CN114439718A - Axial plunger pump variable device with locking function and swash plate type axial plunger pump - Google Patents

Abstract

The invention provides an axial plunger pump variable device with a locking function and a swash plate type axial plunger pump, and belongs to the field of plunger pumps. The variable device of the axial plunger pump realizes the accurate control of the inclination angle of the swash plate by utilizing the characteristics of the precision transmission of the ball screw and the precision driving of the servo motor, and realizes the accurate control of the variable of the swash plate type axial plunger pump when being applied to the swash plate type axial plunger pump.

Description

Axial piston pump variable device with locking function and swash plate axial piston pump

technical field

The invention belongs to the technical field of plunger pumps, and in particular relates to an axial plunger pump variable device with a locking function and a swash plate type axial plunger pump applying the device.

Background technique

The plunger pump is an important component of the hydraulic system. It relies on the reciprocating movement of the plunger in the cylinder to change the volume of the sealed working cavity to achieve oil absorption and oil pressure. It has the advantages of high rated pressure, compact structure and high efficiency.

According to the installation direction of the plunger, it is divided into two categories: axial plunger pump and radial plunger pump. Among them, the plunger of the axial piston pump is installed axially, which has a compact structure, small radial size, small moment of inertia, high volumetric efficiency, low noise, low wear, and can work at high speed and high pressure, so it is widely used. Used in high pressure systems.

Axial piston pumps are divided into two types: swash plate type and inclined shaft type. Among them, the swash plate type axial piston pump controls the size and direction of the reciprocating stroke of the piston by changing the size and direction of the swash plate inclination through the variable mechanism, thereby changing the output flow and the direction of oil suction and discharge of the piston pump. The variable method used by the traditional variable mechanism is mainly in the form of a valve-controlled plunger, and due to the compressibility of hydraulic oil, it is difficult to achieve precise control when controlling variables.

SUMMARY OF THE INVENTION

The present invention is made to solve the above problems, and aims to provide an axial piston pump variable device with a locking function and a swash plate type axial piston pump.

The present invention provides a variable device for an axial piston pump with a locking function, which has the characteristics of including a variable mechanism for adjusting the inclination of the swash plate, and a drive device for driving the variable mechanism, wherein the variable mechanism includes a ball wire Rod, flange, and transmission pin, the nut of the ball screw is connected with the flange, the flange is connected with the transmission pin, the transmission pin is hinged with the swash plate, the driving device includes a servo motor, the servo motor and the screw of the ball screw connect.

In the variable device of the axial piston pump with locking function provided by the present invention, it may also have the following feature: the ball screw is a single-nut ball screw or a double-nut ball screw.

Preferably, the method further includes: a pre-tightening device mounted on the ball screw and used for pre-tightening the nut of the ball screw.

Further, when the ball screw is a double-nut ball screw, a flange is respectively installed on the two nuts of the double-nut ball screw; the preloading device includes a piezoelectric stack, and the piezoelectric stack is installed on the two between two flanges, and its two ends are respectively connected with two flanges.

Furthermore, the number of piezoelectric stacks is plural and distributed along the circumferential direction of the screw of the double-nut ball screw.

The present invention also provides a swash plate type axial piston pump, including the above-mentioned variable device for the axial piston pump with locking function.

The role and effect of the invention

According to the variable device of the axial piston pump with locking function involved in the present invention, compared with the prior art, because the variable mechanism for adjusting the inclination of the swash plate adopts a ball screw, and the drive device for driving the variable mechanism adopts a servo The motor uses the characteristics of the precision transmission of the ball screw and the precision drive of the servo motor. Therefore, the variable device of the axial piston pump realizes the precise control of the inclination of the swash plate. When applied to the swash plate axial piston pump, the precise control of the variables of the swash plate axial piston pump.

Description of drawings

1 is a front view of an axial piston pump variable device with a locking function in an embodiment of the present invention;

Fig. 2 is the side view of the axial piston pump variable device with locking function in the embodiment of the present invention;

FIG. 3 is a schematic structural diagram of a place where a pretensioning device is installed in an embodiment of the present invention.

Description of reference numbers:

10 swash plate; 20 variable mechanism; 21 ball screw; 211 screw rod; 212 nut; 22 flange plate; 23 drive pin; 30 drive device; 31 servo motor; 32 coupling; heap.

Detailed ways

In order to make it easy to understand the technical means, creative features, achieved goals and effects of the present invention, the following embodiments will describe the present invention in detail with reference to the accompanying drawings.

Example

Fig. 1 is a front view of an axial piston pump variable device with a locking function, and Fig. 2 is a side view of the axial piston pump variable device with a locking function.

This embodiment provides a swash plate type axial piston pump, including an axial piston pump variable device with a locking function, and the axial piston pump variable device with a locking function is in phase with the swash plate 10 . connected to adjust the inclination of the swash plate 10 . Wherein, the swash plate type axial piston pump can be a through-shaft structure or a half-shaft structure.

As shown in FIG. 1 and FIG. 2 , the variable device for an axial piston pump with a locking function includes a variable mechanism 20 and a drive device 30 .

The variable mechanism 20 is connected to the swash plate 10 of the swash plate type axial piston pump, and is used to adjust the inclination angle of the swash plate 10 . The variable mechanism 20 includes a ball screw 21 , a flange 22 , and a transmission pin 23 . The ball screw 21 includes a screw 211 and a nut 212. Both ends of the screw 211 are respectively mounted on two mounting plates through bearings, and the two mounting plates are mounted in the casing of the swash plate axial piston pump. The flange 22 is fixedly connected to the nut 212 of the ball screw 21 through bolts. The transmission pin 23 is fixedly connected to the flange 22 , and one end of the transmission pin 23 is hinged to the swash plate 10 .

