Floating swashplate piston pump with constant velocity drive rotary table transmission mechanism for main shaft

Abstract

This invention discloses a floating swashplate axial piston pump with a constant-speed drive mechanism for the rotary table. It incorporates two drive mechanisms: a "three-pivot ball joint-spherical roller type" and a "ball cage ball joint-ball bearing type," achieving constant-speed synchronous rotation of the main shaft, ball joint, rotary table, and cylinder throughout the entire operating cycle. This overcomes the shortcomings of existing technologies that rely on the pistons sequentially driving the rotary table, resulting in periodic peak values ​​of lateral contact force / friction at the piston pair. The invention comprehensively and thoroughly reduces the lateral contact force / friction at the piston pair. A pre-pressurization / pre-depressurization noise reduction cavity is located in the middle groove of the rear end cover, reducing pump source flow pulsation and pressure shock within the piston cavity without affecting installation space requirements. Part of the oil in the distribution holes of the distribution plate flows into the oil reservoir through a fixed-gap damping groove. Combined with the variable-gap fit between the cylinder and the distribution plate, a hydrostatic support is formed at the distribution pair.

Description

Technical Field

[0001] This invention relates to the field of piston pump technology, and in particular to a floating swashplate axial piston pump containing a main shaft constant speed drive rotary table transmission mechanism. Background Technology

[0002] Fluid power, as a crucial supporting technology in equipment for engineering machinery, aerospace, marine, and manufacturing industries, needs to accelerate its evolution during energy transition to support the upgrading of electromechanical equipment. The replacement of internal combustion engines with electric motors in engineering machinery presents new technical requirements and demands for swashplate axial piston pumps, a hydraulic power component, due to the fundamentally different technical characteristics of electric motors and internal combustion engines. The piston-slipper assembly and related piston and slipper pairs in traditional swashplate axial piston pumps are key reasons why they cannot meet the requirements of new electrification technologies. Excessive lateral force in the piston pair leads to a series of serious problems, including cylinder overturning (directly affecting the sealing, lubrication, and load-bearing performance of the distribution pair), excessively long piston / cylinder bore contact length, insufficient lubrication, excessively high PV value, and a swashplate tilt angle generally limited to no more than 20°. Excessive centrifugal force in the slipper pair causes slipper overturning and uneven wear, insufficient negative pressure in the piston cavity, and severe air cavitation.

[0003] Against this backdrop, the inventors proposed a novel floating swashplate axial piston pump, which transfers the huge lateral force of the piston pair based on the "two-force bar" principle, and counteracts and digests the huge lateral force of the piston pair transferred based on the hydrostatic support principle. Based on this, various structural schemes of floating swashplate axial piston pumps were designed. In previous designs of floating swashplate axial piston pumps, torque was transmitted to drive the rotary disc rotation based on the intermittent contact between the conical piston and the cylinder bore, or the rotary disc rotation was driven by a ball joint via a pin or key connection. Regardless of the scheme, since the rotary disc needs to oscillate with the swashplate, the rotary disc and the main shaft are not coaxial when the pump needs to suck or discharge oil. Instead, the center line of the rotary disc and the center line of the main shaft form an angle. Therefore, the rotary disc and the cylinder block cannot achieve completely uniform synchronous rotation, but only quasi-uniform speed. As a result, during one rotation cycle of the piston, there will always be a period in which the side of the piston contacts the cylinder bore, generating a large contact force. This intermittent contact force also brings difficulties to the design of the swashplate oscillation variable control system. At the same time, there is also a certain relative rotational motion between the rotary disc and the ball joint supporting it, resulting in frictional power loss. Although there has been a significant technical improvement compared to the traditional piston slipper type swashplate axial piston pump, its technical level and performance still need to be further improved.

[0004] To this end, the present invention further designs a transmission mechanism that enables the spindle to drive the rotary table at a constant speed, and a floating swashplate axial piston pump containing this mechanism, so as to further reduce the lateral force at the piston pair and the frictional power loss between the rotary table and the ball joint, and improve the variable control performance of the floating swashplate axial piston pump. Summary of the Invention

[0005] The purpose of this invention is to overcome the deficiencies of existing technologies and provide a floating swashplate axial piston pump containing a main shaft constant speed drive rotary table transmission mechanism.

[0006] This invention is achieved through the following technical solution:

[0007] A floating swashplate piston pump with a main shaft constant velocity drive rotary disk transmission mechanism includes a pump body and a main shaft installed in the pump body. A front cover and a rear cover are respectively installed at the front and rear ends of the pump body cavity. In the pump body cavity, behind the front cover, a bearing, a base, a swashplate, a rotary disk, a three-pivot ball joint-spherical roller constant velocity drive mechanism or a ball cage ball joint-ball bearing constant velocity drive mechanism, a cylinder, and a distribution plate are arranged in sequence. The front end of the outer ring of the bearing is fixed to the front cover, the front side of the base is fixedly connected to the rear end of the outer ring of the bearing, and the front side of the swashplate facing the base is installed at the rear end of the base. The rotary disk is parallel to the swashplate, and the front end face of the rotary disk is opposite to the rear end face of the swashplate. A hydrostatic support and an auxiliary support structure are provided on the front end face of the rotary disk and the rear end face of the swashplate to support the load force transmitted by the irregularly shaped piston on the rotary disk, and to fully ensure the friction and lubrication performance of the friction pair composed of the rotary disk and the swashplate, i.e., the rotary disk pair, under various working conditions.There is a certain gap between the outer surface of the rotary table and the inner surface of the swashplate, preventing them from contacting each other. The main shaft is connected to the cylinder body via a spline. The rotary table is driven by a three-pivot ball joint-spherical roller constant velocity drive mechanism or a ball cage ball joint-ball constant velocity drive mechanism. Multiple ball sockets are provided on the rear end face of the rotary table, and multiple cylinder holes are provided on the cylinder body. The ball sockets and cylinder holes are evenly distributed circumferentially around the central axes of the rotary table and the cylinder body, and each ball socket and cylinder hole corresponds to the other. A shaped plunger is slidably installed in each cylinder hole, and the end plunger ball heads of the multiple shaped plungers extend out of the cylinder body and correspond accordingly. The shaped plunger, hinged to multiple ball sockets, has a spherical structure at its tail end, containing one or more sealing rings, and directly contacts the cylinder bore. Each ball socket opening on the rear end face of the rotary disc is formed as a cylindrical opening. The circumferential outer surface of the ball head end of the shaped plunger is formed with an annular groove. The central axis of the annular groove is inclined at a certain angle relative to the central axis of the shaped plunger. The diameter of the cylindrical opening is larger than the diameter of the annular groove. When the ball head end of the shaped plunger is hinged to the ball socket, the annular groove and the cylindrical opening form a dimensional fit. When the cylindrical surface of the annular groove on the ball head of the shaped plunger is the same as the cylindrical surface of the ball socket... When aligned with the axis, the plunger ball head can freely enter and exit the socket. When the cylindrical surface of the ball head and the cylindrical surface of the socket are not coaxial, the plunger ball head is engaged with the socket in the form of a ball joint. The front and rear end faces of the distribution plate contact the cylinder block and the rear end cover, respectively. The distribution plate has double pre-pressure increase damping holes in the low-pressure to high-pressure transition zone and pre-pressure decrease damping holes in the high-pressure to low-pressure transition zone. A pre-pressure decrease cavity and a pre-pressure increase cavity are provided in the middle of the rear end face of the rear end cover. The rear end cover has a pre-pressure increase flow channel and a pre-pressure decrease flow channel. The pre-pressure decrease damping holes connect with the pre-pressure decrease cavity through the pre-pressure decrease flow channel. The cavity is connected, and the double pre-pressurization damping orifice is connected to the pre-pressurization cavity through the pre-pressurization flow channel. Multiple distribution holes are also provided on the distribution plate, which are connected to the oil inlet and outlet ports of the pump body. Oil passages are provided on the rear end face of the cylinder body corresponding to each cylinder hole position, and the oil passages are connected to the corresponding cylinder holes and the distribution holes. Several spring channels are also provided on the cylinder body, and a central spring is provided in the spring channel. The two ends of the central spring act on the cylinder body and the ball joint of the three-pivot ball joint-spherical roller constant velocity drive mechanism or the ball cage ball joint-ball ball constant velocity drive mechanism.

