Hydraulic drive unit for an electro-hydraulic shifter

Description

FIELD OF TECHNOLOGY

[0001] The present disclosure relates to railway or urban track systems, in particular to a hydraulic power unit applicable to an electro-hydraulic switch machine.BACKGROUND

[0002] The electro-hydraulic switch machine, which refers to an important basic device for reliably switching positions of turnouts, changing opening directions of the turnouts, locking switch rails of the turnouts, and reflecting the positions of the turnouts, can well ensure the safety of train operation, improve the transportation efficiency, and reduce the labor intensity of train operation personnel. The electro-hydraulic switch machine is generally used in switching of rail turnouts of a railway or urban track system.

[0003] At present, electromagnetic reversing valves arranged at an oil inlet and an oil outlet of an oil pump are typically used in a hydraulic power unit of the electro-hydraulic switch machine. High-pressure oil in the oil pump can be controlled to enter an oil cylinder by controlling valve elements of the electromagnetic reversing valves, thereby controlling a direction of the oil cylinder in action. Additionally, in the event of power failure, the reversing valves are in the middle position, and two ends of the oil cylinder are connected to each other, which can adapt to manual operation of the electro-hydraulic switch machine.

[0004] The patent applications FR 2 271 098 A2 and US 5 775 647 A both disclose such railway switch arrangements with electro-hydraulic switch machines.

[0005] However, when the electromagnetic reversing valves are used to control the oil pump, each action of the oil cylinder requires a power supply to control the reversing valves. Therefore, the use of the reversing valves has requirements for both an electrical part and the type of the power supply. This leads to poor field adaptability.SUMMARY

[0006] To solve one or more defects in the prior art, a hydraulic power unit applicable to an electro-hydraulic switch machine is proposed according to one aspect of the present disclosure. The hydraulic power unit includes a pump valve assembly and an oil cylinder. The pump valve assembly includes an oil pump configured to pump a hydraulic fluid from an oil sump.

[0007] The pump valve assembly further includes a first hydraulic control reversing valve and a second hydraulic control reversing valve.

[0008] The first hydraulic control reversing valve is connected between a first chamber of the oil cylinder and the oil pump through a hydraulic pipeline.

[0009] The second hydraulic control reversing valve is connected between a second chamber of the oil cylinder and the oil pump through a hydraulic pipeline.

[0010] When the oil pump is in a non-working state, the first chamber of the oil cylinder is in fluid connection with the second chamber of the oil cylinder through the first hydraulic control reversing valve and the second hydraulic control reversing valve, the oil cylinder is in a pressure balance state, and the electro-hydraulic switch machine is capable of being manually operated.

[0011] When the oil pump is in a first working state, the hydraulic fluid pumped by the oil pump from the oil sump enters the first chamber of the oil cylinder through the first hydraulic control reversing valve, so that the oil cylinder moves in a first direction, and the hydraulic fluid in the second chamber of the oil cylinder returns to the oil sump through the second hydraulic control reversing valve.

[0012] When the oil pump is in a second working state, the hydraulic fluid pumped by the oil pump from the oil sump enters the second chamber of the oil cylinder through the second hydraulic control reversing valve, so that the oil cylinder moves in a second direction different from the first direction, and the hydraulic fluid in the first chamber of the oil cylinder returns to the oil sump through the first hydraulic control reversing valve.

[0013] According to the above aspect of the present disclosure, the pump valve assembly further includes a first hydraulic control one-way valve and a second hydraulic control one-way valve.

[0014] The first hydraulic control one-way valve is connected between the oil sump and the first hydraulic control reversing valve through a hydraulic pipeline and is connected to the oil pump through a hydraulic pipeline.

[0015] The second hydraulic control one-way valve is connected between the oil sump and the second hydraulic control reversing valve through a hydraulic pipeline and is connected to the oil pump through a hydraulic pipeline.

[0016] According to the above aspect of the present disclosure, both the first hydraulic control reversing valve and the second hydraulic control reversing valve are hydraulic control reversing valves with two-position three-way structures.

[0017] According to the above aspect of the present disclosure, when the oil pump is in the non-working state, the first chamber of the oil cylinder is connected to the second chamber of the oil cylinder through the first hydraulic control reversing valve and the second hydraulic control reversing valve, both the first hydraulic control one-way valve and the second hydraulic control one-way valve are connected to the hydraulic pipeline connected between the first hydraulic control reversing valve and the second hydraulic control reversing valve, an outer cylinder sleeve of the oil cylinder is in the pressure balance state, and the electro-hydraulic switch machine is capable of being manually operated.

