Pump control and electric push double-control cylinder

Abstract

The pump control and electric push double-control cylinder comprises a cylinder body and a guide sleeve, a piston and a piston rod are arranged in the cylinder body, a rod cavity is formed among the cylinder body, the piston rod and the guide sleeve, a rodless cavity is formed between the other end of the piston and the cylinder body, a driving device is arranged at one end of the rodless cavity, and an output shaft of the driving device is fixedly connected with the tail end of a tooth-shaped lead screw. A lead screw nut in the lead screw containing cavity is matched with the tooth-shaped lead screw, a hydraulic driving assembly is arranged in the piston, and an oil channel used for being connected with the hydraulic driving assembly, the rod cavity and the rodless cavity is formed in the piston. Outer teeth are arranged on the radial circumferential face of threads of the tooth-shaped lead screw. Compared with a hydraulic cylinder and an electric cylinder which are controlled by a traditional hydraulic system, the pump control and electric push double-control cylinder is wide in applicability and high in driving force, has comprehensive bearing capacity aiming at external loads, has bidirectional locking capacity under the working condition that the position needs to be kept, is stable in driving performance, and is suitable for large-scale popularization and application. Driving double insurance is achieved, and the safety performance is improved.

Description

Technical Field

[0001] The present invention belongs to the technical field of hydraulic components, and in particular relates to a pump-controlled electric push double-controlled cylinder. Background Art

[0002] In industrial engineering, the traditional linear displacement driven hydraulic cylinder is used as an actuator. Compared with electric cylinders and pneumatic cylinders, it has the characteristics of high energy density and stable drive. However, the hydraulic cylinder requires special control components and hydraulic systems for control, and complicated connecting pipes are required between the two. There is a high risk of oil leakage, a high failure rate, a large volume, and large energy loss in electrical and hydraulic transmission. In addition, ordinary hydraulic cylinders are inefficient, and there is a delay in dynamic response during high-speed reciprocating work and insufficient adaptability to complex working conditions. The existing electro-hydraulic push rods and electric cylinders are basically realized by carrying a certain volume of motors, transmission components or hydraulic power units on the cylinder end, and the volume increase is inevitable. Therefore, electro-hydraulic push rods and electric cylinders are still widely used. However, it has not broken away from traditional control structures and methods such as hydraulic drive and mechanical transmission. Cylinders are used for light-load conditions and the compressibility of gas is not easy to control. With the development of technology and the current development of new energy and energy storage technologies, more and more equipment uses electric drive. For example, electric cylinders are used in linear drives. However, electric cylinders have defects such as low driving force, limited application scenarios, and many and precise components, high cost, and complex manufacturing. They cannot meet high-load requirements. Based on the above technical background and current application scenario requirements, we explore a dual-drive method that can be driven by hydraulic power and combined with electric conversion to mechanical transmission to achieve large-load displacement, integrating electric and hydraulic linear drive technologies and devices to solve the above problems. Summary of the Invention

[0003] In view of the shortcomings of the existing technology, the present invention provides a pump-controlled electric push double-control cylinder, comprising a cylinder body and a guide sleeve, a piston and a piston rod are arranged in the cylinder body, a rod cavity is formed between the cylinder body, the piston rod and the guide sleeve, a rodless cavity is formed between the other end of the piston and the cylinder body, a driving device is arranged at one end of the rodless cavity, a driving rod assembly is arranged in the cylinder body, the driving rod assembly includes a toothed screw arranged in the cylinder body and a screw nut matched with the toothed screw, the output shaft of the driving device is fixedly connected to the tail end of the toothed screw; a cavity is arranged in the piston rod, the toothed screw passes through the movable The plug extends into the piston rod cavity, and the end of the piston rod cavity is nested with a screw nut; a cavity for installing a hydraulic drive component is provided inside the piston, and an oil channel for connecting the hydraulic drive component, the rod cavity and the rodless cavity is also provided inside the piston; the toothed screw includes a screw body and external teeth provided on the outer peripheral surface of the screw body thread; the hydraulic drive assembly includes a transmission input member connected to the toothed screw, an engaging hole is provided inside the transmission input member, and a key is axially provided on the inner wall of the engaging hole, and the external teeth of the toothed screw engage with the key in the engaging hole of the transmission input member.

