Parallel combined cam drive hydraulic pump

Abstract

This invention discloses a parallel combined cam-driven hydraulic pump, comprising a housing module, a power distribution module, multiple functional modules, and a motor. The multiple functional modules achieve liquid suction and discharge through flow diversion and collection via a first housing flow channel. The functional modules are combined to form hydraulic pumps of different displacement specifications. The initial phases of the two pistons on the pump are complementary; one piston is at its extreme position while the other is in the intermediate position, and the phase difference between the two pistons remains constant. The superposition of the output flow from the two pistons essentially eliminates structural pulsations in pressure and flow. Because the piston's force direction is consistent with its motion direction, wear is low, resulting in high mechanical efficiency, long service life, and suitability for operation over a wide speed range. The pump uses a cylindrical seal piston structure and utilizes the piston's upper groove and the cylinder's upper window for flow distribution, resulting in low leakage and enabling the pump to achieve high pressure. Furthermore, this pump structure can be expanded to have four pistons connected in parallel, achieving even larger displacements.

Description

Technical Field

[0001] This invention belongs to the field of fluid transmission and control technology, and specifically relates to a parallel combined cam-driven hydraulic pump. Background Technology

[0002] Electro-hydrostatic actuators (EHAs) are direct-drive electro-hydraulic volumetric control systems widely used in aircraft control surface adjustment, automotive transmission systems, robot joint drive systems, hydraulic excavators, and powered exoskeletons. They offer advantages such as high integration, high power-to-weight ratio, high reliability, high efficiency, and easy installation and maintenance.

[0003] As the core power component of the EHA (Electrical Harness), the hydraulic pump's main function is to provide sufficient pressure and flow of working fluid. Its performance plays a decisive role in the EHA's performance and efficiency. Existing control pumps are mainly divided into variable displacement, variable speed, and dual variable displacement pumps. The EHA primarily consists of a control pump and a cylinder; the pump and motor together form the control pump. This design is advantageous for variable speed operation. However, existing EHA pumps can only maintain good output performance within a small speed range and cannot meet the output performance requirements over a large speed range. Summary of the Invention

[0004] To address the technical limitation of existing EHA pumps, which can only maintain good output performance within a narrow speed range, this invention provides a parallel combined cam-driven hydraulic pump. The parallel combined pump design of this invention allows for the selection of four functional modules connected in parallel, enabling a larger displacement.

[0005] The technical solution adopted in this invention is: A parallel combined cam-driven hydraulic pump, characterized in that it includes a housing module, a power distribution module, multiple functional modules, and a motor (4); the multiple functional modules are diverted and collected through the flow channel of the first housing to realize liquid suction and discharge, and the combination and configuration of the functional modules constitute hydraulic pumps of different displacement specifications; wherein: The housing module includes a first housing (103), a second housing (106), a third housing (201), an overflow valve (101), a check valve (115), a pipe fitting (104), and a pump cover (102); the first housing (103), the second housing (106), and the third housing (201) are connected by bolts, and the first housing (103) and the second housing (106) are sealed by a first type of housing gasket (105), and the second housing (106) and the third housing (201) are sealed by a second type of housing gasket (107); the second housing ( The first housing (103) is positioned with the third housing (201) by two positioning pins (210); the first housing (103) is provided with a suction port, a discharge port, a pipe joint (104), an overflow valve (101) and three flow channel holes; the second housing (106) is provided with three flow channel holes, which are connected to the three flow channel holes on the first housing (103), and two of the connected flow channel holes are equipped with a one-way valve (115) and a filter screen (113); the pump cover (102) is fixed to the left end face of the first housing (103) by four first-class screws (118); The power distribution module includes a driven gear (202) and a main gear (205). The main gear (205) is connected to the motor shaft of the motor (4) via a spline to transmit torque. The left side of the main gear (205) is axially elastically positioned by a main gear retaining ring (108) and a spring (109) fitted on the main gear retaining ring (108). Driven gears (202) are respectively provided on both sides of the main gear (205), and the main gear (205) transmits the motor torque to the driven gears (202) on both sides. Six inner raceways are evenly distributed in the inner circumference of the hub of the driven gear (202). The camshaft (301) on the functional module corresponding to the inner raceways is provided with the same number of outer raceways. Each inner raceway and outer raceway cooperate to form a raceway. The camshaft (301) is inserted into the hub of the driven gear (202), and three transmission steel balls (302) are installed in each raceway to form a steel ball coupling, so that the camshaft (301) can rotate synchronously circumferentially with the driven gear (202) and move axially with the double-end-face spatial cam (305); the ball retaining ring (204) is fixed to the third housing (201) by three evenly distributed second-type screws (208), and the left end ring face of the ball retaining ring (204) prevents the transmission steel balls (302) from falling out of the raceway; the right end hub of the driven gear (202) is equipped with a tapered roller bearing (203), which is installed in the bearing hole on the third housing (201); the left and right end hubs of the driven gear (202) are equipped with retaining rings (207). The motor (4) is mounted and fixed on the third housing (201). The motor shaft of the motor (4) has an external spline structure, which is used in conjunction with the internal spline structure of the main gear (205). The motor shaft and the third housing (201) are sealed by a skeleton oil seal (206).

