Swash plate plunger pump

Abstract

The invention relates to the technical field of hydraulic power elements, in particular to a rotating and tilting tray type plunger pump which comprises a floating disc assembly, a plunger assembly, a cylinder body, a center rod assembly, a pump body, a pump cover and a flow distribution device. The floating disc assembly, the plunger assembly, the cylinder body and the center rod assembly are arranged in a containing cavity formed by connecting the pump body and the pump cover, the main shaft swash plate assembly is provided with a driving shaft end, the driving shaft end penetrates through a side hole in the end of the pump body to be exposed, the main shaft swash plate assembly is provided with an inclined plane and is matched with the floating disc assembly to restrain the plunger assembly, and the cylinder body is fixed to the pump cover. The plunger assemblies are arranged in plunger holes evenly distributed in the circumference of the cylinder body, and flow distribution devices are arranged between the plunger holes and the oil suction port and between the plunger holes and the pressure port.

Description

Technical Field

[0001] The invention belongs to the technical field of hydraulic power elements, in particular to a swash plate plunger pump. Background Art

[0002] Plunger pumps are widely used in aviation, shipbuilding, industry and other fields due to their advantages such as compactness, high efficiency and high power density ratio. At present, in order to adapt to the needs of electrification and further improve the power density ratio, various fields require higher working pressures and put forward more stringent requirements on the speed and pressure of plunger pumps. The speed range has been greatly increased, the low-speed stability requirements are higher, and the maximum and minimum speeds must reach higher levels. In addition, low-viscosity media are used in special scenarios, which brings greater challenges to the realization of the above requirements. However, the performance of domestic plunger pumps is currently far behind that of foreign ones, and cannot adapt to the current situation of the industry.

[0003] The reasons for this phenomenon include: 1. The swash plate axial piston pump has a large lateral force on the plunger, which easily causes insufficient oil film bearing capacity under high pressure and high speed conditions, resulting in serious friction and wear; 2. The swash plate axial piston pump has a large PV value for the slipper pair and plunger pair, resulting in serious friction and wear; 3. The rotating components of the swash plate axial piston pump and the swash plate axial piston pump include cylinder body, plunger and other parts. Due to the reciprocating motion of the plunger, the overall centrifugal force is in a fluctuating state. Under high-speed conditions, the unstable centrifugal force further aggravates the wear of the friction pair and the instability of movement. 4. The rotating components of the swash plate piston pump have a large rotational inertia, poor speed change characteristics, and are prone to failure of transmission components such as the plunger under strong impact conditions. 5. Traditional swash plate piston pump motors generally use slipper plungers or cylindrical plungers. Due to lateral force, they are prone to friction and wear and failure under high pressure and low viscosity medium conditions. Summary of the invention

[0004] In order to solve the above problems, the present invention invents a swash plate type plunger pump, which reduces the lateral force of the plunger pair and reduces the moment of inertia to meet the needs of aviation, engineering and other fields for high-speed hydraulic pumps, stable low-speed performance, high pressure, and adaptability to low-viscosity medium working conditions.

[0005] The present invention adopts the following technical solutions: A swash plate type plunger pump comprises a floating plate assembly, a plunger assembly, a cylinder body, a center rod assembly, a pump body, a pump cover and a flow distribution device. The pump body and the pump cover are respectively provided with an oil suction port and a pressure port. The floating plate assembly, the plunger assembly, the cylinder body, the center rod assembly are mounted on the pump body and the pump cover are connected to form a cavity. The invention is characterized in that it also comprises a main shaft swash plate assembly, the main shaft swash plate assembly is provided with a drive shaft end, the drive shaft end passes through a side hole at the pump body end and is exposed, the main shaft swash plate assembly is provided with an inclined plane and is engaged with the floating plate assembly through a bevel gear to constrain the plunger assembly, the cylinder body is fixed to the pump cover, the plunger assembly is provided in plunger holes evenly distributed circumferentially on the cylinder body, and a flow distribution device is provided between the plunger holes and the oil suction port and the pressure port.

[0006] The main shaft swash plate assembly is located in a cylindrical body in the pump body, and the end side of the cylindrical body is an inclined plane. The inclined plane on the main shaft swash plate assembly contacts the plane of the floating plate assembly.

[0007] The inclined floating plate assembly and the cylinder body are both provided with bevel gears, and the bevel gears on the two are always in meshing state, and the transmission ratio is 1.

[0008] The bevel gears are distributed on the outside or inside of the floating plate assembly or the cylinder body.

