Four-quadrant ultrahigh pressure plunger pump

Abstract

The invention discloses a four-quadrant ultrahigh-pressure plunger pump which comprises a main shaft, a shell, a first bearing, a swash plate, a plunger return stroke and cylinder body pre-pressing device, an odd number of plunger assemblies, a cylinder body, a second bearing and a valve plate. The flow distribution plate has the function of a pump end cover and is coaxially installed with the shell, the first bearing and the second bearing are installed on the shell and the flow distribution plate respectively, the flow distribution plate and the flow distribution face of a cylinder body are in a spherical shape, two flow distribution windows symmetrically arranged on the flow distribution plate are communicated with an oil inlet and an oil outlet of the pump through three or more transition channels respectively, and the maximum inclination angle of the swash plate does not exceed 13 degrees. The plunger pump can adapt to the four-quadrant working condition and the ultrahigh pressure working condition of 60 MPa or above.

Description

Technical Field

[0001] The invention relates to a plunger pump, and relates to the technical field of hydraulic components, in particular to a four-quadrant ultra-high pressure plunger pump. Background Art

[0002] With the rise of servo pump control technology, plunger pumps that adapt to four-quadrant working conditions are increasingly widely used. The four-quadrant working conditions include: pump working condition clockwise rotation, pump working condition counterclockwise rotation, motor working condition clockwise rotation, and motor working condition counterclockwise rotation.

[0003] At present, the pressure level of the swash plate axial piston pump that adapts to the four-quadrant working conditions is generally between 21MPa and 35MPa, which cannot meet the application requirements of ultra-high pressure working conditions above 60MPa. The main factors that restrict the product from improving the pressure level are: First, the swash plate axial piston pump that adapts to the four-quadrant working conditions needs to adopt a distribution plate for flow distribution. The pump end cover and distribution plate of the traditional structure have too large deformation of the distribution plate under ultra-high pressure conditions, resulting in poor sealing between the distribution plate and the cylinder distribution surface. At the same time, the back of the distribution plate and the contact plane of the pump end cover are poorly sealed, resulting in large internal leakage and low volumetric efficiency. Second, the radial force borne by the plunger of the swash plate plunger pump is proportional to the working pressure. The radial force between the plunger and the plunger hole of the conventional plunger pump is too large under ultra-high pressure conditions, so the contact stress is too large, and the contact work ratio is too large, which will cause the friction pair to wear quickly or even the plunger to be stuck and damaged. Therefore, how to provide a swash plate axial piston pump that can adapt to four-quadrant working conditions and ultra-high pressure conditions is a problem that technicians in this field need to solve urgently. Summary of the invention

[0004] In order to solve the problems existing in the background technology, the present invention provides a four-quadrant ultra-high pressure plunger pump. The structure is a slanted plate axial plunger pump with spherical flow distribution, which is suitable for four-quadrant working conditions and ultra-high pressure working conditions above 60MPa.

[0005] The technical solution adopted by the present invention is:

[0006] The four-quadrant ultra-high pressure plunger pump of the present invention comprises a main shaft, a housing, a first bearing, a swash plate, a plunger return and cylinder pre-compression device, an odd number of plunger assemblies, a cylinder, a second bearing and a distribution plate.

[0007] The distribution plate also has the function of a pump end cover, and the distribution plate is coaxially mounted on the shell.

[0008] The distribution surface of the distribution disk is an outward convex spherical surface. A bearing hole and a waist-shaped distribution window are arranged on one side of the distribution surface of the distribution disk. The end of the main shaft is located in the bearing hole. The waist-shaped distribution window is symmetrically arranged and its distribution circle is coaxial with the bearing hole. The distribution disk is also provided with a pump inlet / outlet and a pump outlet / inlet. Three or more parallel distribution channels are evenly spaced in the circumferential direction of each waist-shaped distribution window. The pump inlet / outlet is connected to the first waist-shaped distribution window through each first distribution channel, and the pump outlet / inlet is connected to the second waist-shaped distribution window through each second distribution channel. The two ends of the waist-shaped distribution window are provided with corresponding connected shock-absorbing grooves or shock-absorbing holes. In specific implementation, in order to facilitate processing, a triangular shock-absorbing groove can be opened, the tip of the shock-absorbing groove is away from the end of the waist-shaped distribution window, and the depth increases linearly from the tip to the waist-shaped distribution window.

