Hydraulic oil pump for hydraulic jack and pump station comprising hydraulic oil pump

Abstract

The utility model relates to the technical field of horizontal jack manufacturing, in particular to a hydraulic oil pump for a hydraulic jack and a pump station comprising the hydraulic oil pump. According to the hydraulic oil pump, a pump body is provided with a first oil duct and a second oil duct, and is provided with a first plunger assembly and a second plunger assembly which are oppositely arranged. A sliding pair is formed between the first plunger and the first plunger sleeve, and a sliding pair is formed between the second plunger and the second plunger sleeve. Force transmission transition between the first plunger and the second plunger is achieved through the force transmission piece, the force transmission piece and the two plungers are assembled in a non-rigid clamping mode, meanwhile, a cam driving mechanism is arranged, and the first plunger and the second plunger are alternately extruded through periodic actions. Thus, on one hand, the cooperative work capacity of the first plunger assembly and the second plunger assembly is enhanced, driving force can be transmitted between the first plunger and the second plunger in real time by means of the force transmission piece, and the working rhythms of the first plunger and the second plunger are matched; on the other hand, the first plunger and the second plunger are evenly stressed, the abrasion difference is reduced, and the service life of the first plunger and the second plunger is prolonged.

Description

Technical Field

[0001] This utility model relates to the field of horizontal jack manufacturing technology, and in particular to a hydraulic oil pump for hydraulic jacks and a pump station including the same. Background Technology

[0002] In the fields of automotive repair and emergency rescue, vehicle-mounted hydraulic jacks are key equipment for ensuring the smooth operation of work, and their performance directly affects repair efficiency and operational safety. The hydraulic pump, as the core component enabling the lifting function of the vehicle-mounted hydraulic jack, provides stable power to the jack through the conversion of mechanical energy and hydraulic energy.

[0003] To optimize the performance of hydraulic pumps, some manufacturers have introduced dual-plunger hydraulic pumps, which offer advantages over traditional single-plunger pumps in terms of increased flow and reduced pressure fluctuations. However, existing dual-plunger hydraulic pumps still face several technical bottlenecks. Currently, the first and second plungers must simultaneously rest against an eccentric camshaft, relying on the camshaft's rotational force for reciprocating motion. This drive method lacks an effective coordination mechanism between the first and second plungers during operation. The absence of a structural design linking them results in relatively independent operation, hindering the full realization of the dual-plunger design's potential. Consequently, the expected flow and pressure increases are difficult to achieve. Furthermore, the force exerted by the eccentric camshaft on the first and second plungers is difficult to precisely balance, leading to significant differences in wear and drastically shortening the overall lifespan of the hydraulic pump. Over time, the wear worsens, inevitably causing significant vibration and noise, affecting not only the pump's performance but also the surrounding environment. Therefore, it is imperative for engineers to address these issues. Utility Model Content

[0004] Therefore, in view of the above-mentioned existing problems and defects, the designers of this utility model collected relevant information, conducted multiple evaluations and considerations, and carried out continuous experiments and modifications by technical personnel with many years of R&D experience in this industry, which ultimately led to the emergence of this hydraulic oil pump for hydraulic jacks.

[0005] This utility model relates to a hydraulic oil pump for a hydraulic jack, comprising:

[0006] The pump body has a first oil passage and a second oil passage inside;

[0007] The first plunger assembly includes a first plunger and a first plunger sleeve; the first plunger sleeve is fitted into the pump body; the first plunger and the first plunger sleeve form a sliding pair, and the first plunger can reciprocate in and out along the axial direction of the first plunger sleeve.

[0008] The second plunger assembly is positioned opposite the first plunger assembly; the second plunger assembly includes a second plunger and a second plunger sleeve; the second plunger sleeve is fitted into the pump body; the second plunger and the second plunger sleeve form a sliding pair, and the second plunger can reciprocate along the axial direction of the second plunger sleeve.

[0009] Force transmission component, serving as a force transmission transition between the first and second plungers;

[0010] A cam-driven mechanism is mounted on the pump body; during the operation of the cam-driven mechanism, the first plunger and the second plunger are alternately squeezed through periodic movements.

