CN114576123A - Oblique shaft type axial plunger pump - Google Patents

Abstract

The invention belongs to the technical field of engineering machinery hydraulic systems, and particularly discloses an inclined shaft type axial plunger pump which comprises a pump body, a main shaft and a cylinder body, wherein the main shaft and the cylinder body are arranged in the pump body; the inclined shaft type axial plunger pump has the remarkable advantages of light weight, compact structure, easiness in wearing, low cost, safety, reliability and the like.

Description

An oblique shaft axial piston pump

technical field

The invention belongs to the technical field of construction machinery hydraulic systems, and in particular relates to an oblique axis type axial piston pump.

Background technique

The axis of the main shaft of the inclined-axis axial piston pump is not on the same line with the axis of rotation of the cylinder, but forms an included angle. The oblique axis axial piston pump relies on the reciprocating motion of the piston in the cylinder body to change the volume of the sealed working chamber to achieve oil absorption and oil pressure. Because of its small size, low friction loss, strong self-priming ability and high starting efficiency, it is widely used in hydraulic systems.

The existing oblique axis axial piston pump mainly includes a distribution plate, a rear end cover of the piston pump, a cylinder block, a piston, a return plate, a bearing, a main shaft and a central shaft. The axis of the transmission main shaft forms an included angle with the rotation axis of the cylinder block, the plunger is installed in the cylinder hole of the cylinder block, and is hinged with the ball socket on the main shaft through the ball head at one end. When the plunger moves from the bottom dead center to the top dead center, an oil suction stroke is obtained, and the oil is sucked into the cylinder through the oil suction port and the waist-shaped window on the valve plate; when the plunger moves from the top dead center to the bottom dead center During the movement, an oil pressure stroke is generated, so that the oil filled in the cylinder hole of the cylinder block is discharged through the distribution plate and the oil outlet; there is a center hole at the axis of the cylinder block, and a center hole is installed in the center hole. One end of the central shaft is hinged with the ball socket of the main shaft through the ball head, and the other end of the central shaft is provided with a preload spring.

In the inclined axis piston pump of this structure, the power of the main shaft is mainly transmitted to the cylinder through the central shaft of the cylinder and the piston, so the power of the main shaft can be transmitted to the cylinder. Insufficient, because the rotating speed of the oblique-axis axial piston pump is very high, a large axial force will be generated during the rotation. The rigidity requirement, on the other hand, cannot avoid the collision between the cylinder block and the main shaft; moreover, since the ball head is hinged through the return disc, this structure has relatively high requirements on the structure, material, machining accuracy, etc. of the return disc.

SUMMARY OF THE INVENTION

In order to solve a series of problems existing in the use of the oblique-axis axial piston pump, the present invention provides a method that can avoid the impact and collision between the piston and the cylinder, reduce the vibration generated by the piston pump, reduce the noise, and improve the Efficient and effectively prolonging the service life of the inclined axis axial piston pump.

Based on the above object, the present invention is realized through the following technical solutions:

An oblique axis type axial piston pump, comprising a pump body, a main shaft and a cylinder body arranged in the pump body, a plunger is arranged between the main shaft and the cylinder body, and characterized in that the main shaft and the cylinder body are connected by a universal joint, The two ends of the universal joint are respectively arranged at the central axis of the main shaft and the cylinder block.

Preferably, the universal joint is a ball fork type universal joint.

Preferably, the ball fork type universal joint can be a constant velocity joint; the universal joint includes a driving fork and a driven fork that cooperate with each other, the driving fork is connected with the main shaft, and the driven fork is connected with the cylinder; There are four matching active curved grooves in the ball end, and four matching driven curved grooves are arranged in the ball end of the driven fork. The active curved groove and the driven curved groove cooperate to form an annular shape. There is a transmission steel ball in the annular groove.

Preferably, the included angle between the axis of the driving fork and the axis of the driven fork is 0-32 degrees; the included angle between the axis of the cylinder block and the axis of the main shaft is 0-45 degrees.

