Comprehensive test bench for hydraulic pumps and motors

Abstract

The present invention discloses a comprehensive test bench suitable for hydraulic pumps and hydraulic motors, which switches the oil supply circuit through a test mode switching valve, can provide pressure oil for both the hydraulic pump test and the hydraulic motor test, and can be used for performance tests of both hydraulic pumps and hydraulic motors, achieving multi-purposes and reducing the investment cost of the test equipment. And only one driving / loading motor is used, which is used as a driving motor when the hydraulic pump is tested and as a loading motor when the hydraulic motor is tested, thereby reducing the number of hydraulic components of the test bench and simplifying the overall structure of the hydraulic system. In addition, compared with the traditional hydraulic pump test bench, the tested pump / loading motor directly absorbs oil from the upper side of the back pressure valve, and there will be no suction phenomenon. In addition, by switching the oil circuit through the rotation direction switching valve, the test requirements of left-handed, right-handed and bidirectional hydraulic pumps / hydraulic motors can be met at the same time, further improving the versatility of the comprehensive test bench.

Description

Technical Field

[0001] The invention relates to the technical field of hydraulic test benches, in particular to a comprehensive test bench suitable for hydraulic pumps and hydraulic motors. Background Art

[0002] The hydraulic test bench is a key equipment for the development and acceptance of hydraulic components. It is mainly used for performance testing of hydraulic pumps and hydraulic motors. The main detection parameters include speed, torque, pressure, flow, temperature, etc. The product performance is evaluated by monitoring the process change law. The traditional hydraulic pump test bench uses a motor to drive the tested hydraulic pump, and uses an electric proportional overflow valve for loading. The overflowed oil returns to the oil tank for cooling circulation. For example, patent CN101328881A discloses a hydraulic pump test bench, which includes a tested pump, a motor, an oil tank, a power recovery motor, an auxiliary pump, an electric proportional overflow valve and corresponding connecting pipelines. The auxiliary pump drives the motor to rotate by driving the power recovery motor until the rated speed is reached and then the motor is started, and then the auxiliary pump is stopped. During the test, the high-pressure oil at the oil outlet of the pump drives the power recovery motor. The traditional hydraulic motor test bench is driven by a pump station and equipped with a motor of the same displacement to load it, but the overflow loss is large and a cooling circulation system with a larger power is required; although some hydraulic motor test benches are also equipped with motor loading, using DC motors to generate electricity, and the generated electricity is connected back to the power grid through frequency conversion and rectification equipment to achieve energy recovery, this system requires a complex safety control system and is relatively expensive. For example, patent CN103511401A discloses a hydraulic motor test bench, which consists of a hydraulic compensation system, a variable frequency mechanical compensation system and a measurement and control system. The motor under test is jointly supplied with oil by a compensation pump and a loading motor. The motor under test has the same displacement as the loading motor. During the test, mechanical compensation and pressure compensation can be performed simultaneously, and hydraulic compensation can also be performed independently.

[0003] Therefore, the existing hydraulic test bench is usually only suitable for the performance test of hydraulic pumps or hydraulic motors, and cannot be used for both hydraulic pumps and hydraulic motors. In addition, the back pressure of the loading motor of the existing hydraulic motor test bench cannot be adjusted, which poses the risk of unstable test pressure or stall, and cannot meet the product test requirements for specific back pressure. In addition, the overflow energy of the existing hydraulic test bench directly returns to the oil tank and is then sucked from the oil tank into the hydraulic system, resulting in a waste of oil suction energy. Summary of the invention

[0004] The invention provides a comprehensive test bench suitable for a hydraulic pump and a hydraulic motor, so as to solve the technical problem that the existing hydraulic test bench cannot be used for performance testing of the hydraulic pump and the hydraulic motor at the same time.

[0005] According to one aspect of the present invention, there is provided a comprehensive test bench suitable for hydraulic pumps and hydraulic motors, comprising a motor, a main drive pump, a safety valve, a test mode switching valve, a drive / loading motor, a hydraulic bridge and an electric proportional loading valve, wherein the motor is drive-connected to the main drive pump, the safety valve is arranged on a bypass oil circuit of the main drive pump, the test mode switching valve is arranged on a main oil circuit of the main drive pump, the oil inlet and outlet of the drive / loading motor, the oil inlet and outlet of a test piece, and the oil inlet of the hydraulic bridge are all connected to the test mode switching valve, the electric proportional loading valve is arranged on an oil outlet pipeline of the hydraulic bridge, the test mode switching valve is used to switch the oil supply circuit for conducting a hydraulic pump test or a hydraulic motor test, the drive / loading motor is connected to the test piece via a coupling, and is used to serve as a drive motor when conducting a hydraulic pump test and as a loading motor when conducting a hydraulic motor test.

