Floating swash plate type axial plunger pump with symmetrical inclined rotating assembly

Abstract

Disclosed is a floating swash plate type axial plunger pump with a symmetrical inclined rotating assembly. A rotating disc is provided on a main shaft of an inner cavity of a pump body; the same number of ball sockets are symmetrically provided on two side surfaces of the rotating disc, respectively; spherical hinges are respectively connected to, by means of splines, or are integrally formed on two sides of the rotating disc on the main shaft; a cylinder body is sleeved on each spherical hinge; a plurality of cylinder holes are formed in the surface of each cylinder body close to the rotating disc; the cylinder holes are in one-to-one correspondence with the ball sockets; a thin rod plunger is provided in each cylinder hole; the end plunger ball heads of the thin rod plungers extend out of the cylinder holes and extend into the ball sockets corresponding to the thin rod plungers; flow distribution discs are provided on the sides of the two cylinder bodies away from the rotating disc; the flow distribution discs are inclinedly fixed to the inner wall of the pump body; and the flow distribution discs are sealedly and tightly attached to the cylinder bodies. According to the present invention, the flow pulsation, the pressure pulsation and the vibration noise of the plunger pump are reduced by greatly increasing the number of plungers, and a lateral force and a friction force of a plunger pair are basically eliminated by designing a transmission mechanism for ensuring the constant-speed synchronous rotation of the inclined cylinder bodies and the main shaft.

Description

A floating swash plate axial piston pump with a symmetrically tilted rotating assembly Technical Field

[0001] The present invention relates to the technical field of plunger pumps, and in particular to a floating swash plate axial plunger pump with a symmetrically inclined rotating assembly. Background Art

[0002] The "dual carbon goals" are the dominant theme of global development today, presenting new opportunities and challenges for the application, innovation, and development of fluid power technology. As a key supporting technology in equipment used in engineering machinery, aerospace and navigation, and manufacturing, fluid power must accelerate its evolution amidst energy transitions to support the upgrading of electromechanical equipment. The prime mover of construction machinery is replaced by an electric motor from an internal combustion engine. Due to the completely different technical characteristics of electric motors and internal combustion engines, the electrification of construction machinery has put forward new technical requirements and demands for the hydraulic power component of the swash plate axial piston pump. The plunger and slipper assembly and its related plunger pair and slipper pair in the traditional plunger and slipper type swash plate axial piston pump are the key to the traditional plunger and slipper type swash plate axial piston pump being unable to adapt to the new technical requirements and demands of electrification. Due to the excessive lateral force of the plunger pair, the cylinder body is easy to overturn (directly affecting the sealing, lubrication and load-bearing performance of the distribution pair), the plunger / cylinder hole contact length is too long, the lubrication is insufficient, the PV value is too large, the variable inclination angle of the swash plate is generally limited to no more than 20 degrees, and a series of serious problems. Due to the excessive centrifugal force of the slipper in the slipper pair, the slipper is easy to overturn and wear, and the plunger cavity oil suction negative pressure is insufficient, resulting in serious air cavitation.

[0003] Against this backdrop, the inventors proposed a new type of floating swash plate axial piston pump. This design utilizes the "two-force rod" principle to transfer the enormous lateral force of the piston pair, and the hydrostatic bearing principle to offset the transferred enormous lateral force. Based on this, they designed a variety of floating swash plate axial piston pump structures and applied for a series of national invention patents. Existing traditional axial piston pumps, float cup pumps, and previously designed floating swash plate axial piston pumps still have technical deficiencies. These deficiencies are primarily manifested in the fact that these pumps typically have 9 to 11 pistons. This small number of pistons results in large flow and pressure pulsations, and significant pump vibration and noise. The float cup pump, a new type of axial piston pump invented in recent years by INNAS of the Netherlands, expands the number of pistons in the pump to 24, significantly reducing the pump's flow and pressure pulsations, as well as vibration and noise. However, this also introduces new challenges. The plunger of the float cup pump is a fixed plunger, that is, it is fixed on the main shaft, and the plunger and the main shaft have no relative motion freedom. The cylinder body is a split cylinder body, and the plunger cavity is independently designed into a new part called "cup body". The cup body is movably mounted on the fixed plunger. At the same time, the two ends of the cup body are clamped in the split cylinder body. The cup body has a certain space of relative sliding motion freedom relative to the split cylinder body. This is the origin of the name of the "float cup pump". The cup body of the float cup pump is driven by the plunger and the split cylinder body clamped on both sides of the cup body, and the split cylinder body of the float cup pump The connection and torque are transmitted to the main shaft through the transmission pin. Since the split cylinder body and the cup body are tilted compared to the main shaft, the rotation axis of the split cylinder body of the float cup pump and the rotation axis of the main shaft are not on the same axis, but at an axis angle. Therefore, the speed of the split cylinder body of the float cup pump and the speed of the main shaft are not completely equal. Therefore, the plunger pair of the float cup pump still has intermittent periodic lateral force and friction. There is also a certain degree of relative sliding motion between the floating cup body of the float cup pump and the split cylinder body that clamps the cup body, which will also generate friction. Summary of the Invention

[0004] The purpose of the present invention is to remedy the defects of the existing technology, further improve the floating swash plate axial piston pump technology system invented by the inventor of the present invention, and propose a floating swash plate axial piston pump with a symmetrical tilted rotating assembly.