[0009] The cylinder body is fixed to the pump cover through a limiting shaft.

[0010] The plunger assembly is a connecting rod plunger. The ball head on one side of the connecting rod plunger cooperates with the plunger ball pair, and the small ball head on the other side of the connecting rod plunger is connected to the plunger universal ball slidingly set in the plunger hole. A static pressure support groove is set on the swash plate, and a sealing belt is set on the floating plate. The two are connected to the plunger hole cavity through the oil hole on the swash plate and the axially set through hole on the connecting rod plunger.

[0011] The plunger assembly can also be a tapered plunger, the ball head on one side of the tapered plunger cooperates with the plunger ball pair, the plunger end on the other side of the tapered plunger is set as a ball pair and is installed with a double sealing ring, which is slidably set in the plunger hole, a static pressure support groove is set on the swash plate, and a sealing belt is set on the floating plate, and the two are connected to the plunger cavity through the oil hole on the swash plate and the axial through hole on the tapered plunger. Different material or processing adjustment grooves are set in the spindle swash plate assembly, and the center of mass of the spindle swash plate assembly is on the rotation axis.

[0012] A universal joint is provided between the floating plate assembly and the cylinder body, and the rotational speed ratio between the floating plate assembly (2) and the cylinder body (4) is 1.

[0013] Compared with the prior art, the present invention can achieve the following technical effects: 1. The lateral force of the plunger is reduced by using the connecting rod plunger and cone plunger structure.

[0014] 2. The swash plate structure is adopted to reduce the inertia moment and achieve dynamic balance.

[0015] 3. The floating plate assembly is used to realize the combination of the swash plate structure and the connecting rod plunger structure, breaking through the limitations of the transmission swash plate plunger pump and the inclined axis plunger pump. While retaining the advantages of the swash plate structure such as low moment of inertia, wide speed range, high speed, and low-speed stability, the lateral force of the plunger is reduced, thereby further improving the pressure and speed. Due to the reduction of the lateral force, it can further adapt to the working conditions of low-viscosity media.

[0016] 4. Bevel gears are used to limit the floating plate and the cylinder body, thus avoiding the change of the connecting rod and plunger phase and the interference between the connecting rod and the plunger. The excellent characteristics of bevel gear transmission are used to further improve the load torque and stability of the operation process, so that the pressure and speed range can be further improved.

[0017] 5. The swash plate is machined with a static pressure balance area. By introducing high-pressure oil into the plunger cavity, static pressure balance of the floating plate and lubrication between the floating plate and the swash plate can be achieved, which further increases the speed and pressure.

[0018] The invention can increase the maximum speed of the swash plate plunger pump, improve low-speed stability, widen the speed range, increase the power density ratio, and improve the speed response. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a schematic diagram of the structure of the present invention; Figure 2 is a schematic structural diagram of Embodiment 2 of the present invention; Figure 3 It is a three-dimensional schematic diagram of the main shaft swash plate assembly of the present invention; Figure 4 is a schematic diagram of a floating plate assembly 2 of the present invention; Figure 5 The present invention Figure 4 Right-facing schematic diagram; Figure 6 The present invention Figure 4 Left-facing schematic diagram; Figure 7 It is a schematic diagram of the universal joint structure adopted in the present invention.

[0020] Among them, 1-spindle swash plate assembly, 2-floating plate assembly, 3-plunger assembly, 4-cylinder body, 5-center rod assembly, 6-bevel gear, 7-pump body, 8-pump cover, 9-limit shaft, 10-inlet check valve, 11-outlet check valve, 12-oil suction port, 13-pressure port, 14-static pressure support groove, 15-sealing belt, 16-oil hole, 17-universal joint, 18-connecting piece, 19-rod connecting piece. DETAILED DESCRIPTION

[0021] Embodiment 1, like Figure 1-6A swash plate type piston pump comprises: a main shaft swash plate assembly 1, a floating plate assembly 2, a plunger assembly 3, a cylinder body 4, a center rod assembly 5, a pump body 7, a pump cover 8 and a flow distribution device.