[0006] Further, the test mode switching valve includes a three-position four-way reversing valve, a first cartridge valve, a second cartridge valve, a third cartridge valve, a fourth cartridge valve, a fifth cartridge valve, a sixth cartridge valve, a seventh cartridge valve and an eighth cartridge valve. The three-position four-way reversing valve and the valve group composed of multiple cartridge valves are all connected to the main oil circuit of the main drive pump. The three-position four-way reversing valve is also connected to the control chamber of the multiple cartridge valves, which is used to control the synchronous switching of the first cartridge valve, the third cartridge valve, the sixth cartridge valve and the eighth cartridge valve and control the second cartridge valve, the fourth cartridge valve, the fifth cartridge valve and the seventh cartridge valve. Valve synchronous switch, when the three-position four-way reversing valve is switched to the right position, the first cartridge valve, the third cartridge valve, the sixth cartridge valve and the eighth cartridge valve are opened synchronously, the second cartridge valve, the fourth cartridge valve, the fifth cartridge valve and the seventh cartridge valve are closed synchronously, and the oil supply circuit is switched to the hydraulic pump test oil circuit; when the three-position four-way reversing valve is switched to the left position, the first cartridge valve, the third cartridge valve, the sixth cartridge valve and the eighth cartridge valve are closed synchronously, the second cartridge valve, the fourth cartridge valve, the fifth cartridge valve and the seventh cartridge valve are opened synchronously, and the oil supply circuit is switched to the hydraulic motor test oil circuit.

[0007] Furthermore, it also includes a rotation direction switching valve for switching the oil supply circuit to perform a left-hand rotation test or a right-hand rotation test. The rotation direction switching valve is arranged on the main oil circuit of the main drive pump and is located before the test mode switching valve, and its oil outlet is connected to an oil inlet of the hydraulic bridge circuit.

[0008] Furthermore, it also includes an electric proportional back pressure valve which is arranged on the oil outlet pipeline of the hydraulic bridge circuit and is located after the electric proportional loading valve.

[0009] Furthermore, it also includes a heat exchanger which is arranged between the electric proportional loading valve and the electric proportional back pressure valve and is used to cool the oil.

[0010] Furthermore, the oil outlet of the hydraulic bridge circuit and the electric proportional loading valve are also connected to the main oil circuit of the main drive pump through a circulating oil circuit, and a circulating check valve and an energy-saving switching valve are sequentially arranged on the circulating oil circuit. The energy-saving switching valve is used to switch to a conducting state when testing a high-power test piece to reduce the overflow flow of the electric proportional loading valve.

[0011] Furthermore, it also includes a pilot system for providing a pilot pressure to the test piece.

[0012] Furthermore, the pilot system includes a pilot motor, a pilot pump, a pilot check valve, a pilot overflow valve, an electric proportional pressure reducing valve and an accumulator. The pilot motor is drive-connected to the pilot pump. The pilot check valve and the electric proportional pressure reducing valve are sequentially arranged on the main oil circuit of the pilot pump. The electric proportional pressure reducing valve is used for steplessly adjusting the output pilot pressure. The pilot overflow valve is arranged on the bypass oil circuit of the pilot pump for adjusting the maximum pressure provided by the pilot. The accumulator is connected to the main oil circuit of the pilot pump and the connection point is located after the pilot check valve for pressure compensation.

[0013] Furthermore, it also includes a data acquisition device for acquiring data during the test process.

[0014] Furthermore, the data acquisition device includes a speed torque meter arranged on the coupling, a pressure sensor, a temperature sensor and a flow meter arranged at the oil inlet, the oil outlet and the oil unloading port of the test piece.

[0015] The present invention has the following effects:

[0016] The comprehensive test bench for hydraulic pumps and hydraulic motors of the present invention switches the oil supply circuit through the test mode switching valve, which can provide pressure oil for both the hydraulic pump test and the hydraulic motor test, and can be used for the performance test of both the hydraulic pump and the hydraulic motor, thus achieving multiple uses and reducing the investment cost of the test equipment. In addition, only one driving / loading motor is used, which serves as a driving motor when conducting a hydraulic pump test and as a loading motor when conducting a hydraulic motor test, thereby reducing the number of hydraulic components of the test bench and simplifying the overall structure of the hydraulic system. In addition, compared with the traditional hydraulic pump test bench, the tested pump / loading motor directly draws oil from the upper side of the back pressure valve, and there will be no air suction phenomenon.

[0017] In addition to the above-described purposes, features and advantages, the present invention has other purposes, features and advantages. The present invention will be further described in detail with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The drawings constituting a part of this application are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0019] Figure 1 It is a schematic diagram of the hydraulic principle of a comprehensive test bench suitable for hydraulic pumps and hydraulic motors according to a preferred embodiment of the present invention.

