Rotating assembly for EHA ultrahigh-speed high-frequency reversing and plunger pump

Abstract

The invention relates to the technical field of hydraulic pressure, and discloses a rotating assembly for EHA ultrahigh-speed high-frequency reversing and a plunger pump, the rotating assembly comprises a cylinder body and a transmission shaft, the cylinder body is axially provided with a through cavity for installing the transmission shaft, the transmission shaft penetrates through the middle of the cylinder body, and the transmission shaft and the cylinder body are arranged in an integrated structure. According to the scheme, the cylinder body and the transmission shaft are of an integrated structure, and when the plunger pump rotates at an ultra-high speed, the cylinder body can counteract the cylinder body overturning moment caused by centrifugal force of a rotating assembly through itself; meanwhile, during high-frequency reversing of the plunger pump, a spline transmission gap between the cylinder body and the transmission shaft does not exist, and impact abrasion of transmission friction pair parts is reduced.

Description

Technical Field

[0001] The invention relates to the field of hydraulic technology, and in particular to a rotating assembly and a plunger pump for EHA ultra-high-speed and high-frequency reversing. Background Art

[0002] EHA (Electric-Hydraulic Actuator) is an electro-hydraulic actuator, a drive system that combines electric motors and hydraulic technology, and is widely used in fields that require high precision and high efficiency.

[0003] A piston pump is a hydraulic pump that sucks in and pushes out liquids through the reciprocating motion of a plunger. Piston pumps are common and efficient power transmission equipment in hydraulic systems, and are widely used in hydraulic drive applications that require high pressure and flow control. In conventional bidirectional piston pumps used for EHA, the linkage between the cylinder and the drive shaft in the rotating assembly is achieved by the clearance-fit involute spline, which has the advantages of large transmission torque and self-centering. During the operation of the cylinder of the piston pump, the bottom surface of the cylinder must fit the plane of the distribution plate to reduce internal leakage. The clearance-fit involute spline can improve the verticality of the bottom surface of the cylinder and the axis of the drive shaft caused by the machining error of the cylinder and the drive shaft, so that the bottom surface of the cylinder is close to the plane of the distribution plate, reducing internal leakage. However, due to the existence of the gap, when the pump rotates at ultra-high speed, the cylinder overturning torque formed by the centrifugal force of the cylinder assembly cannot be completely balanced by the drive shaft, which will cause the cylinder to tilt and form an angle between the bottom surface of the cylinder and the plane of the distribution plate, increasing internal leakage and failing to stably establish high pressure; in addition, when the plunger pump is reversed at high frequency, the cylinder will move under the action of inertia, and the drive shaft and the cylinder will move in opposite directions during the initial period of reversal. The back-and-forth collision between the spline teeth will cause accelerated wear of the cylinder spline teeth. Due to the transmission gap between the cylinder and the drive shaft, the reversing frequency response of the EHA will be reduced, and the oil will be contaminated, accelerating the wear of plunger pump parts and the wear and blockage of valve components, ultimately reducing the service life of the plunger pump and EHA. Summary of the invention

[0004] The present invention is intended to provide a rotating assembly and a plunger pump for ultra-high-speed and high-frequency reversing of EHA, so as to solve the problems that the back-and-forth collision between the spline teeth during the high-frequency reversing of the plunger pump will cause accelerated wear of the cylinder spline teeth, pollute the oil, accelerate the wear of the plunger pump parts and the wear and blockage of the valve assembly, reduce the service life of the plunger pump and EHA, and the plunger pump cannot stably establish high pressure when running at ultra-high speed and has large internal leakage.

[0005] To achieve the above-mentioned purpose, the present invention provides a rotating assembly for EHA ultra-high-speed and high-frequency commutation, comprising: a cylinder body and a transmission shaft, wherein the cylinder body is axially provided with a through cavity for installing the transmission shaft, the transmission shaft passes through the middle of the cylinder body, and the transmission shaft and the cylinder body are arranged in an integrated structure.

[0006] The principle of this solution is that since the transmission shaft and the cylinder body are arranged in an integrated manner, when the transmission shaft rotates, the cylinder body is driven to rotate together, and when the transmission shaft stops rotating, the cylinder body is synchronously stopped from rotating.

