Portable Hydraulic Power Unit

Abstract

A portable hydraulic power unit includes a frame, a fluid tank supported by the frame, and a manifold supported by the frame. The fluid tank is configured to store a source of hydraulic fluid for powering hydraulically driven tools. A first reciprocating pump and a second reciprocating pump are mounted on the outside of the fluid tank and the outside of the manifold. The reciprocating pumps are fixed to the fluid tank and the manifold using fasteners extending through the corresponding hydraulic cylinder bodies of the reciprocating pumps. The reciprocating pumps are installed so that a first fluid connection, a second flow connection, and a driving mechanical connection with the hydraulic power unit are formed simultaneously. A valve is arranged downstream of the second reciprocating pump and guides the hydraulic flow provided by the second reciprocating pump based on the pressure level within the hydraulic circuit of the hydraulic power unit.

Description

[0001] This application is a divisional application of the Chinese patent application filed on April 28, 2018 with the invention name “Portable Hydraulic Power Unit” and application number 201810401792.1.

[0002] CROSS-REFERENCE TO RELATED APPLICATIONS

[0003] This application claims priority to U.S. Provisional Application No. 62 / 491,539, filed on April 28, 2017, entitled “PORTABLE HYDRAULIC POWER UNIT,” the disclosure of which is incorporated herein in its entirety. Background Art

[0004] The present disclosure relates generally to hydraulic power units. More particularly, the present disclosure relates to portable hydraulic power units.

[0005] The hydraulic power unit pumps hydraulic fluid under pressure to the hydraulically driven tool so that the hydraulically driven tool performs work. The hydraulic power unit includes multiple pumps that pump hydraulic fluid through a hydraulic circuit to the hydraulically driven tool. The pump is typically a plunger pump that is immersed in the hydraulic fluid located in the fluid tank of the hydraulic power unit. The pump also includes a trochoid pump immersed in the hydraulic fluid for high flow applications. The built-in pump is exposed to the hydraulic fluid both inside and outside the pump. In order to accumulate a high enough pressure to drive the hydraulically driven tool, the hydraulic power unit adopts a staged approach. Each stage is released by a spring-loaded relief valve when the maximum pressure is reached.

[0006] A lid that closes the fluid tank and a long gasket having a geometry that matches the geometry of the top of the fluid tank are arranged between the lid and the fluid tank to prevent contaminants from entering the fluid tank. To service the internal pump, the user removes the lid (which may expose the hydraulic fluid to contaminants) and removes the internal pump from the hydraulic fluid. In addition, the fluid tank may be installed below other systems on the hydraulic power unit, so that the user needs to remove the other systems before accessing the tank. When the hydraulic power unit is returned from maintenance, the user needs to properly install the long gasket between the fluid tank and the lid to prevent leakage. Summary of the invention

[0007] According to one aspect of the present disclosure, a hydraulic power unit includes a frame, a fluid tank supported by the frame, a manifold supported by the frame, and a first reciprocating pump fixed to the tank outside of the fluid tank and the manifold outside of the manifold. The fluid tank is configured to store a source of hydraulic fluid. The first reciprocating pump is configured to draw hydraulic fluid from the fluid tank and pump a first flow of hydraulic fluid to the manifold.

[0008] According to another aspect of the present disclosure, a method for installing a pump is provided, the pump having a cylinder body and a piston extending at least partially out of the cylinder body, the cylinder body including a fluid outlet passing through an upper mounting portion of the cylinder body, a fluid inlet passing through a lower mounting portion of the cylinder body, the hydraulic power unit having a fluid tank for holding hydraulic fluid, a supply port connected to and fixed to the fluid tank, a manifold connected to the fluid tank, a receiving port connected to and fixed to the manifold, and a drive mechanism; the method comprising: connecting each of the fluid inlets to the The invention relates to a method for aligning the hydraulic cylinder body with the fluid tank and the manifold, wherein the hydraulic cylinder body is configured to align the fluid inlet with the supply port, the fluid outlet with the receiving port, and the piston with the drive mechanism; forming a first fluid connection between the fluid inlet and the supply port, a second fluid connection between the fluid outlet and the receiving port, and a reciprocating mechanical connection between the piston and the drive mechanism; and fixing the hydraulic cylinder body to the fluid tank and the manifold while maintaining the first fluid connection, the second fluid connection, and the reciprocating mechanical connection, and while maintaining the alignment of the fluid inlet with the supply port, the fluid outlet with the receiving port, and the piston with the drive mechanism.

[0009] According to another aspect of the present disclosure, a hydraulic power unit for providing hydraulic fluid to a hydraulically driven tool to power the hydraulically driven tool includes: a fluid tank supported by a frame; a first pump configured to draw the hydraulic fluid from the fluid tank and pump a first hydraulic flow to a combined flow line; a second pump configured to draw the hydraulic fluid from the fluid tank and pump a second hydraulic flow to a high flow line, the high flow line fluid being connected to the combined flow line; a first valve arranged along the high flow line; and a high flow return line extending from a downstream side of the first valve. The first valve is controllable between an open state and a closed state. The high flow return line is configured to provide a return flow of the second hydraulic flow to the fluid tank. The first valve is an electrically actuated valve that switches to an open state based on a hydraulic fluid pressure in the combined flow line exceeding a threshold pressure level and directs the second hydraulic flow to the high flow return line in the open state.

[0010] According to yet another aspect of the present disclosure, a method includes simultaneously powering a first pump and a second pump of a hydraulic power unit, the first pump drawing hydraulic fluid from a fluid reservoir and providing a first flow of the hydraulic fluid to a first valve, the second pump drawing hydraulic fluid from the fluid reservoir and providing a second flow of the hydraulic fluid to the first valve, wherein the first valve is configured to deliver the hydraulic fluid to a hydraulically-driven tool; measuring a hydraulic fluid pressure by a transducer, the hydraulic fluid pressure being indicative of a pressure in a combined flow line upstream of the first valve; and controlling the second valve between an open state and a closed state based on the measured hydraulic fluid pressure, wherein the second valve is configured to divert the second flow to a system return line when in an open state.

[0011] According to another aspect of the present disclosure, a hydraulic power unit includes: a frame; a fluid tank supported by the frame, the fluid tank being configured to store a source of hydraulic fluid; a hydraulic circuit configured to receive hydraulic fluid from the fluid tank, provide the hydraulic fluid to a hydraulically driven tool to power the hydraulically driven tool, and return the hydraulic fluid from the hydraulically driven tool to the fluid tank; a manifold supported by the frame, the manifold forming at least a portion of the hydraulic circuit; and a first reciprocating pump configured to draw hydraulic fluid from the fluid tank and provide a first hydraulic flow to the hydraulic circuit at the manifold, wherein the first reciprocating pump includes a first piston having a first internal check valve, and wherein the first reciprocating pump is configured to output the first hydraulic flow during an ascending stroke of the first piston and a descending stroke of the first piston.

[0012] According to another aspect of the present disclosure, a method includes: mounting a first reciprocating pump external to a hydraulic power unit; drawing a first portion of hydraulic fluid from a fluid tank using the first reciprocating pump, and driving the first portion downstream to a hydraulically driven tool using the first reciprocating pump; and using the first portion of the hydraulic fluid to power the hydraulically driven tool. The first reciprocating pump includes a first piston that at least partially extends out of a first hydraulic cylinder body, the first piston including a first internal valve and configured to drive the first portion downstream during an upstroke of the first piston and a downstroke of the first piston.

[0013] According to another aspect of the present disclosure, a pump system for a hydraulic power unit includes: a first reciprocating pump configured to draw hydraulic fluid from a fluid tank and provide a first flow of hydraulic fluid to a hydraulic fluid circuit, the hydraulic fluid circuit being configured to deliver the hydraulic fluid to a hydraulically driven tool and further deliver a return flow of hydraulic fluid from the hydraulically driven tool to a fluid reservoir; and a second reciprocating pump configured to draw hydraulic fluid from the fluid tank and provide a second flow of hydraulic fluid to the hydraulic fluid circuit. The first reciprocating pump includes a first piston having a first internal check valve and configured to output the first flow during an ascending stroke of the first piston and a descending stroke of the first piston, and the second reciprocating pump includes a second piston having a second internal check valve and configured to output the second flow during an ascending stroke of the second piston and a descending stroke of the second piston. The first reciprocating pump and the second reciprocating pump are mechanically connected so that the first reciprocating pump and the second reciprocating pump simultaneously output the first flow and the second flow. The second reciprocating pump has a larger displacement volume per stroke than the first reciprocating pump. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 is a schematic diagram of the hydraulic power unit.

[0015] Figure 2A is the first isometric view of the hydraulic power unit.

[0016] Figure 2B is a second isometric view of the hydraulic power unit.

[0017] Figure 2C yes Figure 2B A magnified isometric view of detail Z.

[0018] Figure 2D If the four-way valve is removed, Figure 2B A magnified isometric view of detail Z.

[0019] Figure 3 It is along Figure 2A A cross-sectional view of the pump of the hydraulic power unit taken along line 3-3.

[0020] Figure 4 is a side cross-sectional view showing the connection of the first pump and the hydraulic power unit.

[0021] Figure 5 is a side cross-sectional view showing the connection of the second pump to the hydraulic power unit.

[0022] Fig. 6A is a rear isometric view of the pump.

[0023] Figure 6B It is a partial exploded view of the hydraulic power unit.

[0024] Figure 7 It is a partial exploded view of the hydraulic power unit.

[0025] Fig. 8A is the first isometric view of the overhang.

[0026] Figure 8B is a second isometric view of the overhang.

[0027] Figure 8C is a third isometric view of the overhang.

[0028] Fig.8D is the fourth isometric view of the overhang.

[0029] Fig.9A is an isometric view of the first hydraulically powered tool.

[0030] Fig. 9B is an isometric view of a second hydraulically powered tool. DETAILED DESCRIPTION

[0031] Figure 1 1 is a schematic diagram of a hydraulic power unit ("HPU") 10, which includes a hydraulic circuit 12, a fluid reservoir 14, a pump 16, a pump 18, an oil cooler 20, a filter 22a, a filter 22b, a transducer 24, a two-way valve 26, a four-way valve 28, a fluid port 30, a high pressure relief valve 32, a low pressure relief valve 34, a variable pressure relief valve 36, a first check valve 38, a second check valve 40, a valve manifold 42, a distribution manifold 44, a pendant 46, a control circuit 48, a meter 50, a vent 52, and a vent line 54. The hydraulic circuit 12 includes a first pump supply line 56, a second pump supply line 58, a high pressure line 60, a high flow line 62, a combined flow line 64, a high flow return line 66, a tool extend line 68, a tool retract line 70, and a system return line 72. The tool 74 is driven by hydraulic fluid provided by the HPU 10 through the external hydraulic hose 76 a and the external hydraulic hose 76 b , and includes a tool piston 78 .

