CN103883493B - An axial piston pump with a stationary cylinder - Google Patents

Abstract

An axial plunger pump with a stationary cylinder. The cylinder is fixed. When the swashplate rotates driven by the transmission shaft, the plungers in each plunger cavity will be driven by the force of the spring, the hydraulic pressure and the thrust of the swashplate. Under the action, it reciprocates in the axial direction. When the slope of the swash plate pushes the plunger into the plunger chamber, the volume of the plunger chamber decreases, and the oil passes through the oil passage groove, flows into the oil pressure arc groove, and then passes through the pressure arc groove successively. The oil shaft hole and the oil pressure ring groove finally flow out from the oil outlet hole; when the plunger is pushed out of the plunger chamber by the spring, the volume of the plunger chamber increases, and the oil passes through the oil inlet hole, the oil suction ring groove, and the oil suction shaft in sequence The hole, the oil suction arc groove and the oil passage groove are sucked into the plunger chamber, and all the plunger chambers on the cylinder work at the same time, that is, to realize continuous oil suction from the oil inlet hole and discharge from the oil outlet hole. The present invention has the advantages of compact structure and simple transmission. , The moment of inertia is small and the advantages of large displacement can be realized.

Description

An Axial Piston Pump with a Stationary Cylinder

technical field

The invention belongs to the technical field of axial plunger hydraulic pumps, in particular to an axial plunger pump with a stationary cylinder body.

Background technique

The hydraulic pump is an important part of the hydraulic system. A hydraulic pump with excellent performance is an important guarantee for the stable and efficient work of the hydraulic system. In engineering hydraulic systems, the most commonly used hydraulic pump is the axial piston pump. It is a positive displacement hydraulic pump whose plunger is arranged parallel to the transmission shaft. It has the advantages of simple structure, small volume, low noise, high efficiency, long life and self-priming ability.

The working principle of the traditional axial piston pump is usually: the drive shaft directly or indirectly drives the cylinder to rotate, and the plunger installed in the cylinder is driven by a fixed swash plate to reciprocate in the plunger cavity, thereby periodically The volume of the plunger cavity can be changed to realize the actions of oil absorption and oil pressure. Since the plunger cavity rotates together with the drive shaft, the total moment of inertia of the pump is large, and the response speed of the pump's start-stop and speed regulation is slow, which is not conducive to directly adjusting the output flow of the pump by controlling the speed, and because the oil moves with the cylinder With high-speed rotation, cavitation and temperature rise are likely to occur inside the oil, which is not conducive to improving the volumetric efficiency and energy utilization rate of the pump.

Contents of the invention

In order to overcome the above-mentioned shortcomings of the prior art, the object of the present invention is to provide an axial piston pump with a stationary cylinder, which has the advantages of compact structure, simple transmission, small moment of inertia and large displacement.

In order to achieve the above object, the technical scheme that the present invention takes is:

An axial plunger pump with a stationary cylinder body, comprising a pump housing 1, a cylinder body 21 fixedly installed in the pump housing 1, and the cylinder body 21 realizes circumferential The first pump end cover 12 is installed on the pump casing 1, and the cylinder body 21 is pressed and fixed, the first shaft end gland 15 is installed on the first pump end cover 12, and the second pump end The cover 2 is installed on the other side of the pump housing 1, and the second shaft end gland 3 is installed on the second pump end cover 2;

There are more than two plunger holes 20 on the cylinder body 21. The plunger holes 20 are parallel to the central axis of the cylinder body 21 and evenly distributed on the same circumference. A plunger 10 is installed in each plunger hole 20. The plunger 10 can reciprocally slide in the plunger hole 20, and a spring 13 is also installed in each plunger hole 20. The spring 13 withstands the bottom of the plunger 10. The head of the plunger 10 is spherical, and a sliding shoe is installed on it. 9. The sliding shoe 9 can rotate at a corresponding angle on the plunger 10. There are more than two oil passage grooves 16 on one side of the cylinder body 21. The oil passage grooves 16 are radially distributed and communicate with each plunger hole 20 respectively. ;

