CN109026906B - Double-oil tank pressure-reducing type energy recovery hydraulic test bench - Google Patents
Double-oil tank pressure-reducing type energy recovery hydraulic test bench Download PDFInfo
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- CN109026906B CN109026906B CN201811249359.7A CN201811249359A CN109026906B CN 109026906 B CN109026906 B CN 109026906B CN 201811249359 A CN201811249359 A CN 201811249359A CN 109026906 B CN109026906 B CN 109026906B
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- 238000012360 testing method Methods 0.000 title claims abstract description 67
- 238000011084 recovery Methods 0.000 title claims abstract description 34
- 238000007789 sealing Methods 0.000 claims description 22
- 238000002955 isolation Methods 0.000 claims description 18
- 238000006073 displacement reaction Methods 0.000 claims description 15
- 230000009977 dual effect Effects 0.000 claims description 14
- 238000000034 method Methods 0.000 claims description 6
- 230000001105 regulatory effect Effects 0.000 claims description 3
- 239000002184 metal Substances 0.000 description 11
- 239000000843 powder Substances 0.000 description 11
- 238000010586 diagram Methods 0.000 description 7
- 230000008569 process Effects 0.000 description 5
- 238000005299 abrasion Methods 0.000 description 4
- 230000033228 biological regulation Effects 0.000 description 4
- 239000012535 impurity Substances 0.000 description 4
- 230000009467 reduction Effects 0.000 description 4
- 239000007787 solid Substances 0.000 description 4
- 238000002347 injection Methods 0.000 description 3
- 239000007924 injection Substances 0.000 description 3
- 239000007788 liquid Substances 0.000 description 3
- 230000007423 decrease Effects 0.000 description 2
- 230000005611 electricity Effects 0.000 description 2
- 239000012530 fluid Substances 0.000 description 2
- 230000001276 controlling effect Effects 0.000 description 1
- 238000010790 dilution Methods 0.000 description 1
- 239000012895 dilution Substances 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 230000004886 head movement Effects 0.000 description 1
- 238000005259 measurement Methods 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 238000011056 performance test Methods 0.000 description 1
Classifications
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
- F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
- F15B19/00—Testing; Calibrating; Fault detection or monitoring; Simulation or modelling of fluid-pressure systems or apparatus not otherwise provided for
Abstract
The double-oil tank pressure-reducing type energy recovery hydraulic test bench comprises a motor, a tested hydraulic pump, a first oil tank, a hydraulic motor and a generator; the motor is connected with the tested hydraulic pump, the first oil tank is sequentially connected with the tested hydraulic pump and the hydraulic motor through oil pipes, and the generator is connected with the hydraulic motor; the device also comprises a second oil tank and a depressurization unit; the second oil tank is communicated with the output end of the hydraulic motor through an oil pipe; the pressure reducing unit is positioned between the tested hydraulic pump and the hydraulic motor and comprises a pressure reducing cylinder and a non-tested hydraulic pump; the pressure reducing cylinder is internally provided with a piston, the bottom surface of the piston is smaller than the top surface, a first oil cavity is formed between the bottom surface of the piston and the pressure reducing cylinder, and a second oil cavity is formed between the top surface and the pressure reducing cylinder; the tested hydraulic pump is communicated with the first oil cavity; the second oil cavity is respectively communicated with a second oil tank and the input end of the hydraulic motor; the non-test hydraulic pump is located between the second oil tank and the second oil chamber.
Description
Technical Field
The invention relates to the technical field of hydraulic measurement and control, in particular to a double-oil tank pressure-reducing type energy recovery hydraulic test board.
Background
The hydraulic test bench is a device for testing the performance of important elements such as a hydraulic pump, a hydraulic motor, a hydraulic cylinder, a hydraulic valve and the like in a hydraulic system. When the hydraulic test board tests the hydraulic pump, the pressure oil generated by the hydraulic pump directly flows out through the overflow valve, namely, the hydraulic energy is converted into heat energy to be released, so that the energy is wasted.
For this phenomenon, energy recovery hydraulic test stands have been developed to utilize the energy that is wasted without end. Referring to fig. 1, a schematic diagram of a prior art energy recovery hydraulic test bench is shown. The working principle of the existing energy recovery hydraulic test bench is as follows: the motor drives the tested hydraulic pump to suck oil from the oil tank so that the tested hydraulic pump obtains hydraulic energy, the tested hydraulic pump transmits the hydraulic energy to the hydraulic motor, the hydraulic motor converts the hydraulic energy into mechanical energy and transmits the mechanical energy to the generator, meanwhile, the oil is released back to the oil tank, the generator generates electricity to generate electric energy to be fed into a power grid to realize energy recovery, and meanwhile, the oil is recovered.
However, the applicant finds that when the durability and strength of the hydraulic pump to be tested are tested by the energy recovery hydraulic test bench, a long-time ultrahigh pressure test is required, and hydraulic energy in an ultrahigh pressure form can damage the hydraulic motor, so that the service life of the hydraulic motor is short; and the oil tank of the tested hydraulic pump sucking oil is the same as the oil tank of the hydraulic motor releasing oil, so that the tested hydraulic pump running at high strength can be worn to generate metal powder, and the metal powder is mixed into the oil to flow to the hydraulic motor so as to damage the hydraulic motor.
Disclosure of Invention
Accordingly, an object of the present invention is to provide an energy recovery hydraulic test stand capable of converting high-pressure oil output from a hydraulic pump to be tested into low-pressure oil to be input to a hydraulic motor, and preventing abrasion of the hydraulic motor due to mixing of metal powder generated from the hydraulic pump to be tested into the oil.