[0032] The fluid reservoir 14 is configured to store a source of hydraulic fluid for powering the tool 74. A vent line 54 extends from the fluid reservoir 14 to the vent 52. The vent 52 maintains the fluid reservoir 14 at a relatively low pressure or atmospheric pressure. A first pump supply line 56 extends from the fluid reservoir 14 to the pump 16. A filter 22a is disposed on the first pump supply line 56 and is configured to remove contaminants from the hydraulic fluid before the hydraulic fluid enters the pump 16. A second pump supply line 58 extends from the fluid reservoir 14 to the pump 18. A filter 22b is disposed on the second pump supply line 58 and is configured to remove contaminants from the hydraulic fluid before the hydraulic fluid enters the pump 18. The first pump supply line 56 and the second pump supply line 58 may be integrally formed with the fluid reservoir 14 so that the pumps 16 and 18 are mounted directly to the fluid reservoir 14.

[0033] The control circuit 48 is in communication with the transducer 24, the two-way valve 26, the four-way valve 28, and the suspension 46. The control circuit 48 is electrically connected to the transducer 24, the two-way valve 26, and the four-way valve 28, and the control circuit 48 may have any suitable configuration for controlling the operation of the two-way valve 26 and the four-way valve 28, for collecting data, for processing data, etc. In some examples, the control circuit 48 includes a memory configured to store software that, when executed by the control circuit, enables the control circuit 48 to control the position of the two-way valve 26 and the four-way valve 28. The memory may also store information during operation, such as a threshold pressure level. The memory may include any suitable storage medium, such as volatile and / or non-volatile memory included in any other desired options. The control circuit 48 may further include a processor, such as a microprocessor, a controller, a digital signal processor (DSP), an application specific integrated circuit (ASIC), a field programmable gate array (FPGA), or other equivalent discrete or integrated circuits. The processor may execute the software stored in the memory.

[0034] The control circuit 48 can be implemented as a plurality of discrete circuit subassemblies. For example, a discrete control circuit subassembly can receive hydraulic pressure data from the transducer 24 and control the position of the two-way valve 26 based on the hydraulic pressure data. The transducer 24 can be any suitable configuration for sensing the hydraulic pressure in the combined flow line 64, including an analog switch or an electronic sensor. One or more other discrete control circuit subassemblies can receive commands from the pendant 46 to control the position of the four-way valve 28 independently of the control circuit 48 that controls the position of the two-way valve 26. The pendant 46 is configured to provide commands to the control circuit 48 via wired or wireless communication.

[0035] Pump 16 is a high pressure pump that is configured to pump at a relatively high pressure and a relatively low volume of fluid relative to pump 18. In contrast, pump 18 is a high flow pump that is configured to pump at a relatively low pressure and a relatively high volume of fluid relative to pump 16. For example, pump 16 may be configured to pump fluid at about 70 MPa (about 10,000 psi), while pump 18 may be configured to pump fluid at about 25 MPa (about 3,500 psi). Pumps 16 and 18 are mechanically connected to a drive mechanism, such as drive mechanism 86 (in FIG. Figure 3 ), so that pump 16 and pump 18 are driven simultaneously. Thus, HPU 10 is configured so that pump 16 and pump 18 continuously drive hydraulic fluid through hydraulic circuit 12 when HPU 10 is operating.

[0036] The high pressure line 60 extends downstream from the pump 16 to the upstream side of the first check valve 38 and the downstream side of the second check valve 40. The high flow line 62 extends downstream from the pump 18 to the upstream side of the two-way valve 26 and the second check valve 40. The high flow line 62 extends into the high pressure line 60 upstream of the first check valve 38, and the combined high flow line 62 and high pressure line 60 form a combined flow line 64. It should be understood that the high pressure line 60 and the combined flow line 64 form part of a single flow line located between the pump 16 and the four-way valve 28. Therefore, the pump 16 provides a first flow of hydraulic fluid to the combined flow line 64. The first check valve 38 and the second check valve 40 can have any suitable configuration for preventing reverse flow to the pump 16 and the pump 18.

[0037] The variable pressure relief valve 36 is configured to control the maximum hydraulic fluid pressure within the hydraulic circuit 12. When the hydraulic fluid pressure is above the set maximum pressure level of the variable pressure relief valve 36, the variable pressure relief valve 36 releases the hydraulic fluid output from one or both of the pumps 16 and 18 to the system return line 72. The set maximum pressure level of the variable pressure relief valve 36 may be mechanically adjustable. For example, to adjust the set maximum pressure level, a user may adjust the nominal tension on a spring that presses a ball against a valve seat of the variable pressure relief valve 36.

[0038] Based on the hydraulic pressure level in the combined flow line 64, the two-way valve 26 is controlled between an open state and a closed state by the control circuit 48. The two-way valve 26 is an electrically actuated valve. In some examples, the two-way valve 26 is a solenoid-operated valve. For example, the control circuit 48 can activate and deactivate a solenoid so that an internal component (such as a flap or a valve core) is configured to transport hydraulic fluid through the valve body of the two-way valve 26 to switch between an open position and a closed position. A high-flow return line 66 extends from the two-way valve 26 to a system return line 72. The system return line 72 is also arranged downstream of the variable pressure relief valve 36, the high-pressure relief valve 32, the low-pressure relief valve 34, and the four-way valve 28. The system return line 72 is configured to return the hydraulic fluid to the fluid reservoir 14 and / or to the oil cooler 20, and then return to the fluid reservoir 14. The oil cooler 20 is configured to remove excess heat from the hydraulic fluid.

[0039] The combined flow line 64 extends downstream from the first check valve 38 to the four-way valve 28, the high pressure relief valve 32 and the pressure gauge 50. The transducer 24 is connected to the combined flow line 64 and is configured to sense the hydraulic pressure in the combined flow line. The transducer 24 provides hydraulic pressure data to the control circuit 48. The high pressure relief valve 32 is connected to the combined flow line 64 upstream of the four-way valve 28. The high pressure relief valve 32 is a safety valve that is configured to release the hydraulic fluid to the system return line 72 when the hydraulic fluid pressure in the combined flow line 64 exceeds the maximum system operating pressure. In some examples, when the hydraulic fluid pressure exceeds about 75 MPa (about 10850 psi), the high pressure relief valve 32 is configured to release the hydraulic fluid flow to the system return line 72. The pressure gauge 50 is connected to the combined flow line 64 and is configured to provide a visual indication of the hydraulic fluid pressure to the user. The pressure gauge 50 can be any suitable configuration for providing a visual indication such as by an analog readout or a digital readout.

[0040] The four-way valve 28 is connected to the combined flow line 64 and receives hydraulic fluid from the combined flow line 64. The four-way valve 28 can be an electrically actuated valve. For example, the four-way valve 28 can be a solenoid-operated valve. The tool extension line 68 extends from the four-way valve 28 to the fluid port 30. An external hydraulic hose 76a extends from the fluid port 30 to the tool 74. The tool retraction line 70 extends from the four-way valve 28 to the low pressure relief valve 34 and the fluid port 30. The external hydraulic hose 76b extends from the fluid port 30 to the tool 74. In the extended state, the four-way valve 28 delivers hydraulic fluid from the combined flow line 64 to the tool extension line 68 and delivers hydraulic fluid from the tool retraction line 70 to the system return line 72. In the retracted state, the four-way valve 28 delivers hydraulic fluid from the combined flow line 64 to the tool retraction line 70 and from the tool extension line 68 to the system return line 72. The tool piston 78 is arranged in the tool 74 and is driven alternately through an extension stroke and a retraction stroke, depending on the position of the four-way valve 28 .

[0041] The low-pressure relief valve 34 is installed on the tool retraction line 70 downstream of the four-way valve 28. The low-pressure relief valve 34 is configured to limit the hydraulic fluid pressure provided to the tool 74 during the retraction stroke of the tool piston 78. When the hydraulic fluid pressure exceeds the preset limit of the low-pressure relief valve 34, the low-pressure relief valve 34 releases the hydraulic fluid to the system return line 72. For example, such as about 10 MPa (about 1500 psi) required for the retraction of the tool piston 78.

[0042] During operation, pumps 16 and 18 continuously draw hydraulic fluid from fluid reservoir 14 and drive the hydraulic fluid through hydraulic circuit 12. Control circuit 48 positions four-way valve 28 based on commands received from pendant 46, and four-way valve 28 directs hydraulic fluid to tool 74. Tool piston 78 travels through an extension stroke and a retraction stroke to perform work. The speed of tool 74 is proportional to the flow rate of hydraulic fluid flowing to tool 74, and the torque of tool 74 is proportional to the hydraulic fluid pressure provided to tool 74. During the extension stroke, a low flow rate at a relatively high pressure (about 70 MPa (about 10,000 psi)) is desired to produce high torque movement of tool 74. During the retraction stroke, a high flow rate at a relatively low pressure (about 25 MPa (about 3,500 psi)) is desired for fast tool 74 movement.

[0043] To cause the tool piston 78 to enter the extension stroke, the user presses the trigger device of the pendant 46, which causes the pendant 46 to generate an extension command and provide it to the control circuit 48. Based on the extension command, the control circuit 48 switches the four-way valve 28 to the extension state, so that the hydraulic fluid from the combined flow line 64 is provided to the tool extension line 68. The hydraulic fluid flows through the tool extension line 68, flows through the fluid port 30, and is provided to the tool 74 through the external hydraulic hose 76a. The hydraulic fluid drives the tool piston 78 through the extension stroke.

[0044] A limited amount of electrical current (approximately 20 amps) is typically available at a job site. The motors of the HPU 10 that drive the pumps 16 and 18, such as the motor 84 (in Figure 2A-2B 1 (best seen in FIG. 1 ) is configured to use only limited electrical current. Due to limited electrical power resources, the HPU 10 utilizes pumps 16 and pumps 18 to balance the needs of high flow and high pressure without overwhelming the motor. During the extension stroke, hydraulic fluid is provided to the tool 74 at a relatively high pressure of about 70 MPa (about 10,000 psi) to produce high torque movement of the tool 74. When the required hydraulic pressure is above a threshold pressure level, such as about 20 MPa-28 MPa (about 3,000-4,000 psi), then the motor may be unable to overload pump 18, which is a high flow pump that pumps the high pressure hydraulic flow generated by pump 16. In one example, the threshold level is about 24 MPa (about 3,400 psi). As discussed above, pumps 16 and 18 are mechanically connected so that pumps 16 and pumps 18 pump hydraulic fluid simultaneously. Therefore, during the extension stroke of the tool piston 78, pump 18 cannot be separated from pump 16 or otherwise deactivated.

[0045] As the tool 74 encounters resistance, the hydraulic fluid pressure in the hydraulic circuit 12 continues to rise throughout the extension stroke. Initially, the two-way valve 26 is in a closed state, so that hydraulic fluid from both the pump 16 and the pump 18 is provided to the combined flow line 64. The transducer 24 senses the hydraulic fluid pressure in the combined flow line 64 and provides hydraulic pressure data to the control circuit 48. The control circuit 48 is configured to control the position of the two-way valve 26 based on the comparison result of the hydraulic fluid data and the threshold pressure level. The control circuit 48 switches the two-way valve 26 to an open state and maintains it in an open state, wherein the comparison result of the hydraulic fluid data and the threshold pressure level indicates that the hydraulic fluid pressure is at or above the threshold level. As discussed above, the two-way valve 26 can be a solenoid-operated valve, so that the control circuit 48 actuates the two-way valve 26 by directing electricity to the two-way valve 26. It should be understood that the threshold level can be set at any desired level up to and including the maximum hydraulic fluid pressure capacity of the pump 18.