[0011] As a further improvement to the technical solution disclosed in this utility model, the force transmission component is simultaneously non-rigidly engaged with both the first plunger and the second plunger.

[0012] As a further improvement to the technical solution disclosed in this utility model, the force transmission component is a sheet metal component, which is formed by sequentially connecting a first bending arm, a component body, and a second bending arm; the first bending arm is provided with a first snap-fit ​​notch; the second bending arm is provided with a second snap-fit ​​notch; a first necked snap-fit ​​portion adapted to the first snap-fit ​​notch is formed at a set distance near the top contact end of the first plunger; a second necked snap-fit ​​portion adapted to the second snap-fit ​​notch is formed at a set distance near the top contact end of the second plunger.

[0013] As a further improvement to the technical solution disclosed in this utility model, after the snap-fit ​​assembly is completed, the first plunger has an axial displacement degree of freedom relative to the first bent arm; the second plunger has an axial displacement degree of freedom relative to the second bent arm.

[0014] As a further improvement to the technical solution disclosed in this utility model, the first plunger assembly further includes a first sealing cover and a first sealing ring; the first sealing cover is assembled on the pump body, and the first sealing ring is nested between the first plunger and the pump body.

[0015] Analogous to the above technical solution, the second plunger assembly also includes a second sealing cap and a second sealing ring; the second sealing cap is assembled on the pump body, and the second sealing ring is nested between the second plunger and the pump body.

[0016] As a further improvement to the technical solution disclosed in this utility model, the cam drive mechanism includes an eccentric camshaft and a motor; during the process of the eccentric camshaft performing circumferential rotational motion due to the torque from the motor, the first plunger and the second plunger are alternately subjected to periodic extrusion forces.

[0017] As a further improvement to the technical solution disclosed in this utility model, the hydraulic pump for the hydraulic jack also includes a drain valve; when the hydraulic jack completes the lifting operation or needs to be lowered in an emergency, the drain valve is operated to open the second oil passage, and the hydraulic oil is released back.

[0018] As a further improvement to the technical solution disclosed in this utility model, the drain valve includes:

[0019] The valve core assembly, located within the pump body, includes an axially movable inner valve core and an elastic reset element; the inner valve core has a through pressure balance channel; the elastic reset element provides a preload force to seal the initial sealing path between the first oil passage and the second oil passage.

[0020] The pressure balancing mechanism includes an axially movable pusher and a sealing body; in the initial state, the sealing body blocks the pressure balancing channel under the combined action of the pre-tightening force of the elastic reset element and the hydraulic pressure of the first oil passage.

[0021] The drive assembly is configured to sequentially transmit axial drive force to the seal and the inner valve core;

[0022] The action process of the driving component triggers the following actions in sequence:

[0023] First stage: The drive component pushes the pusher, causing the seal to release the blockage of the pressure balance channel, and the first oil passage and the second oil passage are connected through the pressure balance channel to achieve oil pressure balance;

[0024] Second stage: The drive component continues to operate and acts directly on the inner valve core. The inner valve core is able to overcome the preload and move axially. The first oil passage and the second oil passage are connected through the flow path formed after the inner valve core is moved, so as to realize the controllable return of hydraulic oil.

[0025] As a further improvement to the technical solution disclosed in this utility model, the drive assembly includes a power output part and a linkage rod; the linkage rod is rigidly connected to the pusher and forms an axial movement gap with the inner valve core, and the distance of the axial movement gap is greater than the displacement required for the sealing body to release the seal.

[0026] Furthermore, this utility model also discloses a pumping station, including an oil tank, a hydraulic cylinder, and a hydraulic oil pump for hydraulic jacks. During the operation of the pumping station, the hydraulic oil pump for hydraulic jacks draws oil from the oil tank, pressurizes it, and delivers it to the hydraulic cylinder, which then performs work to realize the lifting and lowering action of the hydraulic jacks.

