A durability test system for hydrostatic units with power recovery

Abstract

The invention discloses a hydrostatic unit durability test system with power recovery, which relates to the technical field of hydrostatic transmission unit testing, and includes a driving mechanism, a first cartridge valve, a second cartridge valve and a transmission mechanism; the driving mechanism is transmission-connected to the input end of the hydrostatic unit; the transmission mechanism is used to connect the motor shaft and the pump shaft of the hydrostatic unit; the oil return port of the first cartridge valve is connected to the oil tank; the first working oil port of the first cartridge valve is connected to the first working oil port of the hydrostatic unit; the second working oil port of the first cartridge valve is connected to the second working oil port of the hydrostatic unit; the oil return port of the second cartridge valve is connected to the oil tank; the pressure oil port of the second cartridge valve is connected to the output port of the oil replenishment pump; the oil inlet of the second cartridge valve is connected to the oil inlet of the hydrostatic unit. It is used for hydrostatic unit durability testing, solves the problems of complicated durability testing, difficult operation, and serious waste of resources in the past, and can quickly and effectively detect data in various parts of the system.

Description

Technical Field

[0001] The invention relates to the technical field of hydrostatic transmission unit testing, and in particular to a hydrostatic unit durability testing system capable of power recovery. Background Art

[0002] The static hydraulic unit uses the static pressure of the liquid to transmit force and control movement, and achieves precise control of the mechanical device by controlling the switching state of the hydraulic valve and the pressure of the hydraulic pump.

[0003] The hydrostatic unit mainly includes a hydraulic pump, a hydraulic motor and various accessories. Compared with the hydrostatic transmission system, the hydrostatic transmission unit has the advantages of small size, light weight, high precision and fast response.

[0004] A test system is usually used for testing a hydrostatic unit. For example, the patent with publication number CN112324747A discloses a hydrostatic transmission unit test system. The existing hydrostatic unit test bench cannot achieve power recovery, resulting in serious waste of resources and making it difficult to perform energy-saving, convenient and fast hydrostatic unit testing. Summary of the invention

[0005] The object of the present invention is to provide a hydrostatic unit durability test system capable of power recovery, so as to reduce the test cost.

[0006] To achieve the above object, the present invention provides the following solutions:

[0007] The present invention provides a power-recoverable hydrostatic unit durability test system, comprising a drive mechanism, a first cartridge valve, a second cartridge valve and a transmission mechanism;

[0008] The driving mechanism is in transmission connection with the input end of the hydrostatic unit;

[0009] The transmission mechanism is used to connect the motor shaft and the pump shaft of the hydrostatic unit;

[0010] The oil return port of the first cartridge valve is connected to the oil tank; the first working oil port of the first cartridge valve is connected to the first working oil port of the hydrostatic unit; the second working oil port of the first cartridge valve is connected to the second working oil port of the hydrostatic unit;

[0011] The oil return port of the second cartridge valve is connected to the oil tank; the pressure oil port of the second cartridge valve is connected to the output port of the oil replenishment pump; and the oil inlet of the second cartridge valve is connected to the oil inlet of the hydrostatic unit.

[0012] Optionally, the driving mechanism includes a servo motor and a coupling, and the output shaft of the servo motor is drivingly connected to the input end of the hydrostatic unit through the coupling.

[0013] Optionally, the driving mechanism further includes a torque and speed sensor, and both ends of the torque and speed sensor are respectively connected to the input ends of the servo motor and the hydrostatic unit through the coupling.

[0014] Optionally, the transmission mechanism includes a first gear and a second gear, the first gear is drivingly connected to the motor shaft of the hydrostatic unit, the second gear is drivingly connected to the pump shaft of the hydrostatic unit, and the first gear is meshed with the second gear.

[0015] Optionally, parameters of the first gear and the second gear are the same.

[0016] Optionally, the first cartridge valve includes a relief valve, a ball valve, a second cartridge and a first cartridge; the first interface of the ball valve is connected to the pressure oil port of the relief valve and the external control ports of the first cartridge and the second cartridge respectively; the second interface of the ball valve is connected to the oil tank; the first interface of the first cartridge is connected to the first interface of the second cartridge, the first interface of the ball valve, and the pressure oil port of the relief valve respectively; the second interface of the first cartridge is connected to the first working oil port of the first cartridge valve; the second interface of the second cartridge is connected to the first working oil port of the second cartridge valve; the oil return port of the relief valve is connected to the oil tank.

[0017] Optionally, a first pressure sensor and a first pressure gauge are provided between the second interface of the first cartridge and the first working oil port of the first cartridge valve.