[0046] The control circuit 48 compares the hydraulic fluid pressure data to a threshold level. The control circuit 48 switches the two-way valve 26 to an open state based on the comparison result indicating that the hydraulic fluid pressure in the combined flow line 64 is at or above the threshold level. With the two-way valve 26 in the open state, hydraulic fluid from the pump 18 flows directly to the high flow return line 66 and flows downstream to the system return line 72. From the system return line 72, the hydraulic fluid from the pump 18 flows through the oil cooler 20 and returns to the fluid reservoir 14. When the fluid reservoir 14 is maintained at a relatively low pressure or atmospheric pressure, the pump 18 experiences a relatively small resistance of the two-way valve 26 in the open state. Moreover, the two-way valve 26 is maintained in the open state, so that the pump 18 does not need to accumulate the hydraulic fluid pressure in the high flow line to a sufficiently high level to switch the two-way valve 26 to the open state and release the hydraulic pressure. Since the hydraulic fluid pressure on the downstream side of the second check valve 40 generated by the pump 16 is higher than the hydraulic fluid pressure on the upstream side of the second check valve 40, the pump 18 is prevented from driving fluid into the combined flow line 64. The open two-way valve 26 reduces the load on the pump 18 and reduces energy losses (such as losses due to heat generation) in the hydraulic circuit 12. Therefore, less cooling of the hydraulic fluid is required, and the oil cooler 20 can be less robust. The two-way valve 26 remains in the open state until the control circuit 48 switches the two-way valve 26 back to the closed state.

[0047] Pump 18 continues to drive hydraulic fluid through the open two-way valve 26 as pump 16 drives hydraulic fluid to the combined flow line 64 and downstream to the four-way valve 28. The four-way valve 28 directs the hydraulic fluid from the combined flow line 64 to the tool extension line 68, and the hydraulic fluid flows through the tool extension line 68 and the external hydraulic hose 76a to the tool 74.

[0048] The user releases the trigger of the pendant 46 to initiate a retraction stroke of the tool piston 78. In one example, the pendant 46 generates a retraction command based on the release of the trigger and provides the retraction command to the control circuit 48. In another example, releasing the trigger causes the pendant 46 to stop providing an extension command. Based on the user releasing the trigger, such as in response to the retraction command, the control circuit 48 switches the four-way valve 28 to the retraction position. With the four-way valve 28 in the retracted state, the four-way valve directs the flow of hydraulic fluid to the tool 74 to cause the tool piston 78 to travel through the retraction stroke.

[0049] The hydraulic fluid that drives the tool piston 78 through the extension stroke flows upstream through the external hydraulic hose 76a and the tool extension line 68 to the four-way valve 28. The four-way valve 28 directs the hydraulic fluid from the tool extension line 68 to the system return line 72, where the hydraulic fluid returns to the fluid tank 92. With the four-way valve 28 in the retracted state, the four-way valve 28 delivers the hydraulic fluid flow from the combined flow line 64 to the tool retract line 70. The hydraulic fluid flows downstream through the tool retract line 70 to the fluid port 30 and flows downstream through the external hydraulic hose 76b to the tool 74. The low-pressure relief valve 34 is arranged on the tool retract line 70 to maintain the hydraulic fluid pressure available for the retraction stroke below the desired level for retraction of the tool piston 78, such as about 10 MPa (about 1,500 psi).

[0050] Based on a comparison of the hydraulic fluid data from the transducer 24 indicating that the hydraulic pressure in the combined flow line 64 is below the threshold pressure level with the threshold pressure level, the control circuit 48 switches the two-way valve 26 to the closed state. With the two-way valve 26 in the closed state, both the pump 16 and the pump 18 provide hydraulic fluid to the combined flow line 64 and thus provide the hydraulic fluid downstream to the tool retract line 70 through the four-way valve 28. The hydraulic fluid flows to the tool 74 and drives the tool piston 78 through the retract stroke. Based on the control circuit 48 receiving another extend command, such as when the user again presses the trigger device of the pendant 46, the control circuit 48 switches the four-way valve 28 back to the extend state.

[0051] The HPU 10 provides significant advantages. The pumps 16 and 18 balance high flow and high pressure demands without overwhelming the motors. The two-way valve 26 is an electrically actuated valve that remains open when the hydraulic fluid pressure is at or above a threshold level, directly connecting the output of the pump 18 to the reservoir and reducing the load on the pump 18. Maintaining the two-way valve 26 in an open state further reduces the load on the pump 18 compared to a mechanically actuated valve because the pump 18 does not need to build up pressure in the high flow line 62 to a level sufficient to open the mechanically actuated valve. Maintaining the two-way valve 26 in an open state further reduces energy losses in the hydraulic circuit 12, thereby requiring less hydraulic fluid cooling, which allows the HPU 10 to use a less robust oil cooler 20, thereby saving manufacturing and operating costs.

[0052] Figure 2A is a first isometric view of the HPU 10 . Figure 2B is a second isometric view of the HPU 10 from the opposite side of the HPU 10 . Figure 2C yes Figure 2B A magnified view of the detail Z. Figure 2D If the four-way valve 28 is removed, Figure 2BA magnified view of the detail Z. Figures 2A-2D will be discussed together. HPU 10 includes a fluid reservoir 14, a pump 16 ( Figure 2A )、Pump 18( Figure 2A )、Two-way valve 26( Figure 2C-2D )、Four-way valve 28( Figure 2B-2C )、Fluid port 30( Figure 2A )、valve manifold 42( Figure 2A )、frame 80、control unit 82( Figure 2A )、motor 84、driving mechanism 86、fan guard 88、first cover 90a( Figure 2A ) and the second cover 90b ( Figure 2A ). Fluid reservoir 14 includes fluid box 92, cover 94 and gasket 96. Pump 16 includes hydraulic cylinder body 98, and pump 18 includes hydraulic cylinder body 100.

[0053] The frame 80 surrounds and supports the other components of the HPU 10. The frame 80 may be any suitable material for providing structural integrity to the HPU 10. For example, the frame 80 may be formed from metal tubing. The fluid reservoir 14 is disposed on the frame 80. The fluid tank 92 is configured to store fluid for use with tools such as the tool 74 ( Figure 1 ) is a source of hydraulic fluid for powering hydraulically driven tools. A cover 94 is disposed on the fluid box 92 and encloses a source of liquid fluid within the fluid box 92. A gasket 96 is disposed between the cover 94 and the fluid box 92 and is configured to form a seal between the cover 94 and the fluid box 92. In some examples, the gasket 96 is a long integral seal that matches the edge geometry of the fluid box 92.

[0054] The control unit 82 includes a control circuit 48 (such as Figure 1 ) and mounted on the frame 80. The fan shroud 88 is disposed above the control unit 82 and encloses a cooler (such as the oil cooler 20 (such as the oil cooler 20) configured to remove excess heat from the hydraulic fluid. Figure 1 The motor 84 is mounted between the fan shroud 88 and the drive mechanism 86 and is configured to provide power to both the cooler and the drive mechanism 86. The motor 84 may have any suitable configuration for providing power to the drive mechanism 86, such as, for example, an electromagnetic rotary motor or a pneumatic motor. The drive mechanism 86 converts the rotational output of the motor 84 into a linear reciprocating motion to power both the pump 16 and the pump 18.

[0055] Pump 16 and pump 18 are mounted on one side of HPU 10 and attached to fluid tank 92 and valve manifold 42. Pump 16 and pump 18 are configured to drive hydraulic fluid under pressure. Pump 16 may be a high pressure pump configured to pump at a relatively low fluid volume relative to pump 18, while pump 18 may be a high flow pump configured to pump at a relatively low pressure relative to pump 16. Both pump 16 and pump 18 are configured to draw hydraulic fluid from fluid tank 92 and drive the hydraulic fluid downstream to four-way valve 28 and out of fluid port 30, where the hydraulic fluid is delivered to a hydraulically driven tool (such as tool 74 ( Figure 1 )). In some examples, both pump 16 and pump 18 are dual displacement pumps. Hydraulic cylinder body 98 encloses the pumping elements of pump 16 and is directly mounted to fluid tank 92 and valve manifold 42. Similarly, hydraulic cylinder body 100 encloses the pumping elements of pump 18 and is directly mounted to fluid tank 92 and valve manifold 42. It should be understood that hydraulic cylinder body 98 and hydraulic cylinder body 100 do not necessarily have a cylindrical outer profile; instead, each of hydraulic cylinder body 98 and hydraulic cylinder body 100 includes a cylindrical internal void within which a piston reciprocates to pump fluid. First cover 90 encloses the connection between pump 16 and drive mechanism 86. Second cover 90 encloses the connection between pump 18 and drive mechanism 86. In some examples, first cover 90 and second cover 90 may be integrally formed as a single component.

[0056] As mentioned above about Figure 1 As discussed, the four-way valve 28 and the two-way valve 26 are configured to deliver hydraulic fluid through a hydraulic circuit (such as the hydraulic circuit 12 ( Figure 1 )). The four-way valve 28 is mounted on the valve manifold 42 of the HPU 10, and the four-way valve 28 is modular and accessible from the outside or the HPU 10. The four-way valve 28 is an electrically actuated valve. In some examples, the four-way valve 28 is a solenoid-operated valve. The two-way valve 26 is mounted on the valve manifold 42 of the HPU 10, and the two-way valve 26 is modular and accessible from the outside of the HPU 10. The two-way valve 26 is an electrically actuated valve. In some examples, the two-way valve 26 is a solenoid-operated valve. The valve manifold 42 delivers hydraulic fluid from the pump 16 and the pump 18 to the four-way valve 28, and further delivers hydraulic fluid from the pump 18 to the two-way valve 26. The valve manifold 42 also delivers hydraulic fluid from the four-way valve 28 to the fluid port 30.

[0057] During operation, motor 84 provides power to drive mechanism 86, and drive mechanism 86 drives pump 16 and pump 18 simultaneously. Pump 16 and pump 18 draw hydraulic fluid from fluid tank 92 and drive the hydraulic fluid downstream through hydraulic circuit to four-way valve 28. Four-way valve 28 delivers the hydraulic fluid downstream through fluid port 30 to a hydraulically driven tool. As discussed above, based on the hydraulic fluid pressure within the hydraulic circuit, two-way valve 26 is controlled between an open state and a closed state. Such as control circuit 48 ( Figure 1 ) is configured to switch the two-way valve 26 to an open state so that the two-way valve 26 delivers the output of the pump 18 back to the fluid tank 92 when the hydraulic fluid pressure reaches and / or exceeds the threshold level. Switching the two-way valve to an open state reduces the work of the pump 18, which reduces the load on the motor 84.

[0058] Figure 3 is along Figure 2A 3-3 in the cross-sectional view. The drive mechanism 86 includes a pinion 102, a drive gear 104a, a drive gear 104b, a connecting rod 106a, a connecting rod 106b, a sleeve 108a and a sleeve 108b. The drive gear 104a includes an eccentric drive pin 110a. The drive gear 104b includes an eccentric drive pin 110b. The sleeve 108a includes a slot 112a, and the sleeve 108b includes a slot 112b. The pump 16 includes a hydraulic cylinder body 98, a piston 114, a first dynamic seal 116, a second dynamic seal 118, an upstream fluid chamber 120 and a downstream fluid chamber 122. The piston 114 includes a piston head 124, a piston rod 126 and a piston valve 128. The piston rod 126 includes a first diameter portion 130 and a second diameter portion 132. The pump 18 includes a cylinder body 100, a piston 134, a first dynamic seal 136, a second dynamic seal 138, an upstream fluid chamber 140, and a downstream fluid chamber 142. The piston 134 includes a piston head 144, a piston rod 146, and a piston valve 148. The piston rod 146 includes a first diameter portion 150 and a second diameter portion 152.