[0020] Figure 2 It is a schematic diagram of the hydraulic principle of a comprehensive test bench for hydraulic pumps and hydraulic motors according to a preferred embodiment of the present invention for testing hydraulic pumps.

[0021] Figure 3 It is a schematic diagram of the hydraulic principle of a comprehensive test bench for hydraulic pumps and hydraulic motors according to a preferred embodiment of the present invention for testing hydraulic motors.

[0022] Description of Reference Numerals

[0023] 1. Motor; 2. Main drive pump; 3. Safety valve; 4. Test mode switching valve; 5. Drive / loading motor; 6. Hydraulic bridge; 7. Electric proportional loading valve; 8. Rotation switching valve; 9. Electric proportional back pressure valve; 10. Heat exchanger; 11. Circulation check valve; 12. Energy-saving switching valve; 13. Pilot system; 14. Speed ​​torque meter; 15. Pressure sensor; 16. Temperature sensor; 17. Flow meter; 100. Test piece; 41. Three-position four-way reversing valve; 42. First cartridge valve; 43. Second cartridge valve; 44. Third cartridge valve; 45. Fourth cartridge valve; 46. Fifth cartridge valve; 47. Sixth cartridge valve; 48. Seventh cartridge valve; 49. Eighth cartridge valve; 131. Pilot motor; 132. Pilot pump; 133. Pilot check valve; 134. Pilot relief valve; 135. Electric proportional pressure reducing valve; 136. Accumulator. DETAILED DESCRIPTION

[0024] The embodiments of the present invention are described in detail below with reference to the accompanying drawings. However, the present invention can be implemented in many different ways as defined and covered below.

[0025] like Figure 1As shown, the preferred embodiment of the present invention provides a comprehensive test bench suitable for hydraulic pumps and hydraulic motors, including a motor 1, a main drive pump 2, a safety valve 3, a test mode switching valve 4, a drive / loading motor 5, a hydraulic bridge 6 and an electric proportional loading valve 7. The motor 1 is connected to the main drive pump 2 by driving, and the main drive pump 2 is connected to the oil tank for providing pressure oil. The safety valve 3 is arranged on the bypass oil line of the main drive pump 2 for oil pressure protection. When the oil pressure at the outlet of the main drive pump 2 exceeds the set pressure of the safety valve 3, the safety valve 3 opens to achieve rapid pressure relief. The test mode switching valve 4 is arranged on the main oil line of the main drive pump 2, the oil inlet and outlet of the drive / loading motor 5, the oil inlet and outlet of the test piece 100, and the oil inlet of the hydraulic bridge 6 are all connected to the test mode switching valve 4, and the oil outlet of the hydraulic bridge 6 is connected to the oil tank to achieve oil recycling. The electric proportional loading valve 7 is arranged on the oil outlet pipeline of the hydraulic bridge 6 to achieve stepless regulation of loading pressure. The test mode switching valve 4 is used to switch the oil supply circuit to perform a hydraulic pump test or a hydraulic motor test. When the test mode switching valve 4 is switched to the right position, the oil supply circuit is switched to the hydraulic pump test circuit, and when the test mode switching valve 4 is switched to the left position, the oil supply circuit is switched to the hydraulic motor test circuit. The drive / loading motor 5 is connected to the test piece 100 through a coupling and is used as a drive motor when performing a hydraulic pump test and as a loading motor when performing a hydraulic motor test. When performing a hydraulic pump test, the drive motor is directly driven by the main drive pump 2, and when performing a hydraulic motor test, the loading motor is driven by the motor under test.

[0026] It can be understood that the comprehensive test bench for hydraulic pumps and hydraulic motors of this embodiment can switch the oil supply circuit through the test mode switching valve 4, which can provide pressure oil for both the hydraulic pump test and the hydraulic motor test, and can be used for performance tests of both hydraulic pumps and hydraulic motors at the same time, achieving multi-purpose use and reducing the investment cost of the test equipment. In addition, only one drive / loading motor 5 is used, which serves as a drive motor when conducting a hydraulic pump test and as a loading motor when conducting a hydraulic motor test, thereby reducing the number of hydraulic components of the test bench and simplifying the overall structure of the hydraulic system. In addition, compared with the traditional hydraulic pump test bench, the tested pump / loading motor directly absorbs oil from the upper side of the back pressure valve, and there will be no suction phenomenon.