[0008] The aforementioned three-pivot ball joint-spherical roller constant velocity drive mechanism includes a three-pivot ball joint, spherical rollers, and a corresponding rotary table. The outer spherical surface of the three-pivot ball joint is divided into three spherical segments by three pivots, which are three cylindrical pivots evenly distributed circumferentially on the outer surface of the ball joint. The three-pivot ball joint is connected to the main shaft via a spline. There are three spherical rollers, each with a cylindrical through-hole in the center and a spherical surface on the outer side. The spherical rollers are fitted onto the three pivots through the central cylindrical through-hole and can roll around the three pivots. The rotary table has a through-hole in the center, and a portion of the through-hole's outline is a spherical surface. This spherical surface is divided into three spherical segments by three evenly distributed grooved tracks. The three spherical surfaces on the outer side of the three-pivot ball joint form a hinge. The spring force generated by the central spring acting on the three-pivot ball joint is transmitted to the turntable through the spherical hinge mating surface, pressing the turntable against the slant surface. The three evenly distributed grooved tracks on the central through hole of the turntable cooperate with the three spherical rollers. The three spherical rollers respectively contact the groove surfaces on the corresponding grooved tracks and undergo relative motion. The main shaft drives the three-pivot ball joint to rotate synchronously through a spline connection. The rotating three-pivot ball joint contacts the grooved tracks on the central through hole of the turntable through the spherical rollers fitted on the three pivots and transmits torque, thereby driving the turntable to rotate synchronously at the same speed as the main shaft.

[0009] The connection between the three-pivot ball joint and the main shaft is one of spline connection, key connection, or pin connection. The three-pivot ball joint is either an integral structure or a split structure. When the three-pivot ball joint is a split structure, it is composed of a cylindrical three-pivot and a ball joint containing a spherical surface. The cylindrical three-pivot has a cylindrical profile, with three cylindrical pivots protruding from the outer cylindrical surface for mounting the spherical roller. The ball joint containing a spherical surface has a spherical profile and a cylindrical through-hole. It is mounted on the outer cylindrical surface of the three-pivot cylindrical body through the central through-hole. One end of the ball joint contacts the central spring, and the force of the central spring is transmitted to the rotary table through the spherical hinge of the ball joint and the rotary table.

[0010] The spherical roller allows the axis of its pivot to intersect with the axis of the corresponding grooved track on the turntable. When the angle between the main shaft and the central axis of the turntable is 0°, the automatic centering of the three pivots automatically makes the two axes coincide, and they transmit power at the same speed. When the angle between the main shaft and the central axis of the turntable is not 0°, the spherical roller can move along the pivot axis and slide along the corresponding grooved track, so that the spherical surface of the spherical roller and the groove surface of the corresponding grooved track of the turntable are in contact. The contact generatrix formed by the two can ensure that the force transmission point of the spherical roller is always located on the bisecting plane of the angle between the two axes of the main shaft and the central axis of the turntable, and it also has the characteristic of constant speed transmission. This ensures that the main shaft and the turntable can always transmit power and always transmit power at the same speed.

[0011] The ball-cage type ball joint-ball type constant velocity drive mechanism includes a ball-cage type ball joint, balls, a cage, and a corresponding rotary disk. The ball-cage type ball joint is connected to the main shaft via a spline. The spherical outer surface of the ball-cage type ball joint has several inner raceways evenly distributed circumferentially for the balls to roll. A central spring acts between the rear end face of the ball-cage type ball joint and the cylinder body. The cage has an inner spherical surface and an outer spherical surface. The inner spherical surface of the cage mates with the spherical outer surface of the ball-cage type ball joint, and the outer spherical surface of the cage mates with the spherical surface of the central through hole of the rotary disk. The cage has several oblong through holes evenly distributed circumferentially. The rotary disk has several outer raceways evenly distributed axially on the spherical surface of the central through hole for the rolling of the balls. The balls are spherical and are held in the waist-shaped through hole of the cage. As the angle between the central axis of the ball cage joint and the rotary disk changes, that is, as the inclination angle of the pump swashplate changes, the balls can roll freely between the inner raceway on the ball cage joint and the outer raceway on the rotary disk. The transmission of force and torque between the ball cage joint and the rotary disk is completed through the balls.

[0012] The center of the inner raceway on the ball cage hinge and the center of the outer raceway on the rotary table are offset from the center of the spherical surface of the ball cage hinge or the center of the inner and outer spherical surfaces of the cage by a certain distance. This offset is either "symmetrical offset, i.e., the eccentricity is equal in magnitude and opposite in direction" or "identical offset, i.e., the eccentricity is equal in magnitude and same in direction". The typical number of the inner raceway on the ball cage hinge, the outer raceway on the rotary table, the balls, and the waist-shaped through holes of the cage is 6 each. Depending on the magnitude of the transmitted force and torque, the number can also be other. The ball cage hinge-ball constant velocity drive mechanism may also not contain the cage. The balls are positioned by the cross action between the inner raceway on the ball cage hinge and the outer raceway on the rotary table.

[0013] The inner raceway on the ball cage joint and the outer raceway on the rotary table are either curved grooves or straight grooves. The centerline shape of the curved groove raceway or the outline shape of the bottom of the raceway along the centerline of the corresponding ball cage joint or rotary table is an arc shape. The centerline shape of the straight groove raceway or the outline shape of the bottom of the raceway along the centerline of the corresponding ball cage joint or rotary table is a straight line shape. When both the inner and outer raceways are curved groove raceways, the ball cage joint and the rotary table can only rotate relative to each other and will not have axial displacement during torque transmission. When both the inner and outer raceways are straight groove raceways, the ball cage joint and the rotary table can not only rotate relative to each other during torque transmission, but also have axial displacement allowed. That is, the balls can roll on the straight groove raceways, which can compensate for the axial movement between the ball cage joint and the rotary table caused by working and installation errors.

[0014] In the aforementioned ball-cage type ball joint-ball type constant velocity drive mechanism, the balls roll and rotate between the inner raceway on the ball-cage type ball joint and the outer raceway on the rotary table, transmitting force and torque. The positioning of the balls is achieved by the cross action of the inner raceway on the ball-cage type ball joint and the outer raceway on the rotary table. When the central axes of the ball-cage type ball joint and the rotary table form any angle between them, the centers of all the balls are located on the bisecting plane of the angle between the central axes of the ball-cage type ball joint and the rotary table. Therefore, the ball-cage type ball joint can drive the rotary table to rotate at a constant velocity synchronously. Since the ball-cage type ball joint is connected to the main shaft through a spline, the ball-cage type ball joint and the main shaft always maintain synchronous rotation, thus achieving the same speed synchronous drive of the rotary table by the main shaft.

[0015] Regardless of whether it is a three-pivot ball joint-spherical roller constant velocity drive mechanism or a ball cage ball joint-ball constant velocity drive mechanism, the two ends of the central spring act on the cylinder and the ball joint respectively. The spring force of the central spring acts on the ball joint and the cylinder. Before the piston pump pressure is established, the spring force acting on the ball joint is transmitted to the rotary table through the ball joint and presses the rotary table against the swashplate surface, providing the initial pre-clamping force and pre-sealing force for the rotary table / swashplate surface friction pair, i.e., the rotary table pair. The spring force acting on the cylinder causes the cylinder to press against the distribution plate, providing the initial pre-clamping force and pre-sealing force for the distribution pair.

[0016] The irregularly shaped plunger is one of three types: a conical plunger, a thin rod plunger, and a connecting rod plunger. The conical plunger has a conical shape in the middle section, with its size gradually changing relative to the diameter of the ball head at the front end and the ball surface at the rear end. The thin rod plunger has a thin rod shape in the middle section, with its size abruptly changing to the size of a thin rod relative to the diameter of the ball head at the front end and the ball surface at the rear end. The connecting rod plunger includes a connecting rod and a plunger cylinder. The connecting rod has ball heads at both ends. One ball head of the connecting rod is hinged to a ball socket inside the plunger cylinder, and the other ball head of the connecting rod is hinged to a ball socket on the rotary table. The outer surface of the plunger cylinder has a clearance fit with the cylinder bore.

[0017] The end face of the distribution plate facing the cylinder body is fitted with the cylinder body with a clearance. The front end face of the distribution plate is provided with oil storage tanks on the inner and outer sides of each distribution hole. The oil storage tanks are corresponding to the oil passage openings. Each distribution hole is connected to the corresponding oil storage tank through a damping groove. Part of the oil in the distribution hole enters the oil storage tank through the damping groove, and then flows into the gap between the cylinder body and the distribution plate to form a static pressure support.