[0022] The pump body 7 and the pump cover 8 are connected to form a cavity. The pump body 7 and the pump cover 8 are respectively provided with an oil suction port 12 and a pressure port 13. The main shaft swash plate assembly 1 is provided with a drive shaft end, and the drive shaft end passes through the end side hole of the pump body 7 and is exposed. The main shaft swash plate assembly 1 can be connected and rotated with a motor or an internal combustion engine through the drive shaft end. The main shaft swash plate assembly 1 is located inside the pump body 7 and is divided into a cylindrical body. The end side of the cylindrical body is an inclined plane. Different materials or processing optimization center of mass can be set in the cylindrical body, so that the rotating swash plate structure reduces the inertia moment and realizes dynamic balance. The inclined plane on the main shaft swash plate assembly 1 is in contact with the plane of the floating plate assembly 2, and the floating plate assembly 2 has a ball at the center. The socket is in ball joint contact with the center rod assembly 5, and the center rod of the center rod assembly 5 is matched with the cylindrical pair of the cylinder body 4 and has a spring at the bottom to ensure the close contact between the floating plate assembly 2 and the main shaft swash plate assembly 1. The cylinder body 4 is fixed to the pump cover 8 through the limit shaft 9, and an inlet check valve 10 and an outlet check valve 11 are arranged between each plunger cavity of the cylinder body 4 and the oil suction port 12 and the pressure port 13. The driving shaft of the main shaft swash plate assembly 1 and the cylinder body 4 are coaxial.

[0023] The floating plate assembly 2 is circumferentially provided with ball sockets, which cooperate with the ball head and ball pair of the plunger assembly 3. The ball head on the other side of the plunger assembly 3 cooperates with the plunger ball pair. The cylinder body 4 is circumferentially provided with plunger holes. The plunger of the plunger assembly 3 is in the plunger hole, and oil sealing is achieved through the annular gap between the plunger and the plunger hole.

[0024] Bevel gears 6 are machined on the floating plate assembly 2 and the cylinder body 4, and the two realize the circumferential limit of the floating plate assembly 2 through the bevel gears 6. The bevel gears 6 can be distributed on the outside or inside, and the outside distribution is adopted in Figure 1. In addition to using bevel gears for limiting, such as Figure 7 It can also be achieved by using a universal joint 17, which is universally connected through a connecting piece 18 and a rod connecting piece 19 respectively provided on the floating plate assembly 2 and the cylinder body 4. The universal joint 17 is used to transmit the torque between the floating plate assembly 2 and the cylinder body 4, thereby ensuring that the two do not produce relative rotation, thereby constraining the freedom of the floating plate assembly 2.

[0025] The ball head center of the center rod coincides with the vertex of the cone of the bevel gear 6. During the rotation of the main shaft swash plate assembly 1, the floating plate assembly 2 is limited by the bevel gear 6 and is only in a swinging state and cannot rotate relative to the cylinder body, thereby ensuring the distribution phase of the ball head of the plunger assembly 3. During the swinging of the floating plate assembly 2, the plunger assembly 3 reciprocates in the plunger hole to achieve oil suction and discharge. The flow distribution scheme can adopt valve flow distribution or disc flow distribution.

[0026] The floating plate is machined with a static pressure balance area to introduce high-pressure oil into the plunger cavity to achieve static pressure balance and lubrication between the floating plate and the swash plate. The floating plate is machined with an oil hole 16 to connect the plunger cavity and the static pressure support groove 14 on the swash plate assembly to achieve static pressure balance of the floating plate, and the oil can be sealed by the sealing belt 15 on the floating plate to limit leakage.

[0027] like Figure 1 The plunger assembly 3 is a connecting rod plunger, a ball head on one side of the connecting rod plunger cooperates with the plunger ball pair, and a small ball head on the other side of the connecting rod plunger is connected to a plunger universal ball slidably arranged in the plunger hole.

[0028] Embodiment 2 like Figure 2 The plunger assembly 3 can also be a tapered plunger. The ball head on one side of the tapered plunger cooperates with the plunger ball pair, and the plunger end on the other side of the tapered plunger is provided with a double sealing ring and is slidably arranged in the plunger hole.

[0029] Furthermore, a through hole is axially arranged on the conical plunger, and a static pressure support groove is processed on the inclined plate. Lubrication between the static pressure support of the floating plate and the friction pair can be achieved by introducing high-pressure oil into the plunger cavity.

[0030] The working method is: like Figure 1-7 The motor or internal combustion engine drives the main shaft swash plate assembly 1 to rotate, the oil suction port 12 is connected to the oil, the floating plate assembly 2 and the cylinder body 7 are engaged with the bevel gear 6 to limit the circumferential position, the limit shaft 9 limits the cylinder body 4 to the pump cover 8, and the main shaft swash plate assembly 1 rotates to drive the push-pull floating plate assembly 2 to connect the plurality of plunger assemblies 3 to extend and retract in the plunger hole on the cylinder body 4. When the pressure is negative, the oil is sucked in through the inlet check valve 10. When the pressure is compressed, the high-pressure oil is output to the pressure port 13 through the outlet check valve 11.

