A floating swash plate plunger pump suitable for electrified electric drive working conditions of engineering machinery

Abstract

The present invention discloses a floating swash plate plunger pump suitable for electrified, electric-driven operation of engineering machinery. The pump comprises a pump body, which is equipped with a main shaft, a port plate, a cylinder body, a tapered plunger, a ball joint, a rotary plate, and a swash plate. The port plate has axially symmetrically distributed vibration damping grooves. The main shaft is connected to the center hole of the cylinder body and the ball joint. The rotary plate is annularly sleeved around the ball joint through the center hole, and the center hole of the rotary plate contacts the spherical surface of the spherical joint, or the center hole of the rotary plate is connected to the ball joint key via a spherical, special-shaped key. The outer side of the rotary plate and the inner side of the swash plate have a clearance fit and do not contact each other. The rotary plate ball socket is hinged to the tapered plunger ball head. Static pressure bearings are provided between the cylinder body and the port plate, and between the rotary plate and the swash plate. The swash plate has several fixed-clearance return components for limiting the position of the rotary plate. When the present invention is used as a closed pump, oil is boosted and sucked through an oil charge pump. When used as an open pump, oil is boosted and sucked through a turbine that rotates with the main shaft. The present invention is suitable for operation under electrified, electric-driven operation of engineering machinery.

Description

Technical Field

[0001] The present invention relates to the field of swash plate plunger pumps, in particular to a floating swash plate plunger pump adapted to the electrified electric drive working conditions of engineering machinery. Background Art

[0002] The traditional cylindrical piston-slipper type swash plate axial piston pump and the hydraulic system developed based on it have been very maturely applied in traditional engineering machinery with internal combustion engines as prime movers. After the electrification of engineering machinery, the speed and flow regulation of the motor cannot fully cover all application conditions of engineering machinery, especially in terms of response characteristics and variable control functions. The variable control performance and functions of the traditional cylindrical piston-slipper type swash plate axial piston pump have outstanding advantages after long-term technological development. However, due to its inherent structure, the traditional cylindrical piston-slipper type swash plate axial piston pump is difficult to meet the "higher speed, wide speed range, forward and reverse rotation, and fast start and stop" motor drive working condition requirements in terms of its friction pair performance.

[0003] Through research, it is known that the plunger-slipper assembly and its related plunger pair and slipper pair in the traditional cylindrical plunger-slipper type swash plate axial piston pump are the key reasons why the traditional cylindrical plunger-slipper type swash plate axial piston pump cannot adapt to the new technology 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 cylindrical plunger / cylinder bore contact length is too long, lubrication is insufficient, the PV value is too large, the variable inclination angle of the swash plate is limited (generally not more than 20°), 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 problems.

[0004] To solve the above problems, the applicant previously proposed a new technology based on the new structural principle of "floating swash plate" that "replaces the 'traditional cylindrical plunger-slipper assembly' with a 'conical plunger'. The 'conical plunger' structure is a 'two-force rod' structure that transfers and digests the huge lateral force of the plunger pair in the original cylindrical plunger based on the 'two-force rod' principle." The applicant also applied for invention patents such as "floating swash plate follower ball joint articulated conical plunger variable pump / motor rotating assembly" and "a floating swash plate conical plunger variable pump rotating assembly without a pressure plate." However, in these invention patents related to conical plunger variable pumps / motors previously applied for by the applicant, the new technical requirements for axial piston pumps posed by the electrification transformation of construction machinery were not taken into account. In order to adapt to the application needs of the electrification transformation of construction machinery, there are still the following four technical problems that need to be solved:

[0005] 1. In existing through-axis tapered plunger variable displacement pumps, a circular recess is provided on the side of the swash plate facing the rotary plate. The rotary plate is located in the recess of the swash plate. The rotary plate (or sliding plate) is guided by a bearing provided between the outer side of the rotary plate and the inner side of the swash plate, or the outer side of the rotary plate is in direct contact with the inner side of the swash plate and guided by the inner side of the swash plate. The rotary plate does not have an initial return pre-compression mechanism before the pump is started. In the prior art, an initial return pre-compression mechanism based on a "center spring + ball joint" is designed. However, the contact between the rotating disk and the ball joint is linear, which brings a problem: based on the "two-force rod" principle, the tapered plunger transfers the huge lateral force in the original cylindrical plunger-plunger pair to the ball joint pair at the ball joint between the tapered plunger ball head and the rotating disk. Although part of the force transferred to the ball joint pair along the normal direction of the rotating disk is offset by the static pressure support force of the rotating disk bottom surface, another part of the force is still not offset. The direction of this unoffset force is along the radial direction of the rotating disk. Due to its structural characteristics, the tapered plunger has two states during movement: "driving" and "following". In the "following" state, the radial force component at the tapered plunger ball head is small, but in the "driving" state, the radial force component at the tapered plunger ball head is large. Since the pump has multiple tapered plungers, there is always one tapered plunger in the "driving" state at any time. Therefore, the radial force component for the rotating disk is still always large. In the prior art, the contact stress at the linear contact point between the rotating plate and the ball joint exceeds the contact strength of the materials, affecting the service life of the pump. This radial force component also acts as a dynamic biasing load on the bearings disposed between the outer side of the rotating plate and the inner side of the swash plate, making it difficult to guarantee the service life of the bearings. Furthermore, friction and frictional losses always exist at the bearings, or friction and frictional torque losses always exist at the annular surface where the outer side of the rotating plate contacts the inner side of the swash plate. Furthermore, after this radial force component is transmitted to the inner side of the swash plate through the bearings, it generates a significant contact force between the outer side of the swash plate and the inner side of the swash plate seat. Both the outer side of the swash plate and the inner side of the swash plate seat are rough surfaces. This contact force creates a significant, uncontrollable frictional resistance during the swash plate's variable swing, affecting the swash plate's variable control performance.