[0004] Preferably, the hydraulic drive assembly includes an internal gear, an external gear, and an oil distribution partition block. The external gear is nested inside the internal gear, and the oil distribution partition block is arranged between the internal gear and the external gear. The external gear serves as the transmission input component.

[0005] Preferably, the hydraulic drive assembly includes a swash plate support seat, a swash plate, a straight plate, a valve plate, a plunger assembly between the swash plate and the straight plate, a ball joint, and pressure plates on both sides thereof, which are arranged in sequence. The swash plate support seat, the swash plate, the straight plate, the valve plate, the plunger assembly, the ball joint, and the pressure plates on both sides thereof are all provided with through holes for the toothed lead screw to pass through. The swash plate and the straight plate serve as the transmission input components.

[0006] Preferably, the piston includes an annular body, a front cover and a rear cover arranged on both sides of the annular body. The annular body is connected to the cylinder bore axis, the front cover is fixedly connected to the piston rod, and an oil passage one and an oil passage two are arranged on the annular body. The oil passage one connects the hydraulic drive assembly with the rod chamber, and the oil passage two connects the hydraulic drive assembly with the non-rod chamber.

[0007] Preferably, the piston includes a housing and a housing rear cover installed behind the housing. The housing is in fit with the cylinder bore axis. An oil passage one and an oil passage two are arranged on the housing. The oil passage one communicates with the non-rod chamber, and the oil passage two communicates with the rod chamber.

[0008] Preferably, the output shaft of the drive device is connected to the toothed lead screw. An annular groove is arranged at the place where the toothed lead screw extends out of the bottom through hole of the cylinder. A limit ring is clamped inside the annular groove. A limit cover is fixedly arranged on the other side of the limit ring. The limit cover is fixed to the bottom of the cylinder by a nut. A drive device is arranged on the other side of the limit cover. The cooperation between the limit ring and the limit cover can offset the axial force of the toothed lead screw.

[0009] Preferably, the piston rod passes through the guide sleeve and extends out of the cylinder body. A cylinder sleeve is arranged at the end of the piston rod. The bottom of the cylinder sleeve is fixedly connected to the piston rod by bolts. The whole cylinder sleeve is sleeved on the cylinder body and can perform axial reciprocating motion along the side wall of the cylinder body together with the piston rod.

[0010] Preferably, an axial rotation limit structure is arranged between the cylinder sleeve and the cylinder body. The axial rotation limit structure includes a flat key arranged on the side wall of the cylinder body and a key groove on the inner wall of the cylinder sleeve that cooperates with the flat key.

[0011] Preferably, the drive device can adopt a servo motor, a hydraulic motor, an engine including a gearbox, or any device that can provide forward and reverse driving forces.

[0012] Preferably, an annular cavity is arranged inside the guide sleeve. An annular partition is arranged inside the annular cavity. The annular partition divides the space inside the annular cavity into a high-pressure gas cavity and an oil storage cavity. An oil passage is arranged on one side of the oil storage cavity and communicates with the rod chamber.

[0013] The present invention has the following beneficial effects: The lead screw is rotated by a motor, and then the power is transmitted to the piston part to output hydraulic power. At the same time, the linear driving force is output through the lead screw nut, so as to realize the dual driving ability of the axial force. The overall structure integrates a motor, a hydraulic driving component and an oil compensation device. Compared with the hydraulic cylinders and electric cylinders controlled by traditional hydraulic systems, this pump-controlled electro-hydraulic double-control cylinder has a wide range of applicability and strong driving force. It has an integrated bearing capacity for external loads. In the working condition that requires position holding, it has a two-way locking ability, stable driving performance, realizes double insurance for driving, improves safety performance, and can accurately measure and feedback the displacement according to the rotation amount of the servo motor during linear displacement, omitting the displacement sensor, reducing the control cost, avoiding the problems of large volume and weight of traditional hydraulic control, and there are no problems of insufficient thrust and complex components of traditional electric cylinders. The output flow is directly adjusted through the servo system to realize "energy supply on demand", greatly reducing the overflow and throttling losses. Brief Description of the Drawings