[0018] The rear end cover and the pre-pressurization cavity are designed separately for easy processing, installation and disassembly. A recessed groove is provided in the middle of the rear end face of the rear end cover. A mounting surface and bolt mounting holes are machined on the recessed groove. The center of the recessed groove corresponds to the center line of the main shaft. The pre-pressurization cavity has bolt mounting holes corresponding to those on the recessed groove. The pre-pressurization cavity is fixed in the recessed groove by bolts. The pre-depressurization cavity and the rear end cover are designed as an integrated unit to ensure the consistency of the pump body.

[0019] The advantages of this invention are:

[0020] This invention provides a "three-pivot ball joint-spherical roller type" and "ball cage ball joint-ball bearing type" transmission mechanism that enables constant velocity drive of the rotary table by the main shaft, as well as a floating swashplate axial piston pump containing this mechanism. Based on the constant velocity transmission mechanism in this invention, the rotary table can be actively driven by the main shaft, and the rotational speed of the rotary table is always in the same direction and synchronized with the rotational speed of the main shaft and the cylinder block connected to the main shaft spline. Therefore, it is not necessary to drive the rotary table to rotate through the irregularly shaped plunger installed in the cylinder bore of the cylinder block. Thus, it achieves a further comprehensive reduction in the lateral force at the plunger pair and the frictional power loss between the rotary table and the ball joint. Since the frictional torque between the rotary table and the ball joint, which is the variable piston load torque, is more stable, the variable control performance of the floating swashplate axial piston pump can be improved. Attached Figure Description

[0021] Figure 1 This is a partial sectional view of the overall assembly of the floating swashplate axial piston pump containing an integrated "three-pivot ball joint-spherical roller type" main shaft constant velocity drive rotary table transmission mechanism of the present invention.

[0022] Figure 2 This is a half-sectional view of the overall assembly of the floating swashplate axial piston pump containing an integrated "three-pivot ball joint-spherical roller type" main shaft constant velocity drive rotary table transmission mechanism of the present invention.

[0023] Figure 3 This is a partial sectional view of the overall assembly of the floating swashplate axial piston pump containing a split-type "three-pivot ball joint-spherical roller type" main shaft constant velocity drive rotary table transmission mechanism of the present invention.

[0024] Figure 4 This is a half-sectional view of the overall assembly of the floating swashplate axial piston pump containing the split-type "three-pivot ball joint-spherical roller type" main shaft constant speed drive rotary table transmission mechanism of the present invention.

[0025] Figure 5 This is a partial sectional view of the overall assembly of the floating swashplate axial piston pump with a "ball cage type ball joint-ball type" spindle constant velocity drive rotary table transmission mechanism containing curved groove raceways according to the present invention.

[0026] Figure 6 This is a half-sectional view of the overall assembly of the floating swashplate axial piston pump with a "ball cage type ball joint-ball type" spindle constant velocity drive rotary table transmission mechanism containing curved groove raceways according to the present invention.

[0027] Figure 7 This is a partial sectional view of the overall assembly of the floating swashplate axial piston pump with a "ball cage type ball joint-ball type" spindle constant velocity drive rotary table transmission mechanism containing a straight groove raceway according to the present invention.

[0028] Figure 8 This is a half-sectional view of the overall assembly of the floating swashplate axial piston pump with a "ball cage type ball joint-ball type" spindle constant velocity drive rotary table transmission mechanism containing a straight groove raceway according to the present invention.

[0029] Figure 9 This is a partial assembly sectional view of the main shaft, rotary table, ball joint, plunger, and cylinder block of a floating swashplate axial piston pump containing the transmission mechanism of a constant velocity drive rotary table of the main shaft according to the present invention. (9a is an integrated "three-pivot ball joint-spherical roller integrated" piston pump, 9b is a split "three-pivot ball joint-spherical roller" piston pump, 9c is a "ball cage ball joint-ball bearing" piston pump with curved groove raceway, and 9d is a "ball cage ball joint-ball bearing" piston pump with straight groove raceway.)

[0030] Figure 10This is a schematic diagram of a transmission mechanism for a constant velocity drive rotary table of the main shaft and a rotary table of a floating swashplate axial piston pump containing the mechanism. (10a is a "three-pivot ball joint-spherical roller type" rotary table, 10b is a "ball cage ball joint-ball bearing type" rotary table with curved groove raceway, 10c is a half-sectional view of a "ball cage ball joint-ball bearing type" rotary table with curved groove raceway, 10d is a "ball cage ball joint-ball bearing type" rotary table with straight groove raceway, and 10e is a half-sectional view of a "ball cage ball joint-ball bearing type" rotary table with straight groove raceway.)

[0031] Figure 11 This is a schematic diagram of a transmission mechanism for a constant velocity drive rotary table of a main shaft and a ball joint of a floating swashplate axial piston pump containing this mechanism, according to the present invention. (11a is an integral three-pivot ball joint, 11b is a split three-pivot, 11c is a split three-pivot assembly with a ball joint, 11d is a curved groove raceway ball joint, 11e is a half-sectional view of a curved groove raceway ball joint, 11f is a straight groove raceway ball joint, 11g is a half-sectional view of a straight groove raceway ball joint, and 11h is a cage.)

[0032] Figure 12 This is a partial sectional view of the transmission mechanism for a constant velocity drive rotary table of the main shaft, and a floating swashplate axial piston pump containing the mechanism, along with a ball joint assembly. (12a is a "three-pivot ball joint-spherical roller type" piston pump; 12b is a "ball cage type ball joint-ball bearing type" piston pump with curved groove raceway; 12c is a "ball cage type ball joint-ball bearing type" piston pump with straight groove raceway.)

[0033] Figure 13 for Figure 9 A magnified view of position A in section a.

[0034] Figure 14 This is a front view of the distribution plate of a floating swashplate piston pump containing a main shaft constant speed drive rotary table transmission mechanism according to the present invention.

[0035] Figure 15 This is a partial assembly drawing of the distributor plate and cylinder block of a floating swashplate piston pump containing a main shaft constant speed drive rotary table transmission mechanism according to the present invention.

[0036] Figure 16 This is a cross-sectional view of the pre-pressurization / depressurization chamber of a floating swashplate piston pump with a constant velocity drive rotary table transmission mechanism for the main shaft, according to the present invention. (16a is a pre-pressurization cross-sectional view, and 16b is a pre-depressurization cross-sectional view.)

[0037] Figure 17 This is a front view of the rear end cover of a floating swashplate piston pump containing a main shaft constant speed drive rotary table transmission mechanism according to the present invention.

[0038] Figure 18This is a schematic diagram of the assembly of the rear end cover and the pre-pressurization cavity of a floating swashplate piston pump containing a constant speed drive rotary table transmission mechanism of the main shaft according to the present invention.

[0039] Figure 19 This is a comparison diagram of the piston friction force of a floating swashplate piston pump with a main shaft constant speed drive rotary table transmission mechanism and the piston friction force of a floating swashplate axial piston pump with a main shaft quasi-constant speed drive rotary table.

[0040] Figure 20 This is a schematic diagram of the connecting rod plunger of a floating swashplate plunger pump with a constant velocity drive rotary table transmission mechanism for the main shaft, according to the present invention. (20a is a front view of the connecting rod plunger, and 20b is a half-sectional view of the connecting rod plunger.)

[0041] Figure 21 This is a schematic diagram of the swashplate structure of a floating swashplate piston pump with a constant velocity drive rotary table transmission mechanism of the main shaft according to the present invention (21a is an isometric view of the swashplate, 21b is a rear view of the swashplate).