[0006] 2. Regarding the distribution pair: The distribution pair in the tapered plunger axial piston pump in the existing technology is not designed based on the hydrostatic support principle and has no hydrostatic support structure. Therefore, the lubricating oil film of the distribution pair is insufficient under the low-speed working condition of the electrified electric drive working condition of the engineering machinery. At low speed, the distribution pair has severe friction, large friction power loss, and is prone to wear and failure; the vibration reduction structure of the high-low pressure transition zone of the distribution plate in the existing tapered plunger axial piston pump is not designed based on the axisymmetric relationship. Therefore, when the pump works in the motor working condition, that is, the drive shaft rotates in the opposite direction, it is difficult to ensure the working efficiency and service life of the pump under the motor working condition.

[0007] 3. The electrification of construction machinery requires that axial piston pumps need to operate at higher speeds. However, the tapered plunger axial piston pumps in the existing technology do not have an integrated oil suction booster turbine (corresponding to an open pump) or an oil charge pump (corresponding to a closed pump). Therefore, they cannot meet the oil suction performance requirements of the axial piston pump after the higher speed is achieved, resulting in insufficient oil suction and air cavitation problems.

[0008] 4. The initial return pre-compression return mechanism of the tapered plunger axial piston pump in the prior art is in the form of a "center spring + ball joint". Under some harsh working conditions, or for some large-displacement axial piston pumps, the center spring will inevitably provide insufficient pre-compression force. When the pre-compression force is insufficient, the rotary plate will be too far away from the swash plate surface, resulting in the inability to form a static pressure support between the rotary plate and the swash plate, resulting in excessive leakage flow and the pump failing to operate normally. Summary of the Invention

[0009] The present invention provides a floating swash plate plunger pump adapted to the electric drive working conditions of engineering machinery, so as to solve the problems existing in the prior art mentioned in the above background technology.

[0010] In order to achieve the above object, the technical solution adopted by the present invention is:

[0011] A floating swash plate type plunger pump adapted to the electric drive working conditions of engineering machinery comprises a pump body (9), a main shaft (1) being rotatably mounted in the pump body (9) via a bearing (12), a distribution plate (2), a cylinder body (3), a rotary plate (4), and a swash plate (5) being sequentially distributed along a straight line in the pump body (9), a ball joint (6) being connected to the center of one end face of the cylinder body (3) facing the rotary plate (4), the rotary plate (4) having a center hole, the rotary plate (4) being sleeved on the outside of the ball joint (6) through its center hole, and a plurality of Cylinder holes (3.1), each cylinder hole (3.1) is slidably mounted with a tapered plunger (7), the rotary disk (4) is provided with a plurality of ball sockets (4.1) on the side facing the cylinder body (3), one end of each tapered plunger (7) passes through the end surface of the cylinder body (3) facing the rotary disk (4) and then is hinged to the ball socket (4.1) through a ball head in a one-to-one correspondence, the main shaft (1) sequentially passes through the center hole of the distribution plate (2), the center hole of the cylinder body (3), the center hole of the ball joint (6), and the center hole of the inclined plate (5), and the main shaft (1) is respectively connected to the cylinder The center holes of the cylinder body (3) and the ball joint (6) are connected, and the outer side surface of the rotary disk (4) and the inner side surface of the inclined disk (5) are clearance-fitted, and the side surfaces do not contact each other; the center hole of the rotary disk (4) and the ball joint (6) are in direct spherical contact, or the center hole of the rotary disk (4) and the ball joint (6) are connected by a spherical special-shaped key and maintain spherical contact, so that when the main shaft (1) rotates, the cylinder body (3) and the ball joint (6) rotate synchronously therewith, so that each tapered plunger (7) in the cylinder hole (3.1) of the cylinder body (3) rotates accordingly. , thereby causing the rotary disk (4) to rotate synchronously with the ball joint (6) under the action of each tapered plunger (7); a center spring (14) is provided between the cylinder body (3) and the ball joint (6), and the spring force of the center spring (14) is transmitted to the ball joint (6) and the cylinder body (3) respectively. One end of the spring force of the center spring (14) acts on the ball joint (6), so that the ball joint (6) presses the rotary disk (4) toward the inclined plate (5), and the other end of the spring force of the center spring (14) acts on the cylinder body (3), so that the cylinder body (3) presses toward the distribution plate (2).

[0012] Furthermore, a first oil storage tank (4.2) is provided on one side of the rotary plate (4) facing the swash plate (5) at a position corresponding to each ball socket (4.1), and each first oil storage tank (4.2) is connected to the corresponding ball socket (4.1). The rotary plate (4) is also provided with at least one ring of oil drain ring grooves (4.4) on one side facing the swash plate (5). An oil guide hole (7.1) is provided in each conical plunger (7), one end of the oil guide hole (7.1) is connected to the cylinder hole (3.1) corresponding to the conical plunger (7), and the other end of the oil guide hole (7.1) is connected to the ball socket (4.1) corresponding to the conical plunger (7). The oil distributed to each cylinder hole (3.1) by the distribution plate (2) enters the first oil storage tank (4.2) of the rotary plate (4) through the oil guide hole (7.1) and the ball socket (4.1), thereby forming a first static pressure support between the rotary plate (4) and the swash plate (5).