[0009] The distribution surface of the cylinder body is a concave spherical surface, the radius of which is equal to the radius of the convex spherical surface of the distribution plate. An odd number of plunger holes are evenly distributed on the circumference of the cylinder body, and the bottom of each plunger hole passes through its distribution surface through a transition channel opened in the cylinder body.

[0010] The housing is provided with a first bearing, the distribution plate is provided with a second bearing, the two ends of the main shaft are supported by the first bearing and the second bearing respectively, the cylinder body is coaxially sleeved on the main shaft, the cylinder body and the main shaft are splined, the distribution surface of the cylinder body contacts the distribution surface of the distribution plate, the cylindrical ends of the odd number of plunger assemblies are respectively slidably mounted in the plunger holes uniformly distributed on the cylinder body, the sliding shoe end faces of the odd number of plunger assemblies contact the working surface of the inclined plate, and the plungers The return and cylinder pre-tensioning device is installed between each plunger assembly and the cylinder body to provide return force for each plunger assembly and pre-tensioning elastic force for the cylinder body, so that the end face of the sliding shoe and the working surface of the inclined plate are kept in contact with each other, and the distribution surface of the cylinder body and the distribution surface of the distribution plate are kept in contact with each other; the plunger return and cylinder pre-tensioning device includes a ball joint, a return plate and a spring, the return plate is tilted and mounted on the sliding shoe of each plunger assembly, the ball joint is movably installed in the center of the return plate and coaxially mounted on the main shaft, and the spring is coaxially mounted on the main shaft and is located between the inside of the ball joint and the other end face of the cylinder body.

[0011] The maximum inclination angle α of the swash plate is no greater than 13°.

[0012] The swash plate, plunger return and cylinder pre-tensioning device, cylinder body and distribution plate are coaxially mounted on the main shaft in sequence along the length direction of the main shaft, the housing is coaxially mounted on the swash plate and the cylinder body, and the distribution plate is coaxially mounted on one end of the housing through a plurality of bolts; each plunger assembly is mounted in the cylinder body, and there is spherical contact between the cylinder body and the distribution plate. The distribution plate is symmetrically provided with waist-shaped distribution windows for distribution and provided with a plurality of distribution channels. During the rotation of the cylinder body, the distribution surface of the cylinder body is sequentially connected to the first waist-shaped distribution window, the upper dead center transition zone, the second waist-shaped distribution window and the lower dead center transition zone of the distribution plate.

[0013] The inclination angle of the swash plate is a fixed angle or a variable angle. The invention is applicable to a swash plate type quantitative plunger pump and also to a swash plate type variable plunger pump.

[0014] The top dead center transition zone and the bottom dead center transition zone of the distribution plate are also provided with a plurality of shock-absorbing blind holes. When the plunger pump works under ultra-high pressure conditions, the pressure difference between the waist-shaped distribution windows on both sides of the distribution plate is too large, and the pressure shock is large when the plunger cavity switches between high and low pressure. On the basis of setting the shock-absorbing groove or shock-absorbing hole, the shock-absorbing blind hole is added to play the role of a hydraulic spring, which helps to reduce vibration and noise.

[0015] The second bearing installed on the distribution plate is a needle roller bearing or a cylindrical roller bearing. Under the same load-bearing capacity, the outer diameter of the needle roller bearing or the cylindrical roller bearing is smaller, so the wall thickness between the waist-shaped groove of the distribution plate and the bearing hole is larger, the distribution plate has higher pressure resistance and better rigidity, the distribution surface deformation is smaller, and the distribution surface sealing effect is better.

[0016] A shaft seal is also installed between the housing and the spindle as a rotating dynamic seal, a sealing ring is installed between the housing and the distribution plate as a static seal, and an oil drain port is provided on the distribution plate or the housing. When the plunger pump is installed outside the oil tank, no external leakage will occur. It should be supplemented that when the plunger pump is installed inside the oil tank, the rotating dynamic seal and the static seal can be eliminated; further, if the circumferential gap between the housing and the spindle is large enough, the oil in the pump housing cavity can be connected to the oil tank through the bearing steel ball or roller gap and then through the housing and spindle circumferential gap, and the oil drain port may not be provided on the distribution plate or the housing.