[0006] Furthermore, the functional modules include a cam-roller drive module, a camshaft-piston coupling and support module, and a piston-cylinder module, wherein the piston-cylinder module is installed in the left inner hole of the first housing (103); wherein: The cam-roller transmission module includes a double-end-face spatial cam (305), a left roller carrier (307), a clearance adjusting ring (304), a right roller carrier (303), a camshaft (301), a cam half-stop ring (306), cylindrical rollers (318), and a roller shaft (317). The double-end-face spatial cam (305) and the camshaft (301) are connected by a type B flat key (323). The left roller carrier (307) and the right roller carrier (303) are respectively placed on both sides of the double-end-face spatial cam (305), and each roller carrier is equipped with three pairs of cylindrical rollers (318) arranged mirror-oriented relative to the double-end-face spatial cam (305). The three pairs of cylindrical rollers (318) are respectively aligned with the camshaft (305). The two side contour surfaces of the double-end space cam (305) are in contact; the left end of the left roller carrier (307) is in contact with the middle cover (313); the middle cover (313) and the first housing (103) are sealed at the end face by a fourth type O-ring seal (117); the right end of the right roller carrier (303) is in contact with the left end face of the third housing (201); the left side of the gap adjusting ring (304) is in contact with the left roller carrier (307), and the right side is in contact with the right roller carrier (303); the left and right roller carriers are connected to the second housing (106) by a C-shaped flat key (319). When the double-end space cam (305) rotates, the contour surface is constrained by three pairs of cylindrical rollers to generate axial reciprocating motion. The coupling and support module between the camshaft and piston includes a support sleeve (308), a floating sleeve (315), and a coupling sleeve (314); the support sleeve (308) is installed in the center hole of the left roller carrier (307); the camshaft (301) and piston (311) are each provided with a segment with four semi-circular grooves at their ends; the coupling sleeve (314) is composed of two half-coupling sleeves, each with four semi-circular grooves inside, and the two half-coupling sleeves are engaged with the camshaft (301) and piston (311). In the semi-circular groove of the camshaft (301) and the piston end, eight cylindrical slots are formed. Elastic transmission pins are provided in the cylindrical slots to realize the connection between the piston and the camshaft (301). The floating sleeve (315) is sleeved on the outside of the coupling sleeve (314) and the coupling sleeve (314) is clamped from the outside and installed in the hole of the support sleeve (308). The inner and outer cylindrical surfaces of the floating sleeve form inner and outer sliding oil film support through clearance fit with the outer cylindrical surface of the semi-coupling sleeve and the hole of the support sleeve. The piston-cylinder module includes a piston (311), a cylinder (310), a left sealing ring (312), and a right sealing ring (309). A pump cover (102) is installed on the left side of the cylinder (310), and the pump cover (102) and the cylinder (310) are sealed at the end face by a first type of O-ring seal (110). The piston (311) is installed in the inner hole of the cylinder (310) and rotates and reciprocates axially with the cylinder (310). Three pin holes are evenly distributed along the circumferential direction on the left end face of the cylinder (310) and at the same position on the left inner hole of the first housing (103). Anti-rotation pins (112) are provided in the pin holes. The cylinder body (310) and the first housing (103) are sealed by a fifth type O-ring (321); the left sealing ring (312) is embedded in the left side of the cylinder body (310), and the left side of the left sealing ring (312) contacts the pump cover (102); the right sealing ring (309) is embedded in the right side of the cylinder body (310), and the right side of the right sealing ring (309) is axially fixed by the intermediate cover (313); the left sealing ring (312) and the inner hole of the cylinder body (310) and the right sealing ring (309) and the inner hole of the cylinder body (310) are sealed by a sixth type O-ring (322); During operation, the cam-roller drive module, the coupling between the camshaft and the piston, the support module, and the piston together form a two-dimensional motion component. External power is transmitted through the motor and the main gear and driven gear in the power distribution module to make the two-dimensional motion component rotate and reciprocate, ultimately causing the piston to rotate and reciprocate.

[0007] Furthermore, the double-end-face spatial cam (305) has a "three highs and three lows" structure, and its motion law is three equal accelerations and equal decelerations. Its end face is an equal acceleration and equal deceleration curved surface with axial undulations.

[0008] Furthermore, the double-end-face spatial cam (305) is either "two high and two low" or "four high and four low", which requires corresponding changes to the number of cylindrical rollers installed on the roller holder; a support sleeve is installed in the inner hole of the left roller holder; a needle roller bearing is installed in the inner hole of the right roller holder and connected to the follower gear.

[0009] Furthermore, the camshaft (301) has a central through hole, and a radial through groove is provided on the end face of the camshaft (301) connected to the piston (311). A radial through hole is provided on the half-coupling sleeve, and a shallow groove and a radial through hole are provided on the outer cylindrical surface of the floating sleeve. The lubricating oil enters the inner hole of the floating sleeve through the central hole of the camshaft, the end face groove of the camshaft connected to the piston, and the radial through hole on the half-coupling sleeve, and enters the circumferential oil groove on the outer cylindrical surface of the floating sleeve through the radial through hole of the floating sleeve, so that a supporting oil film is formed inside and outside the floating sleeve.

[0010] Furthermore, the right sealing ring (309) divides the internal cavity of the housing module into two parts. The piston-cylinder module on the left contains the working medium, while the second and third housings on the right are filled with lubricating oil, so that the power distribution module and the cam-roller transmission module are both immersed in the lubricating oil. The interior of the third housing serves as the oil tank inside the pump body.