The driving device 30 is connected with the variable mechanism 20 and drives the variable mechanism 20 to transmit. The driving device 30 includes a servo motor 31 whose output shaft is connected to one end of the ball screw 21 through a coupling 32 .

When it is necessary to change the output flow and the oil suction and discharge direction of the swash plate axial piston pump, the servo motor 31 drives the nut 212 of the ball screw 21 to move along the screw 211, and the nut 212 drives the slant through the flange 22 and the transmission pin 23. The rotation of the plate 10 can change the size and direction of the inclination of the swash plate 10, thereby changing the effective variation of the sealing working volume in the pump, and realizing the variable of the swash plate axial piston pump.

Further, the ball screw 21 may be a single nut ball screw or a double nut ball screw. Because there is a certain axial clearance between the screw 211 of the ball screw 21 and the nut 212, the ball screw 21 will vibrate during the working process, which will reduce the transmission accuracy, thereby affecting the control of the swash plate 10. Therefore, in this In the embodiment, the ball screw 21 is preferably a double-nut ball screw. Compared with a single-nut ball screw, it has the advantages of relatively large load, strong stability and high precision.

The variable device of the axial piston pump with locking function further includes a pre-tightening device 40 , the pre-tightening device 40 is installed on the ball screw 21 and used to pre-tighten the nut 212 of the ball screw 21 to eliminate the shaft to the gap.

FIG. 3 is a schematic structural diagram of the installation place of the preloading device.

As shown in FIG. 3 , for the double nut ball screw, the present preloading device 40 is provided between the two nuts 212 of the double nut ball screw. The pretensioning device 40 includes a plurality of piezoelectric stacks 41 . The flanges 22 are installed on the two nuts 212 of the double-nut ball screw. A plurality of piezoelectric stacks 41 are arranged between the two flanges 22 and are evenly distributed on the peripheral side of the screw 211 in the circumferential direction. Both ends of each piezoelectric stack 41 are fixedly connected to the two flanges 22 through screws, respectively. In this embodiment, the number of piezoelectric stacks 41 is four. When in use, the four piezoelectric stacks 41 are energized, so that the thickness of the four piezoelectric stacks 41 in the axial direction increases, and then the two flanges 22 are pushed, so that the two nuts 212 are pressed against the screws 211. On the other hand, the balls inside each nut 212 are closer to the raceway, so that the preload can eliminate the axial clearance.

Action and effect of the embodiment

In the variable device of the axial piston pump with locking function involved in this embodiment, because the variable mechanism for adjusting the inclination of the swash plate adopts a ball screw, the drive device for driving the variable mechanism adopts a servo motor, and the ball screw is used for precision Due to the characteristics of precision drive of transmission and servo motor, this axial piston pump variable device realizes precise control of the inclination of the swash plate, and when applied to the swash plate axial piston pump, the Precise control of variables to the plunger pump.

Among them, the ball screw can be a single-nut ball screw or a double-nut ball screw, preferably a double-nut ball screw, which has the advantages of relatively large load, strong stability and high precision.

There is also a pre-tightening device on the ball screw, which can eliminate the axial clearance by pre-tightening the nut. For double nut ballscrews, the preload is a piezo stack and is installed between the two nuts. By energizing the piezoelectric stack to increase its thickness, so that the two nuts are pressed on the screw rod, the preload is realized to eliminate the axial gap, the stability of the variable mechanism transmission is increased, the system rigidity is increased, and the control accuracy. The number of piezoelectric stacks can be multiple and distributed on the peripheral side of the screw along the circumferential direction, so as to ensure the force balance of the two nuts.

The above embodiments are preferred cases of the present invention, and are not intended to limit the protection scope of the present invention.

Claims (6)

1. an axial piston pump variable device with a locking function, comprising a variable mechanism for adjusting the inclination of a swash plate, a drive device for driving the variable mechanism, characterized in that, The variable mechanism includes a ball screw, a flange, and a transmission pin, the nut of the ball screw is connected to the flange, the flange is connected to the transmission pin, and the transmission pin hinged to the swash plate, The driving device includes a servo motor connected with the screw of the ball screw. 2. The axial piston pump variable device with locking function according to claim 1, characterized in that: Wherein, the ball screw is a single nut ball screw or a double nut ball screw. 3. The axial piston pump variable device with locking function according to claim 2, wherein: Among them, it also includes: A pre-tightening device is installed on the ball screw and used for pre-tightening the nut of the ball screw. 4. The axial piston pump variable device with locking function according to claim 3, wherein: Wherein, when the ball screw is a double-nut ball screw, the two nuts of the double-nut ball screw are respectively installed with one of the flanges; the preloading device includes a piezoelectric stack, The piezoelectric stack is installed between the two flanges, and two ends of the piezoelectric stack are respectively connected with the two flanges. 5. The axial piston pump variable device with locking function according to claim 4, characterized in that: Wherein, the piezoelectric stacks are plural in number and distributed along the circumferential direction of the screw of the double-nut ball screw. 6 . A swash plate type axial piston pump, characterized in that it comprises the variable device for an axial piston pump with a locking function according to any one of claims 1 to 5 .

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