[0005] The present invention is achieved through the following technical solutions:

[0006] A floating slant plate axial piston pump with a symmetrically inclined rotating assembly includes a pump body, a main shaft is installed in the pump body, a turntable is installed on the main shaft, the same number of ball sockets are symmetrically provided on two side surfaces of the turntable, and ball joints are spline-connected or integrally formed on the main shaft on both sides of the turntable, a cylinder body is installed on the outside of each ball joint, and a plurality of cylinder holes are provided on a surface of each cylinder body close to the turntable, the cylinder holes and the ball sockets correspond one-to-one, a thin rod plunger is provided in each cylinder hole, the end plunger ball head of the thin rod plunger extends out of the cylinder hole and extends into the ball socket of the turntable corresponding thereto, a distribution plate is provided on the side of the two cylinder bodies away from the turntable, the distribution plate is fixed to the inner wall of the pump body at a certain inclination angle, and the distribution surface of the distribution plate is in close contact with the bottom surface of the cylinder body;

[0007] The pump body includes a front pump body and a rear pump body. Bearings are provided between the front pump body, the rear pump body and the main shaft, and a shaft seal is provided between the front pump body and the main shaft. There are 26 thin rod plungers in total, 13 on each side of the turntable, and they are symmetrically installed on both sides of the turntable.

[0008] A plurality of oil through holes connected to the cylinder hole are provided on the side of the cylinder body away from the turntable, and an oil suction waist-shaped through hole and an oil discharge waist-shaped through hole are provided on the distribution plate. The plurality of oil through holes are connected with the oil suction waist-shaped through hole and the oil discharge waist-shaped through hole on the distribution plate, an oil inlet and an oil outlet are provided on the pump body, and an oil inlet flow channel and an oil outlet flow channel are provided inside the pump body, and both ends of the oil inlet flow channel are respectively connected with the oil suction waist-shaped through hole of the distribution plate on both sides, and both ends of the oil outlet flow channel are respectively connected with the oil discharge waist-shaped through hole of the distribution plate on both sides.

[0009] The ball joint is a cylindrical pin type ball joint. Three synchronous cylindrical pins are fixed on the outside of the cylindrical pin type ball joint. An arc groove track corresponding to the three synchronous cylindrical pins is provided on the inner wall of the cylinder body. The synchronous cylindrical pin is located in the arc groove track. The main shaft drives the cylindrical pin type ball joint to rotate. The torque is transmitted through the cooperation of the synchronous cylindrical pin and the arc groove track to drive the cylinder body to rotate.

[0010] The ball joint is a three-pivot ball joint, with three pivots fixed on the outer side of the three-pivot ball joint, spherical rollers installed on the three pivots, and a groove track corresponding to the spherical roller is provided on the inner wall of the cylinder body. The spherical roller is located in the groove track. The main shaft drives the three-pivot ball joint to rotate, and the torque is transmitted through the cooperation of the spherical roller and the groove track to drive the cylinder body to rotate.

[0011] The ball joint is a curved groove raceway type ball joint, and a plurality of curved grooves are provided on the outer side surface of the curved groove raceway type ball joint. A retaining frame is sleeved on the outer side of the curved groove raceway type ball joint, and a corresponding waist-shaped through hole is opened on the retaining frame. Balls are provided in the curved grooves of the curved groove raceway type ball joint and the waist-shaped through holes of the retaining frame, and a plurality of curved raceways corresponding to the balls are provided on the three inner walls of the cylinder body. The balls are located in the curved raceways, and the main shaft drives the curved groove raceway type ball joint to rotate, and the torque is transmitted through the cooperation of the balls and the curved raceways to drive the cylinder body to rotate.

[0012] The ball joint is a linear groove and roller type ball joint, and a plurality of linear grooves are provided on the outer side of the linear groove and roller type ball joint. A retaining frame is sleeved on the outer side of the linear groove and roller type ball joint, and a corresponding waist-shaped through hole is opened on the retaining frame. Balls are provided in the linear grooves of the linear groove and roller type ball joint and the waist-shaped through holes of the retaining frame, and a plurality of linear rollers corresponding to the balls are provided on the four inner walls of the cylinder body. The balls are located in the linear rollers, and the main shaft drives the linear groove and roller type ball joint to rotate, and the torque is transmitted through the cooperation of the balls and the linear rollers to drive the cylinder body to rotate.

[0013] The main shaft and the turntable are formed as one piece, and an annular groove is opened on the end face of the ball joint close to the turntable. A limit plate is connected to the main shaft through a spline. The outer surface of the limit plate is stepped, and the end with a small outer diameter of the limit plate is located in the annular groove of the ball joint. A center spring is connected between the end with a large outer diameter of the limit plate and the end face of the ball joint, and a tool retraction groove is provided on the main shaft near the position of the limit plate.

[0014] The cylindrical pin type ball joint, three-pivot type ball joint, curved groove raceway type ball joint, and straight groove raceway type ball joint are connected to the main shaft via splines;

[0015] The outer side surfaces of the cylindrical pin type ball joint, three-pivot ball joint, curved groove roller type ball joint, and straight groove roller type ball joint are all spherical or partially spherical, and the corresponding middle through holes of cylinder body one, cylinder body two, cylinder body three, and cylinder body four contain a section of spherical surface. The outer spherical surfaces of the cylindrical pin type ball joint, three-pivot ball joint, curved groove roller type ball joint, and straight groove roller type ball joint are in mating contact with the spherical surfaces of the corresponding middle through holes of cylinder body one, cylinder body two, cylinder body three, and cylinder body four.