[0027] It can be understood that the test mode switching valve 4 includes a three-position four-way reversing valve 41, a first cartridge valve 42, a second cartridge valve 43, a third cartridge valve 44, a fourth cartridge valve 45, a fifth cartridge valve 46, a sixth cartridge valve 47, a seventh cartridge valve 48 and an eighth cartridge valve 49. The three-position four-way reversing valve 41 and the valve group composed of multiple cartridge valves are connected to the main oil circuit of the main drive pump 2. The three-position four-way reversing valve 41 is also connected to the control chambers of the multiple cartridge valves, which is used to control the synchronous switching of the first cartridge valve 42, the third cartridge valve 44, the sixth cartridge valve 47 and the eighth cartridge valve 49 and control the second cartridge valve 43, the fourth cartridge valve 45, the fifth cartridge valve 46 and the seventh cartridge valve 48. Valve 48 switches synchronously. When the three-position four-way reversing valve 41 switches to the right position, the first cartridge valve 42, the third cartridge valve 44, the sixth cartridge valve 47 and the eighth cartridge valve 49 are opened synchronously, and the second cartridge valve 43, the fourth cartridge valve 45, the fifth cartridge valve 46 and the seventh cartridge valve 48 are closed synchronously, and the oil supply circuit is switched to the hydraulic pump test oil circuit. When the three-position four-way reversing valve 41 switches to the left position, the first cartridge valve 42, the third cartridge valve 44, the sixth cartridge valve 47 and the eighth cartridge valve 49 are closed synchronously, and the second cartridge valve 43, the fourth cartridge valve 45, the fifth cartridge valve 46 and the seventh cartridge valve 48 are opened synchronously, and the oil supply circuit is switched to the hydraulic motor test oil circuit.

[0028] Specifically, the control chambers of the second cartridge valve 43, the fourth cartridge valve 45, the fifth cartridge valve 46 and the seventh cartridge valve 48 are interconnected, the control chambers of the first cartridge valve 42, the third cartridge valve 44, the sixth cartridge valve 47 and the eighth cartridge valve 49 are interconnected, the first oil ports of the first cartridge valve 42 and the second cartridge valve 43 are both connected to the oil inlet of the drive / loading motor 5, the first oil ports of the third cartridge valve 44 and the fourth cartridge valve 45 are both connected to the oil outlet of the drive / loading motor 5, the first oil ports of the fifth cartridge valve 46 and the sixth cartridge valve 47 are both connected to the oil outlet of the test piece 100, and the first oil ports of the seventh cartridge valve 48 and the eighth cartridge valve 49 are both connected to the oil inlet of the test piece 100. Moreover, the second oil ports of the first cartridge valve 42 and the fifth cartridge valve 46 are connected to the main oil circuit of the main driving pump 2, the second oil ports of the second cartridge valve 43 and the sixth cartridge valve 47 are connected to the third oil port of the hydraulic bridge circuit 6, the second oil ports of the third cartridge valve 44 and the seventh cartridge valve 48 are connected to the first oil port of the hydraulic bridge circuit 6, and the second oil ports of the fourth cartridge valve 45 and the eighth cartridge valve 49 are connected to the second oil port of the hydraulic bridge circuit 6. Through the above connection relationship, the second cartridge valve 43, the fourth cartridge valve 45, the fifth cartridge valve 46 and the seventh cartridge valve 48 are synchronously controlled to switch, and the first cartridge valve 42, the third cartridge valve 44, the sixth cartridge valve 47 and the eighth cartridge valve 49 are synchronously controlled to switch. Among them, the second oil port of the cartridge valve refers to the oil inlet located at the top, and the first oil port refers to the oil inlet located at the side.

[0029] Among them, the right oil inlet of the three-position four-way reversing valve 41 is connected to the control chambers of the second cartridge valve 43, the fourth cartridge valve 45, the fifth cartridge valve 46 and the seventh cartridge valve 48, and the right oil outlet is connected to the control chambers of the first cartridge valve 42, the third cartridge valve 44, the sixth cartridge valve 47 and the eighth cartridge valve 49. When the three-position four-way reversing valve 41 is switched to the right position, the pressure oil provided by the main drive pump 2 flows through the right oil inlet to the control chambers of the second cartridge valve 43, the fourth cartridge valve 45, the fifth cartridge valve 46 and the seventh cartridge valve 48, thereby controlling the second cartridge valve 43, the fourth cartridge valve 45, the fifth cartridge valve 46 and the seventh cartridge valve 48 to be closed synchronously, and at this time, the control chambers of the first cartridge valve 42, the third cartridge valve 44, the sixth cartridge valve 47 and the eighth cartridge valve 49 are connected to the oil tank through the right oil outlet, thereby controlling the first cartridge valve 42, the third cartridge valve 44, the sixth cartridge valve 47 and the eighth cartridge valve 49 to be opened synchronously, and the oil supply pump is switched to the hydraulic pump test oil circuit. The left oil inlet of the three-position four-way reversing valve 41 is connected to the control chambers of the first cartridge valve 42, the third cartridge valve 44, the sixth cartridge valve 47 and the eighth cartridge valve 49, and the left oil outlet is connected to the control chambers of the second cartridge valve 43, the fourth cartridge valve 45, the fifth cartridge valve 46 and the seventh cartridge valve 48. When the three-position four-way reversing valve 41 is switched to the left position, the pressure oil provided by the main driving pump 2 flows to the control chambers of the first cartridge valve 42, the third cartridge valve 44, the sixth cartridge valve 47 and the eighth cartridge valve 49 through the left position oil inlet, thereby controlling the first cartridge valve 42, the third cartridge valve 44, the sixth cartridge valve 47 and the eighth cartridge valve 49 to be closed synchronously, and at this time, the control chambers of the second cartridge valve 43, the fourth cartridge valve 45, the fifth cartridge valve 46 and the seventh cartridge valve 48 are connected to the oil tank through the left position oil outlet, thereby controlling the second cartridge valve 43, the fourth cartridge valve 45, the fifth cartridge valve 46 and the seventh cartridge valve 48 to be opened synchronously, and the oil supply pump is switched to the hydraulic motor test oil circuit. Among them, the three-position four-way reversing valve 41 is an electromagnetic reversing valve. It can be understood that in other embodiments of the present invention, the test mode switching valve 4 can also use a three-position eight-way electromagnetic reversing valve to realize oil circuit switching.