Preferably, the pump body is provided with a rear end cover that is clearance-fitted with the cylinder body, and the rear end cover is provided with a flow distribution plate matched with the cylinder body; the main shaft is provided with a bearing matched with the main shaft, and the bearing is provided with a bearing cover, The bearing cover is matched with the front end cover arranged on the pump body.

Preferably, the driving fork and the driven fork of the universal joint are respectively detachably connected with the main shaft and the cylinder block through splines.

Preferably, a plurality of plunger holes matched with the plunger are evenly distributed on the cylinder body, and an inner spline hole matched with the universal joint is arranged at the central axis of the cylinder body.

Preferably, the central axis of the main shaft close to one end of the cylinder body is provided with an inner spline hole matched with the driving fork, and the end face of the main shaft close to the end of the cylinder body is also provided with a plurality of ball sockets matched with the plunger.

Preferably, the plunger is arranged in two sections, including a cone column section slidably connected to the inner wall of the plunger hole, the cone column section is provided with a sealing ring that is close to the inner wall of the plunger hole; it also includes a ball matched with a ball socket on the main shaft header.

Preferably, the main shaft is a stepped shaft, and the main shaft is movably connected to the pump body through a bearing assembly.

Compared with the prior art, the beneficial effects of the present invention are:

Compared with the prior art, the ball head of the central shaft in the central hole of the cylinder is hinged with the main shaft for transmission, the present invention omits the return disc, and the ball fork type universal joint is arranged between the main shaft and the cylinder body. connection, so that the main shaft is provided with an active fork and a driven fork is provided on the cylinder block, and the main shaft drives the cylinder block to move through the ball fork universal joint. The impact and collision between the two can improve the stress state of the two; reduce the vibration during the operation of the oblique axis axial piston pump, reduce noise, improve efficiency, prolong the service life of the oblique axis axial piston pump, and The ball fork type universal joint has a simple and compact structure and strong bearing capacity.

Description of drawings

Figure 1 is a schematic structural diagram of an existing oblique-axis axial piston pump;

Fig. 2 is the structural representation of the oblique axis type axial piston pump in the embodiment 1;

Fig. 3 is the structural representation of the ball fork type universal joint structure in the embodiment 1;

Fig. 4 is the stress distribution diagram that the plunger of the inclined axis type plunger pump in the prior art produces when the main shaft moment is M=1200N*M;

Fig. 5 is the displacement deformation diagram that the plunger of the inclined axis type plunger pump in the prior art produces when the main shaft moment is M=1200N*M;

Fig. 6 is the stress distribution diagram that embodiment 1 produces when the main shaft moment is M=1200N*M;

FIG. 7 is a diagram of displacement deformation generated when the spindle torque is M=1200N*M in Example 1. FIG.

In the figure, the plunger hole 1, the valve plate 2, the cylinder block 3, the rear end cover 4, the plunger 6, the bearing cover 8, the main shaft 9, the bearing 10, the front end cover 11, the driving fork 12, the transmission steel ball 13, the driven Fork 14 , universal joint 16 , valve plate 17 , rear end cover 18 , cylinder block 19 , plunger 20 , return plate 21 , bearing 22 , main shaft 23 , central shaft 24 .

Detailed ways

The present invention will be described in further detail below through specific examples, but the scope of the present invention is not limited.

Example 1:

An oblique-axis axial piston pump, its structure is shown in Figures 1-3, including a pump body, a main shaft 9 and a cylinder body 3 arranged in the pump body, and a plunger is provided between the main shaft 9 and the cylinder body 3 6. It is characterized in that the main shaft 9 and the cylinder block 3 are connected by a universal joint 16, and the two ends of the universal joint 16 are respectively arranged at the central axis of the main shaft 9 and the cylinder block 3. The universal joint 16 is a ball fork type universal joint. The ball fork type universal joint can be a constant velocity joint; the universal joint 16 includes a driving fork 12 and a driven fork 14 that cooperate with each other, the driving fork 12 is connected with the main shaft 9, and the driven fork 14 is connected with the cylinder block 3. The ball end of the driving fork 12 is provided with four matching active curved grooves, and the spherical end of the driven fork 14 is provided with four matching driven curved grooves. The curved grooves are matched to form an annular groove, and a transmission steel ball 13 is arranged in the annular groove.