[0016] When the spindle and the ball joint are integrally formed, a plurality of long cylindrical pins are installed on the outer side of the ball joint, and a linear groove track corresponding to the long cylindrical pins is provided on the inner wall of the corresponding middle through hole of the cylinder body 5. The other end of the long cylindrical pin is located in the linear groove track. When the ball joint integral with the spindle rotates, the long cylindrical pin and the linear groove track cooperate to transmit torque, thereby driving the cylinder body 5 to rotate; the inner wall of the middle through hole of the cylinder body 5 is a cylindrical surface and does not contain a spherical surface;

[0017] An annular groove 2 is provided at the bottom of the cylinder body 5, and a limiting disk 2, a center spring and a fixed disk are installed in sequence in the annular groove 2. The fixed disk is fixedly connected to the cylinder body. The outer diameter of the limiting disk 2 is smaller than the annular groove 2. The inner spherical surface of the limiting disk 2 matches the spherical surface of the ball joint, and the outside is stepped. The center spring is installed on the outside of the limiting disk 2 and is limited by the fixed disk.

[0018] Pressure plates are fixed on both sides of the turntable, and through holes corresponding to the ball sockets are opened on the pressure plates. The through holes match the outer surface of the thin rod plunger ball head, so that the thin rod plunger ball head is hinged on the turntable ball socket.

[0019] The main shaft and ball joint are integrally formed, and the pressure plate is split, consisting of two semicircular pressure plates;

[0020] When the main shaft and the ball joint are formed in one piece, the main shaft is split, and the split main shaft is respectively installed on both sides of the turntable.

[0021] The floating swash plate axial piston pump with a symmetrically tilted rotating assembly proposed in this invention has the following new structural and technical advantages compared to existing traditional axial piston pumps, float cup pumps, and previously designed floating swash plate axial piston pumps:

[0022] 1. The two rotating assemblies of the present invention are arranged axially symmetrically at the two ends of the pump body cavity. The oil suction and discharge of the two rotating assemblies are respectively combined through the designed oil suction flow channel and oil discharge flow channel in the pump body. That is, an oil inlet flow channel and an oil outlet flow channel are provided inside the pump body. The two ends of the oil inlet flow channel are respectively connected to the oil suction waist-shaped through-holes of the distribution plate on both sides, and the two ends of the oil outlet flow channel are respectively connected to the oil discharge waist-shaped through-holes of the distribution plate on both sides;

[0023] 2. The present invention significantly increases the number of plungers, more than twice the number of plungers in existing traditional axial piston pumps and previous floating swash plate axial piston pumps, and also has two more plungers than existing float cup pumps, which can significantly reduce the flow pulsation, pressure pulsation and vibration noise of the pump;

[0024] 3. Compared with existing traditional axial piston pumps and float cup pumps, the thin rod plunger in the present invention has two ends, the turntable and the cylinder body, which rotate synchronously with the main shaft at a completely constant speed. This eliminates the need for the plunger to transmit torque to drive the cylinder body. Therefore, the side of the plunger does not need to contact the cylinder hole. Therefore, the thin rod plunger is designed. In this way, the plunger pair has basically no lateral force and friction at any time.

[0025] 4. The plungers of the present invention are arranged axially symmetrically, and the axial force generated by the oil pressure in the plunger cavity is completely offset within the pump body cavity. In contrast, in existing traditional axial piston pumps and previously designed floating swash plate axial piston pumps, the axial force cannot be offset, but is instead transmitted through the swash plate to the housing, and ultimately borne by the screws on the flange that secures the pump.

[0026] 5. The present invention designs a floating swash plate axial piston pump with a symmetrically tilted rotating assembly. The plunger is a thin rod plunger hinged to the main shaft turntable via a plunger ball. This allows the plunger to swing freely relative to the main shaft. The cylinder is a one-piece cylinder, eliminating the friction problem between the floating cup and the split cylinder body that exists in existing float cup pumps.

[0027] 6. The variable displacement control system of the present invention is slightly more complex than that of conventional axial piston pumps and previously designed floating swash plate axial piston pumps, comparable to a float cup pump. Relatively speaking, the floating swash plate axial piston pump with a symmetrically tilted rotating assembly proposed in the present invention is more suitable for use as a fixed displacement pump, while the floating swash plate axial piston pump proposed in the previous patent is more suitable for use as a variable displacement pump. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] FIG1 is a cross-sectional view of the middle portion of the first embodiment of the present invention;

[0029] FIG2 is a cross-sectional view of the front side of the first embodiment of the present invention;

[0030] FIG3 is a schematic diagram of the internal structure of the first embodiment of the present invention;

[0031] FIG4 is a schematic diagram of the main shaft and turntable structure of the first embodiment of the present invention

[0032] Figure 5 is a schematic diagram of the main shaft, ball joint, and cylinder installation structure of an embodiment of the present invention; (Figure 5a is a cross-sectional view of a cylindrical pin type ball joint, Figure 5b is a cross-sectional view of a three-pivot type ball joint, Figure 5c is a cross-sectional view of a curved groove raceway type ball joint, Figure 5d is a cross-sectional view of a linear groove raceway type ball joint, Figure 5e is an overall appearance view of a cylindrical pin type ball joint, Figure 5f is an overall appearance view of a three-pivot type ball joint, Figure 5g is an overall appearance view of a curved groove raceway type ball joint, and Figure 5h is an overall appearance view of a linear groove raceway type ball joint).