[0013] Furthermore, the end face of the cylinder body (3) facing the distribution plate (2) is clearance-matched with the corresponding end face of the distribution plate (2), and the end face of the cylinder body (3) facing the distribution plate (2) is provided with a plurality of oil-through holes (3.4) corresponding to the cylinder hole (3.1), and the end face of the cylinder body (3) facing the distribution plate (2) is provided with a second oil storage tank (3.2) at a position corresponding to each oil-through hole (3.4), and each second oil storage tank (3.2) is respectively provided with a damping The hole (3.3) is connected to the corresponding oil-passing orifice (3.4); the oil distributed by the distribution plate (2) to the cylinder hole (3.1) through the oil-passing orifice (3.4) or the oil flowing from the cylinder hole (3.1) to the distribution plate (2) through the oil-passing orifice (3.4) partially flows into the second oil storage tank (3.2) through the damping hole (3.3), and forms a second static pressure support in the gap between the corresponding end faces of the distribution plate (2) and the cylinder body (3) through the second oil storage tank (3.2).

[0014] Furthermore, the distribution plate (2) has a plurality of distribution holes (2.1) that pass through the distribution plate (2), some of the distribution holes (2.1) are used to distribute low-pressure oil flowing into the oil suction channel of the pump body (9) to the oil through hole (3.4) of the cylinder body (3), and the remaining distribution holes are used to distribute high-pressure oil flowing out of the cylinder hole (3.1) of the cylinder body (3) to the oil outlet channel of the pump body (9), and a vibration damping groove (2.2) is provided at a position corresponding to each distribution hole (2.1) on one end surface of the distribution plate (2) facing the cylinder body (3), and the vibration damping groove (2.2) is an axisymmetric structure, and the vibration damping groove (2.2) is respectively connected to the corresponding distribution hole (2.1).

[0015] Furthermore, the vibration-damping groove (2.2) is an axisymmetric triangular groove.

[0016] Furthermore, a plurality of fixed-gap return assemblies (8) are connected to one side of the swash plate (5) facing the rotary plate (4), and the fixed-gap return assemblies (8) include a seat body (8.1) connected to the side of the swash plate (5) facing the rotary plate (4), each seat body (8.1) is located outside the edge of the rotary plate (4), and the seat body (8.1) and the outer side surface of the rotary plate (4) maintain a certain gap and do not contact each other, and the end of the seat body (8.1) is bent toward the edge of the rotary plate (4), and a wear-resistant gasket (8.2) is installed on the bent portion of the seat body (8.1); The rotating disk (4) is expanded near a section of the inclined disk (5) to form an expanded diameter section, and the bent portion of the seat body (8.1) of the fixed-gap return assembly (8) is stuck on the edge of the expanded diameter section of the rotating disk (4), and the wear-resistant gaskets (8.2) in each fixed-gap return assembly (8) respectively maintain a certain gap with the end face of the expanded diameter section of the rotating disk (4) and do not contact each other. The wear-resistant gaskets (8.2) limit the maximum distance of the rotating disk (4) from the inclined disk surface. After reaching this maximum distance, the wear-resistant gaskets (8.2) contact the end face of the expanded diameter section of the rotating disk (4).

[0017] Furthermore, the pump body (9) is integrated with an oil replenishment pump, thereby achieving pressurized oil suction through the oil replenishment pump when used as a closed pump.

[0018] Furthermore, a booster turbine (10) is provided inside the oil suction flow channel of the pump body (9), one end of the main shaft (1) penetrates into the oil suction flow channel of the pump body (9), and the booster worm wheel (10) is fixed to the end of the main shaft (1), thereby achieving boosted oil suction through the booster turbine (10) when used as an open pump.

[0019] In the present invention, in response to the first technical problem mentioned in the background technology, the side surface of the turntable and the inner surface of the inclined plate are changed to a clearance fit, without contacting each other. The linear contact between the turntable and the ball joint is changed to spherical contact, and the spherical contact between the turntable and the ball joint is direct spherical contact. Alternatively, a special-shaped key is installed between the turntable and the ball joint. The special-shaped key is a key with a spherical surface. The spherical contact between the turntable and the ball joint is achieved through the special-shaped key. Without changing the spherical contact relationship and contact area between the turntable and the ball joint, the ball joint and the turntable are forced to rotate synchronously under the drive of the special-shaped key. This brings the following advantages:

[0020] Since the side surface of the rotary plate does not contact the inner surface of the swash plate, the radial force component of the rotary plate on the ball joint pair at the joint of the tapered plunger ball head and the rotary plate ball socket will not be transmitted to the swash plate. The radial force component will act on the ball joint and be transmitted to the main shaft through the ball joint, and finally act on the bearings at both ends of the main shaft as the radial load force of the bearings, which will be borne by the bearings. Since the ball joint is connected to the main shaft through a spline, the cylinder body and the transmission shaft are also connected through a spline, and the tapered plunger is placed in the cylinder hole of the cylinder body, and the tapered plunger ball head is hinged on the ball socket of the turntable. Therefore, when the main shaft rotates, the cylinder body, the ball joint and the main shaft rotate synchronously. At the same time, the tapered plunger in the cylinder hole of the cylinder body also rotates almost synchronously with the cylinder body. The tapered plunger ball head drives the turntable to rotate almost synchronously with the cylinder body, that is, the turntable and the ball joint rotate almost synchronously. Therefore, the radial component of the force exerted by the tapered plunger ball head on the turntable is transmitted to the ball joint which is basically in a relatively stationary state with the turntable, and then transmitted to the transmission shaft which is in a relatively stationary state with the ball joint, and finally acts on the bearings at both ends of the transmission shaft. Moreover, since the rotary plate and the ball joint are designed to be in spherical contact, the surface contact strength is greatly reduced while the limiting and guiding effects on the rotary plate are also achieved; when the pump is constant, that is, the swash plate does not swing, there is almost no relative motion between the rotary plate and the ball joint, so the contact force between the rotary plate and the ball joint will not lead to increased friction and friction loss; when the pump needs to change the displacement, that is, the swash plate swings, there is relative motion between the rotary plate and the ball joint, which brings friction resistance to the variable of the swash plate, but since the surface machining accuracy of the ball joint and the rotary plate is high and the surface is smooth, and they are both immersed in the hydraulic oil in the pump housing, they are fully lubricated, the friction coefficient is small and relatively stable, so the friction and friction loss are small, the friction is relatively stable and easy to achieve compensation control, so as not to affect the variable performance of the pump, combined with the first static pressure support formed between the rotary plate and the swash plate, the friction loss can be further reduced.

