Hydraulic pump

Abstract

A hydraulic pump is provided that includes a housing having a working port, a bladder storing hydraulic fluid, a pump assembly, and a manifold. The pump assembly pumps hydraulic fluid from the bladder to the working port via the outlet line. The manifold includes a first chamber, a first relief valve, a second chamber between the first chamber and the working port, a second relief valve, and a check valve. A first relief valve releases fluid from the outlet line to the bladder when a first pressure is reached within the first chamber. A second relief valve releases fluid from the outlet line to the bladder when a second pressure is reached within the second chamber. A check valve is positioned between the first chamber and the second chamber along the outlet line and prevents fluid flow from the second chamber to the first chamber.

Description

[0001] Related applications

[0002] This application claims priority under USC §119 to U.S. Provisional Patent Application No. 63 / 387,084, filed on December 12, 2022, the entire contents of which are incorporated herein by reference. Technical Field

[0003] The present disclosure relates generally to hydraulic pumps and systems, and more particularly to systems and methods for single-acting cordless hydraulic pumps for use with hydraulic tools. Background Art

[0004] Hydraulic tools can be used to provide a mechanical advantage to an operator performing work on a workpiece. For example, a hydraulic tool can be a cutting device having a blade for cutting an object into separate parts. As another example, a hydraulic tool can be a crimping device used to crimp connections, thereby joining two separate parts together by deforming one or both parts to hold them together. As yet another example, a hydraulic tool can be a lift cylinder for raising and lowering a workpiece and / or a pipe bender for bending a workpiece.

[0005] Generally speaking, hydraulic tools are connected to a hydraulic pump that is operable to pressurize hydraulic fluid. The hydraulic pump transfers the pressurized hydraulic fluid to a cylinder within the hydraulic tool, and the hydraulic tool uses the pressurized hydraulic fluid from the hydraulic pump to perform tasks such as crimping, cutting, lifting, etc. Therefore, the hydraulic pump requires a mechanism for pressurizing, maintaining, and releasing the hydraulic fluid. Summary of the Invention

[0006] In some aspects, a hydraulic pump is provided. The hydraulic pump includes a housing having a working port, a bladder for storing hydraulic fluid, a pump assembly, and a manifold. The pump assembly pumps the hydraulic fluid from the bladder to the working port via an outlet line. The manifold contains a portion of the outlet line and includes a first chamber, a first safety valve, a second chamber located between the first chamber and the working port, a second safety valve, and a check valve. The first safety valve is connected to the first chamber and releases fluid from the outlet line to the bladder when a first pressure is reached in the first chamber. The second safety valve is connected to the second chamber and releases fluid from the outlet line to the bladder when a second pressure is reached in the second chamber. The check valve is positioned between the first chamber and the second chamber along the outlet line and prevents fluid from flowing from the second chamber to the first chamber.

[0007] In another aspect, a single-acting hydraulic pump is provided. The pump includes a housing including a workport, a trigger located on the housing, a bladder for storing hydraulic fluid, a pump assembly for pumping the hydraulic fluid from the bladder to the workport, a motor for operating the pump assembly, and a pump controller for controlling the motor. The trigger is configured to be advanced by an operator between an undepressed state and a fully depressed state. The pump controller controls the speed of the motor by operating the motor at a percentage of full motor power related to the percentage of trigger travel between the undepressed state and the fully depressed state.

[0008] In yet another aspect, a method of operating a single-acting hydraulic pump is provided. The method includes determining a percentage of trigger travel between an undepressed state and a fully depressed state when an operator depresses a trigger on the single-acting hydraulic pump, and operating a pump assembly to pump hydraulic fluid from a bladder to a workport of the single-acting hydraulic pump when the operator depresses the trigger. Operating the pump assembly includes controlling a motor to drive the pump assembly at a percentage of full motor power, wherein the percentage of full motor power is related to the percentage of trigger travel between the undepressed state and the fully depressed state.