[0018] According to the above aspect of the present disclosure, when the oil pump is in the first working state, the hydraulic fluid pumped by the oil pump from the oil sump enters the first hydraulic control reversing valve to form a high-pressure fluid, and a pressure of the high-pressure fluid pushes a first valve element of the first hydraulic control reversing valve to move, so that the high-pressure fluid enters the first chamber; and meanwhile, the pressure of the high-pressure fluid opens the first hydraulic control one-way valve, the high-pressure fluid pushes the outer cylinder sleeve of the oil cylinder to move in the first direction, and the hydraulic fluid in the second chamber returns to the oil sump through the second hydraulic control reversing valve and the opened first hydraulic control one-way valve.

[0019] According to the above aspect of the present disclosure, when the oil pump is in the second working state, the hydraulic fluid pumped by the oil pump from the oil sump enters the second hydraulic control reversing valve to form a high-pressure fluid, and a pressure of the high-pressure fluid pushes a second valve element of the second hydraulic control reversing valve to move, so that the high-pressure fluid enters the second chamber; and meanwhile, the pressure of the high-pressure fluid opens the second hydraulic control one-way valve, the high-pressure fluid pushes the outer cylinder sleeve of the oil cylinder to move in the second direction, and the hydraulic fluid in the second chamber returns to the oil sump through the first hydraulic control reversing valve and the opened second hydraulic control one-way valve.

[0020] According to the above aspect of the present disclosure, the hydraulic power unit further includes a motor and a coupling.

[0021] The motor drives the oil pump of the pump valve assembly by the coupling.

[0022] When the motor does not rotate, the oil pump is in the non-working state.

[0023] When the motor rotates in a first rotational direction thereof, the oil pump is in the first working state.

[0024] When the motor rotates in a second rotational direction thereof, the oil pump is in the second working state.

[0025] The first rotational direction of the motor is opposite to the second rotational direction of the motor.

[0026] According to the above aspect of the present disclosure, the oil cylinder includes the outer cylinder sleeve and a cylinder plunger disposed in the outer cylinder sleeve.

[0027] The cylinder plunger is set to be fixed.

[0028] The cylinder plunger divides an internal space of the outer cylinder sleeve into the first chamber and the second chamber.

[0029] The outer cylinder sleeve is capable of moving or remaining stationary relative to the cylinder plunger based on the pressure of the fluid in the first chamber and the second chamber.

[0030] According to the above aspect of the present disclosure, the pump valve assembly further includes a front valve block and a rear box.

[0031] The oil pump as a whole is mounted and fixed at a front end part of the front valve block, and a mounting shaft of the oil pump is exposed from the front end part of the front valve block.

[0032] The rear box is mounted and fixed on a rear end part of the front valve block and seals the oil pump in the front end part of the front valve block.

[0033] According to the above aspect of the present disclosure, the first and second hydraulic control one-way valves and two overflow valves are disposed at a top of the front valve block.

[0034] An oil dipstick and an air filter are arranged at a top of the rear box.

[0035] According to the above aspect of the present disclosure, a side valve block is mounted and fixed on a side surface of the front valve block.

[0036] The first and second hydraulic control reversing valves are disposed at a top of the side valve block.

[0037] According to the above aspect of the present disclosure, two sets of filter elements and one-way valve groups connected in series respectively are disposed at a bottom of the front valve block.

[0038] A first set of filter element and one-way valve group connected in series is connected between the oil sump and the hydraulic pipeline connected between the oil pump and the first hydraulic control reversing valve.

[0039] A second set of filter element and one-way valve group connected in series is connected between the oil sump and the hydraulic pipeline connected between the oil pump and the second hydraulic control reversing valve.

[0040] According to the above aspect of the present disclosure, one of the two overflow valves is connected to the oil sump and the hydraulic pipeline connected between the oil pump and the first hydraulic control reversing valve.

[0041] The other of the two overflow valves is connected to the oil sump and the hydraulic pipeline connected between the oil pump and the second hydraulic control reversing valve.

[0042] According to the above aspect of the present disclosure, when the oil pump is in the first working state, the hydraulic fluid pumped by the oil pump through the second set of filter element and one-way valve group connected in series from the oil sump enters the first chamber of the oil cylinder through the first hydraulic control reversing valve, so that the oil cylinder moves in the first direction, and the hydraulic fluid in the second chamber of the oil cylinder returns to the oil sump through the second hydraulic control reversing valve.

[0043] When the oil pump is in the second working state, the hydraulic fluid pumped by the oil pump through the first set of filter element and one-way valve group connected in series from the oil sump enters the second chamber of the oil cylinder through the second hydraulic control reversing valve, so that the oil cylinder moves in the second direction different from the first direction, and the hydraulic fluid in the first chamber of the oil cylinder returns to the oil sump through the first hydraulic control reversing valve.