[0007] Advantages of this solution: The cylinder body and the transmission shaft are integrated into a structure. When the plunger pump rotates at ultra-high speed, the cylinder body can offset the cylinder body overturning moment caused by the centrifugal force of the rotating component by itself; at the same time, when the plunger pump is reversed at high frequency, there is no spline transmission gap between the cylinder body and the transmission shaft, reducing the impact wear of the transmission friction pair parts.

[0008] Preferably, a spline interference fit, a flat square interference fit, a square interference fit, a welding connection, a threaded connection or an integrated connection with glue bonding is used.

[0009] Preferably, the interference fit spline includes an interference rectangular spline or an interference involute spline. The composite connection mode of interference fit and spline connection not only ensures the stability of the connection, but also avoids the impact wear of the friction pair parts caused by the spline transmission clearance between the cylinder body and the transmission shaft when the plunger pump is reversed.

[0010] Preferably, the transmission shaft is provided with spline teeth, the spline teeth of the transmission shaft form interference fit portions that cooperate with the cylinder body, the cylinder body is provided with spline grooves that cooperate with the spline teeth, and the spline grooves of the cylinder body form interference fit portions that cooperate with the transmission shaft.

[0011] Preferably, the spline is a rectangular spline. The tooth shape design of the rectangular spline enables it to distribute torque more evenly. Each tooth surface has a large contact area, so it can work under a large torque load, reducing the force on a single tooth and reducing the risk of wear and damage.

[0012] Preferably, a preset portion in the middle of the driving end surface of the cylinder body is convex outwardly. When the transmission shaft is connected to the cylinder body, the convex portion can provide a larger contact surface, ensuring a tighter and more stable fit between the two, avoiding loosening or deviation of the connection due to uneven load or external force, and enhancing the stability of the connection.

[0013] Preferably, the protruding portion of the driving end face is connected to the driving end face of the cylinder body in an arc-shaped transition. By making a smooth transition between the protruding portion and the end face, stress concentration can be effectively reduced, ensuring uniform force distribution, thereby reducing the fatigue risk of the material and improving the structural strength.

[0014] Preferably, the transmission shaft and the cylinder body are formed in one piece.

[0015] Preferably, the cylinder body is provided with a pin hole, the pin hole is close to the through cavity, and the pin hole is provided for installing a support pin, and the support pin cooperates with the cylinder body spring, the return ball and the return plate to press on the inclined plate with a sliding shoe.

[0016] In order to achieve the above-mentioned purpose, the present invention also provides a plunger pump using the above-mentioned rotating assembly for EHA ultra-high-speed high-frequency reversing, including: a pump housing, a pump rear cover, a swash plate, a plunger, a sliding shoe, a return plate, a return ball, a distribution plate, a cylinder spring and a support pin; the swash plate is fixed on the pump housing, and a plurality of plunger cavities are provided on the circumference of the cylinder body, one end of the plunger is hinged to the sliding shoe, and the other end is slidably arranged in the plunger cavity; the sliding shoe is against the swash plate, and the support pin is inserted in the pin hole of the cylinder body. The cylinder spring is placed between the cylinder body and the support pin, and the other end of the support pin is pressed on the return ball. The return ball is connected with the transmission shaft through clearance, and the return ball is against the return plate, and the return plate presses the sliding shoe on the inclined plate; a plurality of oil through ports are provided on the circumference of the cylinder body, and the oil through ports are connected with the plunger cavity, and the oil through ports and the plunger cavity are arranged in a one-to-one correspondence, and the two ends of the oil distribution plate are respectively against the pump rear cover and the cylinder body, and during the rotation of the cylinder body, the oil through port is connected with the oil distribution window on the pump rear cover through the oil distribution plate.

[0017] Preferably, the distribution plate is hemispherical, the arc surface of the distribution plate abuts against the inner wall of the ball socket of the pump rear cover, and the other side of the distribution plate abuts against the cylinder body. The distribution plate adopts a spherical structure, and fits the free swing angle with the ball socket of the pump rear cover, so that the distribution plate adaptively fits the bottom surface of the cylinder body, eliminating the verticality difference caused by the integrated processing of the cylinder body and the transmission shaft in this solution, which causes the cylinder body and the distribution plate to be uneven, thereby reducing the internal leakage of the plunger pump. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 This is a schematic diagram of the structure of the plunger pump according to Example 1 of the present invention.