[0009] The features, functions, and advantages can be achieved independently in various embodiments of the present disclosure, or they may be combined in yet other embodiments, further details of which can be seen with reference to the following description and drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] The novel features which are believed to be characteristic of the illustrative embodiments are set forth in the appended claims. However, the illustrative embodiments, together with the preferred modes of use, further objects and description thereof, will be better understood by reference to the following detailed description of illustrative embodiments of the present disclosure when read in conjunction with the accompanying drawings, in which:

[0011] Figure 1 is a schematic diagram of a hydraulic power tool system including a hydraulic pump according to some embodiments;

[0012] Figure 2 is an isometric view of a hydraulic pump according to some embodiments;

[0013] Figure 3 is connected to the hydraulic tool Figure 2 Another isometric view of the hydraulic pump;

[0014] Figure 4 yes Figure 2 A partial cross-sectional view of a hydraulic pump;

[0015] Figure 5 is a flow chart of an open-loop motor speed control method according to some embodiments;

[0016] Figure 6is a flow chart of a closed-loop motor speed control method according to some embodiments; and

[0017] Figure 7 is a hydraulic schematic diagram of a hydraulic power tool system including a hydraulic pump, according to some embodiments. DETAILED DESCRIPTION

[0018] The following discussion is presented to enable those skilled in the art to make and use embodiments of the present invention. Various modifications to the illustrated embodiments will be apparent to those skilled in the art, and the general principles herein may be applied to other embodiments and applications without departing from embodiments of the present invention. Therefore, embodiments of the present invention are not intended to be limited to the embodiments shown, but rather to the widest scope consistent with the principles and features disclosed herein. The following detailed description is read with reference to the accompanying drawings, in which similar elements in different drawings have similar reference numerals. The drawings, which are not necessarily drawn to scale, depict selected embodiments and are not intended to limit the scope of embodiments of the present invention. Those skilled in the art will recognize that the examples provided herein have many useful alternatives and fall within the scope of embodiments of the present invention.

[0019] As used herein, unless specified or limited otherwise, the terms "mounted," "connected," "supported," and "coupled" and variations thereof are used broadly and encompass both direct and indirect mountings, connections, supports, and couplings. Further, "connected" and "coupled" are not restricted to physical or mechanical connections or couplings.

[0020] Generally speaking, some embodiments provide a single-acting, battery-operated hydraulic pump for use with a hydraulic tool. The hydraulic pump can include a variable speed motor and a pump controller configured to control the variable speed motor using open-loop control based on a percentage of applied motor power or using closed-loop control based on actual motor speed. In addition, the hydraulic pump can include a manifold having an overpressure protection system including dual chambers with corresponding safety valves and check valves therebetween. The overpressure protection system can release pressurized fluid back into a bladder of the hydraulic pump to protect against pump overpressure events as well as external load overpressure events.

[0021] The disclosed embodiments will now be described more fully hereinafter with reference to the accompanying drawings, in which some, but not all, of the disclosed embodiments are shown. Indeed, several different embodiments may be provided, and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the disclosure to those skilled in the art.

[0022] Figure 1A hydraulic power tool system 100 is illustrated that includes a hydraulic pump 102 and a hydraulic tool 104 according to some embodiments. Generally speaking, the hydraulic pump 102 can be operated to provide pressurized fluid (e.g., hydraulic oil) to actuate the hydraulic tool 104. For example, Figure 1 , the hydraulic pump 102 may include a power pack 106, a pump assembly 108, a manifold 110, a bladder 112, a user interface 114, a pump controller 116 having a processor 118 and a memory 120, a work port 122, and a removable power source or battery 124. Alternatively, in some embodiments, the battery 124 may be a non-removable power source configured to be recharged while remaining attached to the hydraulic pump 102. The hydraulic pump 102 may be removably coupled to the hydraulic tool 104 via a fluid supply line 126 (such as a pipe) extending from the work port 122. Additionally, the hydraulic tool 104 may include a tool head 128, a hydraulic cylinder 130, and a return spring 132.