[0042] The diagram labels are as follows: 1.1 Spindle 1, 1.2 Spindle 2, 1.3 Spindle 3, 2 Front end cover, 3 Bearing, 4 Base, 5 Swashplate, 5.1 External auxiliary support band, 5.2 Internal auxiliary support band, 5.3 Sealing band, 6.1 Rotary table, 6.2 Curved groove raceway type rotary table, 6.3 Straight groove raceway type rotary table, 6.4 Static pressure oil groove, 6.5 Oil drain channel, 7.1 Three-pivot ball joint 1, 7.2 Three-pivot, 7.3 Ball joint 2, 7.4 Curved groove raceway type ball joint 3, 7.5 Straight groove raceway type ball joint 7.6 Hinge 4, Cage 5, 8.1 Cylinder 1, 8.2 Cylinder 2, 8.3 Cylinder 3, 9.1 Distributor Plate, 9.2 Distributor Orifice, 9.3 Double Pre-pressurization Damping Orifice, 9.4 Pre-pressurization Damping Orifice, 9.5 Oil Reservoir, 9.6 Damping Groove, 10.1 Pin, 10.2 Drive Pin, 11.1 Spherical Roller, 11.2 Ball, 12.1 Rear End Cover, 12.2 Pre-pressurization Chamber, 12.3 Pre-pressurization Chamber, 12.4 Pre-pressurization Flow Channel, 12.5 Pre-pressurization Flow Channel, 12.6 Plug, 13 Pump Body 14.1 Conical plunger; 14.2 Thin rod plunger; 14.3 Connecting rod; 14.4 Plunger cylinder; 15 Variable displacement lever; 16. Center spring; 17. Ball socket; 18. Annular groove; 19. Cylindrical opening; 20. Cylinder bore; 21. Oil passage opening; 22. Curved groove raceway; 23. Straight groove raceway. Detailed Implementation

[0043] This embodiment discloses a floating swashplate piston pump containing a main shaft constant velocity drive rotary table transmission mechanism, such as... Figure 1 and Figure 2The image shows a floating swashplate axial piston pump with a three-pivot ball joint-spherical roller type constant velocity drive rotary table transmission mechanism, which integrates three pivots and ball joints. Figure 3 and Figure 4 The image shows a floating swashplate axial piston pump with a three-pivot, ball-joint-spherical roller type main shaft constant velocity drive rotary table transmission mechanism, which includes a three-pivot and ball-joint split design. Figure 5 and Figure 6 The image shows a floating swashplate axial piston pump with a "ball cage type ball joint-ball type" spindle constant velocity drive rotary table transmission mechanism containing curved groove raceways, such as... Figure 7 and Figure 8 The image shows a floating swashplate axial piston pump with a "ball cage type ball joint-ball type" spindle constant velocity drive rotary table transmission mechanism containing a straight groove raceway.

[0044] like Figure 1 and Figure 2 As shown, a floating swashplate axial piston pump with a three-pivot ball joint-spherical roller type main shaft constant velocity drive rotary disk transmission mechanism includes a pump body 13 and a main shaft 1.1 installed inside the pump body 13. The front side of the pump body 13 is the cavity opening of the pump body 13, and a front end cover 2 is installed in the cavity opening. A rear end cover 12.1 is connected to the rear side of the pump body 13. In the inner cavity of the pump body 13, behind the front end cover 2, a bearing 3, a base 4, a swashplate 5, a rotary disk 6.1, a cylinder 8.1, a three-pivot ball joint 7.1, a spherical roller 11.1, and a distribution plate 9.1 are arranged in sequence. Among them, the axial directions of the front end cover 2, the rear end cover 12.1, the bearing 3, and the base 4 are all in the front-rear direction. The front end of the outer ring of the bearing 3 is fixed to the rear end of the front end cover 2, and the front side of the base 4 is fixedly connected to the rear end of the outer ring of the bearing 3. The swash plate 5 is mounted on the rear end of the base 4 facing the front side of the base 4, and the central axis of the swash plate 5 forms an acute angle with respect to the straight line in the front-back direction. A variable lever 15 is also installed in the pump body 13. The variable lever 15 is connected to the edge ball joint of the swash plate 5. Pushing the variable lever 15 of the swash plate 5 can adjust the tilt angle of the swash plate 5.

[0045] like Figure 3 and Figure 4As shown, a floating swashplate axial piston pump with a three-pivot and ball-joint split-type main shaft constant velocity drive rotary disk transmission mechanism includes a pump body 13 and a main shaft 1.2 installed inside the pump body 13. The front side of the pump body 13 is the cavity opening of the pump body 13, and a front end cover 2 is installed in the cavity opening. A rear end cover 12.1 is connected to the rear side of the pump body 13. In the inner cavity of the pump body 13, behind the front end cover 2, a bearing 3, a base 4, a swashplate 5, a rotary disk 6.1, a cylinder 8.2, a three-pivot 7.2, a pin 10.1, a ball-roller 11.1, a ball joint 7.3, a transmission pin 10.2, and a distribution plate 9.1 are arranged in sequence. Among them, the axial directions of the front end cover 2, the rear end cover 12.1, the bearing 3, and the base 4 are all in the front-rear direction. The front end of the outer ring of the bearing 3 is fixed to the rear end of the front end cover 2, and the front side of the base 4 is fixedly connected to the rear end of the outer ring of the bearing 3. The swash plate 5 is mounted on the rear end of the base 4 facing the front side of the base 4, and the central axis of the swash plate 5 forms an acute angle with respect to the straight line in the front-back direction. A variable lever 15 is also installed in the pump body 13. The variable lever 15 is connected to the edge ball joint of the swash plate 5. Pushing the variable lever 15 of the swash plate 5 can adjust the tilt angle of the swash plate 5.

[0046] like Figure 5 and Figure 6 As shown, a floating swashplate axial piston pump with a "ball cage-type ball joint-ball type" main shaft constant velocity drive rotary disk transmission mechanism containing curved groove raceways includes a pump body 13 and a main shaft 1.3 installed inside the pump body 13. The front side of the pump body 13 is the cavity opening of the pump body 13, and a front end cover 2 is installed in the cavity opening. A rear end cover 12 is connected to the rear side of the pump body 13. In the inner cavity of the pump body 13, behind the front end cover 2, a bearing 3, a base 4, a swashplate 5, a curved groove raceway rotary disk 6.2, a cylinder 8.3, a curved groove raceway ball joint 7.4, a ball 11.2, a cage 7.6, and a distributor 9.1 are arranged in sequence. Among them, the axial directions of the front end cover 2, the rear end cover 12.1, the bearing 3, and the base 4 are all in the front-rear direction. The front end of the outer ring of the bearing 3 is fixed to the rear end of the front end cover 2, and the front side of the base 4 is fixedly connected to the rear end of the outer ring of the bearing 3. The swash plate 5 is mounted on the rear end of the base 4 facing the front side of the base 4, and the central axis of the swash plate 5 forms an acute angle with respect to the straight line in the front-back direction. A variable lever 15 is also installed in the pump body 13. The variable lever 15 is connected to the edge ball joint of the swash plate 5. Pushing the variable lever 15 of the swash plate 5 can adjust the tilt angle of the swash plate 5.

[0047] like Figure 7 and Figure 8As shown, a floating swashplate axial piston pump with a "ball cage-type ball joint-ball type" main shaft constant velocity drive rotary disk transmission mechanism containing a straight groove raceway includes a pump body 13 and a main shaft 1.3 installed inside the pump body 13. The front side of the pump body 13 is the cavity opening of the pump body 13, and a front end cover 2 is installed in the cavity opening. A rear end cover 12.1 is connected to the rear side of the pump body 13. In the inner cavity of the pump body 13, behind the front end cover 2, a bearing 3, a base 4, a swashplate 5, a straight groove raceway rotary disk 6.3, a cylinder 8.3, a straight groove raceway ball joint 7.5, a ball 11.2, a cage 7.6, and a distributor 9.1 are arranged in sequence. Among them, the axial directions of the front end cover 2, the rear end cover 12.1, the bearing 3, and the base 4 are all in the front-rear direction. The front end of the outer ring of the bearing 3 is fixed to the rear end of the front end cover 2, and the front side of the base 4 is fixedly connected to the rear end of the outer ring of the bearing 3. The swash plate 5 is mounted on the rear end of the base 4 facing the front side of the base 4, and the central axis of the swash plate 5 forms an acute angle with respect to the straight line in the front-back direction. A variable lever 15 is also installed in the pump body 13. The variable lever 15 is connected to the edge ball joint of the swash plate 5. Pushing the variable lever 15 of the swash plate 5 can adjust the tilt angle of the swash plate 5.

