion 401 against the disc 10. Therefore, the monitored critical value of the slipper 40 is the minimum thickness of the wear portion 401 under normal use.

[0040] In this embodiment, a plurality of permanent magnet blocks are also included. These permanent magnet blocks are mounted on the end of the return disk 30 facing the disk 10, and are located between two adjacent slippers 40. Each permanent magnet block is arranged in a uniform circumferential array around the axis of the return disk 30. Furthermore, the critical thickness of the wear portion 401 is greater than the thickness of the permanent magnet blocks to prevent the permanent magnet blocks and the disk 10 from contacting each other. Furthermore, the wear resistance of the disk 10 is higher than that of the wear portion 401 to prevent the disk 10 from wearing out before the wear portion 401, thus preventing damage to the magnetic sensor 20. Specifically, the disk 10 is made of a wear-resistant material, or the surface of the disk 10 has undergone anti-wear strengthening treatment.

[0041] The following is an example of the implementation process for measuring the distance between the magnetic sensor 20 and the magnetic block based on the giant magnetoresistive effect, using a giant magnetoresistive sensor for magnetic sensing:

[0042] Implementation process as follows Figure 5 As shown, when in use, the monitoring device is powered on. At this time, the magnetic layers in the magnetic sensor 20 are arranged in an antiparallel state. Because a permanent magnet applies a magnetic field to the magnetic sensor 20, any change in the applied magnetic field will cause a change in the magnetization direction of the magnetic layers, resulting in a change in the resistance of the giant magnetoresistive sensor. This change in resistance is converted into an electrical signal. The controller receives and processes the electrical signal to obtain an output signal representing the magnetic field information. This output signal is a voltage. The output signal is sent to the programmable logic controller (PLC) via a communication device. The PLC has a preset diagnostic algorithm that converts the output signal into slipper wear, and then checks whether the slipper wear exceeds a preset threshold. The communication device uses an industrial Wi-Fi module, specifically the Siemens Scalance W series SCALANCE W774-1 RJ45, which supports transmitting electrical signals from sensors or other devices to the PLC via a Wi-Fi wireless network. Specifically, the giant magnetoresistive sensor is connected to the input terminal of the Wi-Fi module, thereby sending the signal to the PLC via Wi-Fi.

[0043] Therefore, the size of the output signal represents the distance between the giant magnetoresistance sensor and the permanent magnet block, i.e. the distance between the disc 10 and the return disc 30, i.e. the thickness of the wear part 401, and thus the real-time monitoring of the wear amount of the sliding shoe 40 of the axial plunger pump can be realized. For example, if the size of the output signal exceeds the threshold value, the distance between the disc 10 and the return disc 30 is too small, i.e. the wear amount of the sliding shoe 40 is too large, and the sliding shoe 40 needs to be replaced in time; if the size of the output signal does not exceed the threshold value, the gap distance between the disc 10 and the return disc 30 is normal, i.e. the wear amount of the sliding shoe 40 is acceptable, and the sliding shoe 40 does not need to be replaced.

[0044] In this embodiment, a calculation formula of the distance between the giant magnetoresistance sensor and the magnetic block is provided, as follows:

[0045] The resistance change of the giant magnetoresistance sensor can be represented as:

[0046] R = R0(1 + ΔR)

[0047] Wherein, R0 is the resistance without an external magnetic field, and ΔR is the relative change amount of the resistance.

[0048] The resistance change is converted into a voltage output by using a voltage dividing circuit:

[0049]

[0050] Wherein, V in is the terminal voltage of the voltage dividing circuit, V out is the output voltage, R is the resistance of the giant magnetoresistance sensor, and R i is the reference resistance.

[0051] By measuring the output voltage V out , the resistance change ΔR can be derived, and then the magnetic field strength B can be derived. Then, the distance d between the magnetic block on the return disc and the sensor is calculated through the formula of the relationship between the magnetic field strength and the distance:

[0052]

[0053] Wherein, k is a proportional constant, which depends on the properties of the sensor.