[0033] FIG6 is a schematic diagram of the structure of a pressure plate according to an embodiment of the present invention;

[0034] FIG7 is a schematic diagram of the structure of the distribution plate of the present invention;

[0035] FIG8 is a front view of the distribution plate of the present invention;

[0036] FIG9 is a schematic structural diagram of a limiting plate according to an embodiment of the present invention;

[0037] FIG10 is a schematic diagram of the oil passage structure of the cylinder body of the present invention;

[0038] FIG11 is a schematic structural diagram of a cylindrical pin-type ball joint of a spindle turntable according to a second embodiment of the present invention;

[0039] Figure 12 is a schematic diagram of the cylinder body and ball joint structure of the second embodiment of the present invention;

[0040] FIG13 is a schematic structural diagram of a second limiting plate according to an embodiment of the present invention;

[0041] FIG14 is an exploded view of the installation of the second limiting plate and the cylinder body according to the second embodiment of the present invention;

[0042] FIG15 is a schematic diagram of the installation of the main shaft and the pressure plate according to the second embodiment of the present invention, wherein the pressure plate is a split type;

[0043] FIG16 is a schematic diagram of the installation of the main shaft and the pressure plate according to the second embodiment of the present invention, wherein the main shaft is a split type;

[0044] FIG17 is a schematic diagram of a main shaft cylindrical pin type ball joint body and a split main shaft structure according to embodiment 2 of the present invention.

[0045] Numbers in the figure: 1 Main shaft, 2 Turntable, 3 Shaft seal, 4 Bearing, 5 Distribution plate, 6 Ball joint, 6.1 Cylindrical pin type ball joint, 6.2 Three-pivot ball joint, 6.3 Curved groove roller type ball joint, 6.4 Straight groove roller type ball joint, 7 Cylinder, 7.1 Cylinder one, 7.2 Cylinder two, 7.3 Cylinder three, 7.4 Cylinder four, 7.5 Cylinder five, 8 Thin rod plunger, 9 Pressure plate, 10.1 Limit plate one, 10.2 Limit plate 2. 11 fixed plate, 12 center spring, 13.1 synchronous cylindrical pin, 13.2 spherical roller, 13.3 ball, 13.4 long cylindrical pin, 13.5 retaining rack, 14 oil inlet, 15 oil outlet, 16 oil inlet channel, 17 oil outlet channel, 18 oil through hole, 19 oil suction waist-shaped through hole, 20 oil discharge waist-shaped through hole, 21 ball socket, 22 cylinder hole, 23 undercut groove, 24 front pump body, 25 rear pump body. DETAILED DESCRIPTION

[0046] Example 1:

[0047] This embodiment 1 discloses a floating swash plate axial piston pump with a symmetrically tilted rotating assembly, as shown in Figures 1-4. The pump comprises a front pump body 24, a rear pump body 25, and a main shaft 1 installed therein. The front side of the front pump body 24 forms the opening of the inner cavity, in which a shaft seal 3 is installed. The rear side is connected to the rear pump body 25. The inner cavity of the pump is provided with a bearing 4, a distribution plate 5, a cylinder body 7, a ball joint 6, a limit plate 10.1, a turntable 2, a limit plate 10.1, a ball joint 6, a cylinder body 7, a distribution plate 5, and a bearing 4, arranged axially symmetrically with the turntable 2 as the center. The front pump body 24, the rear pump body 25, the bearing 4, the ball joint 6, and the limit plate 10.1 are all oriented in a front-to-back direction. The front section of the outer ring of the bearing 4 is fixedly connected to the front pump body 24 and the front end of the main shaft 1, respectively. The central axis of the mounting surface of the distribution plate 5 within the front pump body 24 and the rear pump body 25 forms an acute angle relative to the straight line in the front-to-back direction.

[0048] An integrally formed turntable 2 is provided on the main shaft 1, and the same number of ball sockets 21 are symmetrically provided on both sides of the turntable 2. Ball joints 6 are spline-connected on both sides of the main shaft 1, and corresponding cylinder bodies 7 are sleeved on the corresponding ball joints 6. A plurality of cylinder holes 22 are provided on a side of each cylinder body 7 close to the turntable 2. The cylinder holes 22 correspond one-to-one to the ball sockets 21, and a thin rod plunger 8 is provided in each cylinder hole 22. The end plunger ball head of the thin rod plunger 8 is hingedly installed on the ball socket 21, and the other end is placed in the cylinder hole 22. A distribution plate 5 is provided on the side of the two cylinder bodies 7 away from the turntable 2. The distribution plate 5 is fixed to the inner wall of the pump body, and the distribution plate 5 is sealed tightly on the cylinder body 7.

[0049] The total number of thin-rod plungers is typically 14, 18, 22, 26, or 30, and they are symmetrically installed on both sides of the turntable. The present invention employs 26 thin-rod plungers, 13 on each side of the turntable 2, which significantly reduces the pump source flow rate pulsation and pressure pulsation, effectively reducing the pump's vibration and noise.