[0023] In operation, the power unit 106 can be powered by a battery 124 and controlled by a pump controller 116 in response to user input from the user interface 114 to drive the pump assembly 108. The pump assembly 108 pumps pressurized fluid from the bladder 112 through the manifold 110 and the fluid supply line 126 to the hydraulic tool 104. Within the hydraulic tool 104, the pressurized fluid pushes a hydraulic cylinder 130, which actuates a tool head 128. For example, the tool head 128 may include a set of jaws (not shown) and the hydraulic cylinder 130 includes a piston (not shown) that moves one or both jaws toward each other, thereby causing a crimping or cutting operation. In another example, the tool head 128 includes a movable lifting structure (not shown), and the hydraulic cylinder 130 moves the movable lifting structure to change the height of a workpiece supported by the movable lifting structure. Other examples are possible, such as, but not limited to, a tool head 128 having movable elements (e.g., bending dies and / or bending rollers) that can move the workpiece relative to stationary elements (e.g., stationary dies and / or fixed rollers) to change the shape of the workpiece.

[0024] Once the operation is complete, the return spring 132 can force the fluid from the hydraulic tool 104 back through the fluid supply line 126 and back into the hydraulic pump 102. Thus, the hydraulic pump 102 is a single-acting pump. That is, the hydraulic pump 102 includes a single workport 122 and applies force to the fluid in one direction, and the hydraulic tool 104 includes a spring 132 or gravity or other external force to return the fluid to the hydraulic pump 102. Consequently, an external force, such as the spring 132, rather than the hydraulic tool 104 or the user, releases pressure within the hydraulic tool 104 to force the fluid back into the hydraulic pump 102.

[0025] Figures 2 to 4Further illustrated is a hydraulic pump 102 according to some embodiments. Figure 2 and Figure 3 As shown in the external view of , the hydraulic pump 102 may include a housing 134 , a workport 122 , a release valve 136 , a handle 138 , a trigger 140 , a lock 142 , and a battery terminal 144 . Figure 4 The partial interior view of illustrative embodiment illustrates the power pack 106 , pump assembly 108 , manifold 110 , bladder 112 , and release valve 136 .

[0026] refer to Figure 1 and Figure 4 , the power unit 106 can include a motor 146 configured to convert electrical energy into rotational motion to operate the pump assembly 108. In some embodiments, the power unit 106 can include a variable speed motor 146. Additionally, in some embodiments, the power unit 106 can include a brushless direct current (DC) motor 146 having a planetary gear set.

[0027] like Figure 1 As shown in FIG, the power unit 106 can be powered by a power source such as a battery 124. Thus, the hydraulic pump 102 can be considered a cordless pump because it is battery operated. In some embodiments, the battery 124 can be an 18 volt battery. Furthermore, in some embodiments, the battery 124 can be removed from the hydraulic pump 102. For example, Figure 2 As shown in FIG, the hydraulic pump 102 may include a battery terminal 144 to which the battery 124 may be removably coupled. Thus, the battery 124 may be removed from the hydraulic pump 102 and recharged and / or replaced when necessary.

[0028] Additionally, the power unit 106 can be controlled by a pump controller 116. Thus, the pump controller 116 can communicate with the motor 146. The pump controller 116 can be implemented using hardware, software, and / or firmware. For example, Figure 1 As shown in FIG, the pump controller 116 may include one or more processors 118 and a memory 120, such as a non-transitory computer-readable memory storing machine language instructions or other executable instructions. The instructions, when executed by the one or more processors 118, may cause the pump controller 116 to perform various operations of the hydraulic pump 102. Additionally or alternatively, the pump controller 116 may include one or more relays, switches, or other hardware components to perform various operations of the hydraulic pump 102.