[0044] According to the technical solution of the present disclosure, the hydraulic control reversing valves and the hydraulic control one-way valves are used to control an oil path, which can adapt to manual operation of the electro-hydraulic switch machine; and meanwhile, when the switch machine is in action, a power supply is not needed to control the reversing valves, making an electrical part simpler. For requirements on different types of power supplies on site, only the motor needs to be replaced to meet the requirements.

[0045] The pump valve assembly adopts a modular design. The various assemblies are connected by using universal interfaces, making it convenient to replace any of them. According to the present disclosure, the hydraulic control reversing valves, the hydraulic control one-way valves, the overflow valves, the oil dipstick, and the air filter are all located at an upper part of the pump valve assembly as a whole, thereby facilitating repair and replacement.

[0046] By now, to better understand the detailed description of the present disclosure herein, and to better recognize contribution thereof to the prior art, a fairly broad overview of the present disclosure has been provided. Certainly, embodiments of the present disclosure will be described below and will form a subject of the appended claims.

[0047] Likewise, it will be recognized by those skilled in the art that the concept on which the present disclosure is based can be easily used as a basis for designing other structures, methods, and systems to implement the various purposes of the present disclosure. Therefore, it is important that the appended claims should be considered to include such equivalent structures as long as they do not exceed the essence and scope of the present disclosure.BRIEF DESCRIPTION OF THE DRAWINGS

[0048] Through the accompanying drawings below, those skilled in the art will have a better understanding of the present disclosure, and the advantages of the present disclosure can be more clearly embodied. The accompanying drawings described herein are only for the purpose of illustrating the selected embodiments rather than all possible implementations, and are not intended to limit the scope of the present disclosure. FIG. 1 shows a schematic structural diagram of a hydraulic power unit applicable to an electro-hydraulic switch machine according to an embodiment of the present disclosure; FIG. 2 shows a schematic structural diagram of a pump valve assembly of a hydraulic power unit applicable to an electro-hydraulic switch machine according to an embodiment of the present disclosure; FIG. 3 shows a principle diagram of a hydraulic system of a hydraulic power unit applicable to an electro-hydraulic switch machine in a state where a motor is not powered on to rotate according to an embodiment of the present disclosure; FIG. 4 shows a principle diagram of a hydraulic system of a hydraulic power unit applicable to an electro-hydraulic switch machine in a state where a motor is powered on to rotate in a first direction according to an embodiment of the present disclosure; FIG. 5 shows a principle diagram of a hydraulic system of a hydraulic power unit applicable to an electro-hydraulic switch machine in a state where a motor is powered on to rotate in a second direction according to an embodiment of the present disclosure, where the second direction is different from the first direction; and FIG. 6 shows a schematic diagram of a partial structure of a pump valve assembly. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0049] Specific embodiments according to the present disclosure are specifically described below with reference to the accompanying drawings.

[0050] This embodiment relates to railway or urban track systems, in particular to a hydraulic power unit applicable to an electro-hydraulic switch machine, where the electro-hydraulic switch machine is applied to switching of rail turnouts of railway or urban track systems.

[0051] FIG. 1 shows a hydraulic power unit applicable to an electro-hydraulic switch machine, where the hydraulic power unit includes a motor 1, a coupling 2, and a pump valve assembly 3. The motor 1 is connected to pump valve assembly 3 by the coupling 2. The motor 1 and the pump valve assembly 3 are fixed by a bolt, and the three components are mutually connected and fixed to form the hydraulic power unit.

[0052] FIG. 2 shows a schematic structural diagram of a pump valve assembly, where the pump valve assembly 3 includes an oil pump 3-1, a front valve block 3-2, a rear box 3-3, a side valve block 3-4, one-way valve groups 3-5 (see FIG. 6), a first hydraulic control reversing valve 4, a second hydraulic control reversing valve 5, a first hydraulic control one-way valve 6, a second hydraulic control one-way valve 7, overflow valves 8, an oil dipstick 9, filter elements 10 (see FIG. 6), and an air filter 11.

[0053] The oil pump 3-1 as a whole is mounted and fixed at an end part of the front valve block 3-2, and a mounting shaft at a front part of the oil pump is exposed from an outer side of the front valve block.

[0054] The rear box 3-3 is mounted and fixed on the front valve block 3-2 and seals a tail of the oil pump 3-1. The oil dipstick 9 and the air filter 11 are arranged at a top of the rear box 3-3.

[0055] The first hydraulic control one-way valve 6, the second hydraulic control one-way valve 7, and the two overflow valves 8 are arranged at a top of the front valve block 3-2.