The double-oil tank pressure-reducing type energy recovery hydraulic test bench comprises a motor, a tested hydraulic pump, a first oil tank, a hydraulic motor and a generator; the motor is connected with the tested hydraulic pump, the first oil tank is communicated with the input end of the tested hydraulic pump through an oil pipe, the input end of the hydraulic motor is communicated with the output end of the tested hydraulic pump through an oil pipe, and the generator is connected with the hydraulic motor; the device also comprises a second oil tank and a depressurization unit; the second oil tank is communicated with the output end of the hydraulic motor through an oil pipe; the pressure reducing unit is positioned between the tested hydraulic pump and the hydraulic motor and comprises a plurality of pressure reducing cylinders and non-tested hydraulic pumps; the plurality of pressure reducing cylinders are arranged in parallel, a piston is arranged in the pressure reducing cylinders, the area of the bottom surface of the piston is smaller than that of the top surface of the piston, a first oil cavity is formed between the bottom surface of the piston and the pressure reducing cylinders, and a second oil cavity is formed between the top surface of the piston and the pressure reducing cylinders; the tested hydraulic pump is communicated with the first oil cavity through an oil pipe; the second oil cavity is respectively communicated with the second oil tank and the input end of the hydraulic motor through an oil pipe; the non-test hydraulic pump is located between the second oil tank and the second oil chamber.
Compared with the prior art, the double-oil tank pressure-reducing type energy recovery hydraulic test bench has the advantages that the area of the top surface of the piston in the pressure-reducing cylinder is larger than the area of the bottom surface, so that the cross-sectional area of the second oil cavity is larger than that of the first oil cavity, and the pressure of oil in the second oil cavity is lower than that of the oil in the first oil cavity under the condition that the pressure is unchanged according to a pressure formula of F (pressure) =P (pressure) ×S (area), and therefore low-pressure oil in the second oil cavity flows into the hydraulic motor, and the hydraulic motor is protected from being damaged by high-pressure oil from a tested hydraulic pump; in addition, by arranging the second oil tank, a closed oil path from the second oil tank to the non-test hydraulic pump to the second oil cavity to the hydraulic motor to the second oil tank is formed, and the oil flowing into and out of the hydraulic motor is from the second oil tank, so that the oil flowing through the hydraulic motor does not pass through the tested hydraulic pump and the first oil tank for supplying oil to the tested hydraulic pump, and the situation that metal powder worn from the tested hydraulic pump due to high-strength operation of the tested hydraulic pump is mixed into the oil and flows into the hydraulic motor to wear the hydraulic motor is avoided.
Further, the depressurization unit further comprises a depressurization regulation system, the depressurization regulation system comprises a PLC, a plurality of displacement sensors and a plurality of proportional reversing valves, the number of the displacement sensors, the proportional reversing valves and the number of the depressurization cylinders are the same, and each depressurization cylinder corresponds to one displacement sensor and one proportional reversing valve; the displacement sensor is arranged in the pressure reducing cylinder and sends a position signal of the piston to the PLC; the proportional reversing valve is positioned on an oil path between the tested hydraulic pump and the first oil cavity and an oil path between the first oil cavity and the first oil tank, receives a command of the PLC to control to switch on or off the oil path between the tested hydraulic pump and the first oil cavity and the oil path between the first oil cavity and the first oil tank, and controls the oil quantity in the oil path. If only one pressure reducing cylinder works, oil can be provided for the hydraulic motor only in the process of upward movement of the piston, and oil can not be provided for the hydraulic motor in the process of downward movement of the piston. The pressure reducing regulation and control system is arranged, so that a plurality of pressure reducing cylinders can be coordinated to work simultaneously, in the process that the pistons in part of the pressure reducing cylinders move upwards, the pistons in the other part of the pressure reducing cylinders move downwards simultaneously and reciprocate alternately, and the hydraulic energy generated by the tested hydraulic pump is continuously supplied to the hydraulic motor and the generator for energy recovery.
Further, the interior of the pressure reducing cylinder is a T-shaped cavity, and the piston is a T-shaped piston.
Further, a sealing ring is arranged in the pressure reducing cylinder, one end of the sealing ring is fixed on the inner wall of the pressure reducing cylinder, and the other end of the sealing ring surrounds the T-shaped piston; the T-shaped piston comprises a wide head and a narrow waist, wherein the cross-sectional area of the wide head is larger than that of the narrow waist; an upper isolation cavity is formed between the sealing ring and the wide head part, and the upper isolation cavity is communicated with a second oil tank through an oil pipe; an isolation lower cavity is formed between the sealing ring and the narrow waist part, and the isolation lower cavity is communicated with the first oil tank through an oil pipe. Although the tested hydraulic pump and the hydraulic motor are arranged on the two oil ways to avoid damage of the hydraulic motor, a small amount of oil attached to the side wall of the piston still enters the other oil way along with the reciprocating movement of the piston. By arranging the sealing rings and the isolation oil cavities which are respectively communicated with the two oil tanks, the oil mixed with a small amount of pistons is immediately introduced into the oil tanks for dilution and replacement, so that the intersection of the two oil paths is further avoided, and the hydraulic motor is prevented from being damaged by solid impurities mixed in the oil of the oil path where the tested hydraulic pump is positioned.
Further, the depressurization unit further comprises a first energy accumulator, a second energy accumulator and a third energy accumulator; the first accumulator is positioned between the non-test hydraulic pump and the second oil cavity; the second accumulator is positioned between the second oil cavity and the hydraulic motor; and the third energy accumulator receives oil from the tested hydraulic pump and inputs the oil to the first oil cavity through the proportional reversing valve.