The included angle between the axis of the driving fork 12 and the axis of the driven fork 14 is 0-32 degrees; the included angle between the axis of the cylinder block 3 and the axis of the main shaft 9 is 0-45 degrees. The pump body is provided with a rear end cover 4 that is clearance fit with the cylinder body 3, and the rear end cover 4 is provided with a flow distribution plate 2 matched with the cylinder body 3; the main shaft 9 is provided with a bearing 10 matched with the main shaft 9, and the bearing 10 A bearing cover 8 is provided on the upper part, and the bearing cover 8 is matched with the front end cover 11 arranged on the pump body.

The driving fork 12 and the driven fork 14 of the universal joint 16 are detachably connected to the main shaft 9 and the cylinder block 3 through splines, respectively. A plurality of plunger holes 1 that cooperate with the plunger 6 are evenly distributed on the cylinder body 3 , and an inner spline hole that cooperates with the universal joint 16 is arranged at the central axis of the cylinder body 3 . The central axis of the main shaft 9 close to the cylinder block 3 is provided with an inner spline hole matched with the driving fork 12 , and the end face of the main shaft 9 close to the cylinder block 3 is also provided with a plurality of ball sockets for matching with the plunger 6 .

The plunger 6 is arranged in two sections, including a cone column section slidably connected with the inner wall of the plunger hole 1, and a sealing ring that is close to the inner wall of the plunger hole 1 is arranged on the cone column section; Ball head section. The main shaft 9 is a stepped shaft, and the main shaft 9 is movably connected with the pump body through a bearing assembly.

The existing oblique axis axial piston pump mainly includes a distribution plate 17 , a rear end cover 18 , a cylinder block 19 , a plunger 20 , a return plate 21 , a bearing 22 , a main shaft 23 , and a central shaft 24 . The axis of the main shaft 23 forms an included angle with the rotation axis of the cylinder block 19. The plunger 20 is installed in the cylinder hole of the cylinder block 19, and is hinged with the ball socket on the main shaft 9 through the ball head at one end, as shown in Figure 1 As shown in Figure 2 and Figure 3, the inclined axis axial piston pump of the present application is provided with a main shaft 9 and a cylinder block 3 in the pump body, and the main shaft 9 is evenly distributed on the end face of one end of the pump body. The ball socket is annularly distributed with the axis of the main shaft 9 as the center; an oil inlet is provided on one side of the rear end cover 4, an oil outlet is provided on the other side of the rear cover, and an oil drain is provided on the pump body A distribution plate 2 is provided on the side of the cylinder block 3 in the pump body, a spherical distribution structure is formed between the distribution plate 2 and the cylinder block 3, and the axis of the cylinder block 3 and the axis of the main shaft 9 are arranged at an angle of 35 degrees; one end of the cylinder block 3 Close to the distribution plate 2, the central axis of the other end of the cylinder body 3 is provided with an inner spline hole; the cylinder body 3 is also provided with a plunger hole 1 that cooperates with the plunger 6, and a plunger 6 is installed in the plunger hole 1. The plunger 6 is arranged in two sections, including a cone column section that is slidably connected to the inner wall of the plunger hole 1, and a sealing ring that is close to the inner wall of the plunger hole 1 is arranged on the cone column section. The plunger 6 also includes a ball on the main shaft 9. The ball head section matched with the socket; the pump body is provided with a bearing 10 matched with the main shaft 9, the bearing 10 is provided with a bearing cover 8, and the bearing cover 8 and the front end cover 11 are in clearance fit.