[0056] The side valve block 3-4 is mounted and fixed on a side surface of the front valve block 3-2, and the first hydraulic control reversing valve 4 and the second hydraulic control reversing valve 5 are arranged at a top of the side valve block 3-4.

[0057] FIG. 6 shows a schematic diagram of a partial structure of a pump valve assembly, where the one-way valve groups 3-5 and the filter elements 10 are mounted and fixed at a bottom of the front valve block 3-2.

[0058] The pump valve assembly 3 adopts a modular design. The various assemblies are connected by using universal interfaces, making it convenient to replace any of them. The first and second hydraulic control reversing valves, the first and second hydraulic control one-way valves, the overflow valves, the oil dipstick, and the air filter are all located at an upper part of the pump valve assembly as a whole, thereby facilitating repair and replacement.

[0059] FIG. 3 to FIG. 5 show principle diagrams of a hydraulic system of a hydraulic power unit in different states as shown in FIG. 1 and FIG. 2.

[0060] According to one embodiment of the present disclosure, a hydraulic power unit applicable to an electro-hydraulic switch machine is proposed. The hydraulic power unit includes a pump valve assembly 3 and an oil cylinder 12. The pump valve assembly includes an oil pump 3-1. The oil pump 3-1 is configured to pump a hydraulic fluid from an oil sump 13 to the oil cylinder 12.

[0061] The oil cylinder 12 includes an outer cylinder sleeve 12-1 and a cylinder plunger 12-2 disposed in the outer cylinder sleeve 12-1.

[0062] The cylinder plunger 12-2 is set to be fixed.

[0063] The cylinder plunger 12-2 divides an internal space of the outer cylinder sleeve 12-1 into a first chamber 12-3 and a second chamber 12-4.

[0064] The outer cylinder sleeve 12-1 is capable of moving or remaining stationary relative to the cylinder plunger 12-2 based on a pressure of the fluid in the first chamber 12-3 and the second chamber 12-4.

[0065] It can also be understood by those skilled in the art that the outer cylinder sleeve 12-1 may be set to be fixed, and the cylinder plunger 12-2 is capable of moving or remaining stationary relative to the outer cylinder sleeve 12-1 based on the pressure of the fluid in the first chamber 12-3 and the second chamber 12-4.

[0066] The following content is based on the condition that the cylinder plunger 12-2 is set to be fixed and the outer cylinder sleeve 12-1 is capable of moving or remaining stationary relative to the cylinder plunger 12-2, as shown in FIG. 3 to FIG. 5.

[0067] The pump valve assembly 3 further includes a first hydraulic control reversing valve 4 and a second hydraulic control reversing valve 5.

[0068] The first hydraulic control reversing valve 4 is connected between the first chamber 12-3 of the oil cylinder 12 and the oil pump 3-1 through a hydraulic pipeline.

[0069] The second hydraulic control reversing valve 5 is connected between the second chamber 12-4 of the oil cylinder 12 and the oil pump 3-1 through a hydraulic pipeline.

[0070] The pump valve assembly further includes a first hydraulic control one-way valve 6 and a second hydraulic control one-way valve 7.

[0071] The first hydraulic control one-way valve 6 is connected between the oil sump 13 and the first hydraulic control reversing valve 4 through a hydraulic pipeline and is connected to the oil pump 3-1 through a hydraulic pipeline.

[0072] The second hydraulic control one-way valve 7 is connected between the oil sump 13 and the second hydraulic control reversing valve 5 through a hydraulic pipeline and is connected to the oil pump 3-1 through a hydraulic pipeline.

[0073] Both the first hydraulic control reversing valve 4 and the second hydraulic control reversing valve 5 are hydraulic control reversing valves with two-position three-way structures.

[0074] According to the above embodiment of the present disclosure, as shown in FIG. 3, when the oil pump 3-1 is in a non-working state (when the motor 1 does not rotate, the oil pump 3-1 is in a non-working state, and no high pressure of the hydraulic fluid acts on corresponding valve elements of the first hydraulic control reversing valve 4 and the second hydraulic control reversing valve 5), the first chamber 12-3 of the oil cylinder 12 is connected to the second chamber 12-4 of the oil cylinder 12 through the first hydraulic control reversing valve 4 and the second hydraulic control reversing valve 5, both the first hydraulic control one-way valve 6 and the second hydraulic control one-way valve 7 are connected to the hydraulic pipeline connected between the first hydraulic control reversing valve 4 and the second hydraulic control reversing valve 5, the outer cylinder sleeve of the oil cylinder 12 is in a pressure balance state, and the electro-hydraulic switch machine is capable of being manually operated. In this state, both the first hydraulic control one-way valve 6 and the second hydraulic control one-way valve 7 are in a closed state, so that no hydraulic fluid will flow through the first hydraulic control one-way valve 6 and the second hydraulic control one-way valve 7 back to the oil sump 13.