[0011] Furthermore, the cylinder body (310) is provided with two sets of obliquely opened distribution windows (31003) along the axial direction. The positions of the two sets of distribution windows (31003) correspond to the high-pressure flow channel and the low-pressure flow channel, respectively. Each set of distribution windows (31003) includes three distribution windows evenly distributed at 120°, and the two sets of distribution windows are staggered. The cylinder body (310) has two cutting grooves, called low-pressure groove (31001) and high-pressure groove (31002), which communicate with the suction port and discharge port of the first housing (103), respectively. The piston (311) has six uniformly arranged through grooves. The through grooves are larger at the top and smaller at the bottom, and the cross-section is trapezoidal. The positions of the groove openings of the six through grooves are staggered. During operation, the groove openings on the piston communicate with the windows on the cylinder body. The sealed cavity is drawn in when the volume increases and discharged when the volume decreases.

[0012] Furthermore, the first housing (103) and the second housing (106) each have three coaxial flow channel holes, which are connected in series to form the seventh flow channel (507), the eighth flow channel (508), and the ninth flow channel (509) inside the first housing (103) and the tenth flow channel (510), the eleventh flow channel (511), and the twelfth flow channel (512) inside the second housing. The seventh flow channel (507) on the first housing (103) and the tenth flow channel (510) on the second housing (106) are sealed with a second type of O-ring (114); the eighth flow channel (508) on the first housing (103) and the eleventh flow channel (511) on the second housing (106) are sealed with a third type of O-ring (116).

[0013] Furthermore, the double-end-face spatial cam (305) is connected and fixed by two cam half-stop rings (306) mounted on the shoulder of the camshaft (301). The two cam half-stop rings (306) are connected and fixed by two cotter pins (320), so that the cam (305) and the camshaft (301) rotate and reciprocate synchronously.

[0014] Furthermore, the first shell (103) contains three axial flow channels communicating with the second shell (106): the seventh flow channel (507), the eighth flow channel (508), and the ninth flow channel (509). There are also two horizontal flow channels: the first flow channel (501) and the second flow channel (502), which connect to four vertical flow channels: the third flow channel (503), the fourth flow channel (504), the fifth flow channel (505), and the sixth flow channel (506), serving as suction and discharge ports communicating with the hydraulic cylinder. A one-way valve (115) and an overflow valve (116) are installed in the two axial flow channels, the seventh flow channel (507) and the ninth flow channel (509). 101) is used to allow excess working fluid to overflow or flow back into the third housing (201), and to connect the axial flow channels seventh flow channel (507) and ninth flow channel (509) of the overflow valve (101) through the thirteenth flow channel (513) in the vertical direction, and through the axial flow channel eighth flow channel (508) on the first housing (103) and the horizontal flow channel eleventh flow channel (511) on the second housing (106), so that excess working fluid squeezed out from any pressure port can be gathered and flow back into the third housing (201). Flow channels that are not connected to other components are sealed with first-type screw plugs (111) to prevent leakage.

[0015] Furthermore, the third housing (201) has a vertical flow channel, the fourteenth flow channel (514), which is sealed with a second type of screw plug (209).

[0016] Furthermore, the functional modules are set in two or four; when the functional modules are set in four, the fourth housing (601) and the fifth housing (603) are sealed by a third type of housing gasket (602); the fifth housing (603) and the sixth housing (605) are sealed by a fourth type of housing gasket (604).

[0017] The working principle of this invention is as follows: When the motor starts, the motor outputs torque, which is transmitted to the piston in the cylinder through gear transmission and a spatial cam-cylindrical roller mechanism. The distribution groove on the piston and the distribution window on the cylinder form a distribution mechanism. When the piston rotates, the volume of the left and right sealed piston chambers changes according to the piston's movement. The increase and decrease in the volume of the left and right sealed piston chambers realize the function of drawing in or discharging the working fluid into the hydraulic cylinder. During operation, the working fluid leaks into the pump casing, causing the pressure inside the pump casing to exceed the opening pressure of the one-way valve. The one-way valve opens, and the oil enters the low-pressure settling groove of the cylinder and is drawn back into the pump. When the pump outlet pressure exceeds the set pressure of the relief valve, the relief valve opens, and the oil flows directly from the high-pressure area back to the pump's suction chamber, realizing unloading protection.

[0018] Compared with the prior art, the beneficial effects of the present invention are reflected in: 1. In this invention, the initial phases of the two pistons on the pump are complementary, that is, one piston is in its extreme position while the other is in its intermediate position, and the phase difference between the two pistons remains constant. The superposition of the output flow rates of the two pistons essentially eliminates the structural pulsations in pressure and flow. Because the direction of force on the piston is consistent with its direction of movement, its wear is small, resulting in high mechanical efficiency, long service life, and suitability for operation over a wide speed range.

[0019] 2. The piston structure used in the pump of this invention is a cylindrical surface seal, and the flow distribution is achieved by using the flow distribution groove on the piston and the flow distribution window on the cylinder body, resulting in low leakage and the pump can achieve high pressure. In addition, this pump structure can be expanded to four pistons in parallel, which can achieve a larger displacement.

[0020] 3. This invention designs a parallel combined two-dimensional electric hydraulic pump for EHA (Electronic Hydraulic Acid) systems. It utilizes the two-dimensional piston transmission principle to achieve oil suction and discharge functions, and distributes the flow through piston distribution channels. The structure is compact and easy to disassemble. Due to the good dynamic characteristics of the piston transmission mechanism over a wide speed range, the pump has good output performance, low heat generation, and a high power-to-weight ratio, enabling high-pressure output and providing effective power to the EHA. Changing the motor's rotation direction changes the suction and discharge ports, making it suitable for connecting to double-rod hydraulic cylinders. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of a parallel combined piston groove distribution hydraulic pump structure according to one embodiment; Figure 2 This is an exploded view of the power distribution module; Figure 3 This is an exploded view of the housing module; Figure 4 This is an exploded view of the functional modules; Figure 5 This is an exploded view of the four-piston housing module.