The cylinder block 3 and the main shaft 9 are connected by a universal joint 16, and the main shaft 9 and the cylinder block 3 are connected and driven through the universal joint 16 to form a synchronous connection structure; the universal joint 16 can be a constant velocity joint, which can make the main shaft 9 and the The speed between the cylinders 3 remains the same. The ball fork type universal joint allows the maximum intersection angle between the two shafts to be 32 degrees. The universal joint 16 includes a driving fork 12 and a driven fork 14 that cooperate with each other. The driving fork 12 and the main shaft 9 is connected, the driven fork 14 is connected with the cylinder 3; the ball end of the driving fork 12 is provided with four matching active curved grooves, and the ball end of the driven fork 14 is provided with four matching The driven curved groove of the driving fork 12, the driving curved groove cooperates with the driven curved groove to form an annular groove, and a transmission steel ball 13 is arranged in the annular groove; The ball end of the fork 14 is provided with a pair of driven curved panels with clearance fit, and the driven curved panel is matched with the active curved panel; there are four curved grooves on the driving fork 12 and the driven fork 14 respectively, which are formed after assembly. Two intersecting annular grooves are used as raceways for transmission steel balls 13 . The four transmission steel balls 13 are placed in the grooves, and the central steel ball is placed in the grooves in the centers of the driving fork 12 and the driven fork 14 to center.

The main shaft 9 drives the cylinder 3 and the plunger 6 to move through the universal joint 16. The plunger 6 performs a reciprocating linear motion in the plunger hole 1. When the plunger 6 moves away from the distribution plate 2, the plunger hole 1 The volume of the sealed space formed with the plunger 6 increases to complete the oil suction action; when the piston moves towards the direction close to the valve plate 2, the volume of the sealed space formed by the plunger hole 1 and the plunger 6 decreases to complete the oil pressing action ; Through the distribution plate 2 installed between the distribution end face of the cylinder block 3 and the suction and pressure oil passages of the plunger pump, the oil suction and pressure oil passages of the plunger pump are connected, and the oil intake and oil discharge are finally realized.

Wherein, Fig. 4 is the stress distribution diagram of the plunger 20 of the inclined axis plunger pump in the prior art when the torque of the main shaft 23 is M=1200N*M; Fig. 5 is the stress distribution diagram of the inclined axis plunger pump in the prior art; The displacement deformation diagram of the plunger 20 when the torque of the main shaft 23 is M=1200N*M. In Figure 4, different colors are used to indicate the magnitude of the stress generated during the transmission process. In FIG. 5 , different colors are used to indicate the degree of deformation of the cylinder block 19 , the plunger 20 , and the main shaft 23 . The change of color from blue to red corresponds to the increase of displacement and stress respectively. The smaller the displacement, the better the rigidity and stability of the transmission mechanism. The smaller the generated stress, the better the bearing capacity and the greater the transmitted moment. The red block is often the area where the maximum displacement or the maximum stress is generated. For example, in Figure 5, when the torque of the main shaft 9 is M=1200N*M, the maximum deformation of the existing inclined-axis piston pump is about 0.76mm, while the improved Under the same conditions, the maximum deformation of this application is about 0.27mm; it can be clearly seen from this set of data that the improved device has a significant improvement in rigidity and stability.

By comparing the overall displacement values of Figure 5 (the existing oblique axis piston pump) and Figure 7 (the oblique axis axial piston pump of the present application), it is illustrated that the improved device has a significant improvement in rigidity and stability. This experiment is illustrated by comparing the stress values in Figure 4 (the existing oblique axis piston pump) and Figure 6 (the oblique axis axial piston pump of the present application): under the same torque, the less stress generated by each part indicates that its bearing capacity The better the capability, the greater the torque transmitted.

The constraints in Figures 6 and 7 are: the torque of the main shaft 9 is M=1200N*M, the cylinder block 3 is fixed, there is no relative sliding between the transmission steel ball 13 and the annular groove, and its contact is set to "bonded" (binding) The force analysis is carried out in the case of friction transmission between the transmission steel ball 13, the universal joint 16 and the main shaft 9. Fig. 6 is the stress distribution diagram of the embodiment 1 of the present invention when the torque of the main shaft 9 is M=1200N*M, the maximum stress generated at 120N*M is about 2507MPa, and the maximum stress is generated in the area of the transmission steel ball 13, and its color Stress increases from blue to red. Fig. 7 is the displacement deformation diagram produced when the moment of the main shaft 9 is M=1200N*M according to Embodiment 1 of the present invention, the maximum deformation produced when the moment of the main shaft 9 is 120N*M is 0.27mm, and its color is represented by blue to red Displacement deformation increases.