[0021] In this invention, addressing the second technical issue mentioned in the background art, a second hydrostatic bearing is designed within the valve pair formed by the cylinder block and valve plate. This hydrostatic bearing forms an oil film within the valve pair, preventing the high friction losses caused by insufficient lubricating oil film in the valve pair's sealing zone at low speeds, further ensuring lubrication and load-bearing performance under low-speed operating conditions. Furthermore, an axisymmetric vibration-damping groove design is incorporated into the valve plate to safeguard the pump's operating efficiency and service life under motor-operated conditions when the main shaft rotates in the reverse direction.

[0022] In this invention, addressing the third technical issue mentioned in the background technology, by adjusting the charge pressure of the charge pump integrated into the pump body, the invention can achieve boosted oil suction from a low-pressure pipeline when operating as a closed pump. Furthermore, by installing a booster turbine fixed to the main shaft within the oil suction passage of the pump body, the invention can achieve boosted oil suction from a low-pressure pipeline when operating as an open pump. Thus, when the main shaft of the invention operates at higher speeds, the aforementioned boosted oil suction method ensures oil suction performance during high-speed operation, avoiding air cavitation.

[0023] In the present invention, in response to the fourth technical problem mentioned in the background technology, the distance that the turntable deviates from the inclined plate surface can be forced to be mechanically limited through each fixed-gap return component, thereby avoiding the problem of the turntable deviating from the inclined plate surface by too much distance due to insufficient pre-compression force of the center spring in various situations such as harsh working conditions.

[0024] In summary, the present invention has a sufficient lubrication oil film on the friction pair and low friction loss under low-speed conditions, a small contact stress, a large contact area, and a small PV value under high-speed conditions, and has good oil absorption capacity. The vibration reduction structure of the high- and low-pressure transition zones of the distribution plate is axially symmetrically designed. Therefore, the invention has good working performance when the transmission shaft is running at low speed, high speed, forward and reverse directions, and is particularly suitable for the application requirements of electrified electric drive conditions in engineering machinery. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 It is a top sectional view of a closed pump structure according to an embodiment of the present invention.

[0026] Figure 2 This is an exploded view of the internal structure of a closed pump according to an embodiment of the present invention.

[0027] Figure 3 It is a side half-section view of the internal structure of a closed pump according to an embodiment of the present invention.

[0028] Figure 4 It is a side sectional view of the rotary disk structure in a closed pump according to an embodiment of the present invention.

[0029] Figure 5 This is a structural diagram of the assembly of a rotary plate, a swash plate, and a tapered plunger in a closed pump according to a first embodiment of the present invention.

[0030] Figure 6 It is a front view of the assembly structure of the ball joint, rotary plate, swash plate, and fixed clearance return component in a closed pump according to an embodiment of the present invention.

[0031] Figure 7 This is an assembly structure diagram of the swash plate, rotary plate, and fixed-clearance return assembly in a closed pump according to an embodiment of the present invention.

[0032] Figure 8 It is a schematic diagram of the structure of the rotary disk in a closed pump according to an embodiment of the present invention.

[0033] Figure 9 It is a schematic structural diagram of a fixed clearance return assembly in a closed pump according to an embodiment of the present invention.

[0034] Figure 10 It is a schematic diagram of the end face of the distribution plate in the closed pump in embodiment 1 of the present invention.

[0035] Figure 11 This is a structural diagram of the cylinder body and the distribution plate in a closed pump according to an embodiment of the present invention.

[0036] Figure 12 It is a schematic diagram of the end face of the cylinder body in a closed pump according to an embodiment of the present invention.

[0037] Figure 13 This is a schematic diagram of the exploded view of the rotary plate, ball joint and special-shaped key in the closed pump of Example 1 of the present invention.

[0038] Figure 14 It is a side sectional view of the open pump structure of embodiment 2 of the present invention.

[0039] Figure 15 It is a top sectional view of the open pump structure of embodiment 2 of the present invention.

[0040] Figure 16 1. It is a half-sectional view of the structure of the split pump according to the embodiment of the present invention. DETAILED DESCRIPTION

[0041] The present invention will be further described below with reference to the accompanying drawings and examples. Example 1

[0042] This embodiment discloses a floating swash plate type piston pump adapted to the electric drive working conditions of engineering machinery. The floating swash plate type axial piston pump disclosed in this embodiment is used as a closed pump to circulate the oil in the load. The structure is as follows: Figure 1-Figure 3 As shown, the pump body 9 includes a pump body 9, the front end of the pump body 9 is an end cover 11, and the end cover 11 has an oil suction channel 9.1 and an oil discharge channel 9.2. The oil suction channel 9.1 and the oil discharge channel 9.2 are respectively used to connect to the load, thereby allowing the oil in the load to circulate through this embodiment.