[0022] Figure 6 This is an exploded view of the four-piston power distribution module; Figure 7a and Figure 7b These are the structural diagram of the cylinder block and the sectional view along the AA direction, respectively.

[0023] Reference numerals: 101-Relief valve; 102-Pump cover; 103-First housing; 104-Pipe fitting; 105-First type housing gasket; 106-Second housing; 107-Second type housing gasket; 108-Main gear retaining ring; 109-Spring; 110-First type O-ring seal; 111-First type screw plug; 112-Anti-rotation pin; 113-Filter screen; 114-Second type O-ring seal; 115-Check valve; 116-Third type O-ring seal; 117-Class IV O-ring seal; 118-Class I screw; 201-Third housing; 202-Driven gear; 203-Tapered roller bearing; 204-Ball retaining ring; 205-Main gear; 206-Skeleton oil seal; 207-Retaining ring; 208-Class II screw; 209-Class II plug; 210-Locating pin; 301-Camshaft; 302-Drive ball bearing; 303-Right roller carrier; 304-Clearance adjusting ring; 305-Double-end face space cam; 30 6-Cam half retainer ring; 307-Left roller carrier; 308-Support sleeve; 309-Right sealing ring; 310-Cylinder block; 31001-Low pressure groove; 31002-High pressure groove; 31003-Distribution window; 311-Piston; 312-Left sealing ring; 313-Intermediate cover; 314-Coupling sleeve; 315-Floating sleeve; 316-Needle roller bearing; 317-Roller shaft; 318-Cylindrical roller; 319-C-type flat key; 320-Cotter pin; 321-Category 5 O-ring seal; 322-Type VI O-ring seal; 323-Type B key; 4-Motor; 501-First flow channel; 502-Second flow channel; 503-Third flow channel; 504-Fourth flow channel; 505-Fifth flow channel; 506-Sixth flow channel; 507-Seventh flow channel; 508-Eighth flow channel; 509-Ninth flow channel; 510-Tenth flow channel; 511-Eleventh flow channel; 512-Twelfth flow channel; 513-Thirteenth flow channel; 514-Fourteenth flow channel; 601-Fourth housing; 602-Type III housing gasket; 603-Fifth housing; 604-Type IV housing gasket; 605-Sixth housing. Detailed Implementation

[0024] The technical solution of this invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this invention, not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without inventive effort are within the scope of protection of this invention.

[0025] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," indicating orientation or positional relationships, are based on the orientation or positional relationships shown in the accompanying drawings and are used only for the convenience of describing the invention and simplifying the description. They do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention. Furthermore, the terms "first," "second," "third," "first type," "second type," and "third type" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0026] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0027] refer to Figures 1 to 7b The present invention discloses a parallel combined cam-driven hydraulic pump, comprising a housing module, a power distribution module, multiple functional modules, and a motor 4; the multiple functional modules achieve liquid suction and discharge through the flow channel of the first housing, and the combination and configuration of the functional modules constitute hydraulic pumps with different displacement specifications; wherein: The housing module includes a first housing 103, a second housing 106, a third housing 201, an overflow valve 101, a check valve 115, a pipe connector 104, and a pump cover 102; the first housing 103, the second housing 106, and the third housing 201 are connected by bolts, and the first housing 103 and the second housing 106 are sealed by a first type of housing gasket 105, and the second housing 106 and the third housing 201 are sealed by a second type of housing gasket 107; the second housing 106 and... The third housing 201 is positioned by two positioning pins 210; the first housing 103 is provided with a suction port, a discharge port, a pipe connector 104, an overflow valve 101, and three flow channel holes; the second housing 106 is provided with three flow channel holes, which are correspondingly connected to the three flow channel holes on the first housing 103, and a one-way valve 115 and a filter screen 113 are installed in two of the connected flow channel holes; the pump cover 102 is fixed to the left end face of the first housing 103 by four first-type screws 118; The power distribution module includes a driven gear 202 and a main gear 205. The main gear 205 is connected to the motor shaft of the motor 4 via a spline for transmitting torque. The left side of the main gear 205 is axially elastically positioned by a main gear retaining ring 108 and a spring 109 fitted on the main gear retaining ring 108. Driven gears 202 are respectively arranged on both sides of the main gear 205, and the main gear 205 transmits the motor torque to the driven gears 202 on both sides. Six inner raceways are evenly distributed circumferentially within the hub of the driven gear 202. The camshaft 301 on the functional module, corresponding to the inner raceways, has the same number of outer raceways at corresponding positions. Each inner raceway and outer raceway cooperate to form a [missing information - likely a specific configuration or feature]. The camshaft 301 is inserted into the hub of the driven gear 202, and three transmission steel balls 302 are installed in each raceway to form a steel ball coupling, which enables the camshaft 301 to rotate synchronously circumferentially with the driven gear 202 and move axially together with the double-end-face spatial cam 305; the ball retaining ring 204 is fixed to the third housing 201 by three evenly distributed second-type screws 208, and the left end of the ball retaining ring 204 prevents the transmission steel balls 302 from falling out of the raceway; the right end hub of the driven gear 202 is equipped with a tapered roller bearing 203, which is installed in the bearing hole on the third housing 201; the left and right end hubs of the driven gear 202 are equipped with retaining rings 207; The motor 4 is mounted and fixed on the third housing 201. The motor shaft of the motor 4 has an external spline structure, which is used in conjunction with the internal spline structure of the main gear 205. The motor shaft and the third housing 201 are sealed by a skeleton oil seal 206.