Further, the pressure reducing unit further comprises a plurality of first check valves, a plurality of second check valves, a third check valve and a fourth check valve; the first one-way valve is positioned between the first energy accumulator and the second oil cavity, and the second one-way valve is positioned between the second oil cavity and the second energy accumulator; the number of the first check valves and the second check valves is the same as that of the pressure reducing cylinders, each pressure reducing cylinder corresponds to one first check valve and one second check valve, a plurality of the first check valves are arranged in parallel, and a plurality of the second check valves are arranged in parallel; the third check valve is positioned between the tested hydraulic pump and the third energy accumulator, and the fourth check valve is positioned between the non-tested hydraulic pump and the first energy accumulator.
Further, the depressurization unit further includes a fifth check valve located between the non-test hydraulic pump and the second accumulator.
Further, the filter further comprises a first filter and a second filter; the first filter is positioned between the tested hydraulic pump and the third one-way valve, and the second filter is positioned between the second accumulator and the hydraulic motor.
Further, the device also comprises a first overflow valve, wherein one side of the first overflow valve is communicated with the first filter, and the other side of the first overflow valve is communicated with the first oil tank; the depressurization unit further comprises a second overflow valve, one side of the second overflow valve is communicated with the second filter, and the other side of the second overflow valve is communicated with the second oil tank.
Further, the sealing ring and the inner wall of the pressure reducing cylinder are integrally formed.
For a better understanding and implementation, the present invention is described in detail below with reference to the drawings.
Drawings
FIG. 1 is a schematic diagram of a prior art energy recovery hydraulic test stand;
FIG. 2 is a schematic diagram of a dual tank buck energy recovery hydraulic test stand of the present invention;
FIG. 3 is a schematic diagram of the connection structure of the dual tank buck energy recovery hydraulic test stand of the present invention;
fig. 4 is a schematic structural view of the pressure reducing cylinder of the present invention.
Detailed Description
Referring to fig. 2, a schematic diagram of a dual tank buck energy recovery hydraulic test stand according to the present invention is shown. According to the invention, the pressure of oil is reduced by arranging the pressure reducing unit between the tested hydraulic pump and the hydraulic motor, so that the hydraulic motor is protected from being damaged by high-pressure oil; meanwhile, the tested hydraulic pump and the hydraulic motor are respectively connected with different oil tanks, so that the oil passing through the tested hydraulic pump cannot pass through the hydraulic motor, and the situation that the worn metal powder enters the hydraulic motor after being mixed into the oil due to high-strength operation of the tested hydraulic pump and the hydraulic motor is worn is avoided.
Specifically, please refer to fig. 3, which is a schematic diagram of a connection structure of the dual-tank pressure-reducing energy recovery hydraulic test bench according to the present invention. The dual tank depressurization type energy recovery hydraulic test stand of the present invention includes an electric motor 10, a first tank 20, a hydraulic pump under test 30, a depressurization unit 40, a hydraulic motor 50, a generator 60, a second tank 70, a first filter 80, a second filter 90, and a first relief valve 100.
The motor 10 is connected with the tested hydraulic pump 30; the first oil tank 20 is connected to the input end of the tested hydraulic pump 30 through an oil pipe, the output end of the tested hydraulic pump 30 is sequentially connected to the pressure reducing unit 40 and the input end of the hydraulic motor 50 through an oil pipe, and the output end of the hydraulic motor 50 is connected to the second oil tank 70; the generator 60 is connected to the hydraulic motor 50. When the hydraulic pump is in operation, the motor 10 drives the tested hydraulic pump 30 to absorb oil from the first oil tank 20 and convert the oil into high-pressure hydraulic energy, the high-pressure hydraulic energy is reduced by the pressure reducing unit 40 to obtain low-pressure hydraulic energy, the low-pressure hydraulic energy is fed into the hydraulic motor 50 to be converted into mechanical energy, meanwhile, the oil is released into the second oil tank 70, the mechanical energy is converted into electric energy by the generator 60 and is fed into a power grid for a user to use, and the recovery of the energy consumed by the tested hydraulic pump is realized.
In addition, the first filter 80 is located immediately adjacent to the output of the hydraulic pump under test 30; the second filter 90 is located immediately adjacent to the input of the hydraulic motor 50. The filter primarily filters out solid impurities, such as metal powder, in the oil, thereby avoiding abrasion of the tested hydraulic pump 30 and the hydraulic motor 50 by the solid impurities. One end of the first overflow valve 90 is connected to the first filter 80 through an oil pipe, and the other end is connected to the first oil tank 20 through an oil pipe, so as to form a closed oil path including the tested hydraulic pump 30, the first filter 80, the first overflow valve 100 and the first oil tank 20. The closed oil path functions when the tested hydraulic pump 30 bears the working pressure higher than the set working pressure of the first overflow valve 100, and at this time, excessive oil is released back to the first oil tank 20 through the first overflow valve 90, so that the oil pressure of the tested hydraulic pump 30 flowing to the first oil cavity A1 is reduced, the pressure of the whole oil pipe passage is relieved, and protection of the tested hydraulic pump 30 and all parts taking the first oil tank 20 as oil sources is realized.
The pressure reducing unit 40 includes a plurality of pressure reducing cylinders 41, a non-test hydraulic pump 42 and a pressure reducing control system 43, wherein the plurality of pressure reducing cylinders 41 are connected in parallel to each other and connected in an oil path.