The transmission shaft 5 passes through the central axis of the cylinder body 21 and is installed inside the pump housing 1. The swash plate 8 is installed on the transmission shaft 5 through the second key 6 and is supported on the pump housing 1 through the second rolling bearing 7. The part where the shaft 5 is inserted into the first pump end cover 12 is supported on the first pump end cover 12 through the first rolling bearing 17, and the transmission shaft sealing cover 14 is installed at the shaft end on this side to press the inner ring of the first rolling bearing 17 tightly. On the shoulder of the transmission shaft 5, the outer ring of the first rolling bearing 17 abuts against the first shaft end gland 15 to achieve axial positioning on this side. The third rolling bearing 4 is installed from the other end of the transmission shaft 5 and is The second shaft end gland 3 is pressed against the shoulder of the transmission shaft 5 on this side, and realizes the axial positioning of the transmission shaft 5 together with the first rolling bearing 17. The outer ring of the second rolling bearing 7 is covered by the second pump end cover 2 Pressed on the shoulder of the pump housing 1, the inner ring of the second rolling bearing 7 is pressed on the shoulder of the swash plate 8, and the swash plate 8 is pressed on the shoulder of the transmission shaft 5 to realize the rotation of the swash plate 8. Axial positioning, the plunger 10 and the sliding shoe 9 are pushed out by the spring 13, the sliding shoe 9 is pressed on the slope of the swash plate 8, and can slide relatively;

The end of the transmission shaft 5 inserted into the first pump end cover 12 has an axial oil suction shaft hole 24 and an oil pressure shaft hole 23, and the transmission shaft 5 is on the same plane as the oil passage groove 16, and there are circular arcs isolated from each other. The oil suction arc groove 25 and the oil pressure arc groove 22, the symmetry plane of the oil suction arc groove 25 and the oil pressure arc groove 22 is the same plane as the symmetry plane of the swash plate 8, the oil suction arc groove 25 communicates with the oil suction shaft hole 24, and the oil pressure arc groove The groove 22 communicates with the oil pressure shaft hole 23. On the part where the transmission shaft 5 is inserted into the first pump end cover 12, there is also an oil pressure ring groove 26 and an oil suction ring groove 27. The oil pressure ring groove 26 and the oil pressure shaft hole 23 Unicom, the oil suction ring groove 27 communicates with the oil suction shaft hole 24;

The first pump end cover 12 has an oil inlet hole 18 and an oil outlet hole 19, the oil inlet hole 18 communicates with the oil suction ring groove 27 on the transmission shaft 5, and the oil outlet hole 19 communicates with the oil pressure ring groove 26 on the transmission shaft 5 connected.

The distance between the oil suction arc groove 25 and the oil pressure arc groove 22 is not less than the diameter of the plunger hole 20 .

The present invention has the following advantages:

1) Compact structure and simple transmission. The cylinder body 21 of the pump is provided with more than two plungers 10 in the axial direction, and the transmission shaft 5 also has the function of flow distribution, so that the space in the pump casing 1 is fully utilized. The positioning of each part is reliable, and the support of the moving parts is mostly realized by rolling bearings, with small friction and stable work.

2) The moment of inertia is small and the movement is sensitive. The pump drives the plunger 10 to reciprocate through the thrust generated by the rotation of the swash plate 8 and the elastic force of the spring 13. The cylinder body 21 is fixed and does not rotate with the transmission shaft 5, thereby reducing the moment of inertia of the pump, which is beneficial to adjust the pump when necessary. fast occasions.

3) Large displacement can be realized. Since the plunger 10 does not rotate around the transmission shaft, there is no centrifugal force, and the sliding shoe 9 and the inclined surface of the swash plate 8 can achieve a good fit. Therefore, the inclination angle of the swash plate 8 can take a larger value, thereby increasing the force of the plunger 10. stroke, increase displacement.

Description of drawings

Fig. 1 is an axial sectional view of the present invention.

Fig. 2 is a structural view of the end face of the cylinder 21 in the present invention.

Fig. 3 is a structural diagram of the transmission shaft 5 in the present invention.

Fig. 4 is a sectional view of the A-A section of Fig. 3 of the present invention.

Fig. 5 is a sectional view of the B-B section in Fig. 3 of the present invention.

Fig. 6 is a sectional view of the C-C section in Fig. 3 of the present invention.

Detailed ways

The present invention will be described in detail below in conjunction with the accompanying drawings.

Referring to FIG. 1 , an axial piston pump with a stationary cylinder 21 includes a pump housing 1 , and the cylinder 21 is fixedly installed in the pump housing 1 . The cylinder 21 passes through the first key 11 and the The shoulders realize circumferential and axial positioning respectively, the first pump end cover 12 is installed on the pump casing 1, and the cylinder body 21 is pressed and fixed, and the first shaft end gland 15 is installed on the first pump end cover 12 , the second pump end cover 2 is installed on the other side of the pump housing 1, and the second shaft end gland 3 is installed on the second pump end cover 2;

Referring to Fig. 1 and Fig. 2, there are more than two plunger holes 20 on the cylinder body 21, the plunger holes 20 are parallel to the central axis of the cylinder body 21, and are evenly distributed on the same circumference, each plunger hole 20 has A plunger 10 is installed, and the plunger 10 can reciprocally slide in the plunger hole 20, and a spring 13 is also installed in each plunger hole 20, and the spring 13 withstands the bottom of the plunger 10, and the head of the plunger 10 is Spherical, with a sliding shoe 9 installed on it, the sliding shoe 9 can rotate at a corresponding angle on the plunger 10; there are more than two oil passage grooves 16 on one side of the cylinder body 21, and the oil passage grooves 16 are distributed radially, respectively. Each plunger hole 20 communicates. There is an oil chamber at the bottom of the sliding shoe 9, and there are fine holes in the center of the plunger 10 and the sliding shoe 9, which can guide the hydraulic oil in the cavity of the plunger 10 to the oil chamber at the bottom of the sliding shoe 9, and play the role of lubrication and pressure balance .