[0014] Figure 1 is a schematic cross-sectional view of the overall structure of the present invention; Figure 2 is a schematic cross-sectional view of the overall structure during the use of the present invention; Figure 3 is a schematic cross-sectional view of the lead screw nut of the present invention; Figure 4 is a schematic cross-sectional view of the overall structure of the piston part of the present invention; Figure 5 is a schematic diagram of the meshing structure of the internal parts of the gear-type hydraulic driving component of the present invention; Figure 6 is a schematic cross-sectional view of the overall structure of the tooth-shaped lead screw of the present invention; Figure 7 is a schematic cross-sectional view of the tooth-shaped lead screw of the present invention; Figure 8 is Figure 7 the schematic cross-sectional view at A-A in Figure 9 is a schematic diagram of the cylinder block structure of the present invention; Figure 10 is a schematic diagram of the sleeve structure of the present invention; Figure 11 is a schematic cross-sectional view of the internal structure of the sleeve of the present invention; Figure 12 is a schematic cross-sectional view of the overall structure of the plunger-type hydraulic driving component of the present invention; Wherein: 1 - cylinder block, 11 - rod chamber, 12 - rodless chamber, 13 - oil port, 14 - cylinder sleeve, 15 - shaft rotation limit structure, 151 - flat key, 152 - keyway, 16 - limit cover, 17 - limit ring; 2 - Guide sleeve, 21 - Annular spacer, 22 - High - pressure gas chamber, 23 - Oil storage chamber; 3 - Driving device, 31 - Driving rod assembly, 311 - Serrated lead screw, 312 - Lead screw nut, 313 - External teeth; 4 - Piston, 41 - Oil passage 1, 42 - Oil passage 2; 5 - Piston rod, 51 - Lead screw cavity; 611 - Front cover, 612 - Ring body, 613 - Rear cover, 614 - Internal gear, 615 - External gear, 616 - Oil - separating partition block, 617 - Meshing hole; 621 - Housing, 622 - Housing rear cover, 623 - Swash - plate support seat, 624 - Swash - plate, 625 - Straight plate, 626 - Oil distribution plate, 627 - Plunger assembly, 628 - Ball joint, 629 - Pressure plate. Detailed implementation manners

[0015] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0016] Embodiment 1: As Figure 1 shown, a pump - controlled electro - push double - control cylinder includes a cylinder block 1 and a guide sleeve 2 provided at the cylinder head of the cylinder block 1. Threads are provided on the inner wall of the cylinder head of the cylinder block 1, and an oil port 13 is provided on the side wall of the bottom of the cylinder block 1. The guide sleeve 2 is screwed onto the cylinder head of the cylinder block 1 through threads, and a gasket is provided between the guide sleeve 2 and the cylinder block 1 to prevent oil leakage. A hole is provided at the center of the bottom of the cylinder block 1, and a driving device 3 is provided on one side of the rodless cavity 12 of the cylinder block 1. The serrated lead screw 311 connected to the output shaft of the driving device 3 penetrates into the cylinder block 1 through the hole at the center of the bottom of the cylinder block 1, and a piston 4 and a piston rod 5 are provided inside the cylinder block 1.

[0017] As Figure 1-3 shown, the front end of the piston 4 is fixedly connected to the piston rod 5. The piston 4 is in hole - shaft fit with the cylinder block 1, and a sealing ring is provided at the mating part of the piston 4 and the cylinder block 1. An axial through - hole is provided in the middle of the piston 4. The piston rod 5 passes through the guide sleeve 2 and extends out of the cylinder block 1. The piston rod 3 is in shaft - hole connection with the guide sleeve 2. An annular cavity is provided inside the guide sleeve 2, and a movable annular spacer 21 is provided in the annular cavity. Annular gaskets are respectively provided on the inner and outer edges of the annular spacer 21 to divide the space in the annular cavity into a high - pressure gas chamber 22 and an oil storage chamber 23. A gas port is provided on one side of the high - pressure gas chamber 22, and high - pressure gas is filled inside. An oil passage communicating with the rod - side cavity 11 is provided on one side of the oil storage chamber 23, and a lead screw cavity 51 is provided inside the piston rod 5.