[0028] In one embodiment, the functional module includes a cam-roller drive module, a camshaft-piston coupling and support module, and a piston-cylinder module, wherein the piston-cylinder module is installed in the left inner hole of the first housing 103; wherein: The cam-roller transmission module includes a double-end-face spatial cam 305, a left roller carrier 307, a clearance adjusting ring 304, a right roller carrier 303, a camshaft 301, a cam half-stop ring 306, cylindrical rollers 318, and a roller shaft 317. The double-end-face spatial cam 305 is connected to the camshaft 301 via a type B flat key 323. The left roller carrier 307 and the right roller carrier 303 are respectively placed on both sides of the double-end-face spatial cam 305, and each roller carrier is equipped with three pairs of cylindrical rollers 318 mirror-arranged relative to the double-end-face spatial cam 305. The three pairs of cylindrical rollers 318 are respectively connected to the double-end-face spatial cam 305. The two side contour surfaces of the spatial cam 305 are in contact; the left end of the left roller carrier 307 is in contact with the middle cover 313; the middle cover 313 and the first housing 103 are sealed at the end face by a fourth type O-ring seal 117; the right end of the right roller carrier 303 is in contact with the left end face of the third housing 201; the left side of the clearance adjusting ring 304 is in contact with the left roller carrier 307, and the right side is in contact with the right roller carrier 303; the left and right roller carriers are connected to the second housing 106 by a C-shaped flat key 319. When the double-end-face spatial cam 305 rotates, the contour surface is constrained by three pairs of cylindrical rollers to generate axial reciprocating motion. The camshaft and piston coupling and support module includes a support sleeve 308, a floating sleeve 315, and a coupling sleeve 314. The support sleeve 308 is installed in the center hole of the left roller holder 307. The camshaft 301 and piston 311 are each segmented with four semi-circular grooves at their ends. The coupling sleeve 314 is composed of two half-couplings with four semi-circular grooves inside. The two half-couplings are engaged in the semi-circular grooves of the camshaft 301 and piston 311. The camshaft 301 and piston ends form eight cylindrical slots. Elastic transmission pins are provided in the cylindrical slots to connect the piston and camshaft 301. The floating sleeve 315 is sleeved on the outside of the coupling sleeve 314 and secures the coupling sleeve 314 from the outside and installs it in the hole of the support sleeve 308. The inner and outer cylindrical surfaces of the floating sleeve form inner and outer sliding oil film supports through clearance fit with the outer cylindrical surface of the half-coupling and the hole of the support sleeve. The piston-cylinder module includes a piston 311, a cylinder 310, a left sealing ring 312, and a right sealing ring 309. A pump cover 102 is installed on the left side of the cylinder 310, and the pump cover 102 and the cylinder (310) are sealed at the end face by a first type O-ring seal 110. The piston 311 is installed in the inner hole of the cylinder 310 and rotates and reciprocates axially with the cylinder 310. Three pin holes are evenly distributed along the circumferential direction on the left end face of the cylinder 310 and at the same position on the left inner hole of the first housing 103. Anti-rotation pins 1 are provided in the pin holes. 12, used to prevent the cylinder body from rotating with the first housing; the cylinder body 310 and the cylinder bore of the first housing 103 are sealed by a fifth type O-ring 321; the left sealing ring 312 is embedded in the left side of the cylinder body 310, and the left side of the left sealing ring 312 contacts the pump cover 102; the right sealing ring 309 is embedded in the right side of the cylinder body 310, and the right side of the right sealing ring 309 is axially fixed by the intermediate cover 313; the left sealing ring 312 and the inner bore of the cylinder body 310, as well as the right sealing ring 309 and the inner bore of the cylinder body 310, are sealed by a sixth type O-ring 322; During operation, the cam-roller drive module, the coupling between the camshaft and the piston, the support module, and the piston together form a two-dimensional motion component. External power is transmitted through the motor and the main gear and driven gear in the power distribution module to make the two-dimensional motion component rotate and reciprocate, ultimately causing the piston to rotate and reciprocate.

[0029] Specifically, the double-end-face spatial cam 305 has a "three highs and three lows" structure, and its motion law is three equal accelerations and equal decelerations. Its end face is an equal acceleration and equal deceleration curved surface with axial undulations.

[0030] Specifically, the double-end-face spatial cam 305 is either "two high and two low" or "four high and four low", which requires corresponding changes to the number of cylindrical rollers installed on the roller holder; a support sleeve is installed in the inner hole of the left roller holder; a needle roller bearing is installed in the inner hole of the right roller holder and connected to the follower gear.

[0031] In one embodiment, the camshaft 301 has a central through hole, a radial through groove is provided on the end face of the camshaft 301 connected to the piston 311, a radial through hole is provided on the half coupling sleeve, and a shallow groove and a radial through hole are provided on the outer cylindrical surface of the floating sleeve. The lubricating oil enters the inner hole of the floating sleeve through the central hole of the camshaft, the end face groove of the camshaft connected to the piston, and the radial through hole on the half coupling sleeve, and enters the circumferential oil groove on the outer cylindrical surface of the floating sleeve through the radial through hole of the floating sleeve, so that a supporting oil film is formed inside and outside the floating sleeve.

[0032] In one embodiment, the right sealing ring 309 divides the internal cavity of the housing module into two parts. The piston-cylinder module on the left contains the working medium, while the second and third housings on the right are filled with lubricating oil, so that the power distribution module and the cam-roller transmission module are both immersed in the lubricating oil. The interior of the third housing serves as the oil tank inside the pump body.