[0027] In practical applications, the hydraulic oil pump for hydraulic jacks disclosed in this utility model can achieve at least the following beneficial technical effects, specifically:

[0028] 1) The force transmission component acts as a force transmission transition between the first and second plungers, thereby significantly enhancing the collaborative working capability of the first and second plunger assemblies. When the cam drive mechanism operates periodically, the force transmission component can instantly transmit the driving force on the first plunger to the second plunger, or instantly transmit the driving force on the second plunger to the first plunger, so that the working rhythms of the first and second plungers are matched, thus fully utilizing the potential of the dual-plunger structure in increasing flow rate and reducing pressure fluctuations, which is beneficial to improving the overall working efficiency of the hydraulic pump;

[0029] 2) The cam drive mechanism is used to alternately squeeze the first plunger and the second plunger. With the setting of the force transmission component, the first plunger and the second plunger are subjected to more uniform force during operation, which reduces the occurrence of plunger wear difference caused by force imbalance. This effectively extends the service life of the first plunger assembly and the second plunger assembly, thereby improving the durability and reliability of the hydraulic oil pump.

[0030] 3) The coordinated action of the force transmission component and the cam drive mechanism reduces mechanical collisions caused by asynchronous actions and abnormal vibrations caused by uneven force, which helps to significantly reduce vibration and noise during the operation of the hydraulic pump. Attached Figure Description

[0031] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0032] Figure 1 This is a three-dimensional schematic diagram of the pump station disclosed in this utility model.

[0033] Figure 2 This is a three-dimensional schematic diagram of the hydraulic oil pump disclosed in this utility model from one perspective (with hidden lines visible).

[0034] Figure 3 This is a three-dimensional schematic diagram of the hydraulic oil pump disclosed in this utility model from another perspective (with hidden lines visible).

[0035] Figure 4 This is an exploded schematic diagram of the hydraulic oil pump disclosed in this utility model (mainly showing the structural composition and assembly position relationship of the first plunger assembly, the second plunger assembly, the force transmission component, and the cam drive mechanism).

[0036] Figure 5 yes Figure 2 Top view (with hidden lines visible).

[0037] Figure 6 yes Figure 5 AA sectional view.

[0038] Figure 7 yes Figure 6 A magnified view of part of I.

[0039] Figure 8 yes Figure 6 A magnified view of part II.

[0040] Figure 9 yes Figure 5 BB cross-sectional view.

[0041] Figure 10 This is a schematic diagram showing the state of the first plunger assembly, the second plunger assembly, the force transmission component, and the cam drive mechanism of the hydraulic oil pump disclosed in this utility model after they are assembled relative to the pump body (the pump body state is hidden).

[0042] Figure 11 yes Figure 5 CC section view.

[0043] Figure 12 yes Figure 5 DD sectional view.

[0044] Figure 13 yes Figure 12 A magnified view of part III.

[0045] Figure 14 This is a three-dimensional schematic diagram of the force transmission component in the hydraulic oil pump disclosed in this utility model.

[0046] Figure 15 This is a three-dimensional schematic diagram of the eccentric camshaft in the hydraulic oil pump disclosed in this utility model.

[0047] 1-Oil tank; 2-Hydraulic cylinder; 3-Hydraulic oil pump; 31-Pump body; 311-First oil passage; 312-Second oil passage; 32-First plunger assembly; 321-First plunger; 3211-First necked engagement; 322-First plunger sleeve; 323-First sealing cover; 324-First sealing ring; 33-Second plunger assembly; 331-Second plunger; 3311-Second necked engagement; 332-Second plunger sleeve; 333-Second sealing cover; 334-Second sealing ring; 34-Force transmission component; 341-First Bending arm; 3411-First snap-fit ​​notch; 342-Main body; 343-Second bending arm; 3431-Second snap-fit ​​notch; 35-Cam drive mechanism; 351-Eccentric camshaft; 352-Motor; 36-Drain valve; 361-Valve core assembly; 3611-Inner valve core; 36111-Pressure balance channel; 3612-Compression spring; 362-Pressure balance mechanism; 3621-Pushing component; 3622-Sealing body; 363-Drive assembly; 3631-Electromagnetic drive unit; 3632-Linkage rod. Detailed Implementation

[0048] The electric pump station is the core power and control hub of the electric hydraulic horizontal jack, providing stable and powerful power output for its lifting and lowering operations.