By comparing the prior art (shown in FIG. 4 and FIG. 5 ) with the present application (shown in FIG. 6 and FIG. 7 ), it can be clearly seen that the prior art in FIGS. The spring, a ball socket is arranged on the main shaft 23, and the preload spring is subjected to stress transmission through the articulation of the ball head on the central shaft and the ball socket, while the application shown in FIG. 6 and FIG. The improvement of the hinged transmission structure between the ball head of the central shaft of the central hole and the main shaft 9 can avoid the impact collision between the plunger 6 and the cylinder block 3, improve the stress state of the two, and reduce the oblique axis type axial column. Vibration during the operation of the piston pump reduces noise, improves efficiency, and prolongs the service life of the oblique-axis axial piston pump.

Example 2:

An oblique axis type axial piston pump is different from Embodiment 1 in that the included angle between the axis of the cylinder block 3 and the axis of the main shaft 9 is 25 degrees.

Example 3:

An oblique-axis axial piston pump is different from Embodiment 1 in that the included angle between the axis of the cylinder block 3 and the axis of the main shaft 9 is 30 degrees.

Example 4:

An oblique axis type axial piston pump, which is different from Embodiment 1 in that the included angle between the axis of the driving fork 12 and the axis of the driven fork 14 is 16 degrees.

Example 5:

An oblique axis type axial piston pump, which is different from Embodiment 1 in that the included angle between the axis of the driving fork 12 and the axis of the driven fork 14 is 30 degrees.

The above are only preferred embodiments of the present invention, but are not limited to the above examples. Any modifications, equivalent replacements and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention. within.

Claims (10)

1. The inclined shaft type axial plunger pump is characterized in that the main shaft and the cylinder body are connected through a universal joint, and two ends of the universal joint are respectively arranged on the central axis of the main shaft and the central axis of the cylinder body.

2. The slant shaft axial plunger pump of claim 1, wherein the universal joint is a ball and fork type universal joint.

3. The slant shaft axial plunger pump of claim 2, wherein the ballfork joint may be a constant velocity joint; the universal joint comprises a driving fork and a driven fork which are matched with each other, the driving fork is connected with the main shaft, and the driven fork is connected with the cylinder body; the ball end of the driving fork is internally provided with four matched driving curved surface grooves, the ball end of the driven fork is internally provided with four matched driven curved surface grooves, the driving curved surface grooves and the driven curved surface grooves are matched to form annular grooves, and the annular grooves are internally provided with transmission steel balls.

4. The bent-axis axial plunger pump according to claim 3, wherein the included angle between the axis of the driving fork and the axis of the driven fork is 0-32 degrees; the included angle between the cylinder axis and the main shaft axis is 0-45 degrees.

5. The oblique axis type axial plunger pump according to claim 4, wherein the pump body is provided with a rear end cover in clearance fit with the cylinder body, and the rear end cover is provided with a port plate in fit with the cylinder body; the main shaft is provided with a bearing matched with the main shaft, the bearing is provided with a bearing cover, and the bearing cover is matched with a front end cover arranged on the pump body.

6. The bent-axis axial plunger pump according to claim 5, wherein the driving yoke and the driven yoke of the universal joint are detachably connected to the main shaft and the cylinder block, respectively, by splines.

7. The oblique axis type axial plunger pump according to claim 6, wherein a plurality of plunger holes matched with the plungers are uniformly distributed on the cylinder body, and an internal spline hole matched with the universal joint is arranged at the central axis of the cylinder body.

8. The oblique axis type axial plunger pump according to claim 7, wherein the main shaft is provided with an internally splined bore at a central axis near one end of the cylinder body for engaging with the driving fork, and a plurality of ball sockets for engaging with the plunger are provided at an end surface of the main shaft near one end of the cylinder body.

9. The oblique axis type axial plunger pump according to claim 8, wherein the plunger is provided in two stages, and comprises a conical cylinder section slidably connected with the inner wall of the plunger hole, and the conical cylinder section is provided with a sealing ring tightly attached to the inner wall of the plunger hole; and the ball head section is matched with the ball socket on the main shaft.

10. The bent-axis axial plunger pump of claim 9, wherein the main shaft is a stepped shaft, the main shaft being movably connected to the pump body by a bearing assembly.

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