[0059] The pinion 102 is driven by a motor (such as motor 84 ( Figure 2A-2B)) is driven and connected to both the drive gear 104a and the drive gear 104b. Therefore, the pinion 102 drives both the drive gear 104a and the drive gear 104b at the same time and at the same speed. The connecting rod 106a is installed on the eccentric drive pin 110a, and the sleeve 108a is attached to the connecting rod 106a. The connecting rod 106a and the eccentric drive pin 110a convert the rotation output of the drive gear 104a into the linear reciprocating motion of the sleeve 108a. The connecting rod 106b is installed on the eccentric drive pin 110b, and the sleeve 108b is attached to the connecting rod 106b. The connecting rod 106b and the eccentric drive pin 110b convert the rotation output of the drive gear 104b into the linear reciprocating motion of the sleeve 108b.

[0060] The hydraulic cylinder body 98 is directly mounted on the fluid tank 92 and the valve manifold 42. In some examples, the hydraulic cylinder body 98 can be formed by metal (such as aluminum or steel). The piston 114 is at least partially arranged in the hydraulic cylinder body 98 and is configured to drive the hydraulic fluid through the pump 16. The piston head 124 is arranged outside the hydraulic cylinder body 98 and is installed in the slot 112a of the sleeve 108a. The slot 112a passes through the bottom portion of the sleeve 108a and the front portion of the sleeve 108a. The sleeve 108a drives the piston 114 in a linear reciprocating manner through the connection of the piston head 124 and the slot 112a. The piston head 124 is configured to slide into and out of the slot 112a during the installation and removal of the pump 16 on the HPU 10. The piston rod 126 extends from the piston head 124 to the hydraulic cylinder body 98.

[0061] The hydraulic cylinder body 100 is directly mounted on the fluid tank 92 and the valve manifold 42. In some examples, the hydraulic cylinder body 100 can be formed by metal (such as aluminum or steel). The piston 134 is at least partially arranged in the hydraulic cylinder body 100 and is configured to drive the hydraulic fluid through the pump 18. The piston head 144 is installed in the slot 112b of the sleeve 108b. The slot 112b passes through the bottom portion of the sleeve 108b and the front portion of the sleeve 108b to receive the piston head 144. The sleeve 108b drives the piston 134 in a linear reciprocating manner through the connection of the piston head 144 and the slot 112b. The piston head 144 is configured to slide into and out of the slot 112b during the installation and removal of the pump 18 on the pump HPU 10. The piston rod 146 extends from the piston head 144 to the hydraulic cylinder body 100.

[0062] Eccentric drive pins 110a and 110b are circumferentially offset so that piston 114 moves out of phase with piston 134. In some examples, piston 114 moves 180 degrees out of phase with piston 134. Thus, when piston 114 is moving through an upstroke, piston 134 is moving through a downstroke, and when piston 114 is moving through a downstroke, piston 134 is moving through an upstroke.

[0063] A piston valve 128 is disposed within the piston 114. The piston valve 128 is shown as a ball seat check valve, but it should be understood that any suitable check valve may be disposed within the piston 114. An upstream fluid chamber 120 is disposed within the hydraulic cylinder body 98 on the upstream side of the piston 114. A downstream fluid chamber 122 is disposed between a first diameter portion 130 of the piston rod 126 and an inner surface of the hydraulic cylinder body 98. A first dynamic seal 116 is disposed between an inner surface of the hydraulic cylinder body 98 and a second diameter portion 132 of the piston rod 126. The first dynamic seal 116 separates the upstream fluid chamber 120 from the downstream fluid chamber 122. A second dynamic seal 118 is disposed between an inner cylindrical surface of the hydraulic cylinder body 98 and the first diameter portion 130 of the piston rod 126. The piston 114 is configured to move relative to the first dynamic seal 116 and the second dynamic seal 118 during reciprocating motion. However, it should be understood that one or both of the first dynamic seal 116 and the second dynamic seal 118 can be mounted on the piston 114 to move relative to the hydraulic cylinder body 98. In some examples, the first dynamic seal 116 and the second dynamic seal 118 are energized U-cup rings. However, it should be understood that the first dynamic seal 116 and the second dynamic seal 118 can have any desired configuration, such as alternating leather filler rings and polyurethane filler rings.

[0064] A piston valve 148 is disposed within the piston 134. The piston valve 148 is shown as a ball seat check valve, but it should be understood that any suitable check valve may be disposed within the piston 134. An upstream fluid chamber 140 is disposed within the hydraulic cylinder body 100 on the upstream side of the piston 134. A downstream fluid chamber 142 is disposed between a first diameter portion 150 of a piston rod 146 and an inner surface of the hydraulic cylinder body 100. A first dynamic seal 136 is disposed between an inner surface of the hydraulic cylinder body 100 and a second diameter portion 152 of the piston rod 146. The first dynamic seal 136 separates the upstream fluid chamber 140 from the downstream fluid chamber 142. A second dynamic seal 138 is disposed between an inner cylindrical surface of the hydraulic cylinder body 100 and a first diameter portion 150 of the piston rod 146. The first diameter portion 150 has a larger diameter than the second diameter portion 152. As shown, the first diameter portion 150 is formed separately from the second diameter portion 152 and is attached to the second diameter portion 152. However, it should be understood that the first diameter portion 150 can be integrally formed with the second diameter portion 152. The piston 134 is configured to move relative to the first dynamic seal 136 and the second dynamic seal 138 during reciprocating motion. However, it should be understood that one or both of the first dynamic seal 136 and the second dynamic seal 138 can be mounted on the piston 134 to move relative to the hydraulic cylinder body 100. In some examples, the first dynamic seal 136 and the second dynamic seal 138 include alternating leather packing rings and polyurethane packing rings. However, it should be understood that the first dynamic seal 116 and the second dynamic seal 118 can have any desired configuration, such as an energized U-cup seal.

[0065] During operation, the piston 114 is driven in a linear reciprocating motion by the drive mechanism 86. During the upstroke, the hydraulic fluid in the downstream fluid chamber 122 forces the piston valve 128 to close, so that the hydraulic fluid in the downstream fluid chamber 122 is prevented from flowing back into the upstream fluid chamber 120. When the piston 114 is pulled through the upstroke, the second diameter portion 132 reduces the volume of the downstream fluid chamber 122, and the second diameter portion 132 drives the hydraulic fluid downstream out of the downstream fluid chamber 122. The upstroke also increases the volume of the upstream fluid chamber 120, thereby creating a suction state that draws hydraulic fluid from the fluid tank 92 into the upstream fluid chamber 120. During the downstroke, the hydraulic fluid in the upstream fluid chamber 120 causes the piston valve 128 to switch to an open state. The hydraulic fluid in the upstream fluid chamber 120 flows through the piston valve 128 into the second diameter portion 132 and into the downstream fluid chamber 122. During the downstroke, hydraulic fluid flowing into the downstream fluid chamber 122 also flows downstream out of the downstream fluid chamber 122. Thus, the pump 16 outputs a flow of hydraulic fluid during both the upstroke and the downstroke.

[0066] Similar to the piston 114, the piston 134 is driven in a linear reciprocating manner by the drive mechanism 86. During the upward stroke, the hydraulic fluid in the downstream fluid chamber 142 forces the piston valve 148 to close, so that the hydraulic fluid in the downstream fluid chamber 142 is prevented from flowing back into the upstream fluid chamber 140. The second diameter portion 152 reduces the volume of the downstream fluid chamber 142 to drive the hydraulic fluid out of the downstream fluid chamber 142 downstream. The upward stroke also increases the volume of the upstream fluid chamber 140, thereby creating a suction state that draws hydraulic fluid from the fluid tank 92 into the upstream fluid chamber 140. During the downward stroke, the hydraulic fluid in the upstream fluid chamber 140 causes the piston valve 148 to switch to an open state. The hydraulic fluid in the upstream fluid chamber 140 flows through the piston valve 148 into the second diameter portion 152 and into the downstream fluid chamber 142. During the downward stroke, the hydraulic fluid that flows into the downstream fluid chamber 142 also flows out of the downstream fluid chamber 142 downstream. Thus, the pump 18 outputs a flow of hydraulic fluid during both the upstroke and the downstroke.

[0067] Pump 18 has a higher volumetric output than pump 16. Upstream fluid chamber 140 has a larger volume than upstream fluid chamber 120, and downstream fluid chamber 142 has a larger volume than downstream fluid chamber 122. Additionally, first diameter portion 150 has a larger diameter than first diameter portion 130, and second diameter portion 152 has a larger diameter than second diameter portion 132. The relatively larger diameters of cylinder body 100 and piston 134 as compared to cylinder body 98 and piston 114 provide pump 18 with a relatively larger displacement than pump 16. Due to the smaller displacement of pump 16 as compared to pump 18, pump 16 provides a relatively higher pressure output than pump 18.

[0068] Pumps 16 and 18 are each double displacement pumps, which provides significant advantages. Pumps 16 and 18 being double displacement pumps reduces pressure pulsations at lower pump cycle rates, which allows motor 84 to be run at a lower speed while maintaining smooth pressure delivery. Running motor 84 at a lower speed reduces power requirements and reduces wear on HPU 10, and thereby reduces maintenance costs.

[0069] Figure 41 is a side cross-sectional view of the pump 16 showing the connection of the pump 16 and the HPU 10. The pump 16, valve manifold 42, fluid tank 92 and inlet valve 154 of the HPU 10 are shown. The sleeve 108a of the drive mechanism 86 is shown, and the sleeve 108a includes a slot 112a. The pump 16 includes a hydraulic cylinder body 98, a piston 114, a first dynamic seal 116, a second dynamic seal 118, an upstream fluid chamber 120 and a downstream fluid chamber 122. The piston 114 includes a piston head 124, a piston rod 126 and a piston valve 128. The piston rod 126 includes a first diameter portion 130 and a second diameter portion 132. The hydraulic cylinder body 98 includes an upper mounting portion 156, a lower mounting portion 158, a fluid inlet 160 and a fluid outlet 162. The upper mounting portion 156 includes an upper surface 164. The lower mounting portion 158 includes a lower surface 166. The fluid tank 92 includes a supply port 168 and a tank sealing groove 170 . The valve manifold 42 includes a receiving port 172 and a manifold sealing groove 174 .