[0017] The plunger pump of the present invention is suitable for four-quadrant working conditions and ultra-high pressure working conditions above 60MPa; the plunger pump adopts an inclined plate axial piston pump structure with a small moment of inertia, and is particularly suitable for working conditions of high-frequency switching of the main shaft forward and reverse rotations. When applied to a servo pump-controlled volumetric speed regulation system, a smaller moment of inertia can achieve a higher response speed; the distribution plate also serves as the end cover of the pump, and compared with conventional products, it lacks the internal leakage link on the back of the distribution plate, and the distribution surface of the distribution plate and the cylinder body is a spherical distribution surface, the spherical surface has a self-centering function, and the sealing effect of the distribution surface is better, so the volumetric efficiency is higher; the two waist-shaped distribution windows of the distribution plate are connected to the inlet and outlet ports respectively through 3 or more distribution channels, while ensuring the flow area, the partitions between the multiple distribution channels are actually It plays the role of a reinforcing rib, so the distribution plate has better rigidity, the spherical deformation of the distribution plate is smaller under ultra-high pressure, and the sealing performance is better; the distribution plate also serves as an end cover. If the second bearing is installed on the distribution plate, the distance between the two bearing support points of the main shaft is shorter. Therefore, the main shaft has better bending rigidity under the same shaft diameter. When the radial force exerted on the plunger assembly acts on the main shaft through the cylinder body, the flexural deformation of the main shaft is smaller, which can avoid the cylinder body rotating with the main shaft due to large deflection and rotation, resulting in poor sealing of the distribution surface; if the inclination angle of the swash plate does not exceed 13°, the radial force exerted on the plunger assembly under the same pressure is reduced, which can ensure that the contact pressure and contact work ratio between the plunger assembly and the cylinder body hole under ultra-high pressure conditions do not exceed the allowable limit of the material; on the other hand, smaller radial force can further reduce the bending deformation of the main shaft.

[0018] The beneficial effects of the present invention are:

[0019] The structure of the four-quadrant ultra-high pressure plunger pump of the present invention is a spherical flow distribution inclined plate axial plunger pump, which can adapt to four-quadrant working conditions and ultra-high pressure working conditions above 60MPa. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a structural cross-sectional view of Embodiment 1 of the present invention;

[0021] Figure 2 It is a front view of the distribution plate of Example 1 of the present invention;

[0022] Figure 3 It is a cross-sectional view of the distribution plate along the XX direction of Example 1 of the present invention;

[0023] Figure 4 It is a front view of the distribution plate of Example 2 of the present invention;

[0024] In the figure: 1, main shaft, 2, housing, 3, first bearing, 4, inclined plate, 5, plunger return and cylinder pre-tensioning device, 5.1, ball joint, 5.2, return plate, 5.3, spring, 6, plunger assembly, 7, cylinder, 7-1, transition channel, 8, second bearing, 9, distribution plate, 9-1, pump oil inlet / outlet, 9-2, pump oil outlet / inlet, 9-3, oil drain port, 9-4, first waist-shaped distribution window, 9-4-1, first distribution channel, 9-5, second waist-shaped distribution window, 9-5-1, second distribution channel, 9-6, bearing hole, 9-7, shock-absorbing groove, 9-8, shock-absorbing blind hole, 10, shaft seal, 11, sealing ring. DETAILED DESCRIPTION

[0025] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0026] Embodiment 1:

[0027] like Figure 1 , Figure 2 and Figure 3 As shown, the four-quadrant ultra-high pressure plunger pump of the present invention includes a main shaft 1, a housing 2, a first bearing 3, a swash plate 4, a plunger return and cylinder pre-compression device 5, seven plunger assemblies 6, a cylinder 7, a second bearing 8, a distribution plate 9, a shaft seal 10 and a sealing ring 11.