[0031] The floating plate assembly 2 is used to combine the swash plate structure with the connecting rod plunger or cone plunger structure. The lateral force of the plunger is reduced while retaining the advantages of the swash plate structure such as low rotational inertia, wide speed range, high speed, and low-speed stability, thereby further improving the pressure and speed. Due to the reduction in lateral force, it can further adapt to low-viscosity medium working conditions.

[0032] The bevel gear 6 is used to limit the floating plate and the cylinder body 4, thereby avoiding the change of the phase of the connecting rod plunger and the cone plunger, and avoiding the interference between the plunger assembly 3 and the cylinder body hole. In addition, the excellent characteristics of the bevel gear transmission are used to further improve the load torque and stability of the operation process, so that the pressure and speed range can be further improved.

Claims

1. A swash plate type plunger pump, comprising a floating plate assembly (2), a plunger assembly (3), a cylinder body (4), a center rod assembly (5), a pump body (7), a pump cover (8) and a flow distribution device, wherein the pump body (7) and the pump cover (8) are respectively provided with an oil suction port (12) and a pressure port (13), and the floating plate assembly (2), the plunger assembly (3), the cylinder body (4) and the center rod assembly (5) are installed in a cavity formed by connecting the pump body (7) and the pump cover (8), characterized in that: The pump also includes a main shaft swash plate assembly (1), the main shaft swash plate assembly (1) is provided with a drive shaft end, the drive shaft end passes through the end side hole of the pump body (7) and is exposed, the main shaft swash plate assembly (1) is provided with an inclined plane and is engaged with the floating plate assembly (2) through a bevel gear to constrain the plunger assembly (3), the cylinder body (4) is fixed to the pump cover (8), the plunger assembly (3) is arranged in a plunger hole evenly distributed on the circumference of the cylinder body (4), and a flow distribution device is arranged between the plunger hole and the oil suction port (12) and the pressure port (13).

2. A swash plate type plunger pump according to claim 1, characterized in that: The main shaft swash plate assembly (1) is located inside the pump body (7) and is divided into a cylindrical body. The end side of the cylindrical body is an inclined plane. The inclined plane on the main shaft swash plate assembly (1) contacts the plane of the floating plate assembly (2).

3. A swash plate type plunger pump according to claim 2, characterized in that: The inclined floating plate assembly (2) and the cylinder body (4) are both provided with bevel gears (6), and the bevel gears on the two are always in a meshing state, with a transmission ratio of 1.

4. A swash plate type plunger pump according to claim 3, characterized in that: The bevel gear (6) is distributed on the outside or inside of the floating plate assembly (2) or the cylinder body (4).

5. The swash plate type plunger pump according to claim 3, characterized in that: The cylinder body (4) and the pump cover (8) are fixed via a limiting shaft (9).

6. A swash plate type plunger pump according to any one of claims 3 to 5, characterized in that: The plunger assembly (3) is a connecting rod plunger, a ball head on one side of the connecting rod plunger cooperates with a plunger ball pair, a small ball head on the other side of the connecting rod plunger is connected to a plunger universal ball slidably arranged in the plunger hole, a static pressure support groove (14) is arranged on the swash plate, and a sealing belt (15) is arranged on the floating plate, and the two are connected to the plunger hole cavity through an oil hole (16) on the swash plate and an axially arranged through hole on the connecting rod plunger.

7. A swash plate type plunger pump according to any one of claims 3 to 5, characterized in that: The plunger assembly (3) may also be a tapered plunger, wherein a ball head on one side of the tapered plunger cooperates with a plunger ball pair, a plunger end on the other side of the tapered plunger is provided with a ball pair and is provided with a double sealing ring, which is slidably arranged in the plunger hole, a static pressure support groove (14) is provided on the swash plate, and a sealing belt (15) is provided on the floating plate, and the two are connected to the plunger hole cavity via an oil through hole (16) on the swash plate and an axially arranged through hole on the tapered plunger.

8. A swash plate type plunger pump according to any one of claim 2, characterized in that: The spindle swash plate assembly (1) is provided with adjustment grooves made of different materials or processed therein, and the center of mass of the spindle swash plate assembly (1) is located on the rotation axis.

9. The swash plate type plunger pump according to claim 2, characterized in that: A universal joint (17) is provided between the floating plate assembly (2) and the cylinder body (4), and the rotation speed ratio between the floating plate assembly (2) and the cylinder body (4) is 1.

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