[0049] like Figure 1 As shown, the electric pump station mainly consists of several parts, including an oil tank 1, a hydraulic cylinder 2, and a hydraulic pump 3. The hydraulic pump 3 is the core power component and energy conversion hub of the electric pump station, providing hydraulic energy to the electric hydraulic horizontal jack. The electric pump station uses the hydraulic pump 3 as its installation core, pressurizing and transporting the hydraulic oil in the oil tank 1 through pipelines to the hydraulic cylinder 2. The hydraulic cylinder 2 performs work to realize the lifting and lowering action of the hydraulic jack, completing the conversion from electrical energy to hydraulic energy and then to mechanical energy, achieving power output and execution functions.

[0050] Figure 2 , Figure 3 Two different perspective perspectives of the hydraulic oil pump disclosed in this utility model are shown. It can be seen that the hydraulic oil pump 3 is mainly composed of several parts such as pump body 31, first plunger assembly 32, second plunger assembly 33, force transmission component 34, and cam drive mechanism 35.

[0051] like Figure 11 , Figure 12 As shown, the pump body 31 has a first oil passage 311 and a second oil passage 312 formed inside it.

[0052] like Figures 4-6 , Figure 10 As shown, the first plunger assembly 32 and the second plunger assembly 33 are positioned opposite each other in the left-right direction.

[0053] The first plunger assembly 32 mainly consists of a first plunger 321 and a first plunger sleeve 322. The first plunger sleeve 322 is assembled inside the pump body 31. The first plunger 321 and the first plunger sleeve 322 form a sliding pair, and the first plunger 321 can reciprocate along the first plunger sleeve 322 when subjected to axial force.

[0054] The second plunger assembly 33 mainly consists of a second plunger 331 and a second plunger sleeve 332. The second plunger sleeve 332 is assembled inside the pump body 31. The second plunger 331 and the second plunger sleeve 332 form a sliding pair. When the second plunger 331 is subjected to axial force, it can reciprocate along the axial direction of the second plunger sleeve 332.

[0055] The force transmission element 34 is non-rigidly engaged with both the first plunger 321 and the second plunger 331 to serve as a force transmission transition between the two. For example... Figure 7 , Figure 8 , Figure 14 As shown, the force transmission component 34 is a sheet metal part, consisting of a first bent arm 341, a component body 342, and a second bent arm 343 connected sequentially. The first bent arm 341 has a first snap-fit ​​notch 3411. The second bent arm 343 has a second snap-fit ​​notch 3431. The first plunger 321 has a first necked snap-fit ​​portion 3211 formed at a set distance near its top contact end. The second plunger 331 has a second necked snap-fit ​​portion 3311 formed at a set distance near its top contact end. During assembly, the first plunger assembly 32 and the second plunger assembly 33 are installed facing each other inside the pump body 31. The force transmission component 34 forms a detachable connection with the first necked snap-fit ​​portion 3211 and the second necked snap-fit ​​portion 3311 respectively through the first snap-fit ​​notch 3411 and the second snap-fit ​​notch 3431 at both ends. In this way, the driving force is transmitted between the first plunger 321 and the second plunger 331 in real time, and the non-rigid connection provides a certain degree of freedom for the assembly operation.

[0056] like Figure 9 As shown, the cam drive mechanism 35 includes an eccentric camshaft 351 (e.g., Figure 15 (As shown in the diagram) and motor 352. Motor 352 is mounted on the front side wall of pump body 31. An eccentric camshaft 351 is inserted into pump body 31 and laterally passes through force transmission element 34. During operation of motor 352, eccentric camshaft 351 performs circumferential rotation due to the torque from motor 352, and first plunger 321 and second plunger 331 are alternately subjected to periodic compressive forces, which are transmitted through force transmission element 34.

[0057] In practical applications, when the hydraulic pump 3 is running, the motor 352 serves as the power core, outputting torque to drive the eccentric camshaft 351 to rotate circumferentially within the pump body 31. As the eccentric camshaft 351 continues to rotate circumferentially, it periodically and alternately squeezes the opposing first plunger 321 and second plunger 331. When the eccentric camshaft 351 squeezes the first plunger 321, the first plunger 321, under the action of axial force, performs a reciprocating thrusting motion along the first plunger sleeve 322 assembled within the pump body 31; simultaneously, the second plunger 331, which is not squeezed, moves in the opposite direction along the second plunger sleeve 332 due to the direct drag of the force transmission component 34. The two movements are opposite in direction and coordinated in an orderly manner.