[0050] As shown in Figure 5, Figure 5a shows that when the ball joint is a cylindrical pin type ball joint 6.1, the main shaft 1 is dragged and rotated by the prime mover, and the rotating main shaft 1 drives the cylindrical pin type ball joint 6.1 and the cylinder body 7.1 to rotate synchronously through the spline connection. One end of the synchronous cylindrical pin 13.1 is installed on the cylindrical pin type ball joint 6.1, and rotates synchronously with the rotation of the cylindrical pin type ball joint 6.1. The other end is installed in the arc groove track of the cylinder body 7.1. Therefore, the synchronous cylindrical pin 13.1 driven by the cylindrical pin type ball joint 6.1 will contact the arc groove track of the cylinder body 7.1 and transmit torque, thereby driving the cylinder body 7.1 to rotate synchronously with the main shaft 1 at a quasi-constant speed.

[0051] Figure 5b shows that when the ball joint is a three-pivot ball joint 6.2, the main shaft 1 is dragged and rotated by the prime mover. The rotating main shaft 1 drives the three-pivot ball joint 6.2 and the cylinder body 7.2 to rotate synchronously through the spline connection. The spherical roller 13.2 movably mounted on the three-pivot rotates synchronously with the rotation of the three-pivot ball joint 6.2, and the spherical roller 13.2 is embedded in the grooved track of the cylinder body 7.2. Therefore, the spherical surface of the spherical roller 13.2 driven by the three-pivot ball joint 6.2 will contact the grooved track of the cylinder body 7.2 and transmit torque, thereby driving the cylinder body 7.2 to rotate. The spherical roller 13.2 can make the axis of the pivot on which it is located intersect with the axis of the corresponding grooved track on the second cylinder body 7.2. When the angle between the main shaft 1 and the central axis of the second cylinder body 7.2 is not zero, because the spherical roller can also move along the pivot axis, it can also slide along the corresponding grooved track, so that the spherical surface of the spherical roller 13.2 and the groove surface of the corresponding grooved track of the second cylinder body 7.2 fit together. The contact generatrix formed by the two can ensure that the force transmission point of the spherical roller 13.2 is always located on the plane bisector of the angle between the two axes of the main shaft 1 and the central axis of the second cylinder body 7.2. Therefore, it has a constant speed transmission characteristic, which ensures that power can always be transmitted between the main shaft 1 and the second cylinder body 7.2, and the transmission is always constant speed.

[0052] Figure 5c shows that when the ball joint is a curved groove raceway type ball joint 6.3, the main shaft 1 is dragged and rotated by the prime mover, and the rotating main shaft 1 drives the curved groove raceway type ball joint 6.3 to rotate synchronously through the spline connection. The ball 13.3 clamped in the waist-shaped through hole of the retaining frame 13.5 can roll freely between the curved groove on the curved groove raceway type ball joint 6.3 and the curved raceway on the cylinder body three 7.3. When the center axis intersection angle between the cylinder body three 7.3 and the curved groove raceway type ball joint 6.3 is constant, the ball 13.3 clamped in the waist-shaped through hole of the retaining frame 13.5 is positioned by the cross action of the curved groove on the curved groove raceway type ball joint 6.3 and the curved raceway on the cylinder body three 7.3, and the force and torque between the curved groove raceway type ball joint 6.3 and the cylinder body three 7.3 are transmitted by the ball 13.3. Cage 13.5 has an inner spherical surface and an outer spherical surface. The inner spherical surface of cage 13.5 mates with the spherical outer surface of the curved groove raceway ball joint 6.3, while the outer spherical surface of cage 13.5 mates with the spherical surface of cylinder block 3 7.3. In other words, cylinder block 3 7.3 is supported on the curved groove raceway ball joint 6.3 through spherical and ball contact. The centers of all balls 13.3 lie on the plane that bisects the angle between the central axes of the curved groove raceway ball joint 6.3 and cylinder block 3 7.3. This allows the curved groove raceway ball joint 6.3 to synchronously drive the rotation of cylinder block 3 7.3 at a constant speed.

[0053] Figure 5d shows that when the ball joint is a linear groove and roller type ball joint 6.4, the main shaft 1 is dragged and rotated by the prime mover, and the rotating main shaft 1 drives the linear groove and roller type ball joint 6.4 to rotate synchronously through the spline connection. The ball 13.3 clamped in the waist-shaped through hole of the retaining frame 13.5 can roll freely between the linear groove on the linear groove and roller type ball joint 6.4 and the linear roller on the cylinder body 7.4. When the intersection angle of the central axis between the cylinder body 7.4 and the linear groove and roller type ball joint 6.4 is constant, the ball 13.3 clamped in the waist-shaped through hole of the retaining frame 13.5 is positioned by the cross action of the linear groove on the linear groove and roller type ball joint 6.4 and the linear roller on the cylinder body 7.4, and the force and torque between the linear groove and roller type ball joint 6.4 and the cylinder body 7.4 are transmitted by the ball 13.3. Cage 13.5 has an inner spherical surface and an outer spherical surface. The inner spherical surface of cage 13.5 contacts the spherical outer surface of linear grooved track ball joint 6.4, while the outer spherical surface of cage 13.5 contacts the spherical surface of the central through hole of cylinder body 4 7.4. In other words, cylinder body 4 7.4 is supported on linear grooved track ball joint 6.4 through spherical contact and contact between balls 13.3. The centers of all balls 13.3 lie on the plane that bisects the angle between the central axes of linear grooved track ball joint 6.4 and cylinder body 4 7.4. Therefore, linear grooved track ball joint 6.4 can synchronously drive cylinder body 4 7.4 to rotate at a constant speed, while also allowing axial displacement. That is, balls 13.3 can roll axially on the linear track, compensating for axial movement between linear grooved track ball joint 6.4 and cylinder body 4 7.4 caused by operating and installation errors.