[0029] For example, in some embodiments, the memory 120 may include instructions that, when executed by the processor(s) 118, cause the pump controller 116 to operate the electric motor 146 in response to a user input from an operator. Such a user input may be the operator depressing the trigger 140. Figure 2 and Figure 3 As shown in FIG, the trigger 140 can be positioned along the handle 138 of the pump housing 134, thereby allowing an operator to grasp the handle 138 and actuate the trigger 140. However, in other embodiments, the trigger 140 can be located elsewhere along the housing 134.

[0030] In some embodiments, the trigger 140 can act as an on-off switch such that when the trigger 140 is depressed, the pump controller 116 turns on and operates the motor 146 to operate the pump assembly 108, and when the trigger 140 is released, the pump controller 116 turns off the motor 146. In other embodiments, as further described below, the trigger 140 can be a variable trigger 140 such that the pump controller 116 controls the speed of the motor 146 in direct relation to the amount of force applied to the trigger 140 or the amount of trigger travel (i.e., between an undepressed state and a fully depressed state). In such embodiments, the pump controller 116 can still turn off the motor 146 when the trigger 140 is no longer depressed. Additionally, in some embodiments, the hydraulic pump 102 can include additional user inputs to prevent the electric motor from operating. For example, Figure 2 and Figure 3 , the hydraulic pump 102 may include a lock 142, such as on the handle 138, that prevents accidental pulling of the trigger 140. In some embodiments, the lock 142 may be a mechanical lock that prevents the trigger 140 from being depressed. In other embodiments, the lock 142 may be an electronic lock that, when actuated, sends a signal to the pump controller 116 to prevent the motor from operating regardless of input received via the trigger 140.

[0031] As noted above, in some embodiments, the pump controller 116 may operate the motor 146 at a variable speed related, for example, to an operator's force applied to the trigger 140 or the amount of trigger travel. Figure 5 and Figure 6 A method of variable motor speed control according to some embodiments is illustrated. In some embodiments, Figure 5 and Figure 6 The method may be executed by the pump controller 116 (e.g., may be stored in the memory 120 for execution by the processor 118 of the pump controller 116). It should be noted that although some steps are Figure 5 and Figure 6 Although illustrated in the drawings and described below in a particular order, in some embodiments, the steps may be performed in an order different than shown and described, or more or fewer steps may be performed.

[0032] For example, Figure 5 An open loop variable speed motor control method 150 is shown according to some embodiments. Typically, the motor power percentage is varied to achieve Figure 5 The open-loop method 150 is described. More specifically, at step 152, the battery 124 is connected to the hydraulic pump 102, thereby supplying power to the hydraulic pump 102. At step 154, the pump controller 116 determines whether any overload has occurred. For example, an overload may be detected when the motor 146 draws a current above a threshold. As another example, an overload may be detected when the temperature of the motor 146 exceeds a threshold.

[0033] If an overload is detected, as determined in step 154, the pump controller 116 determines in step 156 whether the motor 146 is running. If so, the pump controller 116 stops the motor 146 in step 158. If not, or after the pump controller 116 stops the motor 146 in step 158, the pump controller 116 performs a power cycle on the hydraulic pump 102 in step 160. According to one example, the pump controller 116 can perform a power cycle operation by disconnecting the battery 124 from the motor 146 and then reconnecting the battery 124 and the motor 146. After the power cycle in step 160, the pump controller 116 returns to step 152.

[0034] Returning to step 154, if no overload is detected, the pump controller 116 determines at step 162 whether the variable trigger 140 is depressed to greater than approximately 10% of its total travel (e.g., "total travel" is a fully depressed state). If not, the pump controller 116 determines at step 164 whether the motor 146 is running. If so, the pump controller 116 stops the motor 146 at step 166. If not, or after the pump controller 116 stops the motor 146 at step 166, the pump controller 116 returns to step 152.