[0058] In this process, the force transmission component 34 plays a crucial role. When the first plunger 321 is squeezed by the eccentric camshaft 351, the force transmission component 34 quickly transmits the driving force to the second plunger 331, and vice versa, thereby ensuring that the movement rhythm of the first plunger 321 and the second plunger 331 is precisely matched and they work together. Under the continuous coordinated drive of the eccentric camshaft 351 and the force transmission component 34, the first plunger 321 and the second plunger 331 alternately reciprocate, converting the mechanical energy input by the motor 352 into hydraulic energy through the plunger movement. The hydraulic oil in the oil tank 1 is compressed and pressurized before being pumped into the hydraulic cylinder 2, providing stable power for the hydraulic jack.

[0059] In summary, and after long-term experimental verification, by adopting the above-mentioned technical solution, on the one hand, the force transmission component 34 serves as the force transmission transition between the first plunger 321 and the second plunger 331, thereby significantly enhancing the cooperative working capability of the first plunger assembly 32 and the second plunger assembly 33. When the cam drive mechanism 35 operates periodically, the force transmission component 34 can instantly transmit the driving force on the first plunger 321 to the second plunger 331, or instantly transmit the driving force on the second plunger 331 to the first plunger 321, so that the working rhythm of the first plunger 321 and the second plunger 331 is matched, thereby fully utilizing the potential of the dual-plunger structure in increasing flow and reducing pressure fluctuations, which is beneficial to improving the overall working efficiency of the hydraulic pump 3. On the other hand, by using the cam drive mechanism 35 to alternately squeeze the first plunger 321 and the second plunger 331, in conjunction with the setting of the force transmission component 34, the first plunger 321 and the second plunger 331 are subjected to more uniform force during operation, reducing the occurrence of wear differences in the first plunger 321 and / or the second plunger 331 caused by force imbalance, effectively extending the service life of the first plunger assembly 32 and the second plunger assembly 33, thereby improving the durability and reliability of the hydraulic pump 3.

[0060] Here, it is also important to emphasize that the coordinated action of the force transmission component 34 and the cam drive mechanism 35 reduces mechanical collisions caused by the asynchronous action of the first plunger 321 and the second plunger 331, as well as abnormal vibrations caused by uneven force, which helps to significantly reduce vibration and noise during the operation of the hydraulic oil pump 3.

[0061] During the initial small-batch trial production phase, the following problems arose: the impact force on the first plunger 321 and the second plunger 331 could not be effectively buffered, and after being jammed, they lacked displacement freedom. Under the influence of machining errors or thermal expansion and contraction, this led to unstable operation, and even jamming of the first plunger 321 and the second plunger 331 relative to the force transmission component 34. Therefore, as a further optimization of the above technical solution, such as... Figure 7 , 8 As shown, after the snap-fit ​​assembly is completed, the first plunger 321 has a certain degree of axial displacement freedom relative to the first bent arm 341; the second plunger 331 has a certain degree of axial displacement freedom relative to the second bent arm 343. This endows the first plunger assembly 32 and the second plunger assembly 33 with buffering performance. When the eccentric camshaft 351 presses against the first plunger 321 and the second plunger 331, the preset axial displacement freedom can effectively absorb the impact force, reduce hard collisions, and thus reduce the amount of wear per unit time.

[0062] Based on multiple experimental results, the recommended design dimensions are as follows: Assuming the thicknesses of the first bent arm 341 and the second bent arm 343 are W1 and W2 respectively, and the groove widths of the first necked snap-fit ​​part 3211 and the second necked snap-fit ​​part 3311 are W3 and W4 respectively, then 0.2mm≤W3-W1≤0.5mm, 0.2mm≤W4-W2≤0.5mm. Furthermore, the precisely controlled dimensional differences ensure that under different working conditions, the first plunger 321 and the second plunger 331 can achieve stable force transmission, and can also compensate for machining errors and adapt to thermal deformation through appropriate displacement, avoiding operational failures caused by stress concentration, and improving the stability and reliability of the hydraulic pump 3.