Specifically, a piston 411 is disposed inside the pressure reducing cylinder 41, and the area of the top surface of the piston 411 is larger than the area of the bottom surface. The piston 411 moves back and forth in the pressure reducing cylinder 41, dividing the interior of the pressure reducing cylinder 41 into two independent chambers; wherein, a first oil cavity A1 is formed between the bottom surface of the piston 411 and the bottom surface of the pressure reducing cylinder 41, and a second oil cavity A2 is formed between the top surface of the piston 411 and the top surface of the pressure reducing cylinder 41. The first oil cavity A1 is connected to the first filter 80 through an oil pipe and then to the output end of the tested hydraulic pump 30, so as to receive the oil with high hydraulic energy converted by the tested hydraulic pump 30. The second oil chamber A2 receives oil from the second oil tank 70 via the non-test hydraulic pump 42 on the one hand, and connects the second filter 80 via the oil line to the input of the hydraulic motor 50 on the other hand, so as to release oil from the second oil tank 70 for the hydraulic motor 50 to convert into mechanical energy. According to the pressure formula F (pressure) =p (pressure) ×s (area), since the top surface area of the piston 411 is larger than the bottom surface area, the cross-sectional area of the second oil chamber A2 is larger than that of the first oil chamber A1, and under the condition that the pressure is unchanged, the pressure of the oil in the second oil chamber A2 is lower than that of the oil in the first oil chamber A1, so that the oil flowing into the hydraulic motor 50 has relatively low pressure, that is, hydraulic energy, and the hydraulic motor 50 is protected from being damaged by high hydraulic energy.
The pressure reducing and regulating system 43 comprises a PLC431, a plurality of displacement sensors 432 and a plurality of proportional reversing valves 433, wherein the number of the displacement sensors 432 and the proportional reversing valves 433 is the same as that of the pressure reducing cylinders 41 and corresponds to the number of the pressure reducing cylinders one by one. The displacement sensor 432 is disposed on the piston 411, and is configured to sense a position of the piston 411 in the pressure reducing cylinder 41, and transmit a position signal of the piston 411 to the PLC431. The proportional reversing valve 433 is disposed on the third accumulator 49 and the oil path between the output end of the tested hydraulic pump 30 and the first oil chamber A1, and the oil path between the first oil chamber A1 and the first oil tank 20, and the proportional reversing valve 433 is electrically connected to the PLC; the proportional reversing valve 433 receives the command of the PLC431, controls to turn off or turn on the oil path between the tested hydraulic pump 30 and the first oil chamber A1, and to turn on or turn off the oil path between the first oil chamber A1 and the first oil tank 20, and controls the speed of the flow of the oil, thereby controlling the moving direction and speed of the piston 411 in the pressure reducing cylinder 41. Specifically, when the left station of the proportional reversing valve 433 works, the oil path between the tested hydraulic pump 30 and the first oil chamber A1 is connected, the oil path between the first oil chamber A1 and the first oil tank 20 is disconnected, the oil flows from the tested hydraulic pump 30 to the first oil chamber A1, and the piston 411 moves upwards; when the proportional reversing valve 433 works at the right station, the oil passage between the first oil chamber A1 and the first oil tank 20 is connected, the oil passage between the tested hydraulic pump 30 and the first oil chamber A1 is disconnected, the oil flows from the first oil chamber A1 to the first oil tank 20, and the piston 411 moves downward. And, no matter the proportional reversing valve 433 works in the left station or the right station, when the valve core moves right, the oil quantity in the oil path is increased, and the upward and downward speeds of the piston 411 are increased; when the spool moves leftward, the amount of oil in the oil passage decreases, and the speed of the piston 411 moving upward and downward decreases.
From the above, the first oil tank 20, the tested hydraulic pump 30, the first filter 80, the proportional directional valve 433 (left working position operation), the first oil cavity A1, the proportional directional valve 433 (right working position operation), and the first oil tank 20 form a closed oil path; the second oil tank 70-the non-test hydraulic pump 42-the second oil chamber A2-the second filter 90-the hydraulic motor 50-the second oil tank 70 forms another closed oil path, and the first oil chamber A1 and the second oil chamber A2 are partitioned by the piston 411. It can be seen that the oil flowing through the tested hydraulic pump 30 and the oil flowing through the hydraulic motor 50 do not cross each other, so that the damage to the hydraulic motor caused by the metal powder worn out by the tested hydraulic pump due to high-strength operation mixed into the oil flowing into the hydraulic motor is avoided.
In addition, a first accumulator 44 is disposed between the output end of the non-test hydraulic pump 42 and the second oil chamber A2, a second accumulator 45 is disposed between the second oil chamber A2 and the second filter 80, and a third accumulator 46 is disposed between the first filter 70 and the first oil chamber A1. The characteristics that a small amount of oil can be stored and the oil can be stably output by utilizing the energy accumulator are utilized, so that the oil can timely and stably enter the first oil cavity A1, the second oil cavity A2 and the hydraulic motor 50.
A first check valve 47 is arranged between the first accumulator 44 and the second oil cavity A2, and the first check valve 47 controls the oil to flow from the first accumulator 44 to the second oil cavity A2 in a unidirectional manner; a second one-way valve 48 is disposed between the second oil chamber A2 and the second accumulator 45, and the second one-way valve 48 controls the oil to flow from the second oil chamber A2 to the second accumulator 45 in a unidirectional manner. The number of the first check valves 47 and the second check valves 48 is the same as that of the pressure reducing cylinders 41 and corresponds to one another, that is, the second oil chamber A2 of each pressure reducing cylinder 41 is correspondingly connected with one first check valve 47 and one second check valve 48. A third check valve 49 is disposed between the first filter 70 and the third accumulator 46, and the third check valve 49 controls the oil to flow from the tested hydraulic pump 30 to the third accumulator 46 in a unidirectional manner, so as to avoid damage to the tested hydraulic pump 43 caused by backward flow of the oil to the tested hydraulic pump 30; a fourth check valve 410 is disposed between the output end of the non-test hydraulic pump 42 and the first accumulator 44, and the fourth check valve 410 controls the oil to flow from the non-test hydraulic pump 42 to the first accumulator 44 in a unidirectional manner, so as to avoid damage to the non-test hydraulic pump 42 caused by reverse flow of the oil to the non-test hydraulic pump 42.