[0018] The driving device 3 can adopt a servo motor, a hydraulic motor, an engine with a gearbox, or any driving device with a rotatable output shaft that can rotate forward and backward. The driving device 3 is fixed to the center of the outer side of the bottom of the cylinder block 1 by bolts. The driving rod assembly 31 includes a toothed lead screw 311 and a lead screw nut 312. The output shaft of the driving device 3 is fixedly connected to the toothed lead screw 311. The connection between the toothed lead screw 311 and the output shaft of the driving device 3 is arranged in the central hole of the bottom of the cylinder block 1. An annular groove is arranged at the position where the toothed lead screw 311 extends out of the through hole at the bottom of the cylinder. A limit ring 17 is clamped inside the annular groove. A limit cover 16 is fixedly arranged on the other side of the limit ring 17. The limit cover 16 is fixed to the bottom of the cylinder by a nut. The driving device 3 is fixedly arranged on the other side of the limit cover 16. The cooperation between the limit ring 17 and the limit cover 16 can offset the axial force of the toothed lead screw 311 and prevent the axial force from being transmitted to the driving device 3. The toothed lead screw 311 passes through the axial through hole in the middle of the piston 4 and extends into the lead screw cavity 51 inside the piston rod 5. The piston rod 5 is a cylindrical structure with an opening on one side. A formed flange is arranged at the opening and is fixedly connected to the front end of the piston 4. The lead screw nut 312 is nested inside the opening of the piston rod 5. A limiting device is arranged between the lead screw nut 312 and the piston rod 5 to restrict the circumferential rotation of the two. The lead screw nut 312 cooperates with the toothed lead screw 311. When the toothed lead screw 311 rotates, it can drive the piston rod 5 to move back and forth along the axial direction of the toothed lead screw 311 through the cooperation with the lead screw nut 312. When the toothed lead screw 311 cooperates with the lead screw nut 312, during the rotation of the toothed lead screw 311, it can drive the lead screw nut 312 to generate an axial displacement, thereby driving the piston part to perform an axial displacement. The displacement of the hydraulic drive assembly matches the effective area of the rodless cavity 12. The amount of oil flowing in and out of the rodless cavity 12 is equal to the change in the volume of the rodless cavity 12 after the piston 4 moves. The volume inside the rodless cavity 12 changes as the piston part moves. When the rodless cavity 12 expands, the oil can synchronously fill the space inside the rodless cavity 12 under the distribution of the hydraulic drive assembly. When the rodless cavity 12 contracts, the oil can flow from the rodless cavity 12 to the rod cavity 11 in time under the distribution of the hydraulic drive assembly.

[0019] Such as Figure 2 , Figure 4 and Figure 5As shown in the figure, the piston 4 includes a front cover 611, a ring body 612, and a rear cover 613. An oil passage 41 and an oil passage 42 are provided on the ring body 612. The front cover 611 is fixedly connected to the flange of the piston rod 5 by bolts. The hydraulic drive assembly includes side plates connected to the front cover 611 and the rear cover 613, and an internal gear 614, an external gear 615, and an oil distribution partition 616 between the side plates. The oil distribution partition 616 is arranged between the internal gear 614 and the external gear 615. Symmetrical oil passages are provided on both sides of the hydraulic drive assembly, and both ends of the symmetrical oil passages are respectively communicated with the oil passage 41 and the oil passage 42. The external gear 615 serves as a transmission input member, and a meshing hole 617 is provided in the middle. A key capable of cooperating with the tooth-shaped lead screw 311 is arranged in the meshing hole 617. The tooth-shaped lead screw 311 can drive the external gear 615 to rotate through the meshing hole 617. When the internal gear 614 and the external gear 615 rotate in the same direction, the gears gradually separate on the oil suction side, and the volume between the teeth increases to form a negative pressure. The liquid is sucked in and enclosed between the tooth grooves and the oil distribution partition 616, and moves along the cavity to the oil discharge side as the gears rotate. On the oil discharge side, the gears re-mesh, resulting in a decrease in the sealed volume, and the liquid is squeezed out and output through the oil discharge port.

[0020] As Figure 6 , Figure 7 and Figure 8 shown in the figure, the tooth-shaped lead screw 311 includes threads and a plurality of groups of external teeth 313 arranged on the outer peripheral surface of the threads. Each group of external teeth 313 is arranged axially. The cross-section of the tooth-shaped lead screw 311 presents a circular base body with a plurality of radial protrusions arranged at equal circumferential intervals. The external teeth 313 correspond to the meshing holes 617 in the middle of the internal and external gears 615 of the hydraulic drive assembly. When the tooth-shaped lead screw 311 passes through the rear cover 613, the meshing hole 617, and the front cover 611 of the piston 5, it enters the lead screw cavity 51 through cooperation with the lead screw nut 312. The depth of the thread groove of the lead screw nut 312 is sufficient to accommodate the external teeth 313 and the threads of the tooth-shaped lead screw 311. The threads and the external teeth 313 at the edge of the tooth-shaped lead screw 311 are combined. During the rotation of the tooth-shaped lead screw 311, it can drive the lead screw nut 312 to move axially through the threads and also provide a rotational force to the external gear in the hydraulic drive assembly through the external teeth 313.