[0030] It can be understood that the present invention realizes the switching of the hydraulic pump oil supply circuit and the hydraulic motor oil supply circuit by adopting a three-position four-way reversing valve 41 and eight cartridge valves to form a three-position eight-way reversing valve. It can switch to the corresponding oil supply circuit according to the specific test product. Moreover, the control logic and oil circuit structure are relatively simple. Compared with the conventional three-position eight-way reversing valve, it can also realize large-flow oil supply, which can well meet the performance test of high-power products.

[0031] Optionally, the comprehensive test bench further includes a rotation direction switching valve 8 for switching the oil supply circuit to perform a left-hand rotation test or a right-hand rotation test, the rotation direction switching valve 8 being arranged on the main oil circuit of the main drive pump 2 and before the test mode switching valve 4, and its oil outlet being connected to an oil inlet of the hydraulic bridge circuit 6. Specifically, the rotation direction switching valve 8 is a three-position four-way solenoid reversing valve, the right-position oil inlet of which is connected to the second oil ports of the first cartridge valve 42 and the fifth cartridge valve 46, the right-position oil outlet is connected to the second oil ports of the third cartridge valve 44 and the seventh cartridge valve 48, the left-position oil inlet is connected to the second oil ports of the third cartridge valve 44 and the seventh cartridge valve 48, and the left-position oil outlet is connected to the second oil ports of the first cartridge valve 42 and the fifth cartridge valve 46. When the right-hand hydraulic pump is tested, the rotation direction switching valve 8 is switched to the right position, and the pressure oil of the main oil circuit is delivered to the oil inlet of the driving / loading motor 5 through the right position oil inlet of the rotation direction switching valve 8 and the first cartridge valve 42, and the return oil from the oil outlet of the driving / loading motor 5 flows out through the third cartridge valve 44 and the outlet position oil inlet of the rotation direction switching valve 8. When the left-hand hydraulic pump is tested, the rotation direction switching valve 8 is switched to the left position, and the pressure oil of the main oil circuit is delivered to the oil inlet of the driving / loading motor 5 through the left position oil inlet of the rotation direction switching valve 8 and the third cartridge valve 44, and the return oil from the oil outlet of the driving / loading motor 5 flows out through the first cartridge valve 42 and the left position oil outlet of the rotation direction switching valve 8. It can be understood that the oil circuit switching process of the left-hand hydraulic motor is similar to that of the left-hand hydraulic pump, and the oil circuit switching process of the right-hand hydraulic motor is similar to that of the right-hand hydraulic pump, so it will not be repeated here.

[0032] It can be understood that the present invention switches the oil circuit through the rotation direction switching valve 8, which can simultaneously meet the test requirements of left-hand, right-hand and bidirectional hydraulic pumps / hydraulic motors, further improving the versatility of the comprehensive test bench.

[0033] Optionally, the comprehensive test bench further includes an electric proportional back pressure valve 9 disposed on the oil outlet pipeline of the hydraulic bridge circuit 6 and located after the electric proportional loading valve 7, the electric proportional back pressure valve 9 is connected to the oil outlet of the rotation direction switching valve 8, and the oil flows out of the rotation direction switching valve 8 and is transported to the upstream oil circuit of the electric proportional back pressure valve 9. By providing the electric proportional back pressure valve 9, the back pressure can be infinitely adjusted according to the actual working conditions of the test piece 100, thereby ensuring the stability of the test process.