[0070] The hydraulic cylinder body 98 is mounted on the outside of the fluid tank 92 and on the outside of the valve manifold 42. The lower mounting portion 158 is attached to the fluid tank 92, wherein the lower surface 166 abuts the fluid tank 92. The lower surface 166 is a flat surface. A lower seal 176 is disposed in a tank seal groove 170 between the lower surface 166 and the fluid tank 92. The lower seal 176 can be any suitable seal for sealing the joint between the lower surface 166 and the fluid tank 92. In some examples, the lower seal 176 is an O-ring, such as an elastomeric O-ring. The supply port 168 extends within the fluid tank 92 and is aligned with the fluid inlet 160 in the hydraulic cylinder body 98. In some examples, the supply port 168 is a first pump supply line 56 ( Figure 1 ). The fluid inlet 160 receives hydraulic fluid from the supply port 168. The fluid inlet 160 includes a 90 degree bend between the inlet valve 154 and the upstream fluid chamber 120 to divert the hydraulic fluid from the supply port 168 into the upstream fluid chamber 120.

[0071] The inlet valve 154 extends from the supply passage into the fluid inlet 160. The inlet valve 154 is a normally closed valve, and the inlet valve 154 is configured to prevent hydraulic fluid from flowing back from the fluid inlet 160 and the upstream fluid chamber into the fluid tank 92. During the upward stroke of the piston 114, the suction force generated in the upstream fluid chamber 120 switches the inlet valve 154 to an open state, so that hydraulic fluid can flow from the supply port 168 into the fluid inlet 160. As shown, the inlet valve 154 is a poppet valve. However, it should be understood that any suitable type of check valve for preventing backflow from the fluid inlet 160 can be used. For example, the inlet valve 154 can be a ball check valve, which includes a spring that biases the ball into a closed state.

[0072] The upper mounting portion 156 is attached to the valve manifold 42 by the upper surface 164 abutting the valve manifold 42. The upper surface 164 is a flat surface. An upper seal 178 is disposed in the manifold seal groove 174 between the upper surface 164 and the valve manifold 42. The upper seal 178 can be any suitable seal for sealing the joint between the upper mounting portion 156 and the valve manifold 42. In some examples, the upper seal 178 is an O-ring, such as an elastomeric O-ring. The receiving port 172 extends within the valve manifold 42 and forms a high pressure line 60 ( Figure 1 ). The fluid outlet 162 extends through the upper surface 164 and is aligned with the receiving port 172. The fluid outlet 162 is configured to provide hydraulic fluid from the downstream fluid chamber 122 to the supply port 168.

[0073] During operation, the piston 114 is driven in a linear reciprocating manner through the sleeve 108a due to the connection of the piston head 124 and the slot 112a. During the upward stroke of the piston 114, the piston valve 128 is forced into a closed state by the hydraulic fluid in the downstream fluid chamber 122. The second diameter portion 132 of the piston rod 126 drives the hydraulic fluid downstream out of the downstream fluid chamber 122, to the fluid outlet 162, and into the receiving port 172 of the valve manifold 42. At the same time, a suction state is formed in the upstream fluid chamber 120, which causes the inlet valve 154 to switch to open and draw hydraulic fluid from the fluid tank 92 through the supply port 168, the inlet valve 154 and the fluid inlet 160 into the upstream fluid chamber 120. During the downward stroke of the piston 114, the second diameter portion 132 moves downward into the upstream fluid chamber 120, and the hydraulic fluid in the upstream fluid chamber 120 causes the piston valve 128 to switch to an open state. The inlet valve 154 returns to a closed state. The hydraulic fluid in the upstream fluid chamber 120 flows through the piston valve 128 into the downstream fluid chamber 122 and continues to flow downstream to the fluid outlet 162 and the receiving port 172 .

[0074] The fluid inlet 160, upper surface 164, lower surface 166, and piston 114 facilitate quick installation of the pump 16 on the exterior of the HPU 10. The upper surface 164 and the lower surface 166 are flat surfaces that abut flat surfaces on the valve manifold 42 and the fluid tank 92, respectively. The upper seal 178 is the only seal required at the junction of the upper surface 164 and the valve manifold 42. The lower seal 176 is the only seal required at the junction of the lower surface 166 and the fluid tank 92. Therefore, installing the hydraulic cylinder body 98 on the HPU 10 involves positioning the upper seal 178 in the manifold seal groove 174, positioning the lower seal 176 in the tank seal groove 170, and positioning the hydraulic cylinder body 98 on the valve manifold 42 and the fluid tank 92 and attaching the hydraulic cylinder body 98 to the valve manifold 42 and the fluid tank 92. In addition, the piston 114 is connected to the sleeve 108a by sliding the piston head 124 into the slot 112a. Therefore, the installation of the hydraulic cylinder body 98 does not involve complicated sealing arrangements or accessories. The fluid inlet 160 includes a 90 degree bend that diverts the fluid from the supply port 168 into the upstream fluid chamber 120, thereby allowing the pump 16 to be mounted vertically outside the HPU 10.

[0075] Figure 5 1 is a side cross-sectional view showing the connection of the pump 18 and the HPU 10. The pump 18, the second check valve 40, the valve manifold 42, the fluid tank 92 and the inlet valve 180 of the HPU 10 are shown. The sleeve 108b of the drive mechanism 86 is shown, and the sleeve 108b includes a slot 112b. The pump 18 includes a hydraulic cylinder body 100, a piston 134, a first dynamic seal 136, a second dynamic seal 138, an upstream fluid chamber 140 and a downstream fluid chamber 142. The piston 134 includes a piston head 144, a piston rod 146 and a piston valve 148. The piston rod 146 includes a first diameter portion 150 and a second diameter portion 152. The hydraulic cylinder body 100 includes an upper mounting portion 182, a lower mounting portion 184, a fluid inlet 186 and a fluid outlet 188. The upper mounting portion 182 includes an upper surface 190. The lower mounting portion 184 includes a lower surface. The fluid tank 92 includes a supply port 194 and a tank sealing groove 196 . The valve manifold 42 includes a receiving port 198 and a manifold sealing groove 200 .

[0076] The hydraulic cylinder body 100 of the pump 18 is mounted outside the fluid tank 92 and outside the valve manifold 42. The lower mounting portion 184 is attached to the fluid tank 92 with the lower surface 192 abutting the fluid tank 92b. The lower surface 192 is a flat surface. The lower seal 202 is arranged in the tank seal groove 196 between the lower surface 192 and the fluid tank 92. The lower seal 202 can be any suitable seal for sealing the joint between the lower mounting portion 184 and the fluid tank 92. For example, the lower seal 202 can be an O-ring, such as an elastomeric O-ring. The supply port 194 extends within the fluid tank 92 and is aligned with the fluid inlet 186 in the hydraulic cylinder body 100. In some examples, the supply port 194 is a second pump supply line 58 ( Figure 1 ). The fluid inlet 186 receives hydraulic fluid from the supply port 194. The fluid inlet 186 includes a 90 degree bend between the inlet valve 180 and the upstream fluid chamber 140 to divert the hydraulic fluid into the upstream fluid chamber 140.

[0077] The inlet valve 180 extends from the supply port 194 and enters the fluid inlet 186. The inlet valve 180 is a normally closed valve and is configured to prevent hydraulic fluid from flowing back from the fluid inlet 186 and the upstream fluid chamber 140 into the fluid tank 92. During the upward stroke of the piston 134, the suction force generated in the upstream fluid chamber 140 switches the inlet valve 180 to an open state, so that hydraulic fluid can flow from the supply port 194 into the fluid inlet 186. As shown, the inlet valve 180 is a poppet valve. However, it should be understood that any suitable type of check valve for preventing backflow from the fluid inlet 186 can be used. For example, the inlet valve 180 can be a ball check valve, which includes a spring that biases the ball into a closed state.

[0078] The upper mounting portion 182 is attached to the valve manifold 42 by the upper surface 190 abutting the valve manifold 42. The upper surface 190 is a flat surface. An upper seal 204 is disposed in the manifold seal groove 200 between the upper surface 190 and the valve manifold 42. The upper seal 204 may be any suitable seal for sealing the joint between the upper mounting portion 182 and the valve manifold 42. For example, the upper seal 204 may be an O-ring, such as an elastomeric O-ring. The receiving port 198 extends within the valve manifold 42 and forms a high flow line 62 ( Figure 1 The fluid outlet 188 is aligned with the receiving port 198 and is configured to supply hydraulic fluid from the downstream fluid chamber 142 to the supply port 194. The second check valve 40 is disposed in the receiving port 198 and is configured to prevent hydraulic fluid from flowing back to the pump 18.

[0079] During operation, the piston 134 is driven in a linear reciprocating manner through the sleeve 108b due to the connection of the piston head 144 and the slot 112b. During the upward stroke of the piston 134, the piston valve 148 is forced into a closed state by the hydraulic fluid in the downstream fluid chamber 142. The second diameter portion 152 of the piston rod 146 drives the hydraulic fluid downstream out of the downstream fluid chamber 142, to the fluid outlet 188, and into the receiving port 198 of the valve manifold 42. At the same time, a suction state is formed in the upstream fluid chamber 140, which causes the inlet valve 180 to switch to open and draw hydraulic fluid from the fluid tank 92 through the supply port 194, the inlet valve 180 and the fluid inlet 186 into the upstream fluid chamber 140. During the downward stroke of the piston 134, the second diameter portion 152 moves downward into the upstream fluid chamber 140, and the hydraulic fluid in the upstream fluid chamber 140 causes the piston valve 148 to switch to an open state. The inlet valve 180 returns to a closed state. The hydraulic fluid in the upstream fluid chamber 140 flows through the piston valve 148 into the downstream fluid chamber 142 and continues to flow downstream to the fluid outlet 188 and the receiving port 198 .

[0080] The fluid inlet 186, upper surface 190, lower surface 192, and piston 134 facilitate quick installation of the pump 18 on the exterior of the HPU 10. The upper surface 190 and the lower surface 192 are flat surfaces that abut flat surfaces on the valve manifold 42 and the fluid tank 92, respectively. The upper seal 204 is the only seal required at the junction of the upper surface 190 and the valve manifold 42. The lower seal 202 is the only seal required at the junction of the lower surface 192 and the fluid tank 92. Therefore, installing the hydraulic cylinder body 100 on the HPU 10 involves positioning the upper seal 204 in the manifold seal groove 200, positioning the lower seal 202 in the tank seal groove 196, and positioning the hydraulic cylinder body 100 on the valve manifold 42 and the fluid tank 92 and attaching the hydraulic cylinder body 100 to the valve manifold 42 and the fluid tank 92. In addition, the piston 134 is connected to the sleeve 108b by sliding the piston head 144 into the slot 112b. Therefore, the installation of the hydraulic cylinder body 100 does not involve complicated sealing arrangements or accessories. The fluid inlet 186 includes a 90 degree bend that turns the fluid from the supply port 194 to the upstream fluid chamber 140, thereby allowing the pump 18 to be mounted vertically outside the HPU 10.