[0075] According to the above embodiments of the present disclosure, as shown in FIG. 4, when the oil pump 3-1 is in a first working state (when the motor 1 rotates in a first rotational direction thereof, the oil pump 3-1 is in a first working state), the hydraulic fluid pumped by the oil pump 3-1 from the oil sump 13 enters the first hydraulic control reversing valve 4 to form a high-pressure fluid, and a pressure of the high-pressure fluid pushes a first valve element (not shown) of the first hydraulic control reversing valve 4 to move, so that the high-pressure fluid enters the first chamber 12-3; and meanwhile, the pressure of the high-pressure fluid opens the first hydraulic control one-way valve 6, the high-pressure fluid pushes the outer cylinder sleeve 12-1 of the oil cylinder 12 to move in a first direction (leftwards in FIG. 4), and the hydraulic fluid in the second chamber 12-4 returns to the oil sump 13 through the second hydraulic control reversing valve 5 and the opened first hydraulic control one-way valve 6 (a flow path of the hydraulic fluid is as shown by an arrow in FIG. 4). In this state, the first hydraulic control one-way valve 6 is in an opened state, and the second hydraulic control one-way valve 7 is in a closed state, so that no hydraulic fluid will flow through the second hydraulic control one-way valve 7 back to the oil sump 13. Likewise, in this state, no high pressure of the hydraulic fluid acts on a second valve element (not shown) of the second hydraulic control reversing valve 5.

[0076] According to the above embodiments of the present disclosure, as shown in FIG. 5, when the oil pump 3-1 is in a second working state (when the motor 1 rotates in a second rotational direction thereof, the oil pump 3-1 is in a second working state), the hydraulic fluid pumped by the oil pump 3-1 from the oil sump 13 enters the second hydraulic control reversing valve 5 to form a high-pressure fluid, and a pressure of the high-pressure fluid pushes the second valve element of the second hydraulic control reversing valve 5 to move, so that the high-pressure fluid enters the second chamber 12-4; and meanwhile, the pressure of the high-pressure fluid opens the second hydraulic control one-way valve 7, the high-pressure fluid pushes the outer cylinder sleeve 12-1 of the oil cylinder 12 to move in a second direction (rightwards in FIG. 5), and the hydraulic fluid in the second chamber 12-3 returns to the oil sump 13 through the first hydraulic control reversing valve 4 and the opened second hydraulic control one-way valve 7 (the flow path of the hydraulic fluid is as shown by the arrow in FIG. 4). In this state, the first hydraulic control one-way valve 6 is in a closed state, and the second hydraulic control one-way valve 7 is in an opened state, so that no hydraulic fluid will flow through the first hydraulic control one-way valve 6 back to the oil sump 13. Likewise, in this state, no high pressure of the hydraulic fluid acts on a first valve element of the first hydraulic control reversing valve 4.

[0077] Air in the oil sump 13 can be prevented from entering the hydraulic pipeline by arranging the first hydraulic control one-way valve 6 and the second hydraulic control one-way valve 7.

[0078] The first rotational direction of the motor 1 is opposite to the second rotational direction of the motor 1. For example, the first rotational direction is a counterclockwise direction, and the second rotational direction is a clockwise direction, and vice versa.

[0079] According to the technical solution of this embodiment, the hydraulic control reversing valves and the hydraulic control one-way valves are used to control an oil path, which can adapt to manual operation of the electro-hydraulic switch machine; and meanwhile, when the switch machine is in action, a power supply is not needed to control the reversing valves, making an electrical part simpler. For requirements on different types of power supplies on site, only the motor needs to be replaced to meet the requirements. In addition, the use of the hydraulic control one-way valves can prevent gas in the hydraulic fluid in the oil sump from entering the hydraulic pipeline, thereby ensuring the operational reliability and accuracy of the hydraulic control reversing valves.

[0080] According to another embodiment of the present disclosure, those skilled in the art may also not arrange the first hydraulic control one-way valve 6 and the second hydraulic control one-way valve 7 in the hydraulic pipeline.