[0034] Optionally, the comprehensive test bench further includes a heat exchanger 10 disposed between the electric proportional loading valve 7 and the electric proportional back pressure valve 9 and used to cool the oil. After the oil overflowing from the electric proportional loading valve 7 is cooled by the heat exchanger 10, a part of it returns to the oil tank through the electric proportional back pressure valve 9, and a part of it continues to enter the oil suction side of the loading motor or the tested pump through the hydraulic bridge 6, which effectively solves the problem of oil temperature increase caused by overflow, so that the oil does not need to return to the oil tank and can continue to enter the system for reuse, effectively improving the problem of long or blocked oil suction pipelines in the system.

[0035] Optionally, the oil outlet of the hydraulic bridge circuit 6 and the electric proportional loading valve 7 are also connected to the main oil circuit of the main driving pump 2 through a circulating oil circuit, and a circulating check valve 11 and an energy-saving switching valve 12 are sequentially arranged on the circulating oil circuit. The energy-saving switching valve 12 is used to switch to a conducting state when testing a high-power test piece 100 to reduce the overflow flow of the electric proportional loading valve 7. When the test piece 100 is a high-power product, the main driving pump 2 may have insufficient driving power. At this time, the energy-saving switching valve 12 can be controlled to be turned on, and the high-pressure oil before the electric proportional loading valve 7 can be supplemented to the outlet of the main driving pump 2 to reduce the overflow flow of the electric proportional loading valve 7, reduce overflow loss, and realize energy recovery. The main driving pump 2 only provides a small amount of energy supplement to realize the test of a larger power product, and the entire system works in an energy-saving mode. When the test piece 100 is a low-power product, the energy-saving switching valve 12 is controlled to be closed to switch to the normal mode. Among them, the energy-saving switching valve 12 is a two-position two-way electromagnetic reversing valve.

[0036] Optionally, the integrated test bench further comprises a pilot system 13 for providing a pilot pressure to the test piece 100 , which can satisfy the external control pilot pressure supply of various variable forms of the test piece 100 . Specifically, most of the commonly used hydraulic pumps or hydraulic motors are externally controlled variable types, so the pilot system 13 includes a pilot motor 131, a pilot pump 132, a pilot check valve 133, a pilot relief valve 134, an electric proportional pressure reducing valve 135 and an accumulator 136. The pilot motor 131 is connected to the pilot pump 132 by driving, the pilot check valve 133 and the electric proportional pressure reducing valve 135 are sequentially arranged on the main oil circuit of the pilot pump 132, the electric proportional pressure reducing valve 135 is used to steplessly adjust the output pilot pressure, the pilot relief valve 134 is arranged on the bypass oil circuit of the pilot pump 132, and is used to adjust the maximum pressure provided by the pilot, and the accumulator 136 is connected to the main oil circuit of the pilot pump 132 and the connection point is located after the pilot check valve 133, and is used to perform pressure compensation and maintain pressure stability. The pilot system 13 of the present invention can meet the requirements of different control pressures of the test piece 100.

[0037] Optionally, the comprehensive test bench also includes a data acquisition device for collecting data during the test. Specifically, the data acquisition device includes a speed torque meter 14 arranged on the coupling, a pressure sensor 15, a temperature sensor 16 and a flow meter 17 arranged at the oil inlet, oil outlet and oil unloading port of the test piece 100, so as to collect the speed and torque of the test piece 100, and the pressure, temperature and flow of the oil inlet, oil outlet and oil unloading port. Of course, in other embodiments of the present invention, other data acquisition components may also be included.

[0038] It can be understood that the working process of the comprehensive test bench of the present invention is specifically as follows:

[0039] When testing a hydraulic pump, Figure 2 As shown, before the test, the three-position four-way reversing valve 41 is switched to the right position, and the high-pressure oil provided by the main drive pump 2 passes through the three-position four-way reversing valve 41 to the control chambers of the second cartridge valve 43, the fourth cartridge valve 45, the fifth cartridge valve 46 and the seventh cartridge valve 48, which are closed. The control chambers of the first cartridge valve 42, the third cartridge valve 44, the sixth cartridge valve 47 and the eighth cartridge valve 49 are connected to the oil tank through the three-position four-way reversing valve 41 to fully open them. Then, the rotation direction switching valve 8 is controlled to switch according to the rotation direction of the tested hydraulic pump. The present invention takes the test of the right-handed hydraulic pump as an example for illustrative explanation, that is, the rotation direction switching valve 8 is controlled to switch to the right position. If the tested hydraulic pump is a low-power product, the energy-saving switching valve 12 is controlled not to be powered, and if the tested hydraulic pump is a high-power product, the energy-saving switching valve 12 is controlled to be powered. The high-pressure oil provided by the main driving pump 2 is delivered to the oil inlet of the driving motor through the rotation direction switching valve 8 and the first cartridge valve 42, and the driving motor rotates. The hydraulic oil discharged from the oil outlet of the driving motor is delivered to the upstream oil circuit of the electric proportional back pressure valve 9 through the third cartridge valve 44 and the rotation direction switching valve 8. The driving motor drives the tested hydraulic pump to rotate synchronously through the coupling. The upstream oil of the electric proportional back pressure valve 9 passes through the hydraulic bridge circuit 6 and the eighth cartridge valve 49 to the suction port of the tested hydraulic pump. The high-pressure oil discharged from the oil discharge port of the tested hydraulic pump passes through the sixth cartridge valve 47 and the hydraulic bridge circuit 6 to the front end of the electric proportional loading valve 7. The loading pressure is regulated by adjusting the input current of the electric proportional loading valve 7. The overflowed oil passes through the heat exchanger 10 to the upstream oil circuit of the electric proportional back pressure valve 9. Part of the hydraulic oil in the hydraulic circuit is circulated through the hydraulic bridge circuit 6 to the oil suction port of the tested hydraulic pump, and the remaining oil flows back to the oil tank through the electric proportional back pressure valve 9. This can ensure that the tested hydraulic pump has sufficient oil suction and no air suction occurs.

[0040] When testing a hydraulic motor, Figure 3As shown, before the test, the three-position four-way reversing valve 41 is switched to the left position, and the high-pressure oil provided by the main drive pump 2 passes through the three-position four-way reversing valve 41 to the control chambers of the first cartridge valve 42, the third cartridge valve 44, the sixth cartridge valve 47 and the eighth cartridge valve 49, which are closed. The control chambers of the second cartridge valve 43, the fourth cartridge valve 45, the fifth cartridge valve 46 and the seventh cartridge valve 48 are connected to the oil tank through the three-position four-way reversing valve 41 to fully open them. Then, the rotation direction switching valve 8 is controlled to switch according to the rotation direction of the tested hydraulic motor. The present invention takes the test of the right-handed hydraulic motor as an example for illustrative explanation, that is, the rotation direction switching valve 8 is controlled to switch to the right position. If the tested hydraulic pump is a low-power product, the energy-saving switching valve 12 is controlled not to be powered, and if the tested hydraulic pump is a high-power product, the energy-saving switching valve 12 is controlled to be powered. The high-pressure oil provided by the main driving pump 2 is delivered to the oil inlet of the tested hydraulic motor through the rotation direction switching valve 8 and the fifth cartridge valve 46. The hydraulic oil discharged from the oil outlet of the tested hydraulic motor is delivered to the upstream oil circuit of the electric proportional back pressure valve 9 through the seventh cartridge valve 48 and the rotation direction switching valve 8. The tested hydraulic motor drives the loading motor to rotate synchronously through the coupling. The upstream oil of the electric proportional back pressure valve 9 passes through the hydraulic bridge circuit 6 and the fourth cartridge valve 45 to the oil suction port of the loading motor. The high-pressure oil discharged from the oil discharge port of the loading motor passes through the second cartridge valve 43 and the hydraulic bridge circuit 6 to the front end of the electric proportional loading valve 7. The loading pressure is regulated by adjusting the input current of the electric proportional loading valve 7. The overflowed oil passes through the heat exchanger 10 to the upstream oil circuit of the electric proportional back pressure valve 9.

[0041] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A comprehensive test bench suitable for hydraulic pumps and hydraulic motors, characterized in that: The invention comprises a motor (1), a main drive pump (2), a safety valve (3), a test mode switching valve (4), a drive / loading motor (5), a hydraulic bridge circuit (6) and an electric proportional loading valve (7), wherein the motor (1) is connected to the main drive pump (2) by driving, the safety valve (3) is arranged on a bypass oil circuit of the main drive pump (2), the test mode switching valve (4) is arranged on a main oil circuit of the main drive pump (2), the oil inlet and the oil outlet of the drive / loading motor (5), the test piece (100 ) and the oil inlet and outlet of the hydraulic bridge circuit (6) are connected to the test mode switching valve (4); the electric proportional loading valve (7) is arranged on the oil outlet pipeline of the hydraulic bridge circuit (6); the test mode switching valve (4) is used to switch the oil supply circuit to perform a hydraulic pump test or a hydraulic motor test; the driving / loading motor (5) is connected to the test piece (100) through a coupling and is used as a driving motor when performing a hydraulic pump test and as a loading motor when performing a hydraulic motor test.