Referring to Figure 1, the transmission shaft 5 passes through the central axis of the cylinder body 21 and is installed inside the pump housing 1, the swash plate 8 is installed on the transmission shaft 5 through the second key 6, and is supported on the pump housing through the second rolling bearing 7 1, the part of the transmission shaft 5 inserted into the first pump end cover 12 is supported on the first pump end cover 12 through the first rolling bearing 17, and the transmission shaft sealing cover 14 is installed on the shaft end of this side, and the first rolling bearing 17 The inner ring is pressed against the shoulder of the transmission shaft 5, the outer ring of the first rolling bearing 17 is pressed against the first shaft end gland 15 to realize the axial positioning of this side, and the third rolling bearing 4 moves from the other side of the transmission shaft 5 Installed at one end, pressed by the second shaft end gland 3 on the shoulder of the transmission shaft 5 on this side, together with the first rolling bearing 17 to realize the axial positioning of the transmission shaft 5, the outer ring of the second rolling bearing 7 is held by the second The pump end cover 2 is pressed tightly on the shoulder of the pump casing 1, the inner ring of the second rolling bearing 7 is pressed on the shoulder of the swash plate 8, and the swash plate 8 is pressed on the shoulder of the transmission shaft 5 to realize The axial positioning of the swash plate 8, the plunger 10 and the sliding shoe 9 are pushed out by the spring 13, and the sliding shoe 9 presses on the slope of the swash plate 8 and can slide relatively.

Referring to Fig. 1, Fig. 3, Fig. 4, Fig. 5 and Fig. 6, one end of the transmission shaft 5 inserted into the first pump end cover 12 has an axial oil suction shaft hole 24 and an oil pressure shaft hole 23, and the transmission shaft 5 is connected to the through The oil groove 16 is on the position of the same plane, and there are mutually isolated arc-shaped oil suction arc grooves 25 and oil pressure arc grooves 22. The symmetry plane of the oil suction arc groove 25 and the oil pressure arc groove 22 and the symmetry plane of the swash plate 8 are The same plane, so that for the same plunger 10, when the swash plate 8 pushes it into the plunger hole 20, the oil passage groove 16 connected to it just turns to communicate with the oil pressure arc groove 22 on the transmission shaft 5 , when the spring 13 pushes the plunger 10 out of the plunger hole 20, the oil passage groove 16 connected to it just turns to communicate with the oil suction arc groove 25 on the transmission shaft 5, and the oil suction arc groove 25 and the oil pressure arc groove 22 are connected. The spacing distance is not less than the diameter of the plunger hole 20. The oil suction arc groove 25 communicates with the oil suction shaft hole 24, and the oil pressure arc groove 22 communicates with the oil pressure shaft hole 23. On the part where the transmission shaft 5 is inserted into the first pump end cover 12, there is also An oil pressure ring groove 26 and an oil suction ring groove 27 are provided, the oil pressure ring groove 26 communicates with the oil pressure shaft hole 23 , and the oil suction ring groove 27 communicates with the oil suction shaft hole 24 .

Referring to Fig. 1, an oil inlet hole 18 and an oil outlet hole 19 are opened on the first pump end cover 12, the oil inlet hole 18 communicates with the oil suction ring groove 27 on the transmission shaft 5, and the oil outlet hole 19 communicates with the pressure on the transmission shaft 5. The oil ring groove 26 communicates. Through the oil inlet hole 18 and the oil outlet hole 19, the connection between the oil circuit in the pump and the external oil circuit is realized.