[0021] As Figure 1 , Figure 9 , Figure 10 and Figure 11 shown in the figure, a cylinder sleeve 14 is sleeved outside the cylinder block 1. The bottom of the cylinder sleeve 14 is fixedly connected to the end of the piston rod 5. The cylinder sleeve 14 can perform axial reciprocating movement along the side wall of the cylinder block 1 driven by the piston rod 5. An axial rotation limiting structure 15 is provided between the cylinder sleeve 14 and the cylinder block 1. The axial rotation limiting structure 15 includes a flat key 151 arranged on the side wall of the cylinder block 1 and a key groove 152 on the inner wall of the cylinder sleeve 14. The cooperation of the flat key 151 and 152 restricts the cylinder block 1 and the cylinder sleeve 14 from rotating circumferentially.

[0022] When the working conditions of the first embodiment are complete, when the piston rod 5 extends to work, the piston 5 is located at the bottom of the cylinder block 1 of the cylinder block. At this time, the rod chamber 11 is filled with oil. Start the driving device 3, and the driving device 3 drives the toothed lead screw 311 to start rotating. The toothed lead screw 311 cooperates with the transmission input part to drive the hydraulic driving component to start running. During the operation of the hydraulic driving component, the oil flows from the rod chamber 11 into the first oil passage 41, and enters the rodless chamber 12 through the second oil passage 42 under the control of the hydraulic driving component. At the same time, the piston 5 moves axially along the entire toothed lead screw 311, pushing the piston rod 5 and the cylinder sleeve 14 to extend.

[0023] When the piston rod 5 needs to retract into the cylinder block 1, the driving device 3 rotates in the reverse direction, driving the hydraulic driving component to distribute the oil in the reverse direction, sucking the oil from the rodless chamber 12 through the second oil passage 42, and reversely distributing it to the first oil passage 41 through the symmetrical oil passage and then entering the rod chamber 11. The oil pushes the piston 4 to move axially backward, driving the piston rod 5 to retract into the cylinder block 1.

[0024] The guide sleeve 2 can play a role in compensating and adjusting the volume difference of the oil during the operation of the oil cylinder. When the piston rod 5 retracts, the oil flows from the rodless chamber 12 into the rod chamber 11. Due to the increase in the flow rate and pressure of the oil, the oil enters the oil storage chamber 23 through the oil passage on the guide sleeve 2, compressing the space of the high-pressure gas chamber 22 through the annular separator 21. When the piston rod 5 extends, the oil flows from the rod chamber 11 into the rodless chamber 12. At this time, the pressure in the rod chamber 11 becomes smaller, and the pressure in the oil storage chamber 23 in the guide sleeve 2 also becomes smaller. The high-pressure gas in the high-pressure gas chamber 22 in the guide sleeve 2 starts to push the annular separator 21 outward to compensate the oil in the oil storage chamber 23 into the rod chamber 11.

[0025] Embodiment 2: As Figure 12As shown in the figure, the difference between the second embodiment and the first embodiment lies in that in the second embodiment, the piston 4 includes a housing 621 and a housing rear cover 622. An oil passage one 41 and an oil passage two 42 are respectively arranged on the housing rear cover 622. The end of the housing 621 is fixedly connected to the flange of the piston rod 5 by bolts. The housing 621 is in hole-shaft fit with the cylinder block 1. A sealing ring is arranged at the mating part of the housing 621 and the cylinder block 1. The hydraulic drive assembly is arranged in the enclosed space of the housing 621 and the housing rear cover 622. The hydraulic drive assembly includes a swash plate support 623 nested inside the housing 621 and a swash plate 624 in clearance fit with the swash plate support 623. An oil distribution plate 626 is nested on the housing rear cover 622 and a straight plate 625 connected to the oil distribution plate. A number of plunger assemblies 627 are evenly distributed in a circular pattern between the swash plate 624 and the straight plate 625. In the middle of the number of plunger assemblies 627, the swash plate 624 and the straight plate 625 are hinged and fitted through a ball joint 628 and pressure plates 629 on both sides of the ball joint 628. The swash plate 624 and the straight plate 625 are transmission input parts. Keys are arranged in the axial through holes of the swash plate 624 and the straight plate 625. When the tooth-shaped lead screw 311 passes through, the key can engage with the key teeth on the tooth-shaped lead screw 311. When the tooth-shaped lead screw 311 rotates, it drives the swash plate 623 and the straight plate 624 to rotate through the key teeth. At this time, the plunger assemblies 627 inside the hydraulic drive device start to move axially back and forth to distribute the oil fluid, driving the piston 4 to move axially back and forth along the tooth-shaped lead screw 311.