In summary, two complete oil paths in the invention are as follows: the second oil tank 70-the non-test hydraulic pump 42-the fourth check valve 410-the first accumulator 44-the first check valve 47-the second oil chamber A2-the second check valve 48-the second accumulator 45-the second filter 90-the hydraulic motor 50-the second oil tank 70; and first tank 20-tested hydraulic pump 30-first filter 80-third check valve 49-third accumulator 46-proportional directional valve 433 (left work station) -first oil chamber A1-proportional directional valve 433 (right work station) -first tank 20. In the second oil path, the third accumulator 46 may be connected in parallel with the tested hydraulic pump 30 to the oil path after sucking the oil from the tested hydraulic pump 30, so as to provide the oil for the first oil chamber A1 together.
Further, a fifth check valve 420 is provided between the output of the non-test hydraulic pump 42 and the second accumulator 45. The fifth check valve 420-the second accumulator 45-the second filter 90-the hydraulic motor 50-the second tank 70-the non-test hydraulic pump 42 constitutes a closed circuit. The closed oil path has a supplementary function. When any one-way valve (the first one-way valve 47, the second one-way valve 48 and the fourth one-way valve 410) on the main oil path of the second oil tank 70-the second oil chamber A2-the second accumulator 45-the hydraulic motor 50 fails to cause the oil path to be blocked, the fifth one-way valve 420 is opened, and the closed oil path is communicated to provide oil for the hydraulic motor 50 until the main oil path is restored.
The output end of the non-test hydraulic pump 42 is provided with a second overflow valve 430, one end of the second overflow valve 430 is connected to the output end of the non-test hydraulic pump 42 through an oil pipe, and the other end of the second overflow valve is connected to the second oil tank 70 through an oil pipe, so as to form a closed oil path comprising the second oil tank 70, the non-test hydraulic pump 42 and the second overflow valve 430. The closed oil path functions when the non-test hydraulic pump 42 is subjected to the working pressure set higher than the second relief valve 430, and excessive oil is released back to the second oil tank 70 through the second relief valve 430, so that the oil pressure of the non-test hydraulic pump 42 flowing to the first oil chamber A1 is reduced, and the non-test hydraulic pump 42 and all components taking the second oil tank 70 as oil sources are protected.
Preferably, the interior of the pressure reducing cylinder 41 is a T-shaped cavity, the piston 411 is a T-shaped piston, and the T-shaped piston 411 moves back and forth in the T-shaped cavity. Please refer to fig. 4, which is a schematic diagram of the structure of the pressure reducing cylinder of the present invention. The T-shaped cavity comprises a wide cavity part and a narrow cavity part which is mutually perpendicular to the wide cavity part, wherein the diameter of the wide cavity part is larger than that of the narrow cavity part; the T-shaped piston 411 includes a wide head portion 4111 and a narrow waist portion 4112 perpendicular to the wide head portion 4111, the wide head portion 4111 of the T-shaped piston 411 moves in the wide chamber portion of the pressure reducing cylinder 41, and the narrow waist portion 4112 of the T-shaped piston 411 moves in the wide chamber portion and the narrow chamber portion of the pressure reducing cylinder 41. The first oil chamber A1 formed by the T-shaped piston 411 being partitioned inside the pressure reducing cylinder 41 is located in the narrow chamber portion, and the second oil chamber A2 is located in the wide chamber portion.
The wide cavity portion of the pressure reducing cylinder 41 is further provided with a sealing ring 412, one side of the sealing ring 412 is fixed on the pressure reducing cylinder 41, and the other side of the sealing ring tightly surrounds the narrow waist portion 4112 of the T-shaped piston 411. At this time, the wide head 4111 of the T-shaped piston 411 moves between the seal 412 of the wide chamber portion and the top surface of the pressure reducing cylinder 41. An isolation lower cavity A3 is formed between the bottom surface of the sealing ring 412 and the inner wall of the boundary between the wide cavity part and the narrow cavity part of the pressure reducing cylinder 41, and the isolation lower cavity A3 is communicated with the first oil tank 20 through an oil pipe to replace oil in the isolation lower cavity A3; an upper isolation cavity A4 is formed between the top surface of the sealing ring 412 and the bottom surface of the wide head 4111 of the T-shaped piston 411, and the upper isolation cavity A4 is communicated with the second oil tank 70 through an oil pipe, so that oil in the upper isolation cavity A4 is replaced.
Because the present invention uses two oil paths that do not intersect each other so that the hydraulic motor is not worn by the metal powder generated by the tested hydraulic pump, a small amount of oil from the first oil chamber A1 that adheres to the wall of the piston 411 enters the second oil chamber A2 due to the movement of the piston 411, and thus is mixed into the oil of the second oil chamber A2 to enter the hydraulic motor 50. The sealing ring 412, the isolation lower chamber A3 and the isolation upper chamber A4 can solve the above technical problems. Because the oil adhered to the wall of the piston 411 and mixed into the wide head movement range by the movement of the piston 411 is replaced by the clean oil from the second oil tank 70, the possibility that the hydraulic motor is worn by the metal powder from the tested hydraulic pump oil path is further reduced. Preferably, the sealing ring 42 is integrally formed with the inner wall of the pressure reducing cylinder 41, and the other side closely surrounds the narrow waist portion 4112 of the T-shaped piston 411, so as to achieve a better sealing effect.