[0028] The plunger return and cylinder pre-compression device 5 includes a return plate 5.1, a ball joint 5.2 and a spring 5.3, and its function is to provide a return force for the plunger assembly 6 and a pre-compression elastic force for the cylinder 7. The left end of the spring 5.3 presses the sliding shoe of the plunger assembly 6 through the ball joint 5.2 and then through the return plate 5.1, so that the sliding shoe plane keeps in contact with the plane of the swash plate 4; at the same time, the right side of the spring 5.3 acts on the rear end of the cylinder 7, and the spring force also provides a pre-compression elastic force for the cylinder 7, so that the spherical surface of the cylinder 7 keeps in contact with the spherical surface of the distributor 9.

[0029] The structure of the plunger return and cylinder pre-tensioning device 5 adopted in this embodiment can ensure that the plane of the sliding shoe remains in contact with the plane of the inclined plate 4 under the action of the spring force when the return plate 5.1 or the sliding shoe is worn, that is, it has a wear compensation function. However, the plunger return and cylinder pre-tensioning device can also adopt other solutions, such as adding an end surface limit device to the return plate 5.1, so that the return plate 5.1 and the sliding shoe maintain a small gap close to zero, which can also ensure that the plane of the sliding shoe remains in contact with the plane of the inclined plate 4, providing a return force for the plunger assembly 6; at the same time, the ball joint 5.2 is eliminated, the left end of the spring 5.3 acts on the main shaft 1, and the right end of the spring 5.3 acts on the tail of the cylinder 7 to provide a pre-tensioning elastic force for the cylinder 7. Alternatively, on the basis of the plunger return and cylinder pre-tensioning device in Example 1, an end surface limit device can be added to the return plate 5.1 to improve the return reliability of the plunger assembly 6.

[0030] The distribution plate 9 also has the function of the pump end cover, and the distribution plate 9 is coaxially fixedly installed on the housing 1. In this embodiment, the distribution plate 9 and the housing 1 are fastened by 4 screws. The distribution plate 9 also has the function of the pump end cover, that is, the distribution plate 9 and the pump end cover are integrated. This design has the following advantages: First, compared with conventional products, there is no internal leakage link between the back of the distribution plate 9 and the end cover, so the plunger pump has a higher volumetric efficiency, and the volumetric efficiency decreases less under ultra-high pressure conditions. In other words, it is more suitable for ultra-high pressure conditions. Second, the bearing hole 9-6 is set on the distribution plate 9, and the support center of the second bearing 8 is closer to the support center of the first bearing 3, so the distance between the two bearing support points of the main shaft 1 is shorter, so the bending rigidity of the main shaft 1 is better under the same shaft diameter, and when the radial force of the plunger assembly 6 acts on the main shaft 1 through the cylinder body 7, the flexural deformation of the main shaft 1 is smaller, which can avoid the cylinder body 7 from rotating with the main shaft 1 and causing poor sealing of the distribution surface, which can effectively improve the pressure level of the plunger pump and effectively improve the volumetric efficiency under ultra-high pressure conditions. In conventional products, the second bearing 8 is set on the end cover, and the main shaft 1 passes through the distribution plate 9 and then inserts the second bearing 8, so the distance between the two bearing support points of the main shaft 1 is larger, which is obvious.

[0031] The distribution surface of the distribution plate 9 is an outer convex spherical surface, and the distribution surface of the cylinder body 7 is an inner concave spherical surface. The inner concave spherical surface and the outer convex spherical surface have the same radius, both of which are SR. The two are coupled and matched. In specific implementation, the distribution plate 9 and the distribution spherical surface of the cylinder body 7 are usually ground in pairs to ensure the sealing performance of the distribution surface.

[0032] The flow distribution surface shapes of the cylinder body 7 and the distribution plate 9 are in two forms: plane flow distribution and spherical flow distribution. The plane flow distribution form has low processing cost, but when the cylinder body 7 is subjected to the overturning moment, a wedge-shaped gap will be formed between the flow distribution surface of the cylinder body 7 and the flow distribution surface of the distribution plate 9, and the leakage of the flow distribution surface will increase. The higher the pressure, the more obvious this disadvantage is; the spherical flow distribution has high processing cost, but when the cylinder body 7 is subjected to the overturning moment, the flow distribution spherical surface of the cylinder body 7 can automatically align with the flow distribution spherical surface of the distribution plate 9, so the sealing performance of the flow distribution surface is better, and it is more suitable for ultra-high pressure conditions.