[0081] Fig. 6A is a rear isometric view of the pump 16 . Figure 6B is a partial exploded view of the HPU 10 and the pump 16, wherein the pump 18 (in Figure 3 , 57 ) are removed. The fluid reservoir 14, pump 16, filter 22a, four-way valve 28, fluid port 30, valve manifold 42, frame 80, motor 84, drive mechanism 86, first cover 90a, lower seal 176 and upper seal 178 of HPU 10 are shown. Fluid reservoir 14 includes fluid box 92, cover 94 and gasket 96. Hydraulic cylinder body 98 and piston 114 of pump 16 are shown. Hydraulic cylinder body 98 includes upper mounting portion 156, lower mounting portion 158, fluid inlet 160 ( Fig. 6A ) and fluid outlet 162 ( Fig. 6A The upper mounting portion 156 includes an upper surface 164, an upper fastener opening 206, and an alignment opening 208 ( Fig. 6A ). The lower mounting portion 158 includes a lower surface 166 and a lower fastener opening 210. The piston head 124 and the piston rod 126 of the piston 114 are shown. The sleeve 108a and the sleeve 108b of the drive mechanism 86 are shown. The sleeve 108a includes a slot 112a, and the sleeve 108b includes a slot 112b. The valve manifold 42 includes a receiving port 172, a manifold sealing groove 174, a receiving port 198, a manifold sealing groove 200, an upper threaded opening 212, an alignment pin 214, an upper threaded opening 216, and an alignment pin 218. The fluid tank 92 includes a supply port 168, a tank sealing groove 170, a supply port 194, a tank sealing groove 196, a lower threaded opening 220, and a lower threaded opening 222.

[0082] The frame 80 supports the other components of the HPU 10. The motor 84 provides power to the drive mechanism 86. The drive mechanism 86 is connected to the pump 16 and the pump 18 and drives both the pump 16 and the pump 18. The fluid tank 92 is configured to store a source of hydraulic fluid. The supply port 168 and the supply port 194 extend into the fluid tank 92. The tank seal groove 170 extends around the supply port 168 and is configured to receive the lower seal 176. The filter 22a extends into the supply port 168 and is configured to filter any contaminants from the hydraulic fluid before the hydraulic fluid enters the pump 16. The lower threaded opening 220 extends into the fluid tank 92 near the supply port 168. The cover 94 is attached to the fluid tank 92 and closes the fluid tank 92. The gasket 96 is arranged between the fluid tank 92 and the cover 94.

[0083] The valve manifold 42 is mounted on the fluid tank 92 and is configured to deliver hydraulic fluid from the pump 16 to the four-way valve 28. The fluid port 30 extends from the valve manifold 42 and is configured to deliver hydraulic fluid to a tool 74 ( Figure 1 and from shown), tool 74 '( Fig.9A ) and tool 74″ ( Fig. 9B16 (shown in FIG. 16 ) or conveys hydraulic fluid from a hydraulically driven tool of the hydraulically driven tool. Receiving port 172 extends into valve manifold 42. Manifold seal groove 174 extends around receiving port 172 and is configured to receive upper seal 178. Upper threaded opening 212 extends into valve manifold 42. Alignment pin 214 and alignment pin 218 extend from valve manifold 42. Alignment pin 214 is configured to be received by alignment opening 208, which extends through upper surface 164 into upper mounting portion 156. When pump 16 is installed on HPU 10, alignment pin 214 ensures that upper fastener opening 206 is aligned with upper threaded opening 212 and lower fastener opening 210 is aligned with lower threaded opening 220. Alignment pin 214 is vertically offset from alignment pin 218 to prevent pump 16 from being accidentally installed in the position of pump 18. If pump 16 is positioned on alignment pins 218 , upper fastener openings 206 will not align with upper threaded openings 216 and lower fastener openings 210 will not align with lower threaded openings 222 , such that pump 16 cannot be secured to valve manifold 42 and fluid tank 92 .

[0084] The pump 16 is mounted on the outside of the HPU 10 and is connected to both the valve manifold 42 and the fluid tank 92. The upper mounting portion 156 engages with the valve manifold 42. The upper surface 164 is a flat surface adjacent to the valve manifold 42a. The upper fastener opening 206 extends through the upper mounting portion 156. The upper fastener 224 extends through the upper fastener opening 206 and enters the upper threaded opening 212. The upper fastener 224 includes threads configured to engage with threads in the upper threaded opening 212. Although the upper threaded opening 212 is described as a threaded opening, it should be understood that the upper threaded opening 212 and the upper fastener 224 can be engaged in any desired manner to secure the upper mounting portion 156 to the valve manifold 42, such as a pawl connection. The upper seal 178 is arranged in the manifold seal groove 174 between the upper surface 164 and the valve manifold 42.

[0085] The lower mounting portion 158 is engaged with the fluid tank 92. The lower surface 166 is a flat surface adjacent to the fluid tank 92. A lower fastener opening 210 extends through the lower mounting portion 158. A lower fastener 226 extends through the lower fastener opening 210 and into the lower threaded opening 220. The lower fastener 226 includes threads configured to engage with threads in the lower threaded opening 220. Although the lower threaded opening 220 is described as a threaded opening, it should be understood that the lower threaded opening 220 and the lower fastener 226 can be engaged in any desired manner to secure the lower mounting portion 158 to the fluid tank 92, such as a detent connection. The lower seal 176 is disposed in the tank seal groove 170 between the lower surface 166 and the fluid tank 92a.

[0086] The piston 114 at least partially extends out of the hydraulic cylinder body 98. The piston head 124 is configured to slide into the slot 112a of the sleeve 108a so that the sleeve 108a drives the piston 114 in a linear reciprocating manner due to the connection of the piston head 124 in the slot 112a. The second cover 90a closes the connection between the piston 114 and the sleeve 108a.

[0087] To unload the pump 16 from the HPU 10, the first cover 90a is removed to expose the connection between the piston 114 and the sleeve 108a. Although the first cover 90a is shown as being completely removed from the HPU 10, it should be understood that the first cover 90a can be pivoted relative to the HPU 10 to expose the connection between the piston 114 and the sleeve 108a. The upper fastener 224 is disengaged from the upper threaded opening 212, and the lower fastener 226 is disengaged from the lower threaded opening 220. With the upper fastener 224 and the lower fastener 226 removed, the pump 16 can be pulled away from the HPU 10 with a simple sliding motion. The sliding motion disconnects the four connections between the pump 16 and the HPU 10. Specifically, the sliding motion disconnects the dynamic mechanical connection between the piston head 124 and the slot 112a of the sleeve 108a, the static structural connection between the hydraulic cylinder body 98 and the valve manifold 42 and the fluid tank 92, the fluid connection between the supply port 168 and the fluid inlet 160, and the fluid connection between the fluid outlet 162 and the receiving port 172. Thus, removing the hydraulic cylinder body 98 disconnects the dynamic mechanical connection, the static structural connection, and both fluid connections. In some examples, the filter 22a is attached to the hydraulic cylinder body 98 so that when the pump 16 is removed, the filter 22a is removed from the fluid tank 92a.

[0088] The pump 16 is installed on the HPU 10 by reversing the process of unloading the pump 16. The upper seal 178 is positioned in the manifold seal groove 174, and the lower seal 176 is positioned in the tank seal groove 170. The pump 16 is slid onto the HPU 10 so that the alignment pin 214 is received in the alignment opening 208 and the piston head 124 is disposed in the slot 112a of the sleeve 108a. With the pump 16 disposed on the HPU 10, the upper fastener 224 is inserted through the upper fastener opening 206 and threaded into the upper threaded opening 212, and the lower fastener 226 is inserted through the lower fastener opening 210 and threaded into the lower threaded opening 220. All four connections: a dynamic mechanical connection, a static structural connection, and two fluid connections are thus established between the pump 16 and the HPU 10.

[0089] The connection of the pump 16 to the HPU 10 provides significant advantages. The alignment pin 214 ensures that the pump 16 is correctly positioned on the HPU 10. The alignment pins 214 and 218 prevent the pump 16 and the pump 18 from being installed in an incorrect position on the HPU 10. All mechanical and fluid connections between the pump 16 and the HPU 10 can be established by simply sliding the pump 16 onto the HPU 10 and attaching the pump 16 with the upper fasteners 224 and the lower fasteners 226. All mechanical and fluid connections can be interrupted by removing the upper fasteners 224 and the lower fasteners 226 and sliding the pump 16 out of the HPU 10. The pump 16 is mounted on the outside of the HPU 10 so that the pump 16 can be removed and serviced without having to remove the cover 94 from the fluid tank 92, which provides faster and more efficient maintenance. Repairing an internal pump requires removing the cover 94 and exposing the interior of the fluid tank 92 and the hydraulic fluid to contaminants. In addition, the built-in pump is usually immersed in the hydraulic fluid, which makes maintenance more cumbersome and complicated. Because the gasket 96 has a complex geometry to match the geometry of the fluid box 92, the gasket 96 is also difficult to replace, especially during field maintenance. Therefore, removing the gasket 96 may cause leakage and require repair in a repair shop. In addition, the fluid connection between the pump 16 and the HPU 10 is sealed by two seals, an upper seal 178 and a lower seal 176, which provides a simple and reliable seal and prevents leakage of the hydraulic fluid. The upper seal 178 and the lower seal 176 are usually elastomeric O-rings, which provide better sealing and placement and a smaller surface area than the gasket 96 between the fluid box 92 and the cover 94. In addition, no hose is required to connect the pump 16 to the HPU 10 because the hydraulic cylinder body 98 is directly mounted to both the fluid box 92 and the valve manifold 42, thereby increasing reliability and reducing complexity.

[0090] Figure 71 is a partial exploded view of the HPU 10 and the pump 18. The fluid reservoir 14, pump 16, pump 18, filter 22b, four-way valve 28, fluid port 30, valve manifold 42, frame 80, drive mechanism 86, first cover 90a, second cover 90b, lower seal 202, and upper seal 204 of the HPU 10 are shown. The fluid reservoir 14 includes a fluid tank 92, a cover 94, and a gasket 96. The hydraulic cylinder body 98 of the pump 16 is shown. The hydraulic cylinder body 100 and the piston 134 of the pump 18 are shown. The hydraulic cylinder body 100 includes an upper mounting portion 182 and a lower mounting portion 184. The upper mounting portion 182 includes an upper surface 190 and an upper fastener opening 228. The lower mounting portion 184 includes a lower surface 192 and a lower fastener opening 230. The piston head 144 and the piston rod 146 of the piston 134 are shown. The sleeve 108b of the drive mechanism 86 is shown and includes the slot 112b. The receiving port 198, the manifold sealing groove 200, the upper threaded opening 216, and the alignment pin 218 of the valve manifold 42 are shown. The supply port 194, the tank sealing groove 196, and the lower threaded opening 222 of the fluid tank 92 are shown.

[0091] The frame 80 supports the other components of the HPU 10. The drive mechanism 86 is connected to the pump 16 and the pump 18 and drives both the pump 16 and the pump 18. The fluid tank 92 is configured to store a source of hydraulic fluid. The supply port 194 extends into the fluid tank 92. The tank seal groove 196 extends around the supply port 194 and is configured to receive the lower seal 202. The filter 22b extends into the supply port 194 and is configured to filter out any contaminants of the hydraulic fluid before the hydraulic fluid enters the pump 18. The lower threaded opening 222 extends into the fluid tank 92 near the supply port 194. The cover 94 is attached to the fluid tank 92 and closes the fluid tank 92. The gasket 96 is arranged between the fluid tank 92 and the cover 94.