[0018] Optionally, a second pressure sensor and a second pressure gauge are provided between the second interface of the second cartridge and the second working oil port of the first cartridge valve.

[0019] Optionally, the second cartridge valve includes a three-position four-way reversing valve, a pressure reducing valve and a relief valve; the pressure oil port of the three-position four-way reversing valve is connected to the first pressure oil port of the pressure reducing valve; the oil return port of the three-position four-way reversing valve is connected to the oil tank; the first working oil port of the three-position four-way reversing valve is connected to the oil inlet of the hydrostatic unit;

[0020] The oil return port of the pressure reducing valve is connected to the oil tank; the second pressure oil port of the pressure reducing valve is connected to the pressure oil port of the overflow valve; the oil return port of the overflow valve is connected to the oil tank; the second pressure oil port of the pressure reducing valve and the pressure oil port of the overflow valve are connected to the output port of the oil replenishment pump.

[0021] Optionally, a first filter is provided between the output port of the oil replenishment pump and the pressure reducing valve and the overflow valve, and a first one-way valve is provided between the first filter and the output port of the oil replenishment pump.

[0022] Compared with the prior art, the present invention has achieved the following technical effects:

[0023] The power-recoverable hydrostatic unit durability test system of the present invention is used for hydrostatic unit durability test, which solves the problems of complicated durability test, difficult operation and serious waste of resources in the past. It adopts a servo motor to drive the hydrostatic unit, and a pair of gears with the same parameters are used on the output side of the hydrostatic unit to connect the pump shaft of the hydrostatic unit with the motor shaft. The oil replenishment pump replenishes oil for the hydrostatic unit at the same time, combined with the cartridge valve group, so that it can meet the hydrostatic unit life test and realize power recovery. At the same time, the wide arrangement of various types of instruments and sensors can quickly and effectively detect the flow, pressure, speed, torque and other data in various parts of the system, providing a strong data analysis guarantee for the test personnel. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0025] Figure 1 It is a structural schematic diagram of the durability testing system of the hydrostatic unit with power recovery in the present invention.

[0026] Description of reference numerals:

[0027] 1. First gear; 2. Second gear; 3. Hydrostatic unit; 4. First coupling; 5. Torque speed sensor; 6. Second coupling; 7. Servo motor; 11. First filter; 12. First check valve; 13. Make-up oil pump; 14. Make-up oil pump motor; 15. Oil tank; 24. First ball valve switch; 25. Second filter; 26. Second ball valve switch; 27. Second check valve; 28. Flow meter.

[0028] First cartridge valve: 16, first relief valve; 17, ball valve; 18, second cartridge; 19, second pressure gauge; 20, second pressure sensor; 21, first cartridge; 22, first pressure sensor; 23, first pressure gauge.

[0029] Second cartridge valve: 8. Three-position four-way reversing valve; 9. Pressure reducing valve; 10. Second relief valve. DETAILED DESCRIPTION

[0030] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0031] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0032] like Figure 1 As shown, this embodiment provides a hydrostatic unit durability test system with power recovery, including a drive mechanism, a first cartridge valve, a second cartridge valve and a transmission mechanism; the drive mechanism is transmission-connected to the input end of the hydrostatic unit 3; the transmission mechanism is used to connect the motor shaft and the pump shaft of the hydrostatic unit 3; the return oil port of the first cartridge valve is connected to the oil tank 15; the first working oil port of the first cartridge valve is connected to the first working oil port of the hydrostatic unit 3; the second working oil port of the first cartridge valve is connected to the second working oil port of the hydrostatic unit 3; the return oil port of the second cartridge valve is connected to the oil tank 15; the pressure oil port of the second cartridge valve is connected to the output port of the oil replenishment pump 13; the oil inlet of the second cartridge valve is connected to the oil inlet of the hydrostatic unit 3. The oil replenishment pump motor 14 drives the oil replenishment pump 13.

[0033] The driving mechanism includes a servo motor 7, a torque speed sensor 5, a first coupling 4 and a second coupling 6. The servo motor 7 is connected to the input end of the torque speed sensor 5 through the first coupling 4, and the output end of the torque speed sensor 5 is connected to the input end of the hydrostatic unit 3 through the second coupling 6.

[0034] The transmission mechanism includes a first gear 1 and a second gear 2. The first gear 11 and the second gear 2 are connected to the motor shaft and the pump shaft of the hydrostatic unit 3 through splines, respectively, and the first gear 1 is meshed with the second gear 2. The parameters of the first gear 1 and the second gear 2 are the same. A 1:1 transmission of the speed of the motor shaft and the pump shaft is achieved.