Working principle of the present invention: the cylinder body 21 is fixed, and when the swash plate 8 rotates under the driving of the transmission shaft 5, the plunger 10 in each plunger 10 cavity will be driven by the force of the spring 13, the hydraulic pressure and the thrust of the swash plate 8. Under the action of the shaft, it reciprocates along the axial direction. When the slope of the swash plate 8 pushes the plunger 10 into the cavity of the plunger 10, the volume of the cavity of the plunger 10 decreases, and the oil passes through the oil passage groove 16, flows into the oil pressure arc groove 22, and then successively passes through the oil pressure shaft hole 23 and the pressure oil ring groove 26, and finally flow out from the oil outlet hole 19; when the plunger 10 is pushed out of the plunger 10 cavity by the spring 13 (the sliding shoe 9 is close to the slope of the swash plate 8), the volume of the plunger 10 cavity increases , the oil is sucked into the cavity of the plunger 10 through the oil inlet hole 18, the oil suction ring groove 27, the oil suction shaft hole 24, the oil suction arc groove 25 and the oil passage groove 16 in sequence. All the cavities of the plungers 10 on the cylinder 21 work at the same time, that is to realize continuous oil suction from the oil inlet hole 18 and discharge from the oil outlet hole 19 .

Claims (2)

1. An axial piston pump with a stationary cylinder, comprising a pump casing (1), characterized in that: the cylinder (21) is fixedly installed in the pump casing (1), and the cylinder (21) passes through the first The key (11) and the shoulder on the pump casing (1) realize circumferential and axial positioning respectively, and the first pump end cover (12) is installed on the pump casing (1) to press the cylinder body (21) The first shaft end cover (15) is installed on the first pump end cover (12), the second pump end cover (2) is installed on the other side of the pump housing (1), and the second shaft end cover (15) is The cover (3) is installed on the second pump end cover (2); Have more than two plunger holes (20) on the cylinder body (21), the plunger holes (20) are parallel to the axis of the cylinder body (21), and are evenly distributed on the same circumference, and each plunger hole (20 ) is equipped with a plunger (10), the plunger (10) can slide back and forth in the plunger hole (20), and each plunger hole (20) is also equipped with a spring (13), the spring (13) Withstand the bottom of the plunger (10), the head of the plunger (10) is spherical, and the slide shoe (9) is installed on it, the slide shoe (9) can rotate at a corresponding angle on the plunger (10), and the cylinder There are more than two oil passage grooves (16) arranged on one side of the body (21), and the oil passage grooves (16) are radially distributed and communicated with each plunger hole (20) respectively; The transmission shaft (5) passes through the central axis of the cylinder body (21) and is installed inside the pump casing (1). The swash plate (8) is installed on the transmission shaft (5) through the second Two rolling bearings (7) are supported on the pump casing (1), and the part of the transmission shaft (5) inserted into the first pump end cover (12) is supported on the first pump end cover (12) through the first rolling bearing (17). The transmission shaft sealing cover (14) is installed on the shaft end of this side, and the inner ring of the first rolling bearing (17) is pressed against the shoulder of the transmission shaft (5), and the outer ring of the first rolling bearing (17) is against the On the first shaft end gland (15), the axial positioning of this side is realized. The third rolling bearing (4) is installed from the other end of the transmission shaft (5), and is pressed by the second shaft end gland (3). The transmission shaft (5) is on the shoulder of this side, and realizes the axial positioning of the transmission shaft (5) together with the first rolling bearing (17), and the outer ring of the second rolling bearing (7) is covered by the second pump end cover (2) Press on the shoulder of the pump casing (1), the inner ring of the second rolling bearing (7) presses on the shoulder of the swash plate (8), and press the swash plate (8) on the transmission shaft (5) On the shoulder of the swash plate (8), the axial positioning of the swash plate (8) is realized, the plunger (10) and the sliding shoe (9) are pushed out by the spring (13), and the sliding shoe (9) is pressed against the slope of the swash plate (8), Can slide relatively; The end of the transmission shaft (5) inserted into the first pump end cover (12) has an axial oil suction shaft hole (24) and an oil pressure shaft hole (23). The position of the plane has mutually isolated arc-shaped oil suction arc grooves (25) and oil pressure arc grooves (22), and the symmetrical plane of the oil suction arc grooves (25) and oil pressure arc grooves (22) and the swash plate (8 ) is the same plane, the oil suction arc groove (25) is connected with the oil suction shaft hole (24), the oil pressure arc groove (22) is connected with the oil pressure shaft hole (23), and the transmission shaft (5) is inserted into the first pump On the part of the end cover (12), there are also oil pressure ring grooves (26) and oil suction ring grooves (27). The oil pressure ring grooves (26) communicate with the oil pressure shaft holes (23), and the oil suction ring grooves (27) Communicate with the oil suction shaft hole (24); The first pump end cover (12) has an oil inlet hole (18) and an oil outlet hole (19), the oil inlet hole (18) communicates with the oil suction ring groove (27) on the drive shaft (5), and the oil outlet hole (19) communicates with the pressure oil ring groove (26) on the transmission shaft (5). 2. An axial piston pump with a stationary cylinder according to claim 1, characterized in that: the distance between the oil suction arc groove (25) and the oil pressure arc groove (22) is not less than column Plug hole (20) diameter.