[0063] Similarly, Figures 4-6As described above, the first plunger assembly 32 is further provided with a first sealing cover 323 and a first sealing ring 324. The second plunger assembly 33 is further provided with a second sealing cover 333 and a second sealing ring 334. The first sealing cover 323 and the second sealing cover 333 are respectively mounted on the left and right side walls of the pump body 31 as detachable assembly bases. The first sealing ring 324 is nested between the first plunger 321 and the pump body 31. The second sealing ring 334 is nested between the second plunger 331 and the pump body. In this way, the leakage of high-pressure hydraulic oil during the operation of the hydraulic oil pump 3 can be effectively prevented, which helps to ensure the stability of system pressure and improve energy conversion efficiency; at the same time, it can block the intrusion of external contaminants such as dust and moisture, reduce the wear of the first plunger 321 and the second plunger 331, extend the service life of the equipment, and reduce the risk of failure.

[0064] According to industry practice, during the operation of a hydraulic jack, the system pressure needs to be flexibly controlled to ensure operational safety and equipment stability. Therefore, as a further optimization of the above technical solution, such as... Figure 2 , Figure 3 As shown, the hydraulic oil pump 3 is equipped with an oil drain valve 36, which can be opened or closed by the operator according to actual needs to achieve precise adjustment of the hydraulic oil return flow, making the descent speed and pressure release process of the hydraulic jack controllable, perfectly meeting the operational needs under various complex working conditions.

[0065] like Figure 11 , Figure 12 As shown, the drain valve 36 mainly consists of a valve core assembly 361, a pressure balancing mechanism 362, and a drive assembly 363. The pump body 31 also serves as the mounting base for the valve core assembly 361, allowing the valve core assembly 361, pressure balancing mechanism 362, and drive assembly 363 to be directly integrated into the pump body 31, reducing the need for conventional valve body designs and significantly simplifying the system architecture.

[0066] The valve core assembly 361 is disposed within the pump body 31, and includes an axially movable inner valve core 3611 and a compression spring 3612. For example... Figure 13 As shown, the inner valve core 3611 has a through pressure balance channel 36111. The compression spring 3612 provides a preload force to cause the inner valve core 3611 to block the initial sealing path between the first oil passage 311 and the second oil passage 312.

[0067] The pressure balancing mechanism 362 includes an axially movable pusher 3621 and a sealing body 3622. In the initial state, the sealing body 3622, under the combined action of the preload of the compression spring 3612 and the hydraulic pressure of the first oil passage 311, seals the pressure balancing channel 36111. As... Figure 13 As shown, after the pusher 3621 is inserted relative to the pressure balance channel 36111, the two are in a clearance fit, and the clearance value d on one side is controlled between 0.2 and 0.4 mm.

[0068] Similarly, Figure 11 , Figure 12 As shown, the sealing body 3622 and the inlet end of the pressure balance channel 36111 adopt a conical surface sealing design with a cone angle of 60 to 120°. Combined with a high-precision surface with Ra≤0.4μm, when the sealing body 3622 approaches the inlet of the pressure balance channel 36111, the conical surface geometry generates a radial convergence guiding force, which can automatically correct the eccentricity of the sealing body 3622 and ensure that the spherical surface and the conical surface fit together evenly.

[0069] like Figure 9 , Figure 11 , Figure 12 As shown, the drive assembly 363 includes an electromagnetic drive unit 3631 and a linkage rod 3632. The linkage rod 3632 is rigidly connected to the pusher 3621 and forms an axial movement gap with the inner valve core 3611, and the distance of the axial movement gap is greater than the displacement required for the sealing body 3622 to release the seal.

[0070] Under normal operating conditions of the electric pump station, the hydraulic oil in the system circulates according to the predetermined working oil circuit to maintain the stable working state of the electric hydraulic horizontal jack. At this time, the compression spring 3612 applies a stable preload to the inner valve core 3611 to ensure a reliable isolation between the first oil passage 311 and the second oil passage 312, preventing abnormal short-circuit backflow of the oil. At the same time, under the combined action of the preload of the compression spring 3612 and the hydraulic oil pressure in the first oil passage 311, the seal 3622 tightly seals the inlet of the pressure balance channel 36111, thereby preventing oil from flowing into the pressure balance channel 36111 under unnecessary circumstances, and ensuring that the pressure distribution and oil flow direction in the system meet the normal operating requirements.