[0035] The first cartridge valve includes a first relief valve 16, a ball valve 17, a second cartridge 18 and a first cartridge 21; the first interface of the ball valve 17 is connected to the pressure oil port of the first relief valve 16 and the external control ports of the first cartridge 21 and the second cartridge 18 respectively; the second interface of the ball valve 17 is connected to the oil tank 15; the first interface of the first cartridge 21 is connected to the first interface of the second cartridge 18, the first interface of the ball valve 17 and the pressure oil port of the first relief valve 16 respectively; the second interface of the first cartridge 21 is connected to the first working oil port of the first cartridge valve; the second interface of the second cartridge 18 is connected to the first working oil port of the second cartridge valve; the oil return port of the first relief valve 16 is connected to the oil tank 15. A first ball valve switch 24 is provided between the second interface of the ball valve 17 and the oil tank 15.

[0036] A first pressure sensor 22 and a first pressure gauge 23 are provided between the second interface of the first cartridge 21 and the first working oil port of the first cartridge valve.

[0037] A second pressure sensor 20 and a second pressure gauge 19 are provided between the second interface of the second cartridge 18 and the second working oil port of the first cartridge valve.

[0038] The second cartridge valve includes a three-position four-way reversing valve 8, a pressure reducing valve 9 and a second overflow valve 10; the pressure oil port of the three-position four-way reversing valve 8 is connected to the first pressure oil port of the pressure reducing valve 9; the return oil port of the three-position four-way reversing valve 8 is connected to the oil tank 15; the first working oil port of the three-position four-way reversing valve 8 is connected to the oil inlet of the static hydraulic unit 3; the return oil port of the pressure reducing valve 9 is connected to the oil tank 15; the second pressure oil port of the pressure reducing valve 9 is connected to the pressure oil port of the second overflow valve 10; the return oil port of the second overflow valve 10 is connected to the oil tank 15; the second pressure oil port of the pressure reducing valve 9 and the pressure oil port of the second overflow valve 10 are connected to the output port of the oil replenishment pump 13.

[0039] A first filter 11 is provided between the output port of the oil replenishment pump 13 and the pressure reducing valve 9 and the second relief valve 10 , and a first check valve 12 is provided between the first filter 11 and the output port of the oil replenishment pump 13 .

[0040] The oil inlet of the first filter 25 is connected to the oil return port T of the static hydraulic unit 3, and the oil outlet of the first filter 25 is connected to the oil inlet of the flow meter 28, and the oil outlet of the flow meter 28 is connected to the oil tank 15 through the one-way valve 27. A second ball valve switch 26 is provided between the one-way valve 27 and the oil tank 15.

[0041] The test method of the hydrostatic unit durability test system with power recovery in this embodiment is as follows:

[0042] The servo motor 7 is connected to the input end of the hydrostatic unit 3 through the torque speed sensor 5 to realize power input; the first gear 1 and the second gear 2 on the output side of the hydrostatic unit 3 respectively connect the motor shaft and the pump shaft of the hydrostatic unit 3 through splines to realize a 1:1 speed transmission.

[0043] The first cartridge valve can adjust the load of the hydrostatic unit 3 by adjusting the opening pressure of the first overflow valve 16 to load the hydrostatic unit.

[0044] The oil supply pump 13 provides cooled hydraulic oil to the hydrostatic unit 3 through the second cartridge valve to maintain the system pressure.

[0045] By adjusting the rotation speed of the servo motor 7, the swing angle range of the actuator of the hydrostatic unit 3 and the opening pressure of the second relief valve 16 in the first cartridge valve, the endurance test of the hydrostatic unit at different rotation speeds, different steering directions, different pressures and different loads can be realized, and power recovery can be achieved.

[0046] The pump shaft and the motor shaft in the hydrostatic unit 3 are meshed and connected by the first gear 1 and the second gear 2. When the test bench starts to work, the output power of the hydraulic motor is transmitted to the pump shaft through the meshing of the first gear 1 and the second gear 2 to continue to participate in the work of the hydrostatic unit 3, and a part of the torque on the motor side of the hydrostatic unit 3 is transmitted to the pump side of the hydrostatic unit. This torque can reduce the work done by the servo motor 7, and drive the rotation of the pump in the hydrostatic unit 3 together with the servo motor 7. At this time, the servo motor 7 only needs part of the power input to realize the operation of the test bench, thereby achieving the purpose of power recovery.