[0019] Figure 2 It is a cross-sectional schematic diagram of the plunger pump according to Example 1 of the present invention.

[0020] Figure 3 This is a schematic diagram of the structure of the rotating assembly of Example 1 of the present invention.

[0021] Figure 4 It is a side view schematic diagram of the rotating assembly of Example 1 of the present invention.

[0022] Figure 5 It is a side view schematic diagram of the rotating assembly of Example 1 of the present invention.

[0023] Figure 6 This is a schematic diagram of the structure of the distribution plate in Example 1 of the present invention.

[0024] Figure 7 It is a schematic side view of the distribution plate of Example 1 of the present invention.

[0025] Figure 8 It is a schematic side view of the distribution plate of Example 1 of the present invention.

[0026] Fig. 9 This is a schematic diagram of the structure of the plunger pump according to Example 2 of the present invention.

[0027] Fig.10 This is a schematic diagram of the structure of the plunger pump according to Example 3 of the present invention.

[0028] Fig.11 It is a schematic diagram of the structure of the plunger pump according to embodiment 4 of the present invention.

[0029] Fig.12 This is a schematic diagram of the structure of the plunger pump according to Example 5 of the present invention. DETAILED DESCRIPTION

[0030] The following is further described in detail through specific implementation methods: The figure marks in the drawings of the specification include: cylinder body 1, transmission shaft 2, spline teeth 3, spline grooves 4, pump rear cover 5, distribution plate 6, pump housing 7, swash plate 8, plunger 9, slipper 10, return plate 11, return ball 12, cylinder spring 13, pin hole 14, support pin 15.

[0031] A rotating assembly for EHA ultra-high speed high frequency commutation, as shown in the attached Figure 3 ~Attached Figure 5 As shown, it includes: a cylinder body 1 and a transmission shaft 2. The cylinder body 1 is provided with a through cavity for installing the transmission shaft 2 in the axial direction. The transmission shaft 2 passes through the middle of the cylinder body 1, that is, the transmission shaft 2 and the cylinder body 1 are coaxially arranged, and the transmission shaft 2 and the cylinder body 1 are arranged in an integrated structure. In this scheme, the cylinder body 1 and the transmission shaft 2 are an integrated structure. When the plunger pump rotates at ultra-high speed, the cylinder body 1 can offset the overturning moment of the cylinder body 1 caused by the centrifugal force of the rotating component by itself; at the same time, when the plunger pump is reversed at high frequency, there is no spline transmission gap between the cylinder body 1 and the transmission shaft 2, which reduces the impact wear of the transmission friction pair parts.

[0032] Among them, the transmission shaft 2 and the cylinder body 1 are connected in an integrated manner by using an interference fit spline. The composite connection mode of interference fit and spline connection not only ensures the stability of the connection, but also avoids the collision and wear of the friction pair parts caused by the spline transmission clearance between the cylinder body 1 and the transmission shaft 2 when the plunger pump is reversed. Specifically, the transmission shaft 2 is provided with spline teeth 3, and the spline teeth 3 of the transmission shaft 2 are interference fit parts that match the cylinder body 1. The cylinder body 1 is provided with spline grooves 4, and the spline grooves 4 of the cylinder body 1 are interference fit parts that match the transmission shaft 2. In this embodiment, 6 spline teeth 3 are provided on the transmission shaft 2, and 6 spline grooves 4 are correspondingly provided on the cylinder body 1. In this embodiment, the spline is specifically a rectangular spline. The tooth shape design of the rectangular spline enables it to distribute torque more evenly, and each tooth surface has a larger contact area, so it can work under a larger torque load, reducing the force on a single tooth, and reducing the risk of wear and damage; the interference fit eliminates the collision of the spline teeth and reduces wear.

[0033] The cylinder body 1 is provided with a pin hole 14, which is close to the through cavity. The pin hole 14 is provided for installing a support pin 15, which is pressed on the swash plate 8 with the support pin 15, the cylinder body spring 13, the return ball 12 and the return plate 11 in cooperation with the sliding shoe 10. The pin hole 14 is specifically located between the spline grooves 4 of the cylinder body 1, and the pin holes 14 are evenly distributed on the cylinder body 1. In this embodiment, the number of the pin holes 14 is 6. In this embodiment, a single pin hole 14 is located between the spline grooves 4 of the cylinder body 1.