[0081] According to the above another embodiment of the present disclosure, when the oil pump 3-1 is in a non-working state (when the motor 1 does not rotate, the oil pump 3-1 is in a non-working state, and no high pressure of the hydraulic fluid acts on corresponding valve elements of the first hydraulic control reversing valve 4 and the second hydraulic control reversing valve 5), the first chamber 12-3 of the oil cylinder 12 is connected to the oil sump 13 through the first hydraulic control reversing valve 4, the second chamber 12-4 of the oil cylinder 12 is connected to the oil sump 13 through the second hydraulic control reversing valve 5, the first chamber 12-3 of the oil cylinder 12 is in fluid connection with the second chamber 12-4 of the oil cylinder 12 through the hydraulic control reversing valve 4 and the second hydraulic control reversing valve 5, the oil cylinder 12 is in a pressure balance state, and the electro-hydraulic switch machine is capable of being manually operated.

[0082] According to the above another embodiment of the present disclosure, when the oil pump 3-1 is in a first working state (when the motor 1 rotates in a first rotational direction thereof, the oil pump 3-1 is in a first working state), the hydraulic fluid pumped by the oil pump 3-1 from the oil sump 13 enters the first chamber 12-3 of the oil cylinder 12 through the first hydraulic control reversing valve 4, so that the outer cylinder sleeve 12-1 of the oil cylinder 12 moves in a first direction, and the hydraulic fluid in the second chamber 12-4 of the oil cylinder 12 returns to the oil sump 13 through the second hydraulic control reversing valve 5.

[0083] According to the above another embodiment of the present disclosure, when the oil pump 3-1 is in a second working state (when the motor 1 rotates in a second rotational direction thereof, the oil pump 3-1 is in a second working state), the hydraulic fluid pumped by the oil pump 3-1 from the oil sump 13 enters the second chamber 12-4 of the oil cylinder 12 through the second hydraulic control reversing valve 5, so that the outer cylinder sleeve 12-1 of the oil cylinder 12 moves in a second direction different from the first direction, and the hydraulic fluid in the first chamber 12-3 of the oil cylinder 12 returns to the oil sump 13 through the first hydraulic control reversing valve 4.

[0084] The first rotational direction of the motor 1 is opposite to the second rotational direction of the motor 1. For example, the first rotational direction is a counterclockwise direction, and the second rotational direction is a clockwise direction, and vice versa.

[0085] According to the above embodiments of the present disclosure, two sets of filter elements 10 and one-way valve groups 3-5 connected in series respectively are disposed at a bottom of the front valve block 3-2.

[0086] A first set of filter element 10 and one-way valve group 3-5 connected in series is connected between the oil sump 13 and the hydraulic pipeline connected between the oil pump 3-1 and the first hydraulic control reversing valve 4.

[0087] A second set of filter element 10 and one-way valve group 3-5 connected in series is connected between the oil sump 13 and the hydraulic pipeline connected between the oil pump 3-1 and the second hydraulic control reversing valve 5.

[0088] According to the above embodiments of the present disclosure, one of the two overflow valves 8 is connected to the oil sump 13 and the hydraulic pipeline connected between the oil pump 3-1 and the first hydraulic control reversing valve 4.

[0089] The other of the two overflow valves 8 is connected to the oil sump 13 and the hydraulic pipeline connected between the oil pump 3-1 and the second hydraulic control reversing valve 5.

[0090] The overflow valves 3-8 control the maximum working pressure of the hydraulic system to ensure the system safety when the system is overloaded.

[0091] According to the above embodiments of the present disclosure, as shown in FIG. 4, when the oil pump 3-1 is in a first working state (when the motor 1 rotates in a first rotational direction thereof, the oil pump 3-1 is in a first working state), the hydraulic fluid pumped by the oil pump 3-1 through the second set of filter element 10 and one-way valve group 3-5 connected in series from the oil sump 13 enters the first chamber 12-3 of the oil cylinder 12 through the first hydraulic control reversing valve 4, so that the outer cylinder sleeve 12-1 of the oil cylinder 12 moves in a first direction, and the hydraulic fluid in the second chamber 12-4 of the oil cylinder 12 returns to the oil sump 13 through the second hydraulic control reversing valve 5.

[0092] When the oil pump 3-1 is in a second working state (when the motor 1 rotates in a second rotational direction thereof, the oil pump 3-1 is in a second working state), as shown in FIG. 5, the hydraulic fluid pumped by the oil pump 3-1 through the first set of filter element 10 and one-way valve group 3-5 connected in series from the oil sump 13 enters the second chamber 12-4 of the oil cylinder 12 through the second hydraulic control reversing valve 5, so that the outer cylinder sleeve 12-1 of the oil cylinder 12 moves in a second direction different from the first direction, and the hydraulic fluid in the first chamber 12-3 of the oil cylinder 12 returns to the oil sump 13 through the first hydraulic control reversing valve 4.