[0054] The cylindrical pin type ball joint 6.1, the three-pivot type ball joint 6.2, the curved groove raceway type ball joint 6.3, and the straight groove raceway type ball joint 6.4 are connected to the main shaft 1 via splines.

[0055] The outer side surfaces of the cylindrical pin type ball joint 6.1, the three-pivot ball joint 6.2, the curved groove roller type ball joint 6.3, and the straight groove roller type ball joint 6.4 are all spherical surfaces or partially spherical surfaces, and the corresponding middle through holes of the cylinder body 1 7.1, the cylinder body 2 7.2, the cylinder body 3 7.3, and the cylinder body 4 7.4 contain a section of spherical surface. The outer spherical surfaces of the cylindrical pin type ball joint 6.1, the three-pivot ball joint 6.2, the curved groove roller type ball joint 6.3, and the straight groove roller type ball joint 6.4 are in mating contact with the spherical surfaces of the corresponding middle through holes of the cylinder body 1 7.1, the cylinder body 2 7.2, the cylinder body 3 7.3, and the cylinder body 4 7.4.

[0056] As shown in Figures 2, 7, 8, and 10, a plurality of oil holes 18 communicating with the cylinder bore 22 are provided on a surface of the cylinder body 7 away from the rotary disk 2. A waist-shaped oil suction hole 19 and a waist-shaped oil discharge hole 20 are provided on the distribution plate 5. The plurality of oil holes 18 communicate with the waist-shaped oil suction hole 19 and the waist-shaped oil discharge hole 20 on the distribution plate. An oil inlet 14 and an oil outlet 15 are provided on the pump body. An oil inlet flow channel 16 and an oil outlet flow channel 17 are provided inside the pump body. The two ends of the oil inlet flow channel 16 communicate with the waist-shaped oil suction hole 19 on the distribution plate 5 on both sides, and the two ends of the oil outlet flow channel 17 communicate with the waist-shaped oil discharge hole 20 on the distribution plate 5 on both sides. The oil in the waist-shaped oil suction hole 19 is discharged through the waist-shaped oil discharge hole 20 by the rotation of the cylinder body 7. The hydraulic oil at the oil inlet 14 passes through the oil inlet flow channel 16 and enters the oil suction waist-shaped through hole 19 of the distribution plate 5, then enters the oil through hole 18 of the cylinder body 7, and then enters the cylinder hole 22. The low-pressure oil is rotated and compressed by the thin rod plunger 8 to become high-pressure oil. The high-pressure oil then passes through the oil through hole 18 and the oil discharge waist-shaped through hole 20 of the distribution plate 5, enters the oil outlet flow channel 17, and is then delivered out from the oil outlet 15.

[0057] As shown in Figures 5 and 9, an annular groove is formed on the end face of the ball joint 6 near the turntable 2. A limit plate 10.1 is connected to the main shaft 1 via a spline. The outer surface of the limit plate 10.1 is stepped, with the end of the limit plate 10.1 with a smaller outer diameter positioned within the annular groove of the ball joint 6. A momentary spring 12 is connected between the end of the limit plate 10.1 with a larger outer diameter and the end face of the ball joint 6. A tool release groove 23 is provided on the main shaft 1 near the limit plate 10.1. The diameter of the tool release groove 23 is larger than that of the limit plate 10.1, preventing the limit plate 10.1 from moving to the right. A center spring 12 is installed between the limit plate 10.1 and the ball joint 6. One end of the center spring 12 acts on the limit plate 10.1, and the other end acts on the ball joint 6 and presses against the cylinder body 7, causing the cylinder body 7 to press against the distribution plate 5, providing an initial preload for the distribution pair.

[0058] As shown in FIG6 , pressure plates 9 are fixed to both sides of the turntable 2. The pressure plates 9 have through holes corresponding to the ball sockets 21, which mate with the outer surface of the thin rod plunger 8. The pressure plates 9 prevent the plunger ball from falling, allowing the plunger ball of the thin rod plunger 8 to be hinged to the ball sockets 21 of the turntable 2.

[0059] The pressing plate 9 is fixedly connected to the turntable 2 by bolts.

[0060] Example 2:

[0061] As shown in Figures 11-17, a floating swash plate axial piston pump with a symmetrically tilted rotating assembly comprises a front pump body 24, a rear pump body 25, and a main shaft 1 mounted therein. The front side of the front pump body 24 forms the opening of its internal cavity, where a shaft seal 3 is installed. The rear side is connected to the rear pump body 25. The pump's internal cavity is equipped with a bearing 4, a port plate 5, a cylinder body 7, a rotary disc 2, a cylinder body 7, a port plate 5, and a bearing 4, arranged axially symmetrically around the rotary disc 2. The front pump body 24, the rear pump body 25, and the bearing 4 are all oriented in a front-to-back direction. The front end of the outer ring of the bearing 4 is fixedly connected to the front pump body 24 and the front end of the main shaft 1, respectively. The central axis of the mounting surface of the port plate 5 within the front pump body 24 and the rear pump body 25 forms an acute angle with respect to the front-to-back straight line.