[0034] The preset part in the middle of the driving end face of the cylinder body 1 is convex outward. When the transmission shaft 2 is connected to the cylinder body 1, the convex part can provide a larger contact surface to ensure that the two fit more tightly and stably, avoid loosening or offset of the connection due to uneven load or external force, and enhance the stability of the connection. The convex part of the driving end face is connected to the driving end face of the cylinder body 1 in an arc-shaped transition. By making the connection between the protruding part and the end face into a smooth transition, stress concentration can be effectively reduced, ensuring uniform force distribution, thereby reducing the risk of material fatigue and improving structural strength.

[0035] A plunger pump using the above-mentioned rotating assembly for EHA ultra-high speed high frequency reversing, as shown in the attached Figure 1 , Attachment Figure 2 , Attachment Figure 6 , Attachment Figure 7 , Attachment Figure 8 and attached Fig. 9 As shown, it also includes: a pump housing 7, a pump rear cover 5, a swash plate 8, a plunger 9, a sliding shoe 10, a return plate 11, a return ball 12, a distribution plate 6, a cylinder spring 13 and a support pin 15; the swash plate 8 is fixed on the pump housing 7, a plurality of plunger cavities are provided on the circumference of the cylinder 1, one end of the plunger 9 is hinged with the sliding shoe 10, and the other end is slidably arranged in the plunger cavity; the sliding shoe 10 is against the swash plate 8, the support pin 15 is inserted in the pin hole 14 of the cylinder 1, and the cylinder spring 13 is placed between the cylinder 1 and the support pin 1 5, the other end of the support pin 15 is pressed on the return ball 12, the return ball 12 is connected with the transmission shaft 2 with clearance, and the return ball 12 is against the return plate 11, and the return plate 11 presses the sliding shoe 10 on the inclined plate 8; there are multiple oil through holes on the circumference of the cylinder body 1, the oil through holes are connected with the plunger cavity, and the oil through holes and the plunger cavity are set one by one. The two ends of the oil distribution plate are respectively against the pump rear cover 5 and the cylinder body 1. During the rotation of the cylinder body 1, its oil through hole is connected with the oil distribution window on the pump rear cover 5 through the oil distribution plate. The above structures are all prior arts, and more detailed structures are recorded in the applicant's previous patent application documents, which will not be described in detail here.

[0036] The feature of this solution is that the distribution plate 6 is hemispherical, the arc surface of the distribution plate 6 abuts against the inner wall of the ball socket of the pump rear cover 5, and the other side of the distribution plate 6 abuts against the cylinder body 1. The distribution plate 6 adopts a spherical structure, and the ball socket of the pump rear cover 5 fits the free swing angle, so that the distribution plate 6 adaptively fits the bottom surface of the cylinder body 1, eliminating the verticality difference caused by the integrated processing of the cylinder body 1 and the transmission shaft 2, which causes the cylinder body 1 and the distribution plate 6 to be uneven, thereby reducing the internal leakage of the plunger pump.

[0037] This solution integrates the cylinder body 1 and the transmission shaft 2, avoiding the impact and wear of the gap between the two on the related auxiliary parts in the traditional spline connection method. At the same time, the distribution plate 6 and the pump rear cover 5 are improved so that the distribution plate 6 can adaptively fit the cylinder body 1, solving the problem of uneven fit and leakage between the cylinder body 1 and the distribution plate 6 after the integrated setting.

[0038] The difference between this embodiment and embodiment 1 is that in this embodiment, the transmission shaft 2 and the cylinder body 1 are connected in one piece by using an interference fit involute spline. Fig. 9 shown.

[0039] The difference between this embodiment and embodiment 1 is that the transmission shaft 2 and the cylinder body 1 are connected in one piece by a flat square interference fit. Fig.10 shown.

[0040] The difference between this embodiment and embodiment 1 is that the transmission shaft 2 and the cylinder body 1 are integrally formed in this embodiment. Fig.11 shown.

[0041] The difference between this embodiment and embodiment 1 is that the transmission shaft 2 and the cylinder body 1 are connected in one piece by a four-way interference fit. Fig.12 shown.