[0048] In the three-pivot ball joint-spherical roller type constant velocity drive rotary table transmission mechanism, the main shaft 1.1 is driven to rotate by the prime mover. The rotating main shaft 1.1 drives the three-pivot ball joint 7.1 and the cylinder 8.1 to rotate synchronously through spline connection. The spherical roller 11.1, which is movably mounted on the pivot, rotates synchronously with the rotation of the three-pivot ball joint 7.1. The spherical roller 11.1 is embedded in the grooved track of the rotary table 6.1. Therefore, the spherical surface of the spherical roller 11.1 driven by the three-pivot ball joint 7.1 will contact the grooved track on the middle through hole of the rotary table 6.1 and transmit torque, thereby driving the rotary table 6.1 to rotate. The spherical roller 11.1 allows the axis of its pivot to intersect with the axis of the corresponding grooved track on the rotary table 6.1. When the angle between the central axis of the main shaft 1.1 and the rotary table 6.1 is 0°, the automatic centering of the three pivots automatically makes the two axes coincide, and they transmit power at the same speed. When the angle between the central axis of the main shaft 1.1 and the rotary table 6.1 is not 0°, the spherical roller 11.1 can move along the pivot axis, so it can also slide along the corresponding grooved track, making the spherical surface of the spherical roller 11.1 and the groove surface of the corresponding grooved track on the rotary table 6.1 fit together. The contact generatrix formed by the two can ensure that the force transmission point of the spherical roller 11.1 is always located on the bisecting plane of the angle between the central axes of the main shaft 1.1 and the rotary table 6.1, and it also has the characteristic of constant speed transmission. This ensures that power can always be transmitted between the main shaft 1.1 and the rotary table 6.1, and that the transmission is always at the same speed. The rotary table 6.1 is supported on the spherical surface of the three-pivot ball joint 7.1. The rotary table transmission mechanism, which integrates the three pivots and the ball joint, is driven by the main shaft at the same speed, realizing the synchronous rotation of the rotary table 6.1, the three-pivot ball joint 7.1, and the cylinder 8.1.

[0049] In the three-pivot ball-joint-spherical roller type constant velocity drive rotary table transmission mechanism with separate three-pivot and ball-joint components, the main shaft 1.2 is driven to rotate by the prime mover. The rotating main shaft 1.2 drives the cylinder 8.2 to rotate synchronously through a spline connection, and also drives the three-pivot 7.2 to rotate synchronously through a pin 10.1 connection. The spherical roller 11.1, which is movably mounted on the pivot, rotates synchronously with the rotation of the three-pivot 7.2. The spherical roller 11.1 is embedded in the grooved track of the rotary table 6.1. Therefore, the spherical surface of the spherical roller 11.1 driven by the three-pivot 7.2 will contact the grooved track on the middle through hole of the rotary table 6.1 and transmit torque, thereby driving the rotary table 6.1 to rotate. The spherical roller 11.1 allows the axis of its pivot to intersect with the axis of the corresponding grooved track on the rotary table 6.1. When the angle between the main shaft 1.2 and the central axis of the rotary table 6.1 is 0°, the automatic centering effect of the three pivots automatically makes the two axes coincide, and they transmit power at the same speed. When the angle between the main shaft 1.2 and the central axis of the rotary table 6.1 is not 0°, the spherical roller 11.1 can move along the pivot axis, so it can also slide along the corresponding grooved track, making the spherical surface of the spherical roller 11.1 and the groove surface of the corresponding grooved track of the rotary table 6.1 fit together. The contact generatrix formed by the two can ensure that the force transmission point of the spherical roller 11.1 is always located on the bisecting plane of the angle between the two axes of the main shaft 1.2 and the central axis of the rotary table 6.1, and it also has the characteristic of constant speed transmission. This ensures that power can always be transmitted between the main shaft 1.2 and the rotary table 6.1, and that the transmission is always at the same speed. The turntable 6.1 is supported on the spherical surface of the ball joint 7.3. The rotating cylinder 8.2 drives the ball joint 7.3 to rotate synchronously through the transmission pin 10.2. The turntable transmission mechanism is driven at the same speed by the three-pivot ball joint-spherical roller type main shaft, which is a three-pivot type and a ball joint separate type. This also realizes the synchronous rotation at the same speed among the three-pivot 7.2, the turntable 6.1, the ball joint 7.3 and the cylinder 8.2.

[0050] In the "ball cage type ball joint - ball type" constant velocity drive rotary table transmission mechanism of the main shaft of the curved groove raceway 22, the main shaft 1.3 is driven to rotate by the prime mover. The rotating main shaft 1.3 drives the cylinder 8.3 and the curved groove raceway type ball joint 7.4 to rotate synchronously through a spline connection. As the swashplate tilt angle changes, that is, as the angle between the central axes of the curved groove raceway type rotary table 6.2 and the curved groove raceway type ball joint 7.4 changes, the balls 11.2 clamped in the waist-shaped through hole of the cage 7.6 can move on the curved groove raceway type ball joint 7.4. The inner raceway and the outer raceway on the curved groove raceway type turntable 6.2 roll freely. When the central axis angle between the curved groove raceway type turntable 6.2 and the curved groove raceway type ball joint 7.4 is constant, the ball 11.2 held in the waist-shaped through hole of the cage 7.6 is positioned by the cross action of the inner raceway on the curved groove raceway type ball joint 7.4 and the outer raceway on the curved groove raceway type turntable 6.2. The ball 11.2 transmits force and torque between the curved groove raceway type ball joint 7.4 and the curved groove raceway type turntable 6.2. The cage 7.6 has an inner spherical surface and an outer spherical surface. The inner spherical surface of the cage 7.6 is in contact with the spherical outer surface of the curved grooved raceway type ball joint 7.4, and the outer spherical surface of the cage 7.6 is in contact with the spherical surface of the central through hole of the curved grooved raceway type turntable 6.2. That is, the curved grooved raceway type turntable 6.2 is supported on the curved grooved raceway type ball joint 7.4 through the contact action of the spherical surfaces and the contact action of the balls 11.2. When the central axes of the curved grooved raceway type ball joint 7.4 and the curved grooved raceway type turntable 6.2 are at any angle, the centers of all the balls 11.2 are located on the bisecting plane of the angle between the central axes of the curved grooved raceway type ball joint 7.4 and the curved grooved raceway type turntable 6.2. Therefore, the curved grooved raceway type ball joint 7.4 can drive the curved grooved raceway type turntable 6.2 to rotate at a constant speed and synchronously.

[0051] In the "ball cage type ball joint - ball type" constant velocity drive rotary table transmission mechanism of the straight groove raceway 23, the main shaft 1.3 is driven to rotate by the prime mover. The rotating main shaft 1.3 drives the cylinder 8.3 and the straight groove raceway ball joint 7.5 to rotate synchronously through a spline connection. As the swashplate tilt angle changes, that is, as the angle between the central axes of the straight groove raceway rotary table 6.3 and the straight groove raceway ball joint 7.5 changes, the balls 11.2 clamped in the waist-shaped through hole of the cage 7.6 can move on the straight groove raceway ball joint 7.5. The inner raceway and the outer raceway on the straight groove raceway type turntable 6.3 roll freely. When the central axis angle between the straight groove raceway type turntable 6.3 and the straight groove raceway type ball joint 7.5 is constant, the ball 11.2 held in the waist-shaped through hole of the cage 7.6 is positioned by the cross action of the inner raceway on the straight groove raceway type ball joint 7.5 and the outer raceway on the straight groove raceway type turntable 6.3. The ball 11.2 transmits force and torque between the straight groove raceway type ball joint 7.5 and the straight groove raceway type turntable 6.3. The cage 7.6 has an inner spherical surface and an outer spherical surface. The inner spherical surface of the cage 7.6 engages with the spherical outer surface of the straight groove raceway type ball joint 7.5, and the outer spherical surface of the cage 7.6 engages with the spherical surface of the central through hole of the straight groove raceway type turntable 6.3. In other words, the straight groove raceway type turntable 6.3 is supported on the straight groove raceway type ball joint 7.5 through spherical contact and the contact action of the balls 11.2. When the central axes of the straight groove raceway type ball joint 7.5 and the straight groove raceway type turntable 6.3 form any angle between them, the centers of all the balls 11.2 are located on the bisector of the angle between the central axes of the straight groove raceway type ball joint 7.5 and the straight groove raceway type turntable 6.3. Therefore, the straight groove raceway type ball joint 7.5 can drive the straight groove raceway type turntable 6.3 to rotate at a constant speed and synchronously. Since both the ball joint 7.5 and the rotary table 6.3 have straight groove raceways 23, during torque transmission, the ball joint 7.5 and the rotary table 6.3 can not only rotate relative to each other, but also allow axial displacement. That is, the balls 11.2 can roll axially on the straight raceway, which can compensate for the axial movement between the ball joint 7.5 and the rotary table 6.3 caused by working and installation errors.