[0071] When the system performs an oil release operation (e.g., in specific working conditions such as when an electro-hydraulic horizontal jack needs to be lowered to release the support of a heavy object), the system control signal triggers the electromagnetic drive unit 3631 to be energized and started. The electromagnetic drive unit 3631 then generates electromagnetic force, driving the linkage rod 3632 to move axially. Since the linkage rod 3632 and the pusher 3621 are rigidly connected, the pusher 3621 will synchronously generate axial displacement under the drive of the linkage rod 3632. As the pusher 3621 moves, it will gradually approach and eventually push the seal 3622, allowing it to overcome the preload of the compression spring 3612 and the hydraulic force of the first oil passage 311, thus releasing the blockage of the pressure balance channel 36111. Once the pressure balance channel 36111 is opened, the hydraulic oil with a certain pressure in the first oil passage 311 will quickly flow into the area above the inner valve core 3611 through the pressure balance channel 36111. Through this process, the pressure difference between the front and rear sides of the inner valve core 3611 is quickly balanced, creating favorable pressure conditions for opening the main flow path between the first oil passage 311 and the second oil passage 312. After the pressure balance is completed, the electromagnetic drive unit 3631 remains energized, and the linkage rod 3632 continues to push the pusher 3621 forward. At this time, under the combined action of the residual small pressure difference and the pusher 3621, the inner valve core 3611 overcomes the preload of the compression spring 3612 and begins to undergo axial displacement. As the inner valve core 3611 moves, the originally blocked flow path between the first oil passage 311 and the second oil passage 212 is gradually opened, and the flow path gradually expands as the displacement of the inner valve core 3611 increases. The hydraulic oil in the system under high pressure is driven by the pressure difference and quickly flows back to the oil tank 1 through the connected first oil passage 311 and second oil passage 212, thereby achieving efficient oil discharge operation and meeting the system's requirements for oil discharge speed and flow rate.

[0072] Multiple experiments have verified that by adopting the above-mentioned technical solution, on the one hand, during the oil discharge process, the linkage rod 3632 pushes the pusher 3621, firstly causing the sealing body 3622 to open the pressure balance channel 36111, connecting the first oil passage 311 and the second oil passage 212. In this stage, by balancing the system oil pressure, the pressure difference across the inner valve core 3611 is significantly reduced. Based on this, when opening the main flow path, the inner valve core 3611 only needs to overcome a small resistance to achieve axial displacement, avoiding the flow shock caused by sudden pressure changes in traditional oil discharge valves. This keeps the pressure change gradient within a very small range, effectively reducing system vibration and noise levels, and ensuring a smooth and vibration-free descent of the hydraulic jack. On the other hand, through the coordinated work of the compression spring 3612 and the pressure balance channel 36111, precise pressure control during the oil discharge process is achieved. During the pressure balancing phase, the movement of the seal 3622 pre-adjusts the system pressure, creating stable pressure conditions for the main oil draining phase. During the main oil draining phase, the inner valve core 3611 overcomes the preload under precise axial driving force, forming a flow path linearly related to the driving force. This design effectively reduces the opening and closing pressure error, improving the pressure control accuracy to within the expected design value.

[0073] The above description of the disclosed embodiments enables those skilled in the art to make or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A hydraulic oil pump for a hydraulic jack, characterized in that, include: The pump body has a first oil passage and a second oil passage inside; The first plunger assembly includes a first plunger and a first plunger sleeve; The first plunger assembly is fitted into the pump body; The first plunger and the first plunger sleeve form a sliding pair, and the first plunger can reciprocate in and out along the axial direction of the first plunger sleeve. The second plunger assembly is positioned opposite the first plunger assembly; the second plunger assembly includes a second plunger and a second plunger sleeve; the second plunger sleeve is fitted into the pump body; the second plunger and the second plunger sleeve form a sliding pair, and the second plunger can reciprocate along the axial direction of the second plunger sleeve. A force transmission component, serving as a force transmission transition between the first plunger and the second plunger; A cam drive mechanism is mounted on the pump body; during the operation of the cam drive mechanism, the first plunger and the second plunger are alternately squeezed by periodic actions.