Hereinafter, the operation of the double tank pressure reduction type energy recovery hydraulic test stand of the present invention will be described by taking two pressure reduction cylinders 41 (a first pressure reduction cylinder 41a and a second pressure reduction cylinder 41 b) as an example. Corresponding to the first pressure reducing cylinder 41a are a first T-shaped piston 411a, a first displacement sensor 423a, a first proportional reversing valve 433a, a first check valve 47a and a second check valve 48a, and two oil chambers in the first pressure reducing cylinder 41a are a first oil chamber A1a and a second oil chamber A2b respectively; corresponding to the second pressure reducing cylinder 41b are a second T-shaped piston 411b, a second displacement sensor 423b, a second proportional directional valve 433b, a second first check valve 47b, and a second check valve 48b, and two oil chambers in the second pressure reducing cylinder 41b are a second first oil chamber A1b and a second oil chamber A2b, respectively. In addition, the top surface area of the pressure reducing cylinder 41 is set to be twice the bottom surface area, and the opening pressure of all check valves is set to be zero. Also set the pressure of the first relief valve 100 to zero and the pressure of the second relief valve 430 to 1 mpa before the test begins.
When starting the test of the performance of the hydraulic pump 30 under test, the pressure of the first relief valve 100 was set to 2 mpa and the motor 10 was started. The motor 10 drives the tested hydraulic pump 30 to suck the oil from the first oil tank 20 for testing, and the tested hydraulic pump 30 outputs the oil having high hydraulic energy (high pressure) to the third accumulator 46 for temporary storage. When the pressure of the oil output from the tested hydraulic pump 30 is higher than 2 mpa, part of the oil returns to the first oil tank 20 through the first relief valve 100, so that the pressure of the oil output from the tested hydraulic pump 30 to the third accumulator 46 is not higher than 2 mpa, and all components in the oil path are protected from being damaged by the oil with high pressure (high hydraulic energy). In order to avoid the piston from directly hitting the top and bottom surfaces of the inner wall of the pressure reducing cylinder, causing abrasion of the piston and the inner wall of the pressure reducing cylinder, the highest position and the lowest position of the T-shaped piston 411 moving in the pressure reducing cylinder 41 are set by the PLC431. The T-shaped piston 411 is located at the lowest position before start-up.
The non-test hydraulic pump 42 is started, the non-test hydraulic pump 42 sucks oil from the second oil tank 70, the oil is input into the first accumulator 44 through the fourth one-way valve 410, after the pressure in the first accumulator 44 rises to 1 mpa, the first one-way valve 47a and the second one-way valve 47b are opened, and the oil in the first accumulator 44 flows into the first second oil cavity A2b through the first one-way valve 47a and flows into the second oil cavity A2b through the second one-way valve 47 b.
The pressure of the first relief valve 100 is then increased, allowing more oil to flow from the tested hydraulic pump 30 to the first chamber A1. Meanwhile, the PLC431 is operated, the PLC431 commands the first proportional reversing valve 433a to increase current at a constant speed, so that the valve core of the first proportional reversing valve 433a moves right at a constant speed, left station work is performed, an oil way between the third energy accumulator 430 and the tested hydraulic pump 30 and the first oil cavity A1a is connected, the third energy accumulator 430 and the tested hydraulic pump 30 are used for injecting oil into the first oil cavity A1a at a speed through the first proportional reversing valve 433a, the first T-shaped piston 411a is accelerated to move upwards to push out the oil in the second oil cavity A2a, and the oil enters the second energy accumulator 45 through the second one-way valve 48a for storage. When the first T-shaped piston 411a is accelerated to move up to be close to the highest position set by the PLC431, the first displacement sensor 423a transmits a position signal of the first T-shaped piston 411a to the PLC431, the PLC431 commands the first proportional reversing valve 433a to uniformly reduce current, so that the valve core of the first T-shaped piston moves left, the left station work is still performed, the third accumulator 430 and the tested hydraulic pump 30 continue to inject oil into the first oil cavity A1a through the first proportional reversing valve 433a, but the oil injection speed is reduced, and the first T-shaped piston 411a continues to move up to push out oil in the first second oil cavity A2b, but the upward movement speed is reduced; meanwhile, the PLC431 commands the second proportional directional valve 433b to increase the current at a constant speed, so that the spool of the second proportional directional valve 433b moves right to perform the left-station operation, the third accumulator 430 and the oil path between the tested hydraulic pump 30 and the second first oil chamber A1b are also connected, the third accumulator 430 and the tested hydraulic pump 30 inject the oil into the second first oil chamber A1b through the second proportional directional valve 433b, the second T-shaped piston 411b moves up at an accelerated speed to push out the oil in the second oil chamber A2b, and the oil enters the second accumulator 45 through the second check valve 48b for temporary storage. When the first T-shaped piston 411a moves up to the highest position, the valve core of the first proportional directional valve 433a is located at the middle position and continues to move left, the first proportional directional valve 433a performs right station operation, the third accumulator 430 and the oil path between the tested hydraulic pump 30 and the first oil chamber A1a are disconnected, the oil path between the first oil chamber A1a and the first oil tank 20 is connected, at this time, since the first second oil chamber A2a is connected with the first accumulator 44, the pressure in the first second oil chamber A2a is 1 mpa, the first oil chamber A1a is connected with the first oil tank 20, the pressure in the first oil chamber A1a is 0 mpa, and the first T-shaped piston 411a moves down in an accelerating manner; at the same time, the second T-shaped piston 411b is still accelerating upward to push out the oil in the second oil chamber A2b. The PLC431 sets the downward movement speed of the piston 411 to be greater than the upward movement speed, so that compared with the second T-shaped piston 411b which is accelerated to move up to be close to the highest position, the first T-shaped piston 411a is accelerated to move down to be close to the lowest position, then the first T-shaped piston 411a is decelerated to be lowered to the lowest position and stands by at the lowest position, then the second T-shaped piston 411b is accelerated to move up to be close to the highest position, the second displacement sensor 432b transmits a position signal of the second T-shaped piston 411b to the PLC431, the PLC431 commands the second proportional directional valve 433b