[0052] The rotary table 6.1, or the curved grooved raceway type rotary table 6.2, or the straight grooved raceway type rotary table 6.3, are parallel to the swashplate 5. That is, the central axis of the rotary table forms the same acute angle with respect to the straight line in the front and back direction. The outer surface of the rotary table is opposite to the inner surface of the swashplate 5 and there is a certain gap between them.

[0053] like Figure 9 , Figure 10, Figure 13 As shown, each ball socket 17 of the ball joint mounting surface of the rotary table 6.1, the curved groove raceway type rotary table 6.2, or the straight groove raceway type rotary table 6.3 is respectively formed into a cylindrical opening 19, and also includes a shaped plunger. The shaped plunger is one of three types of plungers: a conical plunger 14.1, a thin rod plunger 14.2, and a connecting rod plunger. The middle part of the conical plunger 14.1 is conical in shape, and its size relative to the diameter of the ball head and the ball tail is [missing information]. The shape gradually changes; the middle part of the thin rod plunger 14.2 is thin rod shaped, and its size changes abruptly to thin rod size relative to the diameter of the ball head at the front end and the spherical surface at the tail end of the plunger; the connecting rod plunger includes a connecting rod 14.3 and a plunger cylinder 14.4. The two ends of the connecting rod are ball heads. The ball head at one end of the connecting rod is hinged to the ball socket inside the plunger cylinder, and the ball head at the other end of the connecting rod is hinged to the ball socket of the rotary disk. The outer surface of the plunger cylinder is clearance-fitted with the cylinder bore. The outer circumferential surface of the ball head end of the conical plunger 14.1 and the thin rod plunger 14.2 is formed with an annular groove 18. The central axis of the annular groove 18 is inclined at a certain angle relative to the central axis of the plunger. The diameter of the cylindrical opening 19 is larger than the diameter of the annular groove 18. When the ball head end of the plunger is hinged to the ball socket 17, the annular groove 18 and the cylindrical opening 19 form a dimensional fit. When the cylindrical surface of the plunger ball head annular groove 18 is coaxial with the cylindrical surface of the ball socket, the plunger ball head can freely enter and exit the ball socket. When the cylindrical surface of the ball head is not coaxial with the cylindrical surface of the ball socket, the plunger ball head is snapped and hinged to the ball socket in the form of a ball joint.

[0054] like Figure 14 , Figure 15 , Figure 16 , Figure 17 , Figure 18 As shown, the axial direction of the distribution plate 9.1 is front-to-back. The distribution plate 9.1 has multiple distribution holes 9.2 that run through the distribution plate 9.1 from front to back. It also has double pre-pressure damping holes 9.3 in the low-pressure to high-pressure conversion zone and pre-pressure damping holes 9.4 in the high-pressure to low-pressure conversion zone. The distribution holes 9.2 are used to connect the cylinder bore 20 and the oil inlet and outlet of the pump body 13. The rear end face of the cylinder body 8.1 facing the distribution plate 9.1 is clearance-fitted with the front end face of the distribution plate 9.1. The rear end face of the cylinder body 8.1 is provided with oil passages 21 corresponding to each cylinder bore 20. The oil passages 21 are connected to the corresponding cylinder bore 20. The double pre-pressure damping holes 9.3 are connected to the pre-pressure cavity 12.2 in the rear end cover 12.1 through the pre-pressure flow channel 12.4. The pre-pressure damping holes 9.4 are connected to the pre-pressure cavity 12.3 in the rear end cover 12.1 through the pre-pressure flow channel 12.5. The front end of the distribution plate 9.1 is provided with oil storage tanks 9.5 on the inner and outer sides of each distribution hole, and each distribution hole is connected to the corresponding oil storage tank 9.5 through a damping groove 9.6.

[0055] The pre-pressurization cavity 12.2 and the rear end cover 12.1 are designed separately and are bolted together. The pre-pressurization cavity 12.2 and the rear end cover 12.1 are connected by a pre-pressurization flow channel 12.4. The pre-depressurization cavity 12.3 is located in the rear end cover 12.1 and is connected by a pre-depressurization flow channel 12.5. Both the pre-pressurization and depressurization cavities are equipped with plugs 12.6.

[0056] like Figure 9 , Figure 12 As shown, cylinder blocks 8.1, 8.2, and 8.3 are oriented in a front-to-back direction. The through holes in the centers of cylinder blocks 8.1, 8.2, and 8.3 are connected to the main shaft 1.1 via splines. Cylinder blocks 8.1, 8.2, and 8.3 have multiple cylinder bores 20 with an axial front-to-back direction, and these bores 20 are evenly distributed circumferentially around the central axis of cylinder blocks 8.1, 8.2, and 8.3. Each cylinder bore 20 is slidably fitted with a conical plunger 14.1 or a thin rod plunger 14.2. The front ends of each conical plunger 14.1 or thin rod plunger 14.2 protrude from the front end faces of cylinder body 1 8.1, cylinder body 2 8.2, and cylinder body 3 8.3, respectively. The ball head of the front plunger of each conical plunger 14.1 or thin rod plunger 14.2 is hinged to the ball sockets 17 at the rear end of the rotary table 6.1, the curved groove raceway type rotary table 6.2, or the straight groove raceway type rotary table 6.3.

[0057] A central spring 16 is provided between cylinder block 1 (8.1), cylinder block 2 (8.2), cylinder block 3 (8.3) and their corresponding three-pivot ball joints 1 (7.1), 2 (7.3), 3 (7.4), and 4 (7.5). One end of the central spring 16 exerts its force on cylinder block 8.1, causing cylinder block 8.1 to press against the distributor plate 9.1. The other end of the central spring 16 exerts its force on the corresponding three-pivot ball joints. Ball joints 7.1 (type 1), 7.3 (type 2), 7.4 (type 3), and 7.5 (type 4) press against their respective rotary discs 6.1, 6.2, and 6.3. The spring force transmits this force, causing the rotary discs 6.1, 6.2, and 6.3 to press against the swashplate 5. The central spring 16 provides initial pre-tightening and pre-sealing forces to the distribution pair formed between the cylinder 8.1 and the distribution plate 9.1, and the rotary disc pairs formed between the rotary discs 6.1, 6.2, and 6.3 and the swashplate 5, respectively, before the pump starts and pressure is established.

[0058] In this example, the oil enters the cylinder bores 20 of cylinder 1 8.1, cylinder 2 8.2, and cylinder 3 8.3 through the distribution hole 9.2 of the distribution plate 9.1, or the oil flowing out of the cylinder bore 20 is discharged through the distribution hole 9.2. Part of the oil in the distribution hole 20 flows into the oil reservoir 9.5 through the damping groove 9.6. A variable clearance fit is formed between the front end face of the distribution plate 9.1 and the rear end face of cylinder 1 8.1, cylinder 2 8.2, and cylinder 3 8.3 by the action of the central spring 16. Under the combined action of the fixed clearance throttling of the damping groove 21 and the variable clearance throttling between cylinder 1 8.1, cylinder 2 8.2, cylinder 3 8.3 and the distribution plate 9.1, a hydrostatic support is formed at the distribution pair.

[0059] like Figure 10 , 21 As shown, hydrostatic support and auxiliary support structures are provided on the front end face of the rotary table 6.1 and the rear end face of the swashplate 5. The hydrostatic support and auxiliary support structures include a plurality of hydrostatic oil grooves 6.4 provided on the front end face of the rotary table 6.1, a plurality of oil guide channels 6.5 provided in the rotary table 6.1, an outer auxiliary support band 5.1, an inner auxiliary support band 5.2 and a sealing band 5.3 provided on the rear end face of the swashplate 5. The positions of the hydrostatic oil grooves 6.4 and the oil guide channels 6.5 correspond one-to-one with the ball sockets 17, and one end of the oil guide channel 6.5 is connected to the ball socket 17 at the corresponding position and the other end is connected to the hydrostatic oil groove 6.4 at the corresponding position. The rear end face of the swashplate 5 is provided with an outer auxiliary support band 5.1, an inner auxiliary support band 5.2 and an outer auxiliary support band 5.3 distributed in a double ring. 1. A sealing strip 5.3 is provided on the rear end face of the swashplate 5 between the inner auxiliary support strips 5.2. The sealing strip 5.3 presses against each hydrostatic oil groove 6.4 on the front end face of the rotary table 6.1. The sealing strip 5.3 and each hydrostatic oil groove 6.4 cooperate to form a hydrostatic oil chamber. The irregular plunger has a central through hole. One end of the central through hole is connected to the corresponding cylinder bore, and the other end of the central through hole is connected to the ball socket 17 at the corresponding position on the ball joint mounting surface of the rotary table 6.1. The hydraulic oil in the cylinder bore is introduced into the hydrostatic oil chamber through the central through hole to form a hydrostatic support between the rotary table 6.1 and the swashplate 5. This support is used to support the irregular plunger to transmit the load force acting on the rotary table and fully ensure the friction and lubrication performance of the friction pair composed of the rotary table and the swashplate under various working conditions.