[0035] Returning to step 162, if the variable trigger 140 is depressed to greater than approximately 10% of its total travel, then at step 168, the pump controller 116 operates the motor 146 at a percentage motor power associated with the percentage travel of the variable trigger 140. For example, if the percentage trigger travel is 50% of its total travel, the pump controller 116 may operate the motor 146 at 50% motor power. As another example, if the percentage trigger travel is 100% (i.e., the trigger 140 is fully depressed), the pump controller 116 may operate the motor 146 at 100% power. Furthermore, the pump controller 116 loops back to step 154 ​​to continuously check for overload while operating the motor 146. In some embodiments, the pump controller 116 may operate the motor 146 at a percentage motor power that directly corresponds to the percentage travel of the variable trigger 140 (e.g., 25% trigger travel corresponds to 25% motor power). In other embodiments, the pump controller 116 may operate the motor 146 at percentage motor power intervals (e.g., 5% intervals, 10% intervals, etc.) that correlate to the percentage travel of the variable trigger 140. For example, operating at a 10% motor power interval may mean that 20-29% trigger travel corresponds to 20% motor power, 30-39% trigger travel corresponds to 30% motor power, and so on.

[0036] Now refer to Figure 6 , Figure 6 A closed loop variable speed motor control method 170 is shown. In general, Figure 6 The closed-loop method 170 is performed by controlling the actual motor speed (eg, in revolutions per minute (RPM)). Figure 6 The closed loop method 170 may initially include Figure 5 154 and 166, respectively. The open-loop method 150 of FIG. 154 is similar to the open-loop method 150 of FIG. 154, and therefore, similar steps are numbered accordingly. However, after step 162, if the variable trigger 140 is depressed to greater than 10% of its total stroke, the pump controller 116 operates the motor 146 at a percentage motor power to achieve the desired motor speed (e.g., a set or calculated motor speed) associated with the percentage stroke of the variable trigger 140 at step 172. Then, at step 174, the pump controller 116 determines whether the speed error is zero. That is, the pump controller 116 determines whether the actual motor speed is equal to the desired motor speed. If so, the pump controller 116 loops back to step 154 ​​to continuously check for overload while operating the motor 146. If, at step 174, the speed error is not equal to zero, the pump controller 116 uses a proportional-integral-derivative control mechanism to update the percentage motor power (e.g., update the duty cycle of the motor 146) at step 176 to attempt to match the actual motor speed to the desired motor speed. The pump controller 116 then loops back to step 154 ​​to continuously check for overload while operating the motor 146 .

[0037] The motor 146 (or more generally, the power unit 106) can be operated according to the methods described herein or other methods not specifically described herein to actuate the pump assembly 108 to provide pressurized fluid to the hydraulic tool 104. For example, the motor 146 can actuate the pump assembly 108 to pump fluid to the hydraulic tool 104 at increasing fluid pressures until a maximum operating pressure is reached. The rate at which the fluid pressure increases toward the maximum operating pressure can be related to the speed at which the motor 146 is controlled and the external load from the hydraulic tool 104. Thus, as described above, by being able to vary the motor speed, the pump speed can also be controlled.

[0038] With further reference to the pump assembly 108, as Figure 1 and Figure 4 As shown, the pump assembly 108 may include a pump 180 coupled to the power pack 106. In some embodiments, the pump 180 may be a radial pump including a single piston and a biasing cam (not shown) driven by the motor 146. For example, Figure 4 As shown in FIG, the pump 180 may include a shaft 182 operatively coupled to the motor 146. The shaft 182 converts the rotary motion of the motor 146 into linear motion of the piston. The reciprocating linear motion of the piston draws fluid from the bladder 112 and supplies pressurized fluid to the workport 122 through the manifold 110.