[0033] A bearing hole 9-6 and two waist-shaped flow distribution windows 9-4 and 9-5 are arranged on one side of the flow distribution surface of the flow distribution plate 9. The two waist-shaped flow distribution windows 9-4 and 9-5 are symmetrically arranged and their distribution circles are coaxial with the bearing hole 9-6. The flow distribution plate 9 is also provided with an oil inlet / outlet port 9-1 and an oil inlet / outlet port 9-2. The oil port 9-1 is connected to the first waist-shaped flow distribution window 9-4 through five parallel first flow distribution channels 9-4-1, and the oil port 9-2 is connected to the second waist-shaped flow distribution window 9-5 through five parallel second flow distribution channels 9-5-1.

[0034] The plunger pump has clockwise and counterclockwise rotation conditions. Looking toward the shaft end: when the main shaft 1 rotates clockwise, the first waist-shaped distribution window 9-4 is an oil suction window and the second waist-shaped distribution window 9-5 is an oil discharge window. The first waist-shaped distribution window 9-4 absorbs oil from the outside through five parallel first distribution channels 9-4-1 and then through the oil port 9-1, and the second waist-shaped distribution window 9-5 discharges oil to the outside through five parallel second distribution channels 9-5-1 and then through the oil port 9-2; when the main shaft 1 rotates counterclockwise, the second waist-shaped distribution window 9-5 is an oil suction window and the first waist-shaped distribution window 9-4 is an oil discharge window. The second waist-shaped distribution window 9-5 absorbs oil from the outside through five parallel second distribution channels 9-5-1 and then through the oil port 9-2, and the first waist-shaped distribution window 9-4 discharges oil to the outside through five parallel first distribution channels 9-4-1 and then through the oil port 9-1.

[0035] In this embodiment, the distribution channels 9-4-1 and 9-5-1 in the two waist-shaped distribution windows 9-4 and 9-5 are five parallel cylindrical holes, and the walls between the holes actually play the role of reinforcing ribs. The reason why the number of distribution channels 9-4-1 and 9-5-1 is emphasized to be 3 or more in the invention content is because a plurality of evenly spaced reinforcing ribs can be formed on the distribution window channels designed in this way, which effectively improves the pressure bearing capacity and rigidity of the distribution plate 9 to adapt to ultra-high pressure conditions. Even under ultra-high pressure conditions, the stress deformation of the distribution sphere of the distribution plate 9 is very small, the sealing performance of the distribution surface is better, and the volumetric efficiency is higher.

[0036] Both ends of the two waist-shaped distribution windows 9-4 and 9-5 are provided with damping grooves 9-7 or damping holes connected to the corresponding distribution windows 9-4 and 9-5 to reduce the pressure shock when the plunger cavity switches between high and low pressures, and reduce noise and vibration. There are many specific forms of the damping grooves 9-7 or damping holes, such as the triangular grooves with gradually changing cross-sections, or stepped arc grooves, or throttling holes in this embodiment. The various forms of the damping grooves 9-7 are common knowledge to those skilled in the art and will not be repeated here.

[0037] There are 7 plunger holes evenly distributed on the circumference of the cylinder body 7, and each plunger hole is installed with a plunger assembly 6. The bottom of the plunger hole passes through the distribution surface through the transition channel 7-1. Compared with using an even number of plunger assemblies 6, the flow pulsation is smaller when an odd number of plunger assemblies 6 is used. The more the number of plunger assemblies 6, the smaller the flow pulsation. The common number of plunger assemblies 6 is 7 or 9, and a few products use 5 or 11 plunger assemblies 6.

[0038] The plunger assembly 6 comprises a plunger body and a sliding shoe, which are spherically hinged. In this embodiment, a ball head is arranged on the plunger body and a ball socket is arranged on the sliding shoe; however, the ball socket may be arranged on the plunger body and the ball head may be arranged on the sliding shoe, and both have their own advantages and disadvantages.