[0092] The valve manifold 42 is mounted on the fluid tank 92 and is configured to deliver hydraulic fluid from the pump 16 to the four-way valve 28, and to deliver hydraulic fluid from the pump 18 to the four-way valve 28 and the two-way valve 26 (shown in FIG. Figure 1 and 2C -2D). Fluid port 30 extends out of valve manifold 42 and is configured to deliver hydraulic fluid to a tool 74 ( Figure 1 ), tool 74 '( Fig.9A ) and tool 74″ ( Fig. 9B190 and the like. The pump 18 is provided with a hydraulically driven tool (shown in FIG. 190 ) and a hydraulic fluid delivered from the hydraulically driven tool. The receiving port 198 extends into the valve manifold 42. The manifold seal groove 200 extends around the receiving port 198 and is configured to receive the upper seal 204. The upper threaded opening 216 extends into the valve manifold 42. An alignment pin 218 extends from the valve manifold 42. The alignment pin 218 is configured to be received through an alignment opening (not shown) that extends through the upper surface 190 into the upper mounting portion 182. When the pump 18 is mounted on the HPU 10, the alignment pin 218 ensures that the upper fastener opening 228 is aligned with the upper threaded opening 216 and the lower fastener opening 230 is aligned with the lower threaded opening 222.

[0093] The pump 18 is mounted on the outside of the HPU 10 and is connected to both the valve manifold 42 and the fluid tank 92. The upper mounting portion 182 engages the valve manifold 42. The upper surface 190 is a flat surface adjacent to the valve manifold 42b. The upper fastener opening 228 extends through the upper mounting portion 182. The upper fastener 232 extends through the upper fastener opening 228 and enters the upper threaded opening 216. The upper fastener 232 includes threads configured to engage with threads in the upper threaded opening 216. Although the upper threaded opening 216 is described as a threaded opening, it should be understood that the upper threaded opening 216 and the upper fastener 232 can be engaged in any desired manner to secure the upper mounting portion 182 to the valve manifold 42, such as a pawl connection. The upper seal 204 is arranged in the manifold seal groove 200 located between the upper surface 190 and the valve manifold 42. The upper mounting portion 182 also includes a manifold seal groove 200 similar to the alignment opening 208 ( Fig. 6A ) of the alignment opening (not shown). However, with the alignment opening 208 and the fluid outlet 162 ( Figure 4 and 6B ) compared to the alignment opening of the upper mounting portion 182, which is arranged relative to the fluid outlet 188 ( Figure 5 ) at different positions to prevent pump 18 from being accidentally installed at the position of pump 16.

[0094] The lower mounting portion 184 is engaged with the fluid tank 92. The lower surface 192 is a flat surface adjacent to the fluid tank 92. A lower fastener opening 230 extends through the lower mounting portion 184. A lower fastener 234 extends through the lower fastener opening 230 and into the lower threaded opening 222. The lower fastener 234 includes threads configured to engage with threads in the lower threaded opening 222. Although the lower threaded opening 222 is described as a threaded opening, it should be understood that the lower threaded opening 222 and the lower fastener 234 can be engaged in any desired manner to secure the lower mounting portion 184 to the fluid tank 92, such as a detent connection. The lower seal 202 is disposed in the tank seal groove 196 between the lower surface 192 and the fluid tank 92.

[0095] The piston 134 at least partially extends out of the cylinder body 100. The piston head 144 is configured to slide into the slot 112b of the sleeve 108b so that the sleeve 108b drives the piston 134 in a linear reciprocating manner due to the connection of the piston head 144 in the slot 112b. The second cover 90b closes the connection between the piston 134 and the sleeve 108b.

[0096] To unload the pump 18 from the HPU 10, the second cover 90b is removed to expose the connection between the piston 134 and the sleeve 108b. Although the second cover 90b is shown as being completely removed from the HPU 10, it should be understood that the second cover 90b can be pivoted relative to the HPU 10 to expose the connection between the piston 134 and the sleeve 108b. The upper fastener 232 is disengaged from the upper threaded opening 216, and the lower fastener 234 is disengaged from the lower threaded opening 222. With the upper fastener 232 and the lower fastener 234 removed, the pump 18 can be pulled away from the HPU 10 with a simple sliding motion. The sliding motion disconnects four connections between the pump 18 and the HPU 10. Specifically, the sliding motion disconnects the dynamic mechanical connection between the piston head 144 and the slot 112b of the sleeve 108b, the static structural connection between the hydraulic cylinder body 100 and the valve manifold 42 and the fluid tank 92, the supply port 194 and the fluid inlet 186 ( Figure 5 ) and a fluid outlet 188 ( Figure 5 198) and the receiving port 198. Thus, removing the hydraulic cylinder body 100 disconnects the dynamic mechanical connection, the static structural connection, and both fluid connections. In some examples, the filter 22b is attached to the hydraulic cylinder body 100 so that when the pump 18 is removed, the filter 22b is removed from the fluid tank 92b.

[0097] The pump 18 is installed on the HPU 10 by reversing the process for unloading the pump 18. The upper seal 204 is positioned in the manifold seal groove 200 and the lower seal 202 is positioned in the tank seal groove 196. The pump 18 is slid onto the HPU 10 so that the alignment pin 218 is received in the alignment opening extending into the upper mounting portion 182 and the piston head 144 is disposed in the slot 112b of the sleeve 108b. With the pump 18 positioned on the HPU 10, the upper fastener 232 is inserted through the upper fastener opening 228 and screwed into the upper threaded opening 216, and the lower fastener 234 is inserted into the lower fastener opening 230 and screwed into the lower threaded opening 222. All four connections: a dynamic mechanical connection, a static structural connection, and two fluid connections are thus established between the pump 18 and the HPU 10.

[0098] The connection of the pump 18 and the HPU 10 provides significant advantages. The alignment pins 218 ensure that the pump 18 is correctly positioned on the HPU 10. All mechanical and fluid connections between the pump 18 and the HPU 10 can be established by simply sliding the pump 18 onto the HPU 10 and attaching the pump 18 with the upper fasteners 232 and the lower fasteners 234. All mechanical and fluid connections can be disconnected by removing the upper fasteners 232 and the lower fasteners 234 and sliding the pump 18 off the HPU 10. The pump 18 is mounted on the outside of the HPU 10 so that the pump 18 can be removed and repaired without having to remove the cover 94 from the fluid tank 92, which provides faster and more efficient repairs. Repairing an internal pump requires removing the cover 94 and exposing the interior of the fluid tank 92 and the hydraulic fluid to contaminants. In addition, an internal pump is typically immersed in the hydraulic fluid, which makes repair more cumbersome and complicated. Because the gasket 96 has a complex geometry to match the geometry of the fluid tank 92, the gasket 96 is also difficult to replace, especially during field repairs. Therefore, removing the gasket 96 may cause leaks and require in-store repairs. In addition, the fluid connection between the pump 18 and the HPU 10 is sealed by two seals, an upper seal 204 and a lower seal 202, which provides a simple and reliable seal and prevents leakage of the hydraulic fluid. The upper seal 204 and the lower seal 202 are typically elastomeric O-rings, which provide better sealing and placement and a smaller surface area than the gasket 96 between the fluid tank 92 and the cover 94. In addition, no hose is required to connect the pump 18 to the HPU 10 because the hydraulic cylinder body 100 is directly mounted to both the fluid tank 92 and the valve manifold 42, thereby increasing reliability and reducing complexity.

[0099] Fig. 8A is a first isometric view of the pendant 46 . Figure 8B is a second isometric view of the pendant 46 . Figure 8Cis a third isometric view of the pendant 46 . Fig.8D is a fourth isometric view of the pendant 46 . Figures 8A-8D The pendant 46 includes a handle 236, a head 238, a trigger 240, and a trigger guard 242. The head 238 includes an antenna 244. The handle 236 includes a first lateral side 246 ( Figures 8A-8C )、the second lateral side 248( Fig. 8A and 8C -8D), front side 250, rear side 252 and port 253 ( Fig. 8A and 8C The trigger device guard 242 includes a fork 254a, a fork 254b, a groove 256, a cross member 257, a gap 258a, a gap 258b, a first side guard 259a ( Fig. 8A and 8B ) and the second side guard 259b ( Figure 8C and 8D ).

[0100] The handle 236 extends from the head 238 and is configured to be grasped by a single hand of a user. The trigger 240 extends from the front side 250 of the handle 236 near the head 238. The trigger guard 242 surrounds the trigger 240 and is configured to prevent undesired actuation of the trigger 240. Although the trigger guard 242 is shown as being integrally formed on the handle 236, it should be understood that in some examples the trigger guard 242 can be a separate component attached to the handle 236, such as by one or more threaded fasteners. The fork 254a and the fork 254b are arranged below the bottom edge of the trigger 240, wherein the trigger 240 is positioned between the fork 254a and 254b. The cross member 257 extends between the fork 254a and the fork 254b. The fork 254a extends from the first lateral side 246 and the front side 250. The fork 254b extends from the second lateral side 248 and the front side 250. The fork 254a and the fork 254b extend further away from the front side 250 than the trigger mechanism 240, thereby preventing the trigger mechanism 240 from being inadvertently actuated when the pendant 46 is lowered. For example, when the pendant 46 is lowered, the pendant 46 can rest on the head 238, the fork 254a and the fork 254b.

[0101] The groove 256 is disposed between the fork 254a and the fork 254b, and the trigger mechanism 240 can be contacted through the groove 256. The groove 256 is shown as a U-shaped groove that opens away from the cross member 257, but it should be understood that the groove 256 can be any suitable shape that provides the user with access to the trigger mechanism 240 by pressing the user's thumb between the fork 254a and 254b. The width of the groove 256 can be greater than the width of the trigger mechanism 240 to provide the user with access to the trigger mechanism 240 through the groove 256.

[0102] The fork 254a is laterally offset relative to the trigger device 240 toward the first lateral side 246, and the fork 254b is laterally offset relative to the trigger device 240 toward the second lateral side 248, so that the trigger device 240 is disposed between the gap 258a and the gap 258b. The first side guard 259a extends vertically from the junction of the first fork 254a and the handle 236 to the lower edge of the head 238. The second side guard 259b similarly extends vertically from the junction of the second fork 254b and the handle 236 to the lower edge of the head 238. The trigger device 240 is disposed between the first side guard 259a and the second side guard 259b.

[0103] Gap 258a is disposed between fork 254a and head 238. Gap 258a is a V-shaped opening that opens away from first side guard 259a. Gap 258b is disposed between fork 254b and head 238. Gap 258b is a V-shaped opening that opens away from second side guard 259b. Although gap 258a and gap 258b are described as V-shaped openings, it should be understood that gap 258a and gap 258b may have any suitable configuration for providing user contact with trigger device 240 by pressing one of the user's fingers through gap 258a, gap 258b, or both. Antenna 244 extends from head 238 and provides wireless communication capabilities for pendant 46. Port 253 extends into handle 236 and is configured to receive a wired communication cable to provide wired communication between pendant 46 and HPU 10 (at Figure 1-2D As such, pendant 46 is configured to communicate via a wired or wireless connection.

[0104] Header 238 houses control circuitry, such as a microcontroller or other logic circuitry, and control circuitry 48 ( Figure 1) for wired and / or wireless communication. The trigger device 240 is operably connected to the control circuit to enable the pendant 46 to generate an extension command and a retraction command and transmit the extension command and the retraction command to the control circuit 48. For example, a user pressing the trigger device 240 can generate an extension command, so that the control circuit 48 turns the four-way valve 28 ( Figure 1 ) to an extended state, wherein hydraulic fluid is delivered to a hydraulically actuated tool to cause a tool piston 78 ( Figure 1 ) of the tool piston through the extension stroke. User release of the trigger device 240 may generate a retract command, causing the control circuit 48 to switch the four-way valve 28 to the retract state, wherein hydraulic fluid is delivered to the hydraulically driven tool to cause the tool piston to travel through the retract stroke.