[0033] In one embodiment, the cylinder body 310 has two sets of obliquely opened distribution windows 31003 along the axial direction, the positions of the two sets of distribution windows 31003 corresponding to the high-pressure flow channel and the low-pressure flow channel, respectively; each set of distribution windows 31003 includes three distribution windows evenly distributed at 120°, and the two sets of distribution windows are staggered; the cylinder body 310 has two cutting grooves, called low-pressure groove 31001 and high-pressure groove 31002, which communicate with the suction port and discharge port of the first housing 103, respectively; the piston 311 has six evenly arranged through grooves, the through grooves are larger at the top and smaller at the bottom, the cross-section is trapezoidal, and the positions of the groove openings of the six through grooves are staggered; during operation, the groove openings on the piston communicate with the windows on the cylinder body, the sealed cavity draws in when the volume increases and discharges when the volume decreases.

[0034] In one embodiment, the first housing 103 and the second housing 106 each have three coaxial flow channel holes, which are connected in series to form the seventh flow channel 507, the eighth flow channel 508, and the ninth flow channel 509 inside the first housing 103 and the tenth flow channel 510, the eleventh flow channel 511, and the twelfth flow channel 512 inside the second housing, connecting the front and rear modules. The seventh flow channel 507 on the first housing 103 and the tenth flow channel 510 on the second housing 106, as well as the ninth flow channel 509 on the first housing 103 and the twelfth flow channel 512 on the second housing 106, are sealed by a second type of O-ring seal 114; the eighth flow channel 508 on the first housing 103 and the eleventh flow channel 511 on the second housing 106 are sealed by a third type of O-ring seal 116.

[0035] In one embodiment, the double-end-face spatial cam 305 is connected and fixed by two cam half-stop rings 306 mounted on the shoulder of the camshaft 301. The two cam half-stop rings 306 are connected and fixed by two cotter pins 320, so that the cam 305 and the camshaft 301 rotate and reciprocate synchronously.

[0036] In one embodiment, the first housing 103 has three axial flow channels communicating with the second housing 106: a seventh flow channel 507, an eighth flow channel 508, and a ninth flow channel 509. There are also two horizontal flow channels: a first flow channel 501 and a second flow channel 502, which connect to four vertical flow channels: a third flow channel 503, a fourth flow channel 504, a fifth flow channel 505, and a sixth flow channel 506, serving as suction and discharge ports communicating with the hydraulic cylinder. A one-way valve 115 and an overflow valve 1 are installed in the two axial flow channels, the seventh flow channel 507 and the ninth flow channel 509. 01 is used to allow excess working fluid to overflow or flow back into the third housing 201, and to connect with the axial flow channels 707 and 909 of the overflow valve 101 through the vertical thirteenth flow channel 513, and also through the axial flow channel 808 on the first housing 103 and the horizontal flow channel 111 on the second housing 106, so that excess working fluid squeezed out from any pressure port can converge and flow back into the third housing 201. Flow channels that do not communicate with other components are sealed with first-type screw plugs 111 to prevent leakage.

[0037] In one embodiment, the third housing 201 has a fourteenth vertical flow channel 514, which is sealed with a second type of screw plug 209.

[0038] In one embodiment, two or four functional modules are provided; when four functional modules are provided, the fourth housing 601 and the fifth housing 603 are sealed together by a third type of housing sealing gasket 602; the fifth housing 603 and the sixth housing 605 are sealed together by a fourth type of housing sealing gasket 604.

[0039] The working principle of this invention is as follows: When the motor 4 starts, the motor 4 outputs torque, which is transmitted to the piston 311 in the cylinder 310 through gear transmission and spatial cam-cylindrical roller mechanism. The distribution groove on the piston 311 and the distribution window on the cylinder 310 form a distribution mechanism. When the piston 311 rotates, the volume of the left and right sealed piston chambers changes with the movement law of the piston 311. The volume of the left and right sealed piston chambers increases and decreases, realizing the function of sucking in or discharging the working fluid into the hydraulic cylinder. When the piston 311 stops moving, that is, the combined pump cannot pump the working fluid into the hydraulic cylinder. At this time, the pump is still working and continuously sucking in. The pumped working fluid flows through the seventh flow channel 507, the eighth flow channel 508, and the ninth flow channel 509, through the one-way valve 115 and the overflow valve 101, and returns to the pump's suction port, keeping the pump in working condition, protecting the pump and the motor, and realizing unloading protection.

[0040] It should be understood that the "this embodiment" mentioned in this invention refers to the technical points described below, and multiple "this embodiments" may refer to the same embodiment or different embodiments.

[0041] Those skilled in the art will understand that the above embodiments are specific examples of implementing this disclosure, and in practical applications, various changes can be made in form and detail without departing from the scope of this disclosure.

[0042] The embodiments described in this specification are merely examples of implementations of the inventive concept. The scope of protection of this invention should not be considered as limited to the specific forms stated in the embodiments. The scope of protection of this invention also extends to equivalent technical means that can be conceived by those skilled in the art based on the inventive concept.