[0026] During use, the piston 4 is located at the bottom of the cylinder of the cylinder block 1. The drive device 3 is started. At this time, the drive device 3 drives the tooth-shaped lead screw 311 to start rotating. During the rotation of the tooth-shaped lead screw 311, through the cooperation between the tooth-shaped lead screw 311 and the transmission input parts inside the hydraulic drive assembly, the hydraulic drive assembly is driven to start operating. By distributing the oil fluid, the piston 4 moves axially as a whole along the tooth-shaped lead screw 311. The oil fluid enters the oil passage two 42 from the rod chamber 11, and after being distributed by the hydraulic drive assembly, it enters the rodless chamber 12 from the oil passage one 41, pushing the piston rod 5 to extend. When the piston rod 5 needs to retract into the cylinder block 1, by reversing the rotation of the drive device 3, the hydraulic drive assembly is driven to distribute the oil fluid in the reverse direction. The oil fluid is distributed from the rodless chamber 12 through the oil passage one 41 to the oil passage two 42 and then enters the rod chamber 11, pushing the piston rod 5 to retract.

[0027] In the embodiments of this patent document, the hydraulic drive components mainly take the internal meshing gear structure, plunger structure, etc. as typical hydraulic components to carry out exemplary explanations. Specifically, the structural designs, working characteristics and application methods in the hydraulic system of the two are disclosed, providing specific references for the implementation modes of the technical solutions. However, it should be particularly noted that the above embodiments are only representative examples for explaining the core innovation points, and the actual technical scope involved is not limited to this - in the devices related to this solution, the hydraulic drive components may also include other hydraulic components not specifically elaborated in the embodiments, such as: hydraulic motors, hydraulic pumps, cycloidal motors, etc. Hydraulic motors include gear motors and plunger motors, and hydraulic pumps include gear pumps or plunger pumps, etc. These components and the pump components in the embodiments together constitute a complete hydraulic system functional module, and all belong to the technical scope covered by the technical solution of the present invention.

Claims

1. A pump-controlled electro-push double-control cylinder, comprising a cylinder block (1) and a guide sleeve (2). A piston (4) and a piston rod (5) are arranged inside the cylinder block (1). A rod chamber (11) is formed among the cylinder block (1), the piston rod (5) and the guide sleeve (2). An end of the piston (4) and the cylinder block (1) form a rodless chamber (12). It is characterized in that: One end of the rodless cavity (12) is provided with a driving device (3), and a driving rod assembly (31) is arranged in the cylinder block (1). The driving rod assembly (31) includes a toothed lead screw (311) arranged in the cylinder block (1) and a lead screw nut (312) matched with the toothed lead screw (311). The output shaft of the driving device (3) is fixedly connected with the tail end of the toothed lead screw (311). A cavity is arranged in the piston rod (5), and the toothed lead screw (311) passes through the piston (4) and extends into the cavity of the piston rod (5). The lead screw nut (312) is nested at the end of the cavity of the piston rod (5). A cavity for installing a hydraulic driving assembly is arranged inside the piston (4), and an oil passage for connecting the hydraulic driving assembly, the rod cavity (11) and the rodless cavity (12) is also arranged in the piston (4). The toothed lead screw (311) includes a lead screw body and external teeth (313) arranged on the outer peripheral surface of the thread of the lead screw body. The hydraulic driving assembly includes a transmission input part in transmission connection with the toothed lead screw (311). A meshing hole (617) is arranged inside the transmission input part, and keys are axially arranged on the inner wall of the meshing hole (617). The external teeth (313) of the toothed lead screw (311) are meshed with the keys of the meshing hole (617) of the transmission input part.