[0039] like Figure 4 As shown in FIG, bladder 112 operates as a reservoir for storing hydraulic fluid (e.g., hydraulic oil). In some embodiments, bladder 112 can include an opening 184 covered by a cap 186. Opening 184 can serve as a fill port, and cap 186 can be removed to allow removal and / or refilling of hydraulic fluid via opening 184. Additionally, in some embodiments, cap 186 or another portion of pump housing 134 can include a transparent window 187 to allow an operator to view the interior of bladder 112. As a result, an operator can quickly check the level of hydraulic fluid within bladder 112 without having to remove cap 186.

[0040] The bladder 112 can store hydraulic fluid at a low pressure level, such as atmospheric pressure or slightly above atmospheric pressure (e.g., in some embodiments, about 30 psi to about 70 psi). As noted above, the pump assembly 108 draws fluid from the bladder 112 and forces the pressurized fluid through the fluid supply line 126 into the hydraulic tool 104. Additionally, as Figure 1 and Figure 4 As shown in FIG, fluid travels through manifold 110 between pump assembly 108, bladder 112, and workport 122.

[0041] More specifically, the manifold 110 can provide fluid control, set operating pressure, and / or provide overpressure relief. For example, a manual release valve 136 accessible to an operator from outside the housing 134 can be selectively manipulated to build up fluid pressure or throttle backflow 7. More specifically, as Figure 2 and Figure 3 As shown in FIG, the release valve 136 may include a rod 188 extending from the pump housing 134 that can be moved by an operator. Figure 4 and Figure 7 , the release valve 136 can be in communication with a fluid line 190 between the bladder 112 and the workport 122. When the operator rotates the lever 188 to a first, "closed" position, the release valve 136 moves to block the fluid line 190, thereby preventing fluid from traveling from the workport 122 back to the bladder 112. This closure, in turn, allows the pump 102 to deliver pressurized fluid through the workport 122 and maintain pressure. When the operator rotates the lever 188 to a second, "open" position, the release valve 136 moves to open the fluid line 190, thereby allowing fluid to travel from the workport 122 back to the bladder 112. As a result, pressure is released and fluid returns from the hydraulic tool 104 to the bladder 112 via the fluid line 190 (e.g., due to a spring 132 or other external force within the hydraulic tool 104 forcing the fluid out of the hydraulic tool 104).

[0042] In addition to the manual release valve 136, in some embodiments, the manifold 110 may include a safety and check valve arrangement to provide overpressure protection for the hydraulic pump 102. More specifically, Figure 7 FIGURE 1 illustrates a hydraulic schematic diagram of a hydraulic power tool system 100 according to some embodiments. Figure 7 The diagram illustrates fluid connections between the bladder 112, the pump assembly 108, the manifold 110, and the hydraulic tool 104. For example, the hydraulic tool 104 includes a pump inlet line 192 between the bladder 112 and the pump assembly 108, an outlet line 194 between the pump assembly 108 and the workport 122 and extending through the manifold 110, a first manifold line 196 between the bladder 112 and the outlet line 194, a second manifold line 198 between the bladder 112 and the outlet line 194, and a third manifold line 190 between the bladder 112 and the outlet line 194.

[0043] Still refer to Figure 7As noted above, the bladder 112 can store hydraulic fluid at or near atmospheric pressure. In some embodiments, the bladder 112 can include a bladder overpressure relief device 200 to maintain the pressure within the bladder 112 at or below a pressure threshold. Additionally, within the pump assembly 108, a first check valve 202 is located upstream of the pump 180 along the pump inlet line 192, and a second check valve 204 is located downstream of the pump 180 along the outlet line 194. The check valves 202, 204 can allow fluid to move from the bladder 112 through the pump 180 and prevent fluid from flowing back from the pump 180 into the bladder 112, thereby enabling the radial piston pump 180 to operate properly to provide pressurized fluid through the outlet line 194.