[0043] Inside the pump body 9 are arranged a valve plate 2, a cylinder body 3, a rotary plate 4, a swash plate 5, a bearing 12, and a main shaft 1 with an axial direction that is horizontal in the front and back directions.

[0044] like Figure 10 、 Figure 11As shown, the axial directions of the distribution plate 2 and the cylinder body 3 are horizontal front to back, the rear side surface of the distribution plate 2 faces the front end surface of the cylinder body 3, and there is a clearance fit between the front end surface of the cylinder body 3 and the rear side surface of the distribution plate 2. The distribution plate 2 is provided with four arc-shaped distribution holes 2.1 that respectively pass through the distribution plate 2. Each distribution hole 2.1 is distributed in a ring direction around the center of the distribution plate 2, and the four distribution holes 2.1 are divided into two groups. The openings of the two distribution holes 2.1 in each group on the rear side of the distribution plate 2 are located in the same arc-shaped groove 2.3 on the rear side of the distribution plate 2. The oil suction channel 9.1 of the end cover 11 is connected with the front side openings of the two distribution holes 2.1 in one group of the distribution plate 2, so that the oil can enter the corresponding distribution holes of the distribution plate 2 through the oil suction channel 9.1; the oil outlet channel 9.2 of the end cover 11 is connected with the front side openings of the two distribution holes 2.1 in another group of the distribution plate 2, so that the oil discharged from the cylinder body 3 can enter the oil outlet channel 9.2 through the distribution hole corresponding to the distribution plate 2, and then be output to the load. Each arcuate slot 2.3 is connected to a vibration-damping slot 2.2 at both ends. The vibration-damping slots 2.2 are all axisymmetric. In this embodiment, the vibration-damping slots 2.2 are all axisymmetric triangular slots. Thus, the opening of the distribution hole 2.1 on the rear side of the distribution plate 2 can communicate with the corresponding two vibration-damping slots 2.2 through the arcuate slot 2.3.

[0045] like Figure 1 、 Figure 2 、 Figure 3 、 Figure 11 、 Figure 12 As shown, the front end face of the cylinder body 3 faces the distribution plate 2, the rear end face of the cylinder body 3 faces the rotary plate 4, and a ball joint 6 is connected to the center of the rear end face of the cylinder body 3. A plurality of cylinder holes 3.1 are provided in the cylinder body 3, and each cylinder hole 3.1 is distributed in a ring direction around the central axis of the cylinder body 3. A conical plunger 7 is slidably installed in each cylinder hole 3.1, and the rear end of the conical plunger 7 passes through the corresponding cylinder hole 3.1. The front end face of the cylinder body 3 is provided with a waist-shaped oil passage opening 3.4 at the position corresponding to each cylinder hole 3.1, and the oil passage opening 3.4 is connected to the corresponding cylinder hole 3.1. The front end face of the cylinder body 3 is provided with a second oil storage tank 3.2 on the two symmetrical sides corresponding to the oil passage opening 3.4, and each second oil storage tank 3.2 is connected to the corresponding oil passage opening 3.4 through a damping hole 3.3.

[0046] like Figure 1 、 Figure 2 、 Figure 3 、 Figure 5 、 Figure 6 As shown, there is an acute angle between the central axis of the rotary disk 4 and the central axis of the cylinder body 3, the front end of the rotary disk 4 faces the rear end of the cylinder body 3, and the center of the rotary disk 4 has a central through hole. The rotary disk 4 is sleeved on the ball joint 6 at the center of the rear end of the cylinder body 3 through the central through hole at its center, and the central through hole of the rotary disk 4 is in direct spherical contact with the ball joint 6, or as shown in FIG. Figure 13The central through hole of the rotating disk 4 is connected to the ball joint 6 via a spherical, special-shaped key 14. The front surface of the rotating disk 4 is provided with multiple ball sockets 4.1, which are distributed annularly around the central axis of the rotating disk 4. The rear ends of the tapered plungers 7 in the cylinder body 3 are hinged to the ball sockets 4.1 on the front surface of the rotating disk 4 via ball joints.

[0047] like Figure 1 、 Figure 2 、 Figure 3 、 Figure 4 、 Figure 5 、 Figure 8 As shown, the rear end of the rotating disk 4 faces the front end of the swash plate 5, and the outer side of the rotating disk 4 is spaced apart from the inner side of the swash plate 5, without any contact between the sides. A waist-shaped first oil reservoir 4.2 is provided on the rear end of the rotating disk 4, corresponding to each ball socket 4.1. Each first oil reservoir 4.2 is connected to the corresponding ball socket 4.1 via an oil passage 4.3. The rear end of the rotating disk 4 is also provided with at least two rings of oil drain grooves 4.4. Each tapered plunger 7 is provided with an oil guide hole 7.1. The front end of the oil guide hole 7.1 connects to the corresponding cylinder bore 3.1 of the tapered plunger 7, and the rear end of the oil guide hole 7.1 connects to the corresponding ball socket 4.1 of the tapered plunger 7.