2. The pump-controlled electro-pushed double-control cylinder according to claim 1, wherein: The hydraulic driving assembly includes an internal gear (614), an external gear (615) and an oil separation block (616). The internal gear (614) nests the external gear (615) inside, and the oil separation block (616) is arranged between the internal gear (614) and the external gear (615). The external gear (615) serves as the transmission input part.

3. The pump-controlled electro-push double-control cylinder according to claim 1, characterized in that: The hydraulic driving assembly includes a swash plate support seat (623), a swash plate (624), a straight plate (625), a valve plate (626) arranged in sequence, and a plunger assembly (627), a ball hinge (628) and pressure plates (629) on both sides thereof between the swash plate (624) and the straight plate (625). The swash plate support seat (623), the swash plate (624), the straight plate (625), the valve plate (626), the plunger assembly (627), the ball hinge (628) and the pressure plates (629) on both sides thereof are all provided with through holes for the toothed lead screw (311) to pass through. The swash plate (624) and the straight plate (625) serve as the transmission input parts.

4. The pump-controlled electro-pushed double-control cylinder according to claim 2, characterized in that: The piston (4) includes an annular body (612) and a front cover (611) and a rear cover (613) arranged on both sides of the annular body (612). The annular body (612) is connected with the hole axis of the cylinder block (1), and the front cover (611) is fixedly connected with the piston rod (5). An oil passage one (41) and an oil passage two (42) are arranged on the annular body (612). The oil passage one (41) connects the hydraulic driving assembly with the rod cavity (11), and the oil passage two (42) connects the hydraulic driving assembly with the rodless cavity (12).

5. The pump-controlled electro-pushed double-control cylinder according to claim 3, wherein: The piston (4) includes a housing (621) and a housing rear cover (622) installed behind the housing (621). The housing (621) is in coaxial fit with the hole of the cylinder block (1). An oil passage one (41) and an oil passage two (42) are provided on the housing (621). The oil passage one (41) communicates with the rodless cavity (42), and the oil passage two (42) communicates with the rod chamber (11).

6. A pump-controlled electro-push double-control cylinder according to any one of claims 1-5, characterized in that: A through hole is provided at the bottom of the cylinder block (1). The output shaft of the driving device (3) is connected to the tooth-shaped lead screw (311). An annular groove is provided at the position where the tooth-shaped lead screw (311) extends out of the through hole at the bottom of the cylinder block. A limit ring (17) is clamped inside the annular groove. A limit cover (16) is fixedly provided on the other side of the limit ring (17). The limit cover (16) is fixed to the bottom of the cylinder block by a nut. The driving device (3) is provided on the other side of the limit cover (16). The cooperation between the limit ring (17) and the limit cover (16) can offset the axial force of the tooth-shaped lead screw (311).

7. A pump-controlled electro-push double-control cylinder according to any one of claims 1-5, characterized in that, The piston rod (5) passes through the guide sleeve (2) and extends out of the cylinder block (1). A cylinder block sleeve (14) is provided at the end of the piston rod (5). The bottom of the cylinder block sleeve (14) is fixedly connected to the piston rod (5) by bolts. The cylinder block sleeve (14) is integrally sleeved on the cylinder block (1) and can perform axial reciprocating motion along the side wall of the cylinder block (1) following the piston rod (5).

8. The pump-controlled electro-push double-control cylinder according to claim 7, characterized in that, An axial rotation limiting structure (15) is provided between the cylinder block sleeve (14) and the cylinder block (1). The axial rotation limiting structure (15) includes a flat key (151) provided on the side wall of the cylinder block (1) and a key groove (152) on the inner wall of the cylinder block sleeve (14) that cooperates with the flat key (151).

9. The pump-controlled electro-pushed double-control cylinder according to claim 1, wherein: The driving device (3) can adopt a servo motor, a hydraulic motor, an engine including a gearbox, or any device that can provide forward and reverse driving forces.

10. A pump-controlled electro-push double-control cylinder according to any one of claims 1-5, characterized in that: An annular cavity is provided inside the guide sleeve (2). An annular separator (21) is provided in the annular cavity. The annular separator (21) divides the space in the annular cavity into a high-pressure gas cavity (22) and an oil storage cavity (23). An oil passage is provided on one side of the oil storage cavity (23) to communicate with the rod chamber (11).

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