[0060] Under the high-speed drag of their respective main shafts 1.1, 1.2, and 1.3, cylinder blocks 8.1, 8.2, and 8.3 reciprocate once per revolution, completing one oil intake and discharge cycle. During the pre-pressurization process of the plunger cavity transitioning from oil intake to discharge, the plunger cavity first contacts the double pre-pressurization damping holes 9.3 on the distribution plate 9.1 and then moves to the discharge waist-shaped hole on the distribution plate 9.1. The distribution holes 9.2 on the distribution plate 9.1 are divided into intake waist-shaped holes and discharge waist-shaped holes. The oil flows dynamically back and forth within the plunger cavity and the pre-pressurization chamber, achieving a buffer pressurization effect and reducing plunger pump outlet flow pulsation and pressure shock within the plunger cavity. During the pre-pressure reduction process, high-pressure oil flows into the pre-pressure reduction chamber 12.3 from the plunger cavity. At this time, the pressure in the pre-pressure reduction chamber increases, and the plunger cavity is in the pre-pressure reduction stage.

[0061] like Figure 20 As shown, the connecting rod plunger includes a connecting rod 14.3 and a plunger cylinder 14.4. The connecting rod has ball ends at both ends. One ball end of the connecting rod is hinged to a ball socket inside the plunger cylinder, and the other ball end of the connecting rod is hinged to a ball socket on the rotary table. The outer surface of the plunger cylinder is clearance-fitted with the cylinder bore.

[0062] The working process of this embodiment is as follows:

[0063] Driven by the prime mover, main shafts 1.1, 1.2, and 1.3 rotate cylinders 8.1, 8.2, and 8.3, and simultaneously drive three-pivot ball joints 7.1, 7.3, 7.4, and 7.5 to rotate synchronously. Conical plunger 14.1 or thin rod plunger 14.2 is installed inside cylinder bore 20 and rotates around its axis under the drive of cylinders 8.1, 8.2, and 8.3. At the same time, three-pivot ball joints 7.1 and 7.5 rotate synchronously. 2. The rotary table 6.1 is driven by the spherical roller 11.1 to rotate synchronously with the corresponding cylinder block 8.1 and cylinder block 8.2. The curved groove raceway ball joint 3 7.4 and the straight groove raceway ball joint 4 7.5 are driven by the ball bearing 11.2 to rotate synchronously with the corresponding cylinder block 8.3. On the other hand, the displacement is changed by the variable lever 15 controlling the swashplate 5. Under the action of the tilt angle of the swashplate 5, the conical plunger 14.1 or the thin rod plunger 14.2 reciprocates within the cylinder bore 20. The rotational and reciprocating motion of the conical plunger 14.1 or the thin rod plunger 14.2 causes the volume of the sealed working chamber of the cylinder bore 20 to change continuously. Oil is drawn in from the suction waist-shaped hole of the spherical distribution plate 9.1 and discharged from the discharge waist-shaped hole.

[0064] like Figure 19 As shown, since the rotary disk 6.1 rotates synchronously with the corresponding cylinder block 8.1 and cylinder block 8.2, or the rotary disk 6.2 with curved groove and the rotary disk 6.3 with straight groove and the rotary disk 8.3 with the corresponding cylinder block 8.3, the rotary disk 6.1 and the rotary disk 6.2 with curved groove and the rotary disk 6.3 with straight groove do not need to be driven by the irregularly shaped plunger to rotate. Therefore, the lateral contact force between the plunger and the cylinder bore 20 can be further reduced, thus the friction force of the plunger pair is further and significantly reduced in a comprehensive manner.

[0065] Each revolution of cylinder block 1 (8.1), cylinder block 2 (8.2), and cylinder block 3 (8.3) causes each shaped plunger to reciprocate once, completing one cycle of oil intake and discharge. During the pre-pressurization process, which transitions the plunger cavity from intake to discharge, the plunger cavity first contacts the double pre-pressurization damping orifice 9.3 on the distribution plate 9.1 and then moves to the discharge waist-shaped orifice on the distribution plate 9.1. The distribution orifice 9.2 on the distribution plate 9.1 is divided into an intake waist-shaped orifice and a discharge waist-shaped orifice. The oil flows dynamically back and forth within the plunger cavity and the pre-pressurization chamber 12.2, achieving a buffering pressurization effect and reducing the pulsation of the plunger pump's flow source and the pressure shock within the plunger cavity. During the pre-depressurization process, the high-pressure oil in the plunger cavity flows into the pre-depressurization chamber 12.3. At this time, the pressure in the pre-depressurization chamber 12.3 increases, and the plunger cavity is in the pre-depressurization stage.

[0066] Part of the oil in the distribution hole 9.1 flows into the oil reservoir 9.5 through the damping groove 9.6. A variable clearance fit is formed between the front end face of the distribution plate 9.1 and the rear end face of the cylinder 8.1 by the action of the central spring 16. Under the combined action of the fixed clearance throttling of the damping groove 9.6 and the variable clearance throttling between the cylinder 8.1 and the distribution plate 9.1, a hydrostatic support is formed at the distribution pair.

Claims

1. A floating swashplate piston pump containing a constant-speed drive rotary disc transmission mechanism for the main shaft, characterized in that: The pump body includes a pump body and a main shaft installed within it. A front cover and a rear cover are installed at the front and rear ends of the pump body cavity, respectively. Within the pump body cavity, behind the front cover, are a bearing, a base, a swashplate, a rotary table, a three-pivot ball joint-spherical roller constant velocity drive mechanism or a ball cage ball joint-ball bearing constant velocity drive mechanism, a cylinder, and a distribution plate. The outer ring of the bearing is fixed to the front cover. The front side of the base is connected to the rear end of the bearing's outer ring. The swashplate is mounted at the rear end of the base, facing the front side. The rotary table is parallel to the swashplate, with its front face facing the rear end face of the swashplate. Static pressure supports and auxiliary support structures are provided on the front and rear ends of the rotary table and the swashplate. A certain gap exists between the outer surface of the rotary table and the inner surface of the swashplate, preventing them from contacting each other. The spindle is connected to the cylinder body via a spline. The rotary table is driven by a three-pivot ball joint-spherical roller constant velocity drive mechanism or a ball cage ball joint-ball constant velocity drive mechanism. Multiple ball sockets are provided on the rear end face of the rotary table, and multiple cylinder holes are provided on the cylinder body. The ball sockets and cylinder holes are evenly distributed circumferentially around the central axes of the rotary table and the cylinder body, and each ball socket and cylinder hole corresponds to the other. A shaped plunger is slidably installed in each cylinder hole. The end plunger ball of the multiple shaped plungers extends out of the cylinder body and is correspondingly hinged to the multiple ball sockets. The tail of the shaped plunger contains a spherical structure with one or more sealing rings, which directly contacts the cylinder hole. Each ball socket opening on the rear end face of the rotary table is formed into a cylindrical opening. The ball end has an annular groove formed on its circumferential outer surface. The central axis of the annular groove is inclined at a certain angle relative to the central axis of the shaped plunger. The diameter of the cylindrical opening is larger than the diameter of the annular groove. When the ball end of the shaped plunger is hinged to the ball socket, the annular groove and the cylindrical opening form a dimensional fit. When the cylindrical surface of the annular groove of the shaped plunger ball end is coaxial with the cylindrical surface of the ball socket, the plunger ball end can freely enter and exit the ball socket. When the cylindrical surface of the ball end and the cylindrical surface of the ball socket are not coaxial, the plunger ball end is snapped and hinged to the ball socket in the form of a ball joint. The front and rear end faces of the distribution plate contact the cylinder block and the rear end cover, respectively. The distribution plate has double pre-pressure increase damping holes in the low-pressure to high-pressure transition zone and pre-pressure decrease damping holes in the high-pressure to low-pressure transition zone. In the rear end face of the rear end cover... The cylinder body is equipped with a pre-pressure reduction cavity and a pre-pressure increase cavity in the intermediate part. The rear end cover is equipped with a pre-pressure increase flow channel and a pre-pressure reduction flow channel. The pre-pressure reduction damping orifice is connected to the pre-pressure reduction cavity through the pre-pressure reduction flow channel. The double pre-pressure increase damping orifice is connected to the pre-pressure increase cavity through the pre-pressure increase flow channel. Multiple distribution holes are also provided on the distribution plate. The distribution holes are connected to the oil inlet and outlet ports of the pump body. Oil passages are provided on the rear end face of the cylinder body corresponding to each cylinder hole position. The oil passages are connected to the corresponding cylinder holes and the oil passages are connected to the distribution holes. Several spring channels are also provided on the cylinder body. A central spring is provided in the spring channel. The two ends of the central spring act on the cylinder body and the ball joint of the three-pivot ball joint-spherical roller constant velocity drive mechanism or the ball cage ball joint-ball constant velocity drive mechanism, respectively. The three-pivot ball joint-spherical roller constant velocity drive mechanism includes a three-pivot ball joint, a spherical roller, and a corresponding rotary table; the outer spherical surface of the three-pivot ball joint is divided into three spherical segments by the three pivots, and the three pivots are three cylindrical pivots that are evenly distributed around the outer surface of the ball joint; the three-pivot ball joint is connected to the main shaft through a spline. The ball cage type ball joint-ball type constant velocity drive mechanism includes a ball cage type ball joint, balls and a corresponding rotary table. The ball cage type ball joint is connected to the main shaft through a spline. Several inner raceways for the balls to roll are evenly distributed circumferentially on the spherical outer surface of the ball cage type ball joint. A central spring acts between the rear end face of the ball cage type ball joint and the cylinder. The front end of the distribution plate is provided with oil storage tanks on the inner and outer sides of each distribution hole, and the oil storage tanks are corresponding to the oil passage openings. Each distribution hole is connected to the corresponding oil storage tank through a damping groove.