2. The comprehensive test bench for hydraulic pumps and hydraulic motors according to claim 1, characterized in that: The test mode switching valve (4) comprises a three-position four-way reversing valve (41), a first cartridge valve (42), a second cartridge valve (43), a third cartridge valve (44), a fourth cartridge valve (45), a fifth cartridge valve (46), a sixth cartridge valve (47), a seventh cartridge valve (48) and an eighth cartridge valve (49). The three-position four-way reversing valve (41) and a valve group consisting of a plurality of cartridge valves are all connected to the main oil circuit of the main drive pump (2). The three-position four-way reversing valve (41) is also connected to the control chambers of the plurality of cartridge valves to control the synchronous switching of the first cartridge valve (42), the third cartridge valve (44), the sixth cartridge valve (47) and the eighth cartridge valve (49) and to control the second cartridge valve (43), the fourth cartridge valve (45), the fifth cartridge valve (46) and the seventh cartridge valve (49). 48) synchronous switch, when the three-position four-way reversing valve (41) is switched to the right position, the first cartridge valve (42), the third cartridge valve (44), the sixth cartridge valve (47) and the eighth cartridge valve (49) are opened synchronously, the second cartridge valve (43), the fourth cartridge valve (45), the fifth cartridge valve (46) and the seventh cartridge valve (48) are closed synchronously, and the oil supply circuit is switched to the hydraulic pump test oil circuit; when the three-position four-way reversing valve (41) is switched to the left position, the first cartridge valve (42), the third cartridge valve (44), the sixth cartridge valve (47) and the eighth cartridge valve (49) are closed synchronously, the second cartridge valve (43), the fourth cartridge valve (45), the fifth cartridge valve (46) and the seventh cartridge valve (48) are opened synchronously, and the oil supply circuit is switched to the hydraulic motor test oil circuit.

3. The comprehensive test bench for hydraulic pumps and hydraulic motors according to claim 1, characterized in that: It also includes a rotation direction switching valve (8) for switching the oil supply circuit to perform a left-hand rotation test or a right-hand rotation test. The rotation direction switching valve (8) is arranged on the main oil circuit of the main drive pump (2) and is located before the test mode switching valve (4). Its oil outlet is connected to an oil inlet of the hydraulic bridge circuit (6).

4. The comprehensive test bench for hydraulic pumps and hydraulic motors according to claim 1, characterized in that: It also includes an electric proportional back pressure valve (9) which is arranged on the oil outlet pipeline of the hydraulic bridge circuit (6) and is located after the electric proportional loading valve (7).

5. The comprehensive test bench for hydraulic pumps and hydraulic motors as claimed in claim 4, characterized in that: It also includes a heat exchanger (10) which is arranged between the electric proportional loading valve (7) and the electric proportional back pressure valve (9) and is used to cool the oil.

6. The comprehensive test bench for hydraulic pumps and hydraulic motors according to claim 1, characterized in that: The oil outlet of the hydraulic bridge circuit (6) and the electric proportional loading valve (7) are also connected to the main oil circuit of the main driving pump (2) through a circulating oil circuit, and a circulating check valve (11) and an energy-saving switching valve (12) are sequentially arranged on the circulating oil circuit. The energy-saving switching valve (12) is used to switch to a conducting state when testing a high-power test piece (100) to reduce the overflow flow of the electric proportional loading valve (7).

7. The comprehensive test bench for hydraulic pumps and hydraulic motors according to claim 1, characterized in that: Also included is a pilot system (13) for providing a pilot pressure to the test piece (100).

8. The comprehensive test bench for hydraulic pumps and hydraulic motors as claimed in claim 7, characterized in that: The pilot system (13) comprises a pilot motor (131), a pilot pump (132), a pilot check valve (133), a pilot relief valve (134), an electric proportional pressure reducing valve (135) and an accumulator (136). The pilot motor (131) is drivingly connected to the pilot pump (132). The pilot check valve (133) and the electric proportional pressure reducing valve (135) are sequentially arranged on the main oil circuit of the pilot pump (132). The electric proportional pressure reducing valve (135) is used for steplessly adjusting the output pilot pressure. The pilot relief valve (134) is arranged on the bypass oil circuit of the pilot pump (132) and is used for adjusting the maximum pressure provided by the pilot. The accumulator (136) is connected to the main oil circuit of the pilot pump (132) and the connection point is located after the pilot check valve (133) for pressure compensation.

9. The comprehensive test bench for hydraulic pumps and hydraulic motors as claimed in claim 1, characterized in that: Also included is a data acquisition device for acquiring data during the test.

10. The comprehensive test bench for hydraulic pumps and hydraulic motors according to claim 9, characterized in that: The data acquisition device comprises a speed torque meter (14) arranged on the coupling, a pressure sensor (15) arranged at the oil inlet, oil outlet and oil discharge port of the test piece (100), a temperature sensor (16) and a flow meter (17).

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