[0048] like Figure 1 、 Figure 2 、 Figure 3 、 Figure 4 、 Figure 5 、 Figure 6 、 Figure 7 、 Figure 9As shown, the front end of the swash plate 5 faces the rear end of the rotary plate 4, and the central axis of the swash plate 5 forms an acute angle with the central axis of the cylinder body 3. The front end of the swash plate 5 is provided with multiple fixed-gap return assemblies 8. These fixed-gap return assemblies 8 include a seat 8.1 connected to the side of the swash plate 5 facing the rotary plate 4. Each seat 8.1 is located outside the edge of the rotary plate 4, with a certain gap between the seat 8.1 and the side of the rotary plate 4, so that the sides do not contact each other. The ends of the seat 8.1 are bent toward the edge of the rotary plate 4, and the bent portion of the seat 8.1 is provided with a number of through-holes parallel to the axial direction of the rotary plate 4, each of which is equipped with a wear-resistant gasket 8.2. To coordinate with the fixed-gap return assembly 8, the axially rearward section of the rotary disk 4 in this embodiment is configured as an expanded diameter section. The expanded diameter section has an outer diameter greater than that of the axially forward section of the rotary disk 4. One end of each wear-resistant gasket in the fixed-gap return assembly 8 is parallel to the end surface of the expanded diameter section of the rotary disk 4 and spaced apart by a certain gap. The side surfaces of the wear-resistant gaskets 8.2 also have a certain gap from the outer surface of the rotary disk 4. Because the rotary disk 4 will slightly float under the influence of oil pressure, this embodiment uses the fixed-gap return assembly 8 to limit the rotary disk 4. This ensures the stability and sealing of the rotary disk when the center spring's compressive force is insufficient, thereby reducing leakage.

[0049] The bearings 12 are fixed to the rear side of the pump body 9 and the end cover 11 respectively. The main shaft 1 passes through the central through hole of the distribution plate 2, the central through hole of the cylinder body 3, the central through hole of the ball joint 6, the central through hole of the swash plate 5, and the inner ring of the bearing 12 in sequence. The main shaft 1 is fixedly connected to the inner ring of the bearing 12, the main shaft 1 and the central through hole of the cylinder body 3 are fixedly connected by a spline, and the main shaft 1 and the central through hole of the ball joint 6 are fixedly connected by a spline.

[0050] In this embodiment, the main shaft 1 is driven by an electric motor, so when the main shaft 1 rotates, the cylinder body 3, the ball joint 6, and the inner ring of the bearing 12 rotate synchronously. When the cylinder body 3 rotates, the various conical plungers 7 in the cylinder bore 3.1 of the cylinder body 3 rotate accordingly, thereby causing the turntable 4 to rotate synchronously with the ball joint 6 under the action of the various conical plungers 7.

[0051] During the half-turn of tapered plunger 7 from top to bottom within cylinder body 1, it gradually extends outward under the action of rotating disk 4 and cylinder body 1, causing the volume of the sealed working chamber of cylinder bore 3.1 of cylinder body 1 to continuously increase, creating a partial vacuum. When cylinder bore 3.1, where the partial vacuum has been created, rotates with cylinder body 1 to align with a set of oil distribution holes 2.1 on port plate 2 corresponding to oil suction channel 9.1, oil from the hydraulic system flowing into oil suction channel 9.1 is drawn through these oil distribution holes 2.1 on port plate 2 into cylinder bore 3.1, where the partial vacuum has been created. On the contrary, during the half-circle of its rotation from bottom to top, the tapered plunger 7 is gradually retracted into the cylinder bore 3.1 by the squeezing force of the inclined rotary disk 4, causing the volume of the sealed working chamber to continuously decrease. When the cylinder bore 3.1 with continuously decreasing volume rotates with the cylinder body 1 to the position of the oil distribution hole 2.1 on the distribution plate 2 corresponding to the oil outlet channel 9.2, the oil in the cylinder bore 3.1 is squeezed out and enters the oil outlet channel 9.2 through this part of the oil distribution holes on the distribution plate 2, and is then output to the load hydraulic system.

[0052] Each time cylinder 3 rotates, each tapered plunger 7 reciprocates once, completing one oil suction and oil compression cycle. In the gap between the front end of cylinder 3 and the rear side of port plate 2, as oil flows through oil opening 3.4 on the front end of cylinder 3, some of it flows through damping orifice 3.3 into second oil reservoir 3.2, forming a second hydrostatic support within the variable gap between cylinder 3 and port plate 2.

[0053] At the same time, the oil in the cylinder bore 3.1 of the cylinder body 3 passes through the oil guide hole 7.1 of the tapered plunger 7 and into the ball socket 4.1 of the rotary plate 4. Then, it flows through the oil passage 4.3 and into the first oil reservoir 4.2 on the rear side of the rotary plate 4, thereby forming a first hydrostatic support between the rotary plate 4 and the swash plate 5. When the swash plate 5 and the rotary plate 4 slide relative to each other, an oil film forms. This first hydrostatic support formed between the rotary plate 4 and the swash plate 5 balances the force exerted by the tapered plunger 7 on the rotary plate 4. A center spring 14 is provided between the ball joint 6 and the cylinder body 3. The spring force of the center spring 14 is transmitted to the ball joint 6 and the cylinder body 4 respectively. One end of the spring force of the center spring 14 acts on the ball joint 6, causing the ball joint 6 to press the rotary plate 4 toward the swash plate 5. The other end of the spring force of the center spring acts on the cylinder body 3, causing the cylinder body 3 to press against the valve plate 2. Under the influence of oil pressure in different operating conditions, the rotary plate 4 will slightly float. When the spring force provided by the center spring 14 is insufficient to compress the rotary plate 4, the fixed clearance return assembly 8 limits the maximum clearance between the rotary plate 4 and the swash plate, ensuring sufficient lubrication and minimal leakage. Adjusting the inclination of the swash plate 5 allows for stepless flow regulation.

[0054] In this embodiment, in order to ensure the oil suction capacity during high-speed operation, the pump body is integrated with an oil replenishment pump, and the oil suction channel 9.1 of the end cover 11 is connected to the oil outlet oil circuit of the oil replenishment pump. The oil replenishment pump is equipped with an overflow valve, which can adjust the oil pressure sent by the oil replenishment pump to the oil suction channel through the overflow valve, thereby ensuring the oil suction performance of this embodiment when used as a closed pump during higher speeds.