[0062] The main shaft 1 and the ball joint 6 are integrally formed. The main shaft 1 is rotated by the prime mover. The rotating main shaft 1 rotates synchronously by driving the long cylindrical pin 13.4. The other end of the long cylindrical pin 13.4 is installed in the linear groove track of the cylinder body 5 7.5. Therefore, the driven long cylindrical pin 13.4 contacts the linear groove track on the cylinder body 5 7.5 and transmits torque, thereby driving the cylinder body 5 7.5 to rotate synchronously with the main shaft 1 at a quasi-constant speed.

[0063] As shown in Figures 13-14: an annular groove is opened at the bottom of the cylinder body 5 7.5, and the limit plate 2 10.2, the center spring 12, and the fixed plate 11 are installed in sequence. The outer diameter of the limit plate 2 10.2 is smaller than the annular groove 2, and the inner spherical surface of the limit plate 2 10.2 cooperates with the ball joint 6, and the outer part is stepped. The center spring 12 is installed on the outside of the limit plate 2 10.2 and is restricted by the fixed plate 11. The fixed plate 11 is installed on the inner bottom surface of the cylinder body 5 7.5 by bolts, and the bolt installation surface is lower than the distribution surface. One end of the center spring 12 acts on the limit plate 2 10.2 and acts on the ball joint part, and the other end acts on the fixed plate 11 and is transmitted to the cylinder body 5 7.5, so that the cylinder body 5 7.5 is pressed against the distribution plate 5, providing an initial preload for the distribution pair.

[0064] As shown in FIG15 , when the spindle 1 , the turntable 2 , and the ball joint 6 are integrally formed, the pressure plate 9 is a split type, and the pressure plate 9 is composed of two semicircular pressure plates.

[0065] As shown in Figures 16 and 17, when the main shaft 1 and the ball joint 6 are formed in one piece, the main shaft 1 is a split type, and the split main shafts are respectively installed on both sides of the turntable 2.

[0066] The embodiments described above are merely descriptions of preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Without departing from the spirit of the present invention, various modifications and improvements made to the technical solutions of the present invention by persons skilled in the art should fall within the scope of protection defined by the claims of the present invention.

Claims

1. A floating swash plate axial piston pump with a symmetrically inclined rotating assembly, characterized in that: It comprises a pump body, a main shaft is installed in the pump body, a turntable is installed on the main shaft, the same number of ball sockets are symmetrically arranged on two sides of the turntable, ball joints are spline-connected or integrally formed on the main shaft at both sides of the turntable, a cylinder body is installed on the outside of each ball joint, a plurality of cylinder holes are arranged on a surface of each cylinder body close to the turntable, the cylinder holes correspond to the ball sockets one by one, a thin rod plunger is arranged in each cylinder hole, the end plunger ball head of the thin rod plunger extends out of the cylinder hole and extends into the ball socket of the turntable corresponding thereto, a distribution plate is arranged on the side of the two cylinder bodies away from the turntable, the distribution plate is fixed on the inner wall of the pump body at a certain inclination angle, and the distribution surface of the distribution plate is closely attached to the bottom surface of the cylinder body; The pump body includes a front pump body and a rear pump body, bearings are arranged between the front pump body, the rear pump body and the main shaft, and a shaft seal is also arranged between the front pump body and the main shaft; there are 26 thin rod plungers, 13 on each side of the turntable, and they are symmetrically installed and arranged on both sides of the turntable; A plurality of oil through holes connected to the cylinder hole are arranged on a surface of the cylinder body away from the turntable, and an oil suction waist-shaped through hole and an oil discharge waist-shaped through hole are arranged on the distribution plate. The plurality of oil through holes are connected to the oil suction waist-shaped through hole and the oil discharge waist-shaped through hole on the distribution plate, an oil inlet and an oil outlet are arranged on the pump body, and an oil inlet flow channel and an oil outlet flow channel are arranged inside the pump body, and two ends of the oil inlet flow channel are respectively connected to the oil suction waist-shaped through hole of the distribution plate on both sides, and two ends of the oil outlet flow channel are respectively connected to the oil discharge waist-shaped through hole of the distribution plate on both sides.

2. A floating swash plate axial piston pump with a symmetrically inclined rotating assembly according to claim 1, characterized in that: The ball joint is a cylindrical pin type ball joint, three synchronous cylindrical pins are fixed on the outside of the cylindrical pin type ball joint, and an arc groove track corresponding to the three synchronous cylindrical pins is provided on the inner wall of the cylinder body. The synchronous cylindrical pin is located in the arc groove track, and the main shaft drives the cylindrical pin type ball joint to rotate, and the torque is transmitted through the cooperation of the synchronous cylindrical pin and the arc groove track to drive the cylinder body to rotate.