[0093] According to the technical solution of this embodiment, only the hydraulic control reversing valves are used instead of the hydraulic control one-way valves to control an oil path, which can also adapt to manual operation of the electro-hydraulic switch machine; and meanwhile, when the switch machine is in action, a power supply is not needed to control the reversing valves, making an electrical part simpler. For requirements on different types of power supplies on site, only the motor needs to be replaced to meet the requirements. In addition, the structure of the hydraulic power unit as a whole can be simplified without using the hydraulic control one-way valves, thereby reducing costs.

[0094] The foregoing disclosure provides illustration and description, but is not intended to be exhaustive or to limit embodiments to the precise form disclosed.

Claims

1. A hydraulic power unit applicable to an electro-hydraulic switch machine, comprising a pump valve assembly (3) and an oil cylinder (12), the pump valve assembly (3) comprising an oil pump (3-1) configured to pump a hydraulic fluid from an oil sump (13), wherein the pump valve assembly (3) further comprises a first hydraulic control reversing valve (4) and a second hydraulic control reversing valve (5); the first hydraulic control reversing valve (4) is connected between a first chamber (12-3) of the oil cylinder (12) and the oil pump (3-1) through a hydraulic pipeline; the second hydraulic control reversing valve (5) is connected between a second chamber (12-4) of the oil cylinder (12) and the oil pump (3-1) through a hydraulic pipeline; when the oil pump (3-1) is in a non-working state, the first chamber (12-3) of the oil cylinder (12) is connected to the second chamber (12-4) of the oil cylinder (12) through the first hydraulic control reversing valve (4) and the second hydraulic control reversing valve (5), the oil cylinder (12) is in a pressure balance state, and the electro-hydraulic switch machine is capable of being manually operated; when the oil pump (3-1) is in a first working state, the hydraulic fluid pumped by the oil pump (3-1) from the oil sump (13) enters the first chamber (12-3) of the oil cylinder (12) through the first hydraulic control reversing valve (4), so that the oil cylinder (12) moves in a first direction, and the hydraulic fluid in the second chamber (12-4) of the oil cylinder (12) returns to the oil sump (13) through the second hydraulic control reversing valve (5); and when the oil pump (3-1) is in a second working state, the hydraulic fluid pumped by the oil pump (3-1) from the oil sump (13) enters the second chamber (12-4) of the oil cylinder (12) through the second hydraulic control reversing valve (5), so that the oil cylinder (12) moves in a second direction different from the first direction, and the hydraulic fluid in the first chamber (12-3) of the oil cylinder (12) returns to the oil sump (13) through the first hydraulic control reversing valve (4).

2. The hydraulic power unit according to claim 1, characterized in that the pump valve assembly (3) further comprises a first hydraulic control one-way valve and a second hydraulic control one-way valve; the first hydraulic control one-way valve is connected between the oil sump (13) and the first hydraulic control reversing valve (4) through a hydraulic pipeline and is connected to the oil pump (3-1) through a hydraulic pipeline; and the second hydraulic control one-way valve is connected between the oil sump (13) and the second hydraulic control reversing valve (5) through a hydraulic pipeline and is connected to the oil pump (3-1) through a hydraulic pipeline.

3. The hydraulic power unit according to claim 2, characterized in that both the first hydraulic control reversing valve (4) and the second hydraulic control reversing valve (5) are hydraulic control reversing valves with two-position three-way structures.

4. The hydraulic power unit according to claim 3, characterized in that when the oil pump (3-1) is in the non-working state, the first chamber (12-3) of the oil cylinder (12) is connected to the second chamber (12-4) of the oil cylinder (12) through the first hydraulic control reversing valve (4) and the second hydraulic control reversing valve (5), both the first hydraulic control one-way valve and the second hydraulic control one-way valve are connected to the hydraulic pipeline connected between the first hydraulic control reversing valve (4) and the second hydraulic control reversing valve (5), an outer cylinder sleeve of the oil cylinder (12) is in the pressure balance state, and the electro-hydraulic switch machine is capable of being manually operated.

5. The hydraulic power unit according to claim 3, characterized in that when the oil pump (3-1) is in the first working state, the hydraulic fluid pumped by the oil pump (3-1) from the oil sump (13) enters the first hydraulic control reversing valve (4) to form a high-pressure fluid, and a pressure of the high-pressure fluid pushes a first valve element of the first hydraulic control reversing valve (4) to move, so that the high-pressure fluid enters the first chamber (12-3); and meanwhile, the pressure of the high-pressure fluid opens the first hydraulic control one-way valve, the high-pressure fluid pushes the outer cylinder sleeve of the oil cylinder (12) to move in the first direction, and the hydraulic fluid in the second chamber (12-4) returns to the oil sump (13) through the second hydraulic control reversing valve (5) and the opened first hydraulic control one-way valve.