[0039] The housing 2 is fixedly mounted with a first bearing 3, and the distribution plate 9 is fixedly mounted with a second bearing 8. The second bearing 8 mounted on the distribution plate 9 is preferably a needle bearing or a cylindrical roller bearing, because under the same load-bearing capacity, the outer diameter of the needle bearing or the roller bearing is smaller than the outer diameter of the ball bearing, so that the wall thickness between the distribution channels 9-4-1, 9-5-1 of the distribution plate 9 and the bearing hole 9-6 is thicker, the distribution plate 9 is more rigid, the distribution sphere surface deformation is smaller under ultra-high pressure conditions, and the distribution surface seal is more reliable.

[0040] The two ends of the main shaft 3 are supported by the first bearing 3 and the second bearing 8 respectively. The cylinder body 7 is coaxially mounted on the main shaft 3. The cylinder body 7 and the main shaft 1 are splined. The spline is usually an involute spline, and the internal spline and the external spline are clearance fit. In this way, the cylinder body 7 can deflect relatively slightly relative to the main shaft 1 to compensate for the flexible deformation of the main shaft 1 when it is subjected to radial force, ensuring that the distribution surface of the cylinder body 7 is in close contact with the distribution surface of the distribution plate 9.

[0041] The plunger pump in this embodiment is a fixed displacement pump, and the inclination angle of the swash plate 4 is fixed. The swash plate 4 is installed in the inner cavity of the housing 2. To prevent the swash plate 4 from rotating, a stop pin or other anti-rotation device is required. However, the scheme described in the present invention is also applicable to a variable displacement pump, and the angle of the swash plate 4 is adjustable. When applied to a variable displacement pump, a variable displacement mechanism and a variable displacement control valve are also required.

[0042] Whether it is a fixed displacement pump or a variable displacement pump, the maximum inclination angle of the swash plate 4 is not greater than 13°. The angle of the swash plate 4 of a conventional plunger pump is generally 17° to 21°. The present invention limits the angle of the swash plate 4 to no more than 13°, which is proposed for ultra-high pressure conditions above 60MPa. The higher the required pressure level, the smaller the recommended angle of the swash plate 4. The reason is that the plunger assembly 6 of the swash plate plunger pump will bear a large radial force, which is proportional to the pressure and the tangent value of the inclination angle of the swash plate 4. If the angle of the swash plate 4 is taken according to the conventional product value, when it is applied to ultra-high pressure conditions, on the one hand, the contact stress between the plunger body and the plunger hole of the assembly 6 is too large, and the contact specific work is too large, which not only leads to aggravated wear and shortened service life, but also may be stuck because the contact stress and contact specific work exceed the allowable limit of the material; on the other hand, the weak point of the plunger assembly 6 is at its neck. The larger the angle of the swash plate 4, the larger the relative swing angle between the plunger body and the sliding shoe is required, and the smaller the neck diameter is, which is easy to cause excessive stress at the neck and break when applied to ultra-high pressure conditions.

[0043] The plunger pump in this embodiment is suitable for installation outside the oil tank. A rotating dynamic seal (shaft seal 10) is also installed between the housing 2 and the main shaft 1, and a static seal (sealing ring 11) is installed between the housing 2 and the distribution plate 9; the distribution plate 9 is also provided with an oil drain port 9-3 connected to the inner cavity of the housing 2, and the oil drain port 9-3 can also be set on the housing 2.

[0044] However, when the plunger pump is installed inside the oil tank, the rotating dynamic seal and the static seal can be eliminated; further, if the circumferential gap between the housing 2 and the main shaft 1 is large enough, the oil in the pump housing cavity can pass through the gap between the bearing steel balls or rollers and then through the circumferential gap between the housing 2 and the main shaft 1 to connect to the oil tank, and the oil drain port 9-3 may not be set on the distribution plate 9 or the housing 2.

[0045] Embodiment 2:

[0046] like Figure 4 As shown, another embodiment of the distribution plate 9 of the present invention is shown. Compared with the embodiment 1, the transition zones of the top dead center and the bottom dead center of the distribution plate 9 are further provided with a plurality of shock-absorbing blind holes 9-8, respectively, and the remaining structural features are the same as those of the embodiment 1. When the plunger pump works under ultra-high pressure conditions, the pressure difference between the distribution windows 9-4 and 9-5 on both sides of the distribution plate 9 is too large, and the pressure shock is large when the plunger cavity switches between high and low pressures. On the basis of providing the shock-absorbing groove 9-7 or the shock-absorbing hole, the shock-absorbing blind hole is added to the transition zone, which can play the role of a hydraulic spring and help reduce vibration and noise.