Claims

1. A parallel combined cam-driven hydraulic pump, characterized in that, It includes a housing module, a power distribution module, multiple functional modules, and a motor (4); the multiple functional modules are diverted and collected through the first housing flow channel to achieve liquid suction and discharge, and the combination and configuration of the functional modules constitute hydraulic pumps of different displacement specifications; wherein: The housing module includes a first housing (103), a second housing (106), a third housing (201), an overflow valve (101), a check valve (115), a pipe fitting (104), and a pump cover (102); the first housing (103), the second housing (106), and the third housing (201) are connected by bolts, and the first housing (103) and the second housing (106) are sealed by a first type of housing gasket (105), and the second housing (106) and the third housing (201) are sealed by a second type of housing gasket (107); the second housing ( The first housing (103) is positioned with the third housing (201) by two positioning pins (210); the first housing (103) is provided with a suction port, a discharge port, a pipe joint (104), an overflow valve (101) and three flow channel holes; the second housing (106) is provided with three flow channel holes, which are connected to the three flow channel holes on the first housing (103), and two of the connected flow channel holes are equipped with a one-way valve (115) and a filter screen (113); the pump cover (102) is fixed to the left end face of the first housing (103) by four first-class screws (118); The power distribution module includes a driven gear (202) and a main gear (205). The main gear (205) is connected to the motor shaft of the motor (4) via a spline to transmit torque. The left side of the main gear (205) is axially elastically positioned by a main gear retaining ring (108) and a spring (109) fitted on the main gear retaining ring (108). Driven gears (202) are respectively provided on both sides of the main gear (205), and the main gear (205) transmits the motor torque to the driven gears (202) on both sides. Six inner raceways are evenly distributed in the inner circumference of the hub of the driven gear (202). The camshaft (301) on the functional module corresponding to the inner raceways is provided with the same number of outer raceways. Each inner raceway and outer raceway cooperate to form a raceway. The camshaft (301) is inserted into the hub of the driven gear (202), and three transmission steel balls (302) are installed in each raceway to form a steel ball coupling, so that the camshaft (301) can rotate synchronously circumferentially with the driven gear (202) and move axially with the double-end-face spatial cam (305); the ball retaining ring (204) is fixed to the third housing (201) by three evenly distributed second-type screws (208), and the left end ring face of the ball retaining ring (204) prevents the transmission steel balls (302) from falling out of the raceway; the right end hub of the driven gear (202) is equipped with a tapered roller bearing (203), which is installed in the bearing hole on the third housing (201); the left and right end hubs of the driven gear (202) are equipped with retaining rings (207). The motor (4) is mounted and fixed on the third housing (201). The motor shaft of the motor (4) has an external spline structure, which is used in conjunction with the internal spline structure of the main gear (205). The motor shaft and the third housing (201) are sealed by a skeleton oil seal (206).

2. The parallel combined cam-driven hydraulic pump as described in claim 1, characterized in that, The functional modules include a cam-roller drive module, a camshaft-piston coupling and support module, and a piston-cylinder module, wherein the piston-cylinder module is installed in the left inner hole of the first housing (103); wherein: The cam-roller transmission module includes a double-end-face spatial cam (305), a left roller carrier (307), a clearance adjusting ring (304), a right roller carrier (303), a camshaft (301), a cam half-stop ring (306), cylindrical rollers (318), and a roller shaft (317). The double-end-face spatial cam (305) and the camshaft (301) are connected by a type B flat key (323). The left roller carrier (307) and the right roller carrier (303) are respectively placed on both sides of the double-end-face spatial cam (305), and each roller carrier is equipped with three pairs of cylindrical rollers (318) arranged mirror-oriented relative to the double-end-face spatial cam (305). The three pairs of cylindrical rollers (318) are respectively aligned with the camshaft (305). The two side contour surfaces of the double-end space cam (305) are in contact; the left end of the left roller carrier (307) is in contact with the middle cover (313); the middle cover (313) and the first housing (103) are sealed at the end face by a fourth type O-ring seal (117); the right end of the right roller carrier (303) is in contact with the left end face of the third housing (201); the left side of the gap adjusting ring (304) is in contact with the left roller carrier (307), and the right side is in contact with the right roller carrier (303); the left and right roller carriers are connected to the second housing (106) by a C-shaped flat key (319). When the double-end space cam (305) rotates, the contour surface is constrained by three pairs of cylindrical rollers to generate axial reciprocating motion. The coupling and support module between the camshaft and piston includes a support sleeve (308), a floating sleeve (315), and a coupling sleeve (314); the support sleeve (308) is installed in the center hole of the left roller carrier (307); the camshaft (301) and piston (311) are each provided with a segment with four semi-circular grooves at their ends; the coupling sleeve (314) is composed of two half-coupling sleeves, each with four semi-circular grooves inside, and the two half-coupling sleeves are engaged with the camshaft (301) and piston (311). In the semi-circular groove of the camshaft (301) and the piston end, eight cylindrical slots are formed. Elastic transmission pins are provided in the cylindrical slots to realize the connection between the piston and the camshaft (301). The floating sleeve (315) is sleeved on the outside of the coupling sleeve (314) and the coupling sleeve (314) is clamped from the outside and installed in the hole of the support sleeve (308). The inner and outer cylindrical surfaces of the floating sleeve form inner and outer sliding oil film support through clearance fit with the outer cylindrical surface of the semi-coupling sleeve and the hole of the support sleeve. The piston-cylinder module includes a piston (311), a cylinder (310), a left sealing ring (312), and a right sealing ring (309). A pump cover (102) is installed on the left side of the cylinder (310), and the pump cover (102) and the cylinder (310) are sealed at the end face by a first type of O-ring seal (110). The piston (311) is installed in the inner hole of the cylinder (310) and rotates and reciprocates axially with the cylinder (310). Three pin holes are evenly distributed along the circumferential direction on the left end face of the cylinder (310) and at the same position on the left inner hole of the first housing (103). Anti-rotation pins (112) are provided in the pin holes. The cylinder body (310) and the first housing (103) are sealed by a fifth type O-ring (321); the left sealing ring (312) is embedded in the left side of the cylinder body (310), and the left side of the left sealing ring (312) contacts the pump cover (102); the right sealing ring (309) is embedded in the right side of the cylinder body (310), and the right side of the right sealing ring (309) is axially fixed by the intermediate cover (313); the left sealing ring (312) and the inner hole of the cylinder body (310) and the right sealing ring (309) and the inner hole of the cylinder body (310) are sealed by a sixth type O-ring (322); During operation, the cam-roller drive module, the coupling between the camshaft and the piston, the support module, and the piston together form a two-dimensional motion component. External power is transmitted through the motor and the main gear and driven gear in the power distribution module to make the two-dimensional motion component rotate and reciprocate, ultimately causing the piston to rotate and reciprocate.