3. A floating swash plate axial piston pump with a symmetrically inclined rotating assembly according to claim 1, characterized in that: The ball joint is a three-pivot ball joint, three pivots are fixed on the outer side of the three-pivot ball joint, spherical rollers are installed on the three pivots, a groove track corresponding to the spherical roller is provided on the inner wall of the cylinder body, the spherical roller is located in the groove track, the main shaft drives the three-pivot ball joint to rotate, and the torque is transmitted through the cooperation of the spherical roller and the groove track to drive the cylinder body to rotate.

4. A floating swash plate axial piston pump with a symmetrically inclined rotating assembly according to claim 1, characterized in that: The ball joint is a curved groove roller type ball joint, and a plurality of curved grooves are provided on the outer side of the curved groove roller type ball joint, and a retaining frame is sleeved on the outer side of the curved groove roller type ball joint, and a corresponding waist-shaped through hole is opened on the retaining frame, and balls are provided in the curved grooves of the curved groove roller type ball joint and the waist-shaped through hole of the retaining frame, and a plurality of curved rollers corresponding to the balls are provided on the three inner walls of the cylinder body, and the balls are located in the curved rollers, and the main shaft drives the curved groove roller type ball joint to rotate, and the torque is transmitted through the cooperation of the balls and the curved rollers to drive the cylinder body to rotate.

5. A floating swash plate axial piston pump with a symmetrically inclined rotating assembly according to claim 1, characterized in that: The ball joint is a linear groove and roller type ball joint, and a plurality of linear grooves are arranged on the outer side of the linear groove and roller type ball joint, and a retaining frame is sleeved on the outer side of the linear groove and roller type ball joint, and a corresponding waist-shaped through hole is opened on the retaining frame, and balls are arranged in the linear grooves of the linear groove and roller type ball joint and the waist-shaped through holes of the retaining frame, and a plurality of linear rollers corresponding to the balls are arranged on the four inner walls of the cylinder body, and the balls are located in the linear rollers, and the main shaft drives the linear groove and roller type ball joint to rotate, and the torque is transmitted through the cooperation of the balls and the linear rollers to drive the cylinder body to rotate.

6. A floating swash plate axial piston pump with a symmetrically inclined rotating assembly according to claim 1, characterized in that: The main shaft and the turntable are integrally formed, and an annular groove is opened on the end face of the ball joint close to the turntable. A limit plate is connected to the main shaft through a spline. The outer portion of the limit plate is stepped, and the end with a small outer diameter of the limit plate is located in the annular groove of the ball joint. A center spring is connected between the end with a large outer diameter of the limit plate and the end face of the ball joint, and a tool retraction groove is provided on the main shaft near the limit plate.

7. A floating swash plate axial piston pump with a symmetrically inclined rotating assembly according to any one of claims 2 to 5, characterized in that: The cylindrical pin type ball joint, three-pivot type ball joint, curved groove raceway type ball joint, and linear groove raceway type ball joint are connected to the main shaft via splines; The outer side surfaces of the cylindrical pin ball joint, three-pivot ball joint, curved groove roller type ball joint and linear groove roller type ball joint are all spherical or partially spherical, and the corresponding middle through holes of cylinder body one, cylinder body two, cylinder body three and cylinder body four contain a section of spherical surface. The outer spherical surfaces of the cylindrical pin ball joint, three-pivot ball joint, curved groove roller type ball joint and linear groove roller type ball joint are in mating contact with the spherical surfaces of the corresponding middle through holes of cylinder body one, cylinder body two, cylinder body three and cylinder body four.

8. The floating swash plate axial piston pump with a symmetrically inclined rotating assembly according to claim 1, characterized in that: When the spindle and the ball joint are integrally formed, a plurality of long cylindrical pins are installed on the outer side of the ball joint, and a linear groove track corresponding to the long cylindrical pins is provided on the inner wall of the middle through hole of the cylinder body 5 corresponding thereto, and the other end of the long cylindrical pin is located in the linear groove track. When the ball joint integral with the spindle rotates, the long cylindrical pin and the linear groove track cooperate to transmit torque, thereby driving the cylinder body 5 to rotate; the inner wall of the middle through hole of the cylinder body 5 is a cylindrical surface, and does not contain a spherical surface; An annular groove 2 is opened at the bottom of the cylinder body 5, and a limiting disk 2, a center spring and a fixed disk are installed in the annular groove 2 in sequence. The fixed disk is fixedly connected to the cylinder body. The outer diameter of the limiting disk 2 is smaller than the annular groove 2. The inner spherical surface of the limiting disk 2 matches the spherical surface of the ball joint, and the outer part is stepped. The center spring is installed on the outside of the limiting disk 2 and is limited by the fixed disk.

9. A floating swash plate axial piston pump with a symmetrically inclined rotating assembly according to claim 1, characterized in that: Pressure plates are fixed on both sides of the turntable, and through holes corresponding to the ball sockets are opened on the pressure plates. The through holes match the outer surface of the thin rod plunger ball head, so that the thin rod plunger ball head is hinged on the turntable ball socket.

10. A floating swash plate axial piston pump with a symmetrically inclined rotating assembly according to claim 9, characterized in that: When the main shaft and the ball joint are integrally formed, the pressing plate is a split type, and the pressing plate is composed of two semicircular pressing plates; When the main shaft and the ball joint are formed in one piece, the main shaft is split, and the split main shaft is respectively installed on both sides of the turntable.

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