[0047] The above description of the disclosed embodiments enables those skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A four-quadrant ultra-high pressure plunger pump, comprising a main shaft (1), a housing (2), a first bearing (3), a swash plate (4), a plunger return and cylinder pre-compression device (5), an odd number of plunger assemblies (6), a cylinder (7), a second bearing (8) and a port plate (9), characterized in that: The distribution plate (9) also has the function of a pump end cover, and the distribution plate (9) is coaxially mounted on the housing (2); The distribution surface of the distribution plate (9) is an outer convex spherical surface. A bearing hole (9-6) and waist-shaped distribution windows (9-4, 9-5) are arranged on one side of the distribution surface of the distribution plate (9). The waist-shaped distribution windows (9-4, 9-5) are symmetrically arranged and their distribution circles are coaxial with the bearing hole (9-6). The distribution plate (9) is also provided with a pump inlet / outlet port (9-1) and a pump outlet / inlet port (9-2). Each waist-shaped distribution window (9-4, 9-5) has three or more The parallel flow distribution channels (9-4-1, 9-5-1) are connected in parallel, the pump oil inlet / outlet (9-1) is connected to the first waist-shaped flow distribution window (9-4) through each first flow distribution channel (9-4-1), the pump oil outlet / inlet (9-2) is connected to the second waist-shaped flow distribution window (9-5) through each second flow distribution channel (9-5-1), and both ends of the waist-shaped flow distribution windows (9-4, 9-5) are provided with correspondingly connected damping grooves (9-7) or damping holes; The flow distribution surface of the cylinder body (7) is an inner concave spherical surface, the radius of the inner concave spherical surface of the cylinder body (7) is equal to the radius of the outer convex spherical surface of the flow distribution plate (9), an odd number of plunger holes are evenly distributed on the circumference of the cylinder body (7), and the bottom of each plunger hole passes through its flow distribution surface through a transition channel (7-1) opened in the cylinder body (7); The housing (2) is provided with a first bearing (3), the distribution plate (9) is provided with a second bearing (8), the two ends of the main shaft (1) are supported by the first bearing (3) and the second bearing (8), respectively, the cylinder body (7) is coaxially sleeved on the main shaft (1), the cylinder body (7) and the main shaft (1) are spline-connected, the distribution surface of the cylinder body (7) contacts the distribution surface of the distribution plate (9), and the cylindrical ends of the odd-numbered plunger assemblies (6) are respectively slidably mounted on the main shaft (1). Installed in the plunger holes evenly distributed on the circumference of the cylinder body (7), the end faces of the sliding shoes of the odd number of plunger assemblies (6) are in contact with the working surface of the swash plate (4), and the plunger return and cylinder body pre-compression device (5) is installed between each plunger assembly (6) and the cylinder body (7) to provide a return force for each plunger assembly (6) and a pre-compression elastic force for the cylinder body (7), so that the end face of the sliding shoe and the working surface of the swash plate (4) are kept in contact, and the distribution surface of the cylinder body (7) and the distribution surface of the distribution plate (9) are kept in contact; The maximum inclination angle α of the swash plate (4) is no greater than 13°.

2. A four-quadrant ultra-high pressure plunger pump according to claim 1, characterized in that: The inclination angle of the swash plate (4) is a fixed angle or a variable angle.

3. A four-quadrant ultra-high pressure plunger pump according to claim 1, characterized in that: The upper dead point transition zone and the lower dead point transition zone of the distribution plate (9) are also respectively provided with a plurality of shock-absorbing blind holes (9-8).

4. A four-quadrant ultra-high pressure plunger pump according to claim 1, characterized in that: The second bearing (8) installed on the distribution plate (9) is a needle roller bearing or a cylindrical roller bearing.

5. A four-quadrant ultra-high pressure plunger pump according to claim 1, characterized in that: A shaft seal (10) is installed between the housing (2) and the main shaft (1) as a rotating dynamic seal, a sealing ring (11) is installed between the housing (2) and the distribution plate (9) as a static seal, and an oil drain port (9-3) is provided on the distribution plate (9) or on the housing (2).

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