[0055] When high-pressure oil from the load hydraulic system flows into the pump from the oil outlet channel 9.2, the pump main shaft 1 will rotate in the reverse direction. At this time, the pump operates in motor mode. Since the vibration-damping grooves 2.2 in the valve plate 2 are axially symmetrically distributed, the operating efficiency of the pump when the main shaft 1 rotates in the reverse direction can be guaranteed to be the same as when the main shaft 1 rotates in the forward direction. Example 2

[0056] like Figure 14 、 Figure 15 、 Figure 16 As shown, this embodiment discloses a floating swash plate type piston pump adapted for the electric drive working conditions of engineering machinery. The floating swash plate type axial piston pump disclosed in this embodiment is used as an open pump for delivering oil from the oil tank to the load system. The open pump structure of this embodiment is the same as that of the first embodiment, and both include a pump body 9 and an end cover 11. The end cover 11 is provided with an oil suction flow channel 9.1 and an oil discharge flow channel 9.2. The pump body 9 is equipped with a distribution plate 2, a cylinder body 3, a rotary plate 4, a swash plate 5, a bearing 12, and a main shaft 1. The cylinder body 3 is connected to a ball joint 6, and the cylinder body 3 is provided with a tapered plunger 7. The assembly structure of each component is the same as that of the first embodiment. This embodiment differs from the first embodiment in that the volume of the rear section of oil suction channel 9.1 is smaller than that of the front section. The rear section of oil suction channel 9.1 serves as a boost chamber 13, within which a turbine 10 is located. The front end of the main shaft 1 extends into the oil suction channel 9.1, and turbine 10 is fixed to the main shaft 1. During operation, the rotation of the main shaft 1 drives turbine 10, causing oil entering the oil suction channel 9.1 to be pressurized by turbine 10 in the boost chamber 13 before entering the corresponding distribution holes of the port plate 2. This ensures the oil suction performance of this embodiment as an open-type pump at higher speeds.

[0057] When the high-pressure oil of the load hydraulic system is poured into the pump from the oil outlet channel 9.2, the pump main shaft 1 will rotate in the opposite direction. At this time, the pump operates in the motor mode. Since the vibration-damping grooves 2.2 in the distribution plate 2 are axially symmetrically distributed, the working efficiency of the pump when the main shaft 1 rotates in the opposite direction can be guaranteed to be consistent with the working efficiency of the pump when the main shaft 1 rotates in the forward direction. For the turbine 10, when the main shaft 1 rotates in the forward direction, that is, the pump operates in the pump mode, the turbine 10 operates in the centrifugal pump mode to achieve oil boosting. Conversely, when the main shaft 1 rotates in the opposite direction, that is, the pump operates in the motor mode, the turbine 10 operates in the turbine mode, driving the main shaft 1 to rotate in the opposite direction to output torque and speed.

[0058] The preferred embodiments of the present invention are described in detail above with reference to the accompanying drawings. The embodiments described in the present invention are merely descriptions of the preferred embodiments of the present invention and do not limit the concept and scope of the present invention. The various specific technical features described in the above specific embodiments can be combined in any suitable manner unless there is any contradiction. Such combinations should also be regarded as the contents disclosed in this disclosure as long as they do not violate the concept of the present invention. In order to avoid unnecessary repetition, the present invention will not further describe various possible combinations.

[0059] The present invention is not limited to the specific details of the above-mentioned embodiments. Within the scope of the technical concept of the present invention and without departing from the design concept of the present invention, various modifications and improvements made to the technical solution of the present invention by those skilled in the art should fall within the scope of protection of the present invention. The technical contents for which protection is sought in the present invention have been fully recorded in the claims.

Claims

1. A floating swash plate type plunger pump adapted to the electric drive working conditions of engineering machinery, comprising a pump body (9), a main shaft (1) being rotatably mounted in the pump body (9) via a bearing (12), a distribution plate (2), a cylinder body (3), a rotary plate (4), and a swash plate (5) being sequentially arranged along a straight line in the pump body (9), a ball joint (6) being connected to the center of one end face of the cylinder body (3) facing the rotary plate (4), the rotary plate (4) having a center hole, the rotary plate (4) being sleeved on the outside of the ball joint (6) through the center hole thereof, a plurality of cylinder holes (3.1) being provided in the cylinder body (3), each of which is provided with a plurality of cylinder holes (3.1) A conical plunger (7) is slidably installed in each cylinder hole (3.1), and a plurality of ball sockets (4.1) are provided on the side of the rotary disk (4) facing the cylinder body (3). One end of each conical plunger (7) passes through the end surface of the cylinder body (3) facing the rotary disk (4) and is then hinged to the ball socket (4.1) through a ball head one by one. The main shaft (1) passes through the center hole of the distribution plate (2), the center hole of the cylinder body (3), the center hole of the ball joint (6), and the center hole of the inclined plate (5) in sequence, and the main shaft (1) is connected to the center hole of the cylinder body (3) and the center hole of the ball joint (6), respectively. It is characterized in that The outer side surface of the rotary disk (4) and the inner side surface of the inclined disk (5) are clearance-fitted, and the side surfaces do not contact each other; the center hole of the rotary disk (4) and the ball joint (6) are in direct spherical contact, or the center hole of the rotary disk (4) and the ball joint (6) are connected by a spherical special-shaped key and maintain spherical contact, so that when the main shaft (1) rotates, the cylinder body (3) and the ball joint (6) rotate synchronously, causing the various tapered plungers (7) in the cylinder hole (3.1) of the cylinder body (3) to rotate accordingly, thereby causing the rotary disk (4) rotates synchronously with the ball joint (6) under the action of each tapered plunger (7); a center spring (14) is provided between the cylinder body (3) and the ball joint (6), and the spring force of the center spring (14) is transmitted to the ball joint (6) and the cylinder body (3) respectively. One end of the spring force of the center spring (14) acts on the ball joint (6), so that the ball joint (6) presses the rotary plate (4) toward the swash plate (5), and the other end of the spring force of the center spring (14) acts on the cylinder body (3), so that the cylinder body (3) presses the distribution plate (2); The side of the slant plate (5) facing the rotary disk (4) is connected to a plurality of fixed-gap return components (8), the fixed-gap return components (8) comprising a seat body (8.1) connected to the side of the slant plate (5) facing the rotary disk (4), each seat body (8.1) being located outside the edge of the rotary disk (4), the seat body (8.1) and the outer side surface of the rotary disk (4) maintaining a certain gap and not contacting each other, the end of the seat body (8.1) being bent toward the edge of the rotary disk (4), and a wear-resistant gasket (8.2) being installed on the bent portion of the seat body (8.1); The turntable (4) is enlarged to form an enlarged diameter section near the swash plate (5), and the bent portion of the seat body (8.1) of the fixed-gap return assembly (8) is stuck on the edge of the enlarged diameter section of the turntable (4), and the wear-resistant gaskets (8.2) in each fixed-gap return assembly (8) respectively maintain a certain gap with the end face of the enlarged diameter section of the turntable (4) and do not contact each other. The wear-resistant gaskets (8.2) limit the maximum distance of the turntable (4) from the swash plate surface. After reaching this maximum distance, the wear-resistant gaskets (8.2) contact the end face of the enlarged diameter section of the turntable (4).