[0042] The above is only an embodiment of the present invention, and the common sense such as the known specific technical schemes and / or characteristics in the scheme is not described in detail here. It should be pointed out that for those skilled in the art, without departing from the technical scheme of the present invention, several deformations and improvements can be made, such as the scheme of realizing the integrated connection of the transmission shaft and the cylinder body by welding connection, threaded connection or glue bonding, which should also be the protection scope of the present application. In the present invention, unless otherwise clearly specified and limited, the terms "installation", "connection", "connection", "fixation" and the like should be understood in a broad sense, for example, it can be a fixed connection, or a detachable connection, or an integral connection; it can be directly connected, or indirectly connected through an intermediate medium, or it can be the internal connection of two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to the specific circumstances. The scope of protection required by this application shall be based on the content of its claims, and the specific implementation methods and other records in the specification can be used to interpret the content of the claims.

Claims

1. A rotating assembly for EHA ultra-high-speed high-frequency commutation, characterized in that: include: A cylinder body and a transmission shaft, wherein the cylinder body is axially provided with a through cavity for installing the transmission shaft, the transmission shaft passes through the middle of the cylinder body, and the transmission shaft and the cylinder body are arranged in an integrated structure.

2. A rotating assembly for EHA ultra-high-speed high-frequency commutation according to claim 1, characterized in that: The transmission shaft and the cylinder body are connected in an integrated manner by spline interference fit, flat square interference fit, square interference fit, welding connection, threaded connection or glue bonding.

3. A rotating assembly for EHA ultra-high-speed high-frequency commutation according to claim 2, characterized in that: The interference spline fit includes an interference rectangular spline or an interference involute spline.

4. A rotating assembly for EHA ultra-high-speed high-frequency commutation according to claim 3, characterized in that: The transmission shaft is provided with spline teeth, and the spline teeth of the transmission shaft form interference fit parts that match the cylinder body. The cylinder body is provided with spline grooves that match the spline teeth, and the spline grooves of the cylinder body form interference fit parts that match the transmission shaft.

5. A rotating assembly for EHA ultra-high-speed high-frequency commutation according to claim 4, characterized in that: A preset portion in the middle of the driving end surface of the cylinder body is arranged to protrude outwards.

6. A rotating assembly for EHA ultra-high-speed high-frequency commutation according to claim 5, characterized in that: The protruding portion of the driving end surface is connected to the driving end surface of the cylinder body in an arc-shaped transition.

7. A rotating assembly for EHA ultra-high-speed high-frequency commutation according to claim 1, characterized in that: The transmission shaft and the cylinder body are processed in an integrally formed manner.

8. The rotating assembly for EHA ultra-high-speed high-frequency commutation according to claim 1, characterized in that: The cylinder body is provided with a pin hole, and the pin hole is close to the through cavity.

9. A plunger pump for a rotating assembly for EHA ultra-high speed high frequency reversing according to claim 1, further comprising: Pump housing, pump rear cover, swash plate, plunger, slipper, return plate, return ball, valve plate, cylinder spring and support pin; The swash plate is fixed on the pump housing, and a plurality of plunger cavities are provided on the circumference of the cylinder body. One end of the plunger is hinged with the sliding shoe, and the other end is slidably arranged in the plunger cavity; the sliding shoe abuts against the swash plate, the support pin is inserted into the pin hole of the cylinder body, the cylinder spring is placed between the cylinder body and the support pin, and the other end of the support pin is pressed on the return ball, the return ball is connected with the transmission shaft with clearance, and the return ball abuts against the return plate, and the return plate presses the sliding shoe against the swash plate; a plurality of oil ports are provided on the circumference of the cylinder body, the oil ports are connected with the plunger cavities, and the oil ports and the plunger cavities are arranged in a one-to-one correspondence, the two ends of the oil distribution plate abut against the pump rear cover and the cylinder body respectively, and during the rotation of the cylinder body, its oil ports are connected with the oil distribution window on the pump rear cover through the oil distribution plate.

10. The plunger pump according to claim 9, characterized in that: The distribution plate is hemispherical, the arc surface of the distribution plate abuts against the inner wall of the ball socket of the pump rear cover, and the other surface of the distribution plate abuts against the cylinder body.

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