[0054] In this embodiment, a specific program segment of the PLC internal algorithm is provided, as follows:

[0055] VAR

[0056] V_in: REAL; / / input voltage value

[0057] V_set: REAL; / / set voltage value

[0058] Alarm: BOOL; / / alarm signal

[0059] Wear_mm: REAL; / / Wear of the shoe

[0060] Display: STRING; / / Display output string

[0061] END_VAR

[0062] BEGIN

[0063] / / Initialization of the set value

[0064] V_set := 5.0; / / Set value is 5.0 V

[0065] / / Read the voltage value from the analog input

[0066] V_in := "Input".Value; / / Analog input address is "Input"

[0067] / / Convert the input voltage value to the wear of the shoe

[0068] Wear_mm := V_in * 1.2; / / 1 V corresponds to 1.2 mm of wear

[0069] / / Determine whether the voltage value exceeds the set value

[0070] IF V_in > V_set THEN

[0071] Alarm := TRUE; / / Trigger the alarm

[0072] ELSE

[0073] Alarm := FALSE; / / Release the alarm

[0074] END_IF;

[0075] / / Generate the display output string

[0076] Display := CONCAT('Wear_mm:', REAL_TO_STRING(Wear_mm),'mm');

[0077] / / Display the wear of the shoe on the screen

[0078] "ScreenOutput".Text := Display; / / Output device address is "ScreenOutput"

[0079] END_PROGRAM

[0080] Wherein, the Input corresponding port is connected with the giant magnetoresistance sensor, and receives the electric signal from the giant magnetoresistance sensor; the Output corresponding port is connected with the alarm, to provide the electric signal for generating the alarm.

[0081] The embodiment also provides an axial plunger pump comprising the real-time monitoring device for the wear amount of the sliding shoe as described above.

[0082] The above embodiments are only for illustrating the technical concept and characteristics of the present application, and the purpose is to enable those skilled in the art to understand the present application and implement it, and cannot limit the protection scope of the present application. Any equivalent changes or modifications made according to the spirit and essence of the present application shall be covered within the protection scope of the present application.

Claims

1. A real-time monitoring device for slipper wear, used in an axial piston pump, characterized in that, A disc, detachably mounted on a swashplate, and at least one magnetic sensor is provided inside the disc; The return plate has a plurality of slippers arranged in a uniform circumferential array. Under the elastic force of the central spring, the return plate presses one end of the slipper against the plate, and the other end of the slipper passes through the return plate to connect to the plunger. The slipper includes a wear portion and a connecting portion that are connected to each other, and the radial dimension of the wear portion is larger than the radial dimension of the connecting portion. The connecting portion passes through the return plate, and the return plate presses against the wear portion, thereby pressing the wear portion against the disc. It also includes at least one permanent magnet, which is disposed on the return disk and located between two adjacent slippers. As the slippers wear down, the return disk gradually gets thinner and gets closer to the disk, so that the permanent magnet gradually gets closer to the magnetic sensor, so that the magnetic sensor is in a magnetic field of different strengths. as well as The controller is used to receive the electrical signals output by the magnetic sensor under different magnetic field strengths, and to determine whether the thickness of the slipper has reached a critical value based on the electrical signals.

2. The real-time monitoring device for skate shoe wear as described in claim 1, characterized in that, The disk contains several magnetic sensors arranged in a uniform circular array around its axis.

3. The real-time monitoring device for skate shoe wear as described in claim 2, characterized in that, The disk has an annular groove coaxial with the disk's axis, and a plurality of magnetic sensors are disposed within the annular groove.

4. The real-time monitoring device for skate shoe wear as described in claim 3, characterized in that, It also includes a number of permanent magnets, which are installed at one end of the return disk facing the disk, and the permanent magnets are located between two adjacent slippers, and each of the permanent magnets is arranged in a uniform circumferential array around the axis of the return disk.

5. The real-time monitoring device for slipper wear as described in claim 4, characterized in that, The critical thickness of the wear portion is greater than the thickness of the permanent magnet.

6. The real-time monitoring device for skate shoe wear as described in claim 1, characterized in that, The wear resistance of the disc is higher than that of the wear portion.

7. The real-time monitoring device for skate shoe wear as described in claim 1, characterized in that, The swash plate is provided with a mounting groove, the disc is installed in the mounting groove, and a limiting mechanism is provided between the disc and the swash plate.

8. The real-time monitoring device for skate shoe wear as described in claim 7, characterized in that, The limiting mechanism includes a positioning protrusion on the side wall of the mounting groove and a positioning groove on the outer side of the disc, wherein the positioning groove and the positioning protrusion are adapted to each other.

9. An axial piston pump, characterized in that, Includes the real-time monitoring device for ski wear as described in any one of claims 1-8.

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