6. The hydraulic power unit according to claim 3, characterized in that when the oil pump (3-1) is in the second working state, the hydraulic fluid pumped by the oil pump (3-1) from the oil sump (13) enters the second hydraulic control reversing valve (5) to form a high-pressure fluid, and a pressure of the high-pressure fluid pushes a second valve element of the second hydraulic control reversing valve (5) to move, so that the high-pressure fluid enters the second chamber (12-4); and meanwhile, the pressure of the high-pressure fluid opens the second hydraulic control one-way valve, the high-pressure fluid pushes the outer cylinder sleeve of the oil cylinder (12) to move in the second direction, and the hydraulic fluid in the second chamber (12-4) returns to the oil sump (13) through the first hydraulic control reversing valve (4) and the opened second hydraulic control one-way valve.

7. The hydraulic power unit according to claim 3, characterized in that the hydraulic power unit further comprises a motor and a coupling, wherein the motor drives the oil pump (3-1) of the pump valve assembly (3) by the coupling; when the motor does not rotate, the oil pump (3-1) is in the non-working state; when the motor rotates in a first rotational direction thereof, the oil pump (3-1) is in the first working state; when the motor rotates in a second rotational direction thereof, the oil pump (3-1) is in the second working state; and the first rotational direction of the motor is opposite to the second rotational direction of the motor.

8. The hydraulic power unit according to one of claims 4 to 6, characterized in that the oil cylinder (12) comprises the outer cylinder sleeve and a cylinder plunger disposed in the outer cylinder sleeve, wherein the cylinder plunger is set to be fixed; the cylinder plunger divides an internal space of the outer cylinder sleeve into the first chamber (12-3) and the second chamber (12-4); and the outer cylinder sleeve is capable of moving or remaining stationary relative to the cylinder plunger based on the pressure of the fluid in the first chamber (12-3) and the second chamber (12-4).

9. The hydraulic power unit according to claim 3, characterized in that the pump valve assembly (3) further comprises a front valve block and a rear box; the oil pump (3-1) as a whole is mounted and fixed at a front end part of the front valve block, and a mounting shaft of the oil pump (3-1) is exposed from the front end part of the front valve block; and the rear box is mounted and fixed on a rear end part of the front valve block and seals the oil pump (3-1) in the front end part of the front valve block.

10. The hydraulic power unit according to claim 9, characterized in that the first and second hydraulic control one-way valves and two overflow valves are disposed at a top of the front valve block; and an oil dipstick and an air filter are arranged at a top of the rear box.

11. The hydraulic power unit according to claim 10, characterized in that a side valve block is mounted and fixed on a side surface of the front valve block; and the first and second hydraulic control reversing valves (5) are disposed at a top of the side valve block.

12. The hydraulic power unit according to claim 11, characterized in that two sets of filter elements and one-way valve groups connected in series respectively are disposed at a bottom of the front valve block; a first set of filter element and one-way valve group connected in series is connected between the oil sump (13) and the hydraulic pipeline connected between the oil pump (3-1) and the first hydraulic control reversing valve (4); and a second set of filter element and one-way valve group connected in series is connected between the oil sump (13) and the hydraulic pipeline connected between the oil pump (3-1) and the second hydraulic control reversing valve (5).

13. The hydraulic power unit according to claim 12, characterized in that one of the two overflow valves is connected to the oil sump (13) and the hydraulic pipeline connected between the oil pump (3-1) and the first hydraulic control reversing valve (4); and the other of the two overflow valves is connected to the oil sump (13) and the hydraulic pipeline connected between the oil pump (3-1) and the second hydraulic control reversing valve (5).

14. The hydraulic power unit according to claim 13, characterized in that when the oil pump (3-1) is in the first working state, the hydraulic fluid pumped by the oil pump (3-1) through the second set of filter element and one-way valve group connected in series from the oil sump (13) enters the first chamber (12-3) of the oil cylinder (12) through the first hydraulic control reversing valve (4), so that the outer cylinder sleeve of the oil cylinder (12) moves in the first direction, and the hydraulic fluid in the second chamber (12-4) of the oil cylinder (12) returns to the oil sump (13) through the second hydraulic control reversing valve (5); and when the oil pump (3-1) is in the second working state, the hydraulic fluid pumped by the oil pump (3-1) through the first set of filter element and one-way valve group connected in series from the oil sump (13) enters the second chamber (12-4) of the oil cylinder (12) through the second hydraulic control reversing valve (5), so that the outer cylinder sleeve of the oil cylinder (12) moves in the second direction different from the first direction, and the hydraulic fluid in the first chamber (12-3) of the oil cylinder (12) returns to the oil sump (13) through the first hydraulic control reversing valve (4).