[0105] The trigger mechanism guard 242 allows a user to access the trigger mechanism 240 from a plurality of different positions. The trigger mechanism guard 242 provides two ways to access the trigger mechanism 240 in a right-hand orientation, and two ways to access the trigger mechanism 240 in a left-hand orientation. As discussed above, the fork 254a and the fork 254b extend further away from the front side 250 than the trigger mechanism 240 to prevent the trigger mechanism 240 from being inadvertently actuated. The groove 256 is disposed between the fork 254a and the fork 254b. The trigger mechanism guard 242 does not include a cover for enclosing the trigger mechanism 240; instead, the fork 254a and the fork 254b provide the only protection against inadvertent actuation of the trigger mechanism 240. The fork 254a and the fork 254b extend

[0106] In the right-hand orientation, the user can contact the trigger mechanism 240 with the user's thumb by grasping the handle 236 so that the first lateral side 246 is placed in the palm of the user and the user's thumb is positioned within the groove 256 between the fork 254a and the fork 254b. The user's fingers can wrap around the back side 252 toward the second lateral side 248 of the handle 236. The user can then press the trigger mechanism 240 with the user's thumb. Alternatively, the user can grasp the handle 236 so that the second lateral side 248 of the handle 236 rests in the palm of the user. The user can extend a finger, such as an index finger, through the gap 258b to contact and press the trigger mechanism 240.

[0107] In the left-handed orientation, the user can contact the trigger mechanism 240 with the user's thumb by grasping the handle 236 so that the second lateral side 248 is placed in the palm of the user and the user's thumb is positioned within the groove 256 between the fork 254a and the fork 254B. The user's fingers can wrap around the rear side 252 toward the first lateral side 246 of the handle 236. The user can then press the trigger mechanism 240 with the user's thumb. Alternatively, the user can grasp the handle 236 so that the first lateral side 246 of the handle 236 rests in the palm of the user. The user can extend a finger, such as an index finger, through the gap 258a to contact and press the trigger mechanism 240.

[0108] The pendant 46 provides significant advantages. The trigger guard 242 enables the user to depress the trigger 240 with the user's left hand or the user's right hand. The user can contact the trigger 240 with a finger through the gap 258a or the gap 258b, and the user can contact the trigger 240 with a thumb through the groove 256. The trigger guard 242 provides ergonomic control of the pendant 46 and provides the user with flexibility in controlling the pendant 46, thereby reducing user fatigue.

[0109] Fig.9A is an isometric view of tool 74'. Fig. 9B is an isometric view of tool 74″. Fig.9A and Fig. 9B The tool 74 ′ includes a tool body 260 ′ and a socket 262 . The tool 74 ″ includes a tool body 260 ″, a bracket 264 , and a drive head 266 .

[0110] Tool 74' includes an internal tool piston, such as tool piston 78 ( Figure 1 ), which drives the rotation of the socket 262 through the ratchet mechanism. The hydraulic fluid is connected to the fluid port 30 (at Figure 2A ) and a hydraulic hose (such as external hydraulic hose 76a (best seen in FIG. Figure 1 ) and external hydraulic hose 76b ( Figure 1 )) is provided to the tool body 260'. The hydraulic fluid acts on the tool piston to drive the rotation of the socket 262. The socket 262 is configured to receive the head of the fastener to tighten or loosen the fastener in high torque applications and other uses.

[0111] Similarly, tool 74" includes an internal tool piston, such as tool piston 78 ( Figure 1 ), which drives the rotation of the drive head 266 through a ratchet mechanism. The bracket 264 is configured to support and prevent rotation of the tool 74" against the anchor point during operation. The hydraulic fluid is connected to the fluid port 30 (at Figure 2A) and a hydraulic hose (such as external hydraulic hose 76a (best seen in FIG. Figure 1 ) and external hydraulic hose 76b ( Figure 1 )) is provided to the tool body 260". The hydraulic fluid acts on the tool piston to drive the rotation of the drive head 266. The drive head 266 is configured to extend into the socket of the fastener to tighten or loosen the fastener in high torque applications and other uses.

[0112] Although the present invention has been described with reference to exemplary embodiments, it will be appreciated by those skilled in the art that various changes may be made and elements thereof may be replaced with equivalents without departing from the scope of the present invention. In addition, many modifications may be made to adapt specific circumstances or materials to the teachings of the present invention without departing from the essential scope of the present invention. Therefore, it is intended that the present invention is not limited to the specific embodiments disclosed, but that the present invention will include all embodiments falling within the scope of the appended claims.

Claims

1. A hydraulic power unit for supplying hydraulic fluid to a hydraulically driven tool to provide power to the hydraulically driven tool, the hydraulic power unit comprising: a fluid tank supported by the frame, the fluid tank configured to store a source of hydraulic fluid; a first pump configured to draw the hydraulic fluid from the fluid tank and pump a first hydraulic flow to a combined flow line; a second pump configured to draw the hydraulic fluid from the fluid tank and pump a second hydraulic flow to a high flow line fluidly connected to the combined flow line, the combined flow line configured to provide the first hydraulic flow and the second hydraulic flow to the hydraulically-driven tool; a first valve disposed along the high flow line, the first valve being controllable between an open state and a closed state; a high flow return line extending from a downstream side of the first valve, the high flow return line bypassing the combined flow line and the hydraulically-actuated tool and configured to provide a return flow of the second hydraulic flow to the fluid tank; as well as a second valve configured to direct the hydraulic fluid from the combined flow line to the hydraulically-driven tool and configured to receive the hydraulic fluid from the hydraulically-driven tool and to deliver the hydraulic fluid received from the hydraulically-driven tool to the fluid tank; Wherein the first valve is an electrically actuated valve configured to switch to the open state based on hydraulic fluid pressure in the combined flow line exceeding a threshold pressure level, and wherein the first valve directs the second hydraulic flow to the high flow return line in the open state.

2. The hydraulic power unit according to claim 1, further comprising: a drive mechanism mechanically connecting the first pump and the second pump; as well as A single electric motor is configured to power the drive mechanism.

3. The hydraulic power unit according to claim 1, further comprising: a transducer configured to sense the hydraulic fluid pressure in the combined flow line and generate a hydraulic pressure output; as well as A control circuit is configured to receive the hydraulic pressure output from the transducer and control the first valve between the open state and the closed state based on the hydraulic pressure output.

4. The hydraulic power unit of claim 3, wherein the control circuit is configured to compare the hydraulic pressure output with the threshold pressure level and control the first valve between the open state and the closed state based on the comparison result of the hydraulic pressure output with the threshold pressure level.

5. A hydraulic power unit according to claim 4, wherein the control circuit is configured to switch the first valve to and maintain an open position based on a comparison result of the hydraulic pressure output with the threshold pressure level indicating that the hydraulic fluid pressure in the combined flow pipeline is at or above the threshold pressure level.

6. A hydraulic power unit according to claim 5, wherein the control circuit is configured to switch the valve to and maintain the closed position based on a comparison result of the hydraulic pressure output and the threshold pressure level indicating that the hydraulic fluid pressure in the combined flow pipeline is lower than the threshold pressure level.

7. A hydraulic power unit according to any one of claims 3 to 6, wherein the threshold pressure level is between 3000-4000 psi.

8. The hydraulic power unit according to any one of claims 1 to 6, wherein the first valve is a solenoid operated two-way valve.

9. The hydraulic power unit according to any one of claims 1 to 6, wherein the first pump is mechanically connected to the second pump such that a first piston of the first pump and a second piston of the second pump are configured to reciprocate simultaneously.

10. The hydraulic power unit of claim 9, wherein the first piston and the second piston are configured to reciprocate out of phase.

11. The hydraulic power unit according to claim 9, wherein: the first piston including a piston rod configured to reciprocate to pump the hydraulic fluid and having a first upper diameter portion and a first lower diameter portion, the first lower diameter portion having a larger diameter than the first upper diameter portion; as well as the second piston including a piston rod configured to reciprocate to pump the hydraulic fluid and having a second upper diameter portion and a second lower diameter portion, the second lower diameter portion having a larger diameter than the second upper diameter portion; Wherein the second lower diameter portion has a larger diameter than the first lower diameter portion.

12. The hydraulic power unit according to any one of claims 1 to 6, further comprising: A check valve is disposed between the combined flow line and the high flow line, the check valve being configured to prevent the hydraulic fluid in the combined flow line from flowing into the high flow line.

13. The hydraulic power unit of any one of claims 1 to 6, wherein the first pump is configured to pump the hydraulic fluid at a pressure of up to 10,000 psi, and the second pump is configured to pump the hydraulic fluid at a pressure of up to 3,500 psi.

14. A method of pumping using a hydraulic power unit, comprising: simultaneously powering a first pump and a second pump of a hydraulic power unit, the first pump drawing hydraulic fluid from a fluid reservoir and providing a first flow of the hydraulic fluid to a first valve, the second pump drawing hydraulic fluid from the fluid reservoir and providing a second flow of the hydraulic fluid to the first valve, wherein the first valve is configured to deliver the hydraulic fluid to a hydraulically-actuated tool; measuring, by a transducer, a hydraulic fluid pressure indicative of a pressure in a combined flow line upstream of the first valve; as well as A second valve is controlled between an open state and a closed state based on a measured hydraulic fluid pressure, wherein the second valve is configured to divert the second flow to a system return line when in an open state, such that when the second valve is in an open state, the second fluid bypasses the combined flow line and the hydraulically-driven tool.

15. The method according to claim 14, further comprising: diverting the second flow to the system return line using the second valve when the second valve is in an open state to prevent the second flow from flowing to the first valve and to the hydraulically-actuated tool, such that only the first flow powers the hydraulically-actuated tool when the hydraulic fluid pressure is above a threshold pressure level; and The second flow is directed to the first valve using the second valve when the second valve is in a closed state such that both the first flow and the second flow power the hydraulically-driven tool when the hydraulic fluid pressure is below the threshold pressure level.

16. The method of claim 15, wherein when the second valve is in the open state, the second valve diverts the second flow to the system return line to prevent a single motor powering the first pump and the second pump from being overwhelmed by the hydraulic pressure requirements of the hydraulically-driven tool.

17. The method of any one of claims 14 to 16, wherein the step of controlling the second valve between the open state and the closed state based on the hydraulic fluid pressure comprises: comparing, by control circuitry of the hydraulic power unit, a hydraulic fluid pressure from the transducer to a threshold pressure level; switching the second valve to an open position based on a comparison indicating that the hydraulic fluid pressure is greater than or equal to the threshold pressure level; and In the event that hydraulic fluid pressure exceeds the threshold pressure level, the second valve is maintained in the open position.

18. The method according to claim 17, further comprising: The second valve is switched to the closed state based on a comparison indicating that the hydraulic fluid pressure is less than the threshold pressure level.

19. The method of any one of claims 17, wherein the threshold pressure level is between 3000 and 4000 psi.

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