to uniformly reduce the current so that the valve core of the second proportional directional valve 433b moves left, the second proportional directional valve 433b still performs left-position operation, the third accumulator 430 and the tested hydraulic pump 30 can still continuously inject oil into the second first oil cavity A1b through the second proportional directional valve 433b, but the oil injection speed is slow, and the second T-shaped piston 411b continues to move up to push out the oil in the second oil cavity A2b; meanwhile, the PLC431 commands the first proportional reversing valve 433a to increase the current at a constant speed, so as to perform the left-station operation, switch on the third accumulator 430 and the oil path between the tested hydraulic pump 30 and the first oil chamber A1a, accelerate the injection of the oil in the first oil chamber A1a, push the first T-shaped piston 411a to accelerate to move upwards, and push the oil in the second oil chamber A2a into the second accumulator 45 for temporary storage. When the second T-shaped piston 411b is shifted up to the highest position at a reduced speed, the spool of the second proportional directional valve 433b is at the middle position and continues to shift left, the second proportional directional valve 433b performs the right-hand work, the third accumulator 430 and the oil path between the tested hydraulic pump 30 and the second first oil chamber A1b are disconnected, the oil path between the second first oil chamber A1b and the first oil tank 20 is connected, at this time, since the second oil chamber A2b is connected to the first accumulator 44, the pressure in the second oil chamber A2b is 1 mpa, the second first oil chamber A1b is connected to the first oil tank 20, the pressure in the second oil chamber A1b is 0 mpa, the second T-shaped piston 411b is accelerated to shift down, and before the first T-shaped piston 411a is accelerated to shift up to the highest position, the second T-shaped piston 411b is accelerated to shift down to the lowest position and then is decelerated to the lowest position and stands by.
The first T-shaped piston 411a and the second T-shaped piston 411b repeatedly perform the above actions, the oil in the second accumulator 45 is continuously replenished, and the pressure is gradually increased until the hydraulic motor 50 can be driven to convert mechanical energy into mechanical energy for the generator 60 to generate electricity, so that energy recovery is realized. In the working process of the device, the pressure of the oil liquid input into the hydraulic motor 50 is only half of the pressure of the oil liquid generated by the tested hydraulic pump 30, and the hydraulic motor 50 is protected from being damaged while the performance test of the hydraulic pump is completed; in addition, the tested hydraulic pump 30 and the hydraulic motor 50 are positioned in two non-intersecting oil paths, so that the abrasion of the hydraulic motor caused by the mixing of the metal powder abraded from the tested hydraulic pump 30 into the oil is avoided.
Compared with the prior art, the double-oil tank pressure-reducing type energy recovery hydraulic test bench has the advantages that the area of the top surface of the piston in the pressure-reducing cylinder is larger than the area of the bottom surface, so that the cross-sectional area of the second oil cavity is larger than that of the first oil cavity, and the pressure of oil in the second oil cavity is lower than that of the oil in the first oil cavity under the condition that the pressure is unchanged according to a pressure formula of F (pressure) =P (pressure) ×S (area), and therefore low-pressure oil in the second oil cavity flows into the hydraulic motor, and the hydraulic motor is protected from being damaged by high-pressure oil from a tested hydraulic pump; meanwhile, the hydraulic motor and the tested hydraulic pump are positioned in two oil paths which are not intersected with each other, so that the situation that metal powder worn from the tested hydraulic pump is mixed into oil liquid and flows into the hydraulic motor to wear the hydraulic motor due to high-strength operation of the tested hydraulic pump is avoided; in addition, the pressure reducing regulation system is arranged so as to coordinate a plurality of pressure reducing cylinders to work simultaneously, and in the process of upward movement of the pistons in part of the pressure reducing cylinders, the pistons in the other part of the pressure reducing cylinders move downward simultaneously and alternately reciprocate, so that the hydraulic energy generated by the tested hydraulic pump is continuously supplied to the hydraulic motor and the generator for energy recovery; in addition, through setting up the sealing washer and setting up the isolation oil pocket that communicates with each other with two oil tanks to make the fluid that mixes with the piston a small amount be passed into the oil tank immediately and dilute the replacement, further avoided the intersection of two oil circuits, ensured that hydraulic motor is not damaged by the solid impurity that mixes in the oil circuit fluid that is tested hydraulic pump place.
The above examples illustrate only a few embodiments of the invention, which are described in detail and are not to be construed as limiting the scope of the invention. It should be noted that it will be apparent to those skilled in the art that several variations and modifications can be made without departing from the spirit of the invention, which are all within the scope of the invention.
Claims (10)
1. A dual tank buck energy recovery hydraulic test stand comprising: the hydraulic pump is tested by the motor, the tested hydraulic pump, the first oil tank, the hydraulic motor and the generator; the motor is connected with the tested hydraulic pump, the first oil tank is communicated with the input end of the tested hydraulic pump through an oil pipe, the input end of the hydraulic motor is communicated with the output end of the tested hydraulic pump through an oil pipe, and the generator is connected with the hydraulic motor; the method is characterized in that: the device also comprises a second oil tank and a depressurization unit; the second oil tank is communicated with the output end of the hydraulic motor through an oil pipe; the pressure reducing unit is positioned between the tested hydraulic pump and the hydraulic motor and comprises a plurality of pressure reducing cylinders and non-tested hydraulic pumps; the plurality of pressure reducing cylinders are arranged in parallel, a piston is arranged in the pressure reducing cylinders, the area of the bottom surface of the piston is smaller than that of the top surface of the piston, a first oil cavity is formed between the bottom surface of the piston and the pressure reducing cylinders, and a second oil cavity is formed between the top surface of the piston and the pressure reducing cylinders; the tested hydraulic pump is communicated with the first oil cavity through an oil pipe; the second oil cavity is respectively communicated with the second oil tank and the input end of the hydraulic motor through an oil pipe; the non-test hydraulic pump is located between the second oil tank and the second oil chamber.