2. A floating swashplate piston pump with a constant velocity drive rotary table transmission mechanism for the main shaft according to claim 1, characterized in that: There are three spherical rollers, each with a cylindrical through-hole in the center and a spherical surface on the outer side. The rollers are fitted onto three pivots through the central through-hole and roll around the pivots. The turntable has a central through-hole, a portion of which is a spherical surface. This spherical surface is evenly divided into three segments by three evenly distributed grooved tracks. The three spherical segments of the turntable's central through-hole engage with the three spherical segments on the outer side of the three-pivot ball joint to form a hinge. The spring force generated by the central spring on the three-pivot ball joint passes through the spherical hinge engagement surface. The torque is transmitted to the rotary table, pressing it against the slant surface. Three evenly distributed grooved tracks in the central through-hole of the rotary table cooperate with three spherical rollers. Each spherical roller contacts the grooved surface of its corresponding track and moves relative to the other. The main shaft, connected by a spline, drives a three-pivot ball joint to rotate synchronously. The rotating three-pivot ball joint, through the spherical rollers mounted on the three pivots, contacts the grooved tracks in the central through-hole of the rotary table and transmits torque, thereby driving the rotary table to rotate synchronously at the same speed as the main shaft.

3. A floating swashplate piston pump with a constant velocity drive rotary table transmission mechanism for the main shaft according to claim 2, characterized in that: The connection between the three-pivot ball joint and the main shaft is either a key connection or a pin connection. The three-pivot ball joint is either an integral structure or a split structure. When the three-pivot ball joint is a split structure, it is composed of a cylindrical three-pivot and a ball joint containing a spherical surface. The cylindrical three-pivot has a cylindrical profile, with three cylindrical pivots protruding from the outer cylindrical surface for mounting the spherical roller. The outer profile of the ball joint containing the spherical surface contains three spherical surfaces, with a cylindrical through-hole in the middle. The ball joint is mounted on the cylindrical outer cylindrical surface of the three-pivot through the middle through-hole. A transmission pin is installed between the ball joint and the cylinder. The cylinder drives the ball joint to rotate synchronously through the transmission pin. One end of the ball joint contacts the central spring. The force of the central spring is transmitted to the rotary disk through the spherical hinge of the ball joint and the rotary disk.

4. A floating swashplate piston pump with a constant velocity drive rotary table transmission mechanism for a main shaft according to claim 1, characterized in that: The ball cage type ball joint-ball type constant velocity drive mechanism further includes a cage, which has an inner spherical surface and an outer spherical surface. The inner spherical surface of the cage is in contact with the spherical outer surface of the ball cage type ball joint, and the outer spherical surface of the cage is in contact with the spherical surface of the central through hole of the rotary disk. The cage is circumferentially provided with a plurality of waist-shaped through holes. The spherical surface of the central through hole of the rotary disk is axially provided with a plurality of outer raceways for the balls to roll. The balls are spherical and are clamped in the waist-shaped through holes of the cage. As the angle between the central axis of the ball cage type ball joint and the rotary disk changes, that is, as the inclination angle of the pump swashplate changes, the balls roll freely between the inner raceway on the ball cage type ball joint and the outer raceway on the rotary disk. The transmission of force and torque between the ball cage type ball joint and the rotary disk is completed by the balls.

5. A floating swashplate piston pump with a constant velocity drive rotary table transmission mechanism for a main shaft according to claim 4, characterized in that: The center of the inner raceway on the ball cage hinge and the center of the outer raceway on the rotary table are offset from the center of the spherical surface of the ball cage hinge or the center of the inner and outer spherical surfaces of the cage by a certain distance. This offset is either symmetrical or identical. Symmetrical offset means that the eccentricity is equal in magnitude but opposite in direction. Identical offset means that the eccentricity is equal in magnitude and the same in direction.

6. A floating swashplate piston pump with a constant velocity drive rotary table transmission mechanism for a main shaft according to claim 5, characterized in that: The inner raceway on the ball cage joint and the outer raceway on the rotary table are curved grooves or straight grooves. The centerline shape of the curved groove raceway or the outline shape of the bottom of the raceway along the centerline of the corresponding ball cage joint or rotary table is an arc shape. The centerline shape of the straight groove raceway or the outline shape of the bottom of the raceway along the centerline of the corresponding ball cage joint or rotary table is a straight line shape. When both the inner and outer raceways are curved groove raceways, the ball cage joint and the rotary table can only rotate relative to each other and will not produce axial displacement during torque transmission. When both the inner and outer raceways are straight groove raceways, the ball cage joint and the rotary table can not only rotate relative to each other during torque transmission, but also allow axial displacement, that is, the balls roll on the straight groove raceways to compensate for the axial movement between the ball cage joint and the rotary table caused by working and installation errors.

7. A floating swashplate piston pump with a constant velocity drive rotary table transmission mechanism for the main shaft according to claim 1, characterized in that: The irregularly shaped plunger is one of three types: a conical plunger, a thin rod plunger, and a connecting rod plunger. The conical plunger has a conical shape in the middle section, with its size gradually changing relative to the diameter of the ball head at the front end and the ball surface at the rear end. The thin rod plunger has a thin rod shape in the middle section, with its size abruptly changing to the size of a thin rod relative to the diameter of the ball head at the front end and the ball surface at the rear end. The connecting rod plunger includes a connecting rod and a plunger cylinder. The connecting rod has ball heads at both ends. One ball head of the connecting rod is hinged to a ball socket inside the plunger cylinder, and the other ball head of the connecting rod is hinged to a ball socket on the rotary table. The outer surface of the plunger cylinder has a clearance fit with the cylinder bore.

8. A floating swashplate piston pump with a constant velocity drive rotary table transmission mechanism for a main shaft according to claim 1, characterized in that: The rear end cover and the pre-pressurization cavity are designed separately. A recessed groove is provided in the middle of the rear end face of the rear end cover. A mounting surface and bolt mounting holes are machined on the recessed groove. The center of the recessed groove corresponds to the center line of the main shaft. The pre-pressurization cavity has bolt mounting holes corresponding to those on the recessed groove. The pre-pressurization cavity is fixed in the recessed groove by bolts. The pre-depressurization cavity and the rear end cover are designed as an integrated unit.

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