2. A floating swash plate plunger pump adapted to the electric drive working conditions of engineering machinery according to claim 1, characterized in that: A first oil storage tank (4.2) is provided on one side of the rotary plate (4) facing the swash plate (5) at the position of each ball socket (4.1), and each first oil storage tank (4.2) is connected to the corresponding ball socket (4.1). The rotary plate (4) is also provided with at least one ring of oil drain ring grooves (4.4) on one side facing the swash plate (5). An oil guide hole (7.1) is provided in each tapered plunger (7), one end of the oil guide hole (7.1) is connected to the cylinder hole (3.1) corresponding to the tapered plunger (7), and the other end of the oil guide hole (7.1) is connected to the ball socket (4.1) corresponding to the tapered plunger (7). The oil distributed to each cylinder hole (3.1) by the distribution plate (2) enters the first oil storage tank (4.2) of the rotary plate (4) through the oil guide hole (7.1) and the ball socket (4.1), thereby forming a first static pressure support between the rotary plate (4) and the swash plate (5).

3. A floating swash plate type plunger pump adapted to the electric drive working conditions of engineering machinery according to claim 1, characterized in that: The end face of the cylinder body (3) facing the distribution plate (2) is clearance-matched with the corresponding end face of the distribution plate (2), and the end face of the cylinder body (3) facing the distribution plate (2) is provided with a plurality of oil-through holes (3.4) corresponding to the cylinder hole (3.1), and the end face of the cylinder body (3) facing the distribution plate (2) is provided with a second oil storage tank (3.2) at a position corresponding to each oil-through hole (3.4), and each second oil storage tank (3.2) is respectively connected to the damping hole (3 .3) is connected to the corresponding oil-passing orifice (3.4); the oil distributed by the distribution plate (2) to the cylinder hole (3.1) through the oil-passing orifice (3.4) or the oil flowing from the cylinder hole (3.1) to the distribution plate (2) through the oil-passing orifice (3.4) partially flows into the second oil storage tank (3.2) through the damping hole (3.3), and forms a second static pressure support in the gap between the corresponding end faces of the distribution plate (2) and the cylinder body (3) through the second oil storage tank (3.2).

4. A floating swash plate plunger pump adapted to the electric drive working conditions of engineering machinery according to claim 3, characterized in that: The distribution plate (2) has a plurality of distribution holes (2.1) that pass through the distribution plate (2), some of the distribution holes (2.1) are used to distribute low-pressure oil flowing into the oil suction channel of the pump body (9) to the oil through hole (3.4) of the cylinder body (3), and the remaining distribution holes are used to distribute high-pressure oil flowing out of the cylinder hole (3.1) of the cylinder body (3) to the oil outlet channel of the pump body (9). A vibration damping groove (2.2) is provided on one end surface of the distribution plate (2) facing the cylinder body (3) at a position corresponding to each distribution hole (2.1), the vibration damping groove (2.2) being an axisymmetric structure, and the vibration damping groove (2.2) is respectively connected to the corresponding distribution hole (2.1).

5. A floating swash plate type plunger pump adapted to the electric drive working conditions of engineering machinery according to claim 4, characterized in that: The vibration-damping groove (2.2) is an axisymmetric triangular groove.

6. The floating swash plate type plunger pump adapted to the electric drive working conditions of engineering machinery according to claim 1, characterized in that: The pump body (9) is integrated with an oil replenishment pump, thereby achieving pressurized oil suction through the oil replenishment pump when used as a closed pump.

7. The floating swash plate type plunger pump adapted to the electric drive working conditions of engineering machinery according to claim 1, characterized in that: A supercharger turbine (10) is provided inside the oil suction flow channel of the pump body (9), one end of the main shaft (1) penetrates into the oil suction flow channel of the pump body (9), and the supercharger turbine (10) is fixed to the end of the main shaft (1), thereby achieving supercharged oil suction through the supercharger turbine (10) when used as an open pump.

Images