[0044] Still refer to Figure 7 , the manifold 110 can include at least a portion of an outlet line 194. Within the manifold 110, the hydraulic pump 102 can include a first chamber 206, a first safety valve 208, a second chamber 210, a second safety valve 212, an optional check valve 214, and a portion of the manual release valve 136 described above. Via the outlet line 194, the first chamber 206 can be connected to the pump assembly 108, the second chamber 210 can be connected to the first chamber 206, and the workport 122 can be connected to the second chamber 210 (which can further be connected to the hydraulic tool 104). A check valve 214 can be positioned along the outlet line 194 between the first chamber 206 and the second chamber 210 to allow fluid to flow from the first chamber 206 to the second chamber 210 and prevent fluid from flowing from the second chamber 210 to the first chamber 206.

[0045] The first relief valve 208 can be connected to the first chamber 206 such that when the first chamber 206 reaches a first pressure, the first relief valve 208 opens to allow fluid to flow from the outlet line 194 back to the bladder 112 via the first manifold line 196. As a result, when the first pressure is reached, the pressure within the outlet line 194 drops, which can protect the pump assembly 108 from building excessive pressure within the hydraulic pump 102. Thus, the first chamber 206 and the first relief valve 208 can function as a primary pump overpressure protection mechanism.

[0046] Furthermore, a second safety valve 212 can be connected to the second chamber 210 such that when the second chamber 210 reaches a second pressure, the second safety valve 212 opens to allow fluid to flow from the outlet line 194 back into the bladder 112 via the second manifold line 198. As a result, when the second pressure is reached, the pressure within the outlet line 194 drops, which can protect the hydraulic pump 102 from overpressure from external loads (e.g., from the hydraulic tool 104). Furthermore, the second chamber 210 and the second safety valve 212 can function as a secondary pump overpressure protection mechanism. For example, in some embodiments, the first safety valve 208 can be set to a lower pressure than the second safety valve 212. Therefore, if the first safety valve 208 fails, the second safety valve 212 can still relieve the pump overpressure in the event of an overpressure condition. In one embodiment, the first pressure is approximately 10,250 psi, and the second pressure is approximately 11,500 psi. In such an embodiment, the hydraulic pump 102 can be considered rated for 10,000 psi.

[0047] In view of the foregoing, some embodiments provide a single-acting, battery-powered hydraulic pump for use with a hydraulic tool. The hydraulic pump may include a variable speed motor controlled via an open-loop mechanism, where the percentage motor power is controlled, or a closed-loop mechanism, where the actual pump speed is controlled via a PID control mechanism. Furthermore, the hydraulic pump may include a manifold with primary and secondary overpressure protection, which can relieve overpressure in the hydraulic pump due to pump overpressure or external overpressure.

[0048] The terms "about" or "substantially" with reference to quantities or measurements described herein mean that the recited characteristic, parameter, or value need not be achieved precisely, but rather that deviations or variations, including, for example, tolerances, measurement errors, measurement accuracy limitations, and other factors known to those skilled in the art, may occur in an amount that does not preclude the effect that the characteristic is intended to provide. In one example, such deviations or variations may be ±1%, ±2%, ±5%, or another number.

[0049] The description of the various advantageous embodiments has been presented for purposes of illustration and description and is not intended to be exhaustive or limited to the embodiments in the form disclosed. Many modifications and variations will be apparent to those of ordinary skill in the art. Furthermore, different advantageous embodiments may provide different advantages over other advantageous embodiments. The selected embodiment or embodiments were chosen and described in order to best explain the principles of the embodiments, their practical application, and to enable others of ordinary skill in the art to understand the disclosure of various embodiments with various modifications as are suitable for the particular use contemplated.

Claims

1. A hydraulic pump, comprising: a housing including a working port; a bladder storing hydraulic fluid; a pump assembly that pumps hydraulic fluid from the bladder to the workport via an outlet line; and a manifold containing a portion of the outlet line, the manifold comprising: First chamber, a first safety valve connected to the first chamber, the first safety valve releasing fluid from the outlet line to the bladder when a first pressure is reached in the first chamber, a second chamber, the second chamber being located between the first chamber and the working port, a second safety valve connected to the second chamber, the second safety valve releasing fluid from the outlet line to the bladder when a second pressure is reached within the second chamber, and A check valve is positioned along the outlet line between the first chamber and the second chamber, the check valve preventing fluid from flowing from the second chamber to the first chamber. 2 . The hydraulic pump of claim 1 , further comprising a relief valve extending into the manifold, the relief valve being manually adjustable to selectively release fluid from the outlet line to the bladder.