[0047] It should be noted that it is obvious to those skilled in the art that the present invention is not limited to the details of the above exemplary embodiments, and that the present invention can be implemented in other specific forms without departing from the spirit or essential features of the present invention. Therefore, no matter from which point of view, the embodiments should be regarded as exemplary and non-restrictive, and the scope of the present invention is defined by the appended claims rather than the above description, and it is intended that all changes falling within the meaning and scope of the equivalent elements of the claims are included in the present invention, and any figure mark in the claims should not be regarded as limiting the claims involved.

[0048] The present specification uses specific examples to illustrate the principles and implementation methods of the present invention. The above examples are only used to help understand the method and core idea of ​​the present invention. At the same time, for those skilled in the art, according to the idea of ​​the present invention, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as limiting the present invention.

Claims

1. A hydrostatic unit durability test system with power recovery, characterized in that: It includes a driving mechanism, a first cartridge valve, a second cartridge valve and a transmission mechanism; The driving mechanism is in transmission connection with the input end of the hydrostatic unit; The transmission mechanism is used to connect the motor shaft and the pump shaft of the hydrostatic unit; The oil return port of the first cartridge valve is connected to the oil tank; the first working oil port of the first cartridge valve is connected to the first working oil port of the hydrostatic unit; the second working oil port of the first cartridge valve is connected to the second working oil port of the hydrostatic unit; The oil return port of the second cartridge valve is connected to the oil tank; the pressure oil port of the second cartridge valve is connected to the output port of the oil replenishment pump; and the oil inlet of the second cartridge valve is connected to the oil inlet of the hydrostatic unit.

2. The power recovery hydrostatic unit durability test system according to claim 1, characterized in that: The driving mechanism comprises a servo motor and a coupling, and the output shaft of the servo motor is transmission-connected to the input end of the hydrostatic unit through the coupling.

3. The power recovery hydrostatic unit durability test system according to claim 2, characterized in that: The driving mechanism further comprises a torque speed sensor, and two ends of the torque speed sensor are respectively connected to the servo motor and the input end of the hydrostatic unit through the coupling.

4. The hydrostatic unit durability test system with power recovery according to claim 1, characterized in that: The transmission mechanism includes a first gear and a second gear, the first gear is drivingly connected to the motor shaft of the hydrostatic unit, the second gear is drivingly connected to the pump shaft of the hydrostatic unit, and the first gear is meshed with the second gear.

5. The power recovery hydrostatic unit durability test system according to claim 4, characterized in that: The parameters of the first gear and the second gear are the same.

6. The hydrostatic unit durability test system with power recovery according to claim 1, characterized in that: The first cartridge valve includes a relief valve, a ball valve, a second cartridge and a first cartridge; the first interface of the ball valve is connected to the pressure oil port of the relief valve and the external control ports of the first cartridge and the second cartridge respectively; the second interface of the ball valve is connected to the oil tank; the first interface of the first cartridge is connected to the first interface of the second cartridge, the first interface of the ball valve and the pressure oil port of the relief valve respectively; the second interface of the first cartridge is connected to the first working oil port of the first cartridge valve; the second interface of the second cartridge is connected to the first working oil port of the second cartridge valve; the oil return port of the relief valve is connected to the oil tank.

7. The hydrostatic unit durability test system with power recovery according to claim 6, characterized in that: A first pressure sensor and a first pressure gauge are provided between the second interface of the first cartridge and the first working oil port of the first cartridge valve.

8. The hydrostatic unit durability test system with power recovery according to claim 6, characterized in that: A second pressure sensor and a second pressure gauge are provided between the second interface of the second cartridge and the second working oil port of the first cartridge valve.

9. The hydrostatic unit durability test system with power recovery according to claim 1, characterized in that: The second cartridge valve includes a three-position four-way reversing valve, a pressure reducing valve and a relief valve; the pressure oil port of the three-position four-way reversing valve is connected to the first pressure oil port of the pressure reducing valve; the oil return port of the three-position four-way reversing valve is connected to the oil tank; the first working oil port of the three-position four-way reversing valve is connected to the oil inlet of the hydrostatic unit; The oil return port of the pressure reducing valve is connected to the oil tank; the second pressure oil port of the pressure reducing valve is connected to the pressure oil port of the overflow valve; the oil return port of the overflow valve is connected to the oil tank; the second pressure oil port of the pressure reducing valve and the pressure oil port of the overflow valve are connected to the output port of the oil replenishment pump.

10. The hydrostatic unit durability test system with power recovery according to claim 9, characterized in that: A first filter is arranged between the output port of the oil replenishment pump and the pressure reducing valve and the overflow valve, and a first check valve is arranged between the first filter and the output port of the oil replenishment pump.

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