2. The hydraulic oil pump for a hydraulic jack according to claim 1, characterized in that, The force transmission component is simultaneously and non-rigidly engaged with both the first plunger and the second plunger.

3. The hydraulic oil pump for a hydraulic jack according to claim 2, characterized in that, The force transmission component is a sheet metal part, which is formed by sequentially connecting a first bending arm, a component body, and a second bending arm; the first bending arm is provided with a first snap-fit ​​notch; the second bending arm is provided with a second snap-fit ​​notch; a first necked snap-fit ​​portion adapted to the first snap-fit ​​notch is formed at a set distance near the top contact end of the first plunger; a second necked snap-fit ​​portion adapted to the second snap-fit ​​notch is formed at a set distance near the top contact end of the second plunger.

4. The hydraulic oil pump for a hydraulic jack according to claim 3, characterized in that, After the snap-fit ​​assembly is completed, the first plunger has an axial displacement degree of freedom relative to the first bent arm; the second plunger has an axial displacement degree of freedom relative to the second bent arm.

5. The hydraulic oil pump for a hydraulic jack according to claim 1, characterized in that, The first plunger assembly further includes a first sealing cap and a first sealing ring; the first sealing cap is assembled on the pump body, and the first sealing ring is nested between the first plunger and the pump body.

6. The hydraulic oil pump for a hydraulic jack according to claim 1, characterized in that, The second plunger assembly further includes a second sealing cap and a second sealing ring; the second sealing cap is assembled to the pump body, and the second sealing ring is nested between the second plunger and the pump body.

7. The hydraulic oil pump for a hydraulic jack according to claim 1, characterized in that, The cam drive mechanism includes an eccentric camshaft and a motor; during the process of the eccentric camshaft performing circumferential rotation due to the torque from the motor, the first plunger and the second plunger are alternately subjected to periodic compressive forces.

8. The hydraulic oil pump for a hydraulic jack according to any one of claims 1-7, characterized in that, It also includes a drain valve; when the hydraulic jack completes the lifting operation or needs to be lowered in an emergency, the drain valve is operated to open the second oil passage, allowing the hydraulic oil to flow back and be released.

9. The hydraulic oil pump for a hydraulic jack according to claim 8, characterized in that, The drain valve includes: A valve core assembly, disposed within the pump body, includes an axially movable inner valve core and an elastic reset element; the inner valve core is provided with a through pressure balance channel; the elastic reset element provides a preload force to cause the inner valve core to block the initial sealing path between the first oil passage and the second oil passage; The pressure balancing mechanism includes an axially movable pusher and a sealing body; in the initial state, the sealing body blocks the pressure balancing channel under the combined action of the pre-tightening force of the elastic reset element and the hydraulic pressure of the first oil passage. A drive assembly configured to sequentially transmit axial driving force toward the seal and the inner valve core; The action process of the driving component triggers the following actions in sequence: First stage: The drive component pushes the pusher, causing the seal to release the blockage of the pressure balance channel, and the first oil passage and the second oil passage are connected through the pressure balance channel to achieve oil pressure balance; Second stage: The drive component continues to operate and acts directly on the inner valve core, which overcomes the preload and moves axially. The first oil passage and the second oil passage are connected through the flow path formed after the inner valve core moves, so as to realize the controllable return of hydraulic oil.

10. The hydraulic oil pump for a hydraulic jack according to claim 9, characterized in that, The drive assembly includes a power output section and a linkage rod; the linkage rod is rigidly connected to the pusher and forms an axial movement gap with the inner valve core, and the distance of the axial movement gap is greater than the displacement required for the sealing body to release the seal.

11. A pumping station, characterized in that, It includes an oil tank, a hydraulic cylinder, and a hydraulic oil pump for a hydraulic jack as described in any one of claims 1-10; during the operation of the pump station, the hydraulic oil pump for the hydraulic jack draws oil from the oil tank, pressurizes it, and delivers it to the hydraulic cylinder, and the hydraulic cylinder performs work to realize the lifting and lowering action of the hydraulic jack.

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