3. A parallel combined cam-driven hydraulic pump as described in claim 2, characterized in that, The camshaft (301) has a central through hole, and a radial through groove is provided on the end face of the camshaft (301) connected to the piston (311). A radial through hole is provided on the half-coupling sleeve, and a shallow groove and a radial through hole are provided on the outer cylindrical surface of the floating sleeve. The lubricating oil enters the inner hole of the floating sleeve through the central hole of the camshaft, the end face groove of the camshaft connected to the piston, and the radial through hole on the half-coupling sleeve, and enters the circumferential oil groove on the outer cylindrical surface of the floating sleeve through the radial through hole of the floating sleeve, so that a supporting oil film is formed inside and outside the floating sleeve.

4. A parallel combined cam-driven hydraulic pump as described in claim 2, characterized in that, The right sealing ring (309) divides the internal cavity of the housing module into two parts. The piston-cylinder module on the left contains the working medium, while the second and third housings on the right are filled with lubricating oil, so that the power distribution module and the cam-roller transmission module are both immersed in the lubricating oil. The interior of the third housing serves as the oil tank inside the pump body.

5. A parallel combined cam-driven hydraulic pump as described in claim 2, characterized in that, The cylinder body (310) is provided with two sets of obliquely opened distribution windows (31003) along the axial direction. The positions of the two sets of distribution windows (31003) correspond to the high-pressure flow channel and the low-pressure flow channel, respectively. Each set of distribution windows (31003) includes three distribution windows evenly distributed at 120°, and the two sets of distribution windows are staggered. The cylinder body (310) has two cutting grooves, called low-pressure groove (31001) and high-pressure groove (31002), which communicate with the suction port and discharge port of the first housing (103), respectively. The piston (311) has six uniformly arranged through grooves. The through grooves are larger at the top and smaller at the bottom, and the cross-section is trapezoidal. The positions of the groove openings of the six through grooves are staggered. During operation, the groove openings on the piston communicate with the windows on the cylinder body. The sealed cavity draws in when the volume increases and discharges when the volume decreases.

6. A parallel combined cam-driven hydraulic pump as described in claim 2, characterized in that, The first housing (103) and the second housing (106) each have three coaxial flow channel holes, which are connected in series to form the seventh flow channel (507), the eighth flow channel (508), and the ninth flow channel (509) inside the first housing (103) and the tenth flow channel (510), the eleventh flow channel (511), and the twelfth flow channel (512) inside the second housing. The seventh flow channel (507) on the first housing (103) and the tenth flow channel (510) on the second housing (106) are sealed with a second type of O-ring (114); the eighth flow channel (508) on the first housing (103) and the eleventh flow channel (511) on the second housing (106) are sealed with a third type of O-ring (116).

7. A parallel combined cam-driven hydraulic pump as described in claim 2, characterized in that, The double-end-face spatial cam (305) is connected and fixed by two cam half-stop rings (306) installed on the shoulder of the camshaft (301). The two cam half-stop rings (306) are connected and fixed by two cotter pins (320), so that the cam (305) and the camshaft (301) rotate and reciprocate synchronously.

8. A parallel combined cam-driven hydraulic pump as described in claim 2, characterized in that, The first housing (103) contains three axial flow channels that communicate with the second housing (106): the seventh flow channel (507), the eighth flow channel (508), and the ninth flow channel (509). There are also two horizontal flow channels: the first flow channel (501) and the second flow channel (502), which communicate with four vertical flow channels: the third flow channel (503), the fourth flow channel (504), the fifth flow channel (505), and the sixth flow channel (506), serving as suction and discharge ports that communicate with the hydraulic cylinder. The seventh flow channel (507) and the ninth flow channel (509) are equipped with a check valve (115) and an overflow valve (10). 1) It is used to allow excess working fluid to overflow or flow back into the third housing (201), and to connect the axial flow channels seventh flow channel (507) and ninth flow channel (509) of the overflow valve (101) through the thirteenth flow channel (513) in the vertical direction. It also connects the axial flow channel eighth flow channel (508) on the first housing (103) and the horizontal flow channel eleventh flow channel (511) on the second housing (106), so that excess working fluid squeezed out from any pressure port can be gathered and flow back into the third housing (201). The flow channels that are not connected to other components are sealed with first-type screw plugs (111) to prevent leakage.

9. A parallel combined cam-driven hydraulic pump as described in claim 8, characterized in that, The third housing (201) has a vertical flow channel, the fourteenth flow channel (514), which is sealed with a second type of screw plug (209).

10. A parallel combined cam-driven hydraulic pump as described in claim 1, characterized in that, The functional modules are set in two or four; when the functional modules are set in four, the fourth housing (601) and the fifth housing (603) are sealed by a third type of housing gasket (602); the fifth housing (603) and the sixth housing (605) are sealed by a fourth type of housing gasket (604).

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