2. The dual tank buck energy recovery hydraulic test stand of claim 1, wherein: the pressure reducing unit further comprises a pressure reducing regulating system, the pressure reducing regulating system comprises a PLC, a plurality of displacement sensors and a plurality of proportional reversing valves, the number of the displacement sensors, the proportional reversing valves and the number of the pressure reducing cylinders are the same, and each pressure reducing cylinder corresponds to one displacement sensor and one proportional reversing valve; the displacement sensor is arranged in the pressure reducing cylinder and sends a position signal of the piston to the PLC; the proportional reversing valve is positioned on an oil path between the tested hydraulic pump and the first oil cavity and an oil path between the first oil cavity and the first oil tank, receives a command of the PLC to control to switch on or off the oil path between the tested hydraulic pump and the first oil cavity and the oil path between the first oil cavity and the first oil tank, and controls the oil quantity in the oil path.
3. The dual tank buck energy recovery hydraulic test stand of claim 2, wherein: the inside of the pressure reducing cylinder is a T-shaped cavity, and the piston is a T-shaped piston.
4. The dual tank buck energy recovery hydraulic test stand of claim 3, wherein: a sealing ring is further arranged in the pressure reducing cylinder, one end of the sealing ring is fixed on the inner wall of the pressure reducing cylinder, and the other end of the sealing ring surrounds the T-shaped piston;
the T-shaped piston comprises a wide head and a narrow waist, wherein the cross-sectional area of the wide head is larger than that of the narrow waist; an upper isolation cavity is formed between the sealing ring and the wide head part, and the upper isolation cavity is communicated with a second oil tank through an oil pipe; an isolation lower cavity is formed between the sealing ring and the narrow waist part, and the isolation lower cavity is communicated with the first oil tank through an oil pipe.
5. The dual tank buck energy recovery hydraulic test stand of either of claims 2 or 4, wherein: the depressurization unit further comprises a first energy accumulator, a second energy accumulator and a third energy accumulator; the first accumulator is positioned between the non-test hydraulic pump and the second oil cavity; the second accumulator is positioned between the second oil cavity and the hydraulic motor; and the third energy accumulator receives oil from the tested hydraulic pump and inputs the oil to the first oil cavity through the proportional reversing valve.
6. The dual tank buck energy recovery hydraulic test stand of claim 5, wherein: the pressure reducing unit further comprises a plurality of first check valves, a plurality of second check valves, a third check valve and a fourth check valve; the first one-way valve is positioned between the first energy accumulator and the second oil cavity, and the second one-way valve is positioned between the second oil cavity and the second energy accumulator; the number of the first check valves and the second check valves is the same as that of the pressure reducing cylinders, each pressure reducing cylinder corresponds to one first check valve and one second check valve, a plurality of the first check valves are arranged in parallel, and a plurality of the second check valves are arranged in parallel; the third check valve is positioned between the tested hydraulic pump and the third energy accumulator, and the fourth check valve is positioned between the non-tested hydraulic pump and the first energy accumulator.
7. The dual tank buck energy recovery hydraulic test stand of claim 6, wherein: the depressurization unit further includes a fifth check valve located between the non-test hydraulic pump and the second accumulator.
8. The dual tank buck energy recovery hydraulic test stand of either of claims 6 or 7, wherein: the filter further comprises a first filter and a second filter; the first filter is positioned between the tested hydraulic pump and the third one-way valve, and the second filter is positioned between the second accumulator and the hydraulic motor.
9. The dual tank buck energy recovery hydraulic test stand of claim 8, wherein: the first overflow valve is communicated with the first filter at one side and communicated with the first oil tank at the other side; the depressurization unit further comprises a second overflow valve, one side of the second overflow valve is communicated with the second filter, and the other side of the second overflow valve is communicated with the second oil tank.
10. The dual tank buck energy recovery hydraulic test stand of claim 4, wherein: and the sealing ring and the inner wall of the pressure reducing cylinder are integrally formed.
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| JP2004239373A (en) * | 2003-02-06 | 2004-08-26 | Tamura Electric Works Ltd | Hydraulic apparatus and power generating facility |
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| CN108547833A (en) * | 2018-05-14 | 2018-09-18 | 山东大学 | It is a kind of to be used for the electrohydraulic system and working method that heave compensator energy regenerating utilizes |
| CN209278258U (en) * | 2018-10-25 | 2019-08-20 | 广东天恒液压机械有限公司 | A kind of double fuel tank voltage-dropping type energy regenerating hydraulic test beds |
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2018
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2004239373A (en) * | 2003-02-06 | 2004-08-26 | Tamura Electric Works Ltd | Hydraulic apparatus and power generating facility |
| KR100908579B1 (en) * | 2009-01-21 | 2009-07-22 | 티엠디이엔지(주) | Performance test apparatus of axial fan hydraulic blade adjustment for use in generator equipment |
| CN107420384A (en) * | 2017-09-15 | 2017-12-01 | 太原理工大学 | Lifting device gravitional force P-V storage system |
| CN108397444A (en) * | 2018-04-16 | 2018-08-14 | 中国人民解放军陆军工程大学 | A kind of electric-controlled hydraulic energy storage experimental stand system with pressure sensing function |
| CN108547833A (en) * | 2018-05-14 | 2018-09-18 | 山东大学 | It is a kind of to be used for the electrohydraulic system and working method that heave compensator energy regenerating utilizes |
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