3. The hydraulic pump according to claim 2, wherein: The release valve includes a lever that is accessible from outside the housing for manual adjustment of the release valve.

4. The hydraulic pump according to claim 1, wherein The first pressure is lower than the second pressure.

5. The hydraulic pump according to claim 1, wherein The pump assembly includes a pump, a first pump check valve upstream of the pump between the bladder and the pump, and a second pump check valve downstream of the pump in the outlet line.

6. The hydraulic pump according to claim 1, wherein The housing includes a trigger, and wherein the pump assembly pumps the hydraulic fluid from the bladder to the workport when the trigger is depressed.

7. The hydraulic pump of claim 1, further comprising a power unit to operate the pump assembly.

8. The hydraulic pump according to claim 7, wherein: The housing also includes battery terminals configured to receive a removable battery that powers the power pack.

9. The hydraulic pump of claim 8, further comprising a pump controller that controls the power unit.

10. A single-acting hydraulic pump, comprising: a housing including a working port; a trigger located on the housing, the trigger configured to be traveled by an operator between an undepressed state and a fully depressed state; a bladder storing hydraulic fluid; a pump assembly that pumps the hydraulic fluid from the bladder to the workport; a motor that operates the pump assembly; and A pump controller controls the speed of the motor by operating the motor at a percentage of full motor power that is related to a percentage of trigger travel between the undepressed state and the fully depressed state.

11. The single-acting hydraulic pump according to claim 10, wherein: The pump controller operates the motor at a percentage of full motor power to set a desired motor speed via a closed loop control mechanism.

12. The single-acting hydraulic pump according to claim 11, wherein: The closed-loop control mechanism comprises: operating the motor at a percentage of full motor power to achieve the desired speed, determining whether the actual motor speed matches the desired speed, and When the actual motor speed does not match the desired speed, proportional-integral-derivative control is used to update the motor duty cycle.

13. The single-acting hydraulic pump of claim 10, further comprising a lock that prevents the trigger from being depressed when actuated.

14. The single-acting hydraulic pump according to claim 10, wherein: The housing also includes a battery terminal configured to receive a removable battery that powers the motor.

15. The single-acting hydraulic pump according to claim 10, wherein: The pump controller is configured to stop motor operation when the trigger is no longer depressed.

16. The single-acting hydraulic pump according to claim 10, wherein: The pump controller is configured to stop motor operation when the percentage of trigger travel is less than approximately 10%.

17. A method of operating a single-acting hydraulic pump, the method comprising: determining a percentage of trigger travel between an undepressed state and a fully depressed state when an operator depresses a trigger on the single-acting hydraulic pump; and When the operator depresses the trigger, the pump assembly is operated to pump hydraulic fluid from the bladder to the working port of the single-acting hydraulic pump, wherein Operating the pump assembly includes: A motor is controlled to drive the pump assembly at a percentage of full motor power, the percentage of full motor power being related to a percentage of trigger travel between the undepressed state and the fully depressed state.

18. The method according to claim 17, further comprising: determining a desired motor speed in relation to a percentage of full motor power; determining whether an actual motor speed matches the desired motor speed; and When the actual motor speed does not match the desired motor speed, the motor duty cycle is updated through proportional-integral-derivative control to adjust the actual motor speed to the desired motor speed.

19. The method of claim 17, further comprising determining whether an overload exists; and power cycling the motor when an overload exists.

20. The method of claim 17, further comprising stopping the motor when the percentage of trigger travel is less than approximately 10%.

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