Low-pressure pulsation hydraulic pump flow distribution mechanism and hydraulic pump

Abstract

The invention relates to the technical field of hydraulic pumps, in particular to a low-pressure pulsation hydraulic pump flow distribution mechanism and a hydraulic pump. The low-pressure pulsation hydraulic pump flow distribution mechanism comprises a flow distribution plate unit and a buffer unit. The valve plate unit comprises a valve plate body; the valve plate body is disc-shaped; an oil absorption area, a pressure increasing transition area, an oil discharging area and a pressure reducing transition area are sequentially distributed on the valve plate body in the circumferential direction of the valve plate body. First damping holes are formed in the valve plate body; the first damping holes are located in the boosting transition area. The buffer unit comprises a buffer shell; a buffer accommodating cavity is formed in the buffer shell; an oil inlet and an oil outlet are formed in the buffer shell; the oil liquid inlet is communicated with the buffer accommodating cavity; the oil liquid outlet is communicated with the buffer accommodating cavity; the first damping hole is communicated with the oil liquid inlet; and the oil liquid outlet is communicated with the oil discharge area. In this way, the problem that the pressure pulsation restraining effect of the hydraulic pump is poor in the oil discharging and oil discharging process is solved.

Description

Technical Field

[0001] The present invention relates to the technical field of hydraulic pumps, and in particular, to a flow distribution mechanism and a hydraulic pump for a low-pressure pulsation hydraulic pump. Background Art

[0002] The core components of a hydraulic pump include a plunger pair, a swash plate mechanism, and a flow distribution system of a distribution plate. The hydraulic pump adjusts the swash plate angle to drive the plunger rod of the hydraulic pump to reciprocate in the cylinder block hole, and cooperates with the oil suction port and the oil discharge port on the distribution plate to realize the processes of oil suction and oil discharge, thereby completing the directional transportation of hydraulic oil. The plunger pair and the cylinder block hole adopt a high-precision fit clearance design, and can maintain a stable working state under high-pressure conditions.

[0003] However, in the current hydraulic pump, pressure pulsation will occur during the oil discharge and oil outlet processes. The pressure pulsation phenomenon is mainly caused by the coupling effect of the flow rate fluctuation generated by the periodic movement of the plunger and the instantaneous impact during the flow distribution process of the distribution plate. At the same time, the flow rate superposition effect generated by the cooperative work of multiple plungers will exacerbate the pressure oscillation caused by the compressibility of the oil under high-pressure difference conditions, resulting in limited pressure pulsation suppression effect, and it is difficult to meet the increasingly stringent requirements of the aerospace field for the integration, light weight, and low-pressure pulsation of hydraulic pumps. Summary of the Invention

[0004] To solve the problem of poor pressure pulsation suppression effect of the hydraulic pump during the oil discharge and oil outlet processes, the present invention provides a flow distribution mechanism and a hydraulic pump for a low-pressure pulsation hydraulic pump.

[0005] In a first aspect, the present invention provides a flow distribution mechanism for a low-pressure pulsation hydraulic pump, and the flow distribution mechanism for a low-pressure pulsation hydraulic pump includes: A distribution plate unit, the distribution plate unit includes a distribution plate body; the distribution plate body is in a disc shape; the distribution plate body is sequentially provided with an oil suction area, a pressure boosting transition area, an oil discharge area, and a pressure reducing transition area along its circumferential direction; the distribution plate body has a first damping hole; the first damping hole is located in the pressure boosting transition area; the length of the pressure boosting transition area in the circumferential direction of the distribution plate is a first arc length; in the circumferential direction of the distribution plate, the interval distance between the first damping hole and the oil discharge area is a second arc length; the second arc length is less than half of the first arc length; both the oil suction area and the oil discharge area extend along the circumferential direction of the distribution plate; the width direction of the oil suction area and the oil discharge area is the radial direction of the distribution plate; the diameter of the first damping hole is less than the width of the oil discharge area; A buffer unit, the buffer unit includes a buffer housing; a buffer cavity is provided inside the buffer housing; an oil inlet and an oil outlet are provided on the buffer housing; the oil inlet is communicated with the buffer cavity; the oil outlet is communicated with the buffer cavity; the first shock absorption hole is communicated with the oil inlet; the oil outlet is communicated with the oil drainage area.

[0006] In some embodiments, the buffer cavity includes a first buffer cavity; the diameter of the first buffer cavity is larger than the diameter of the oil inlet; the diameter of the first buffer cavity is larger than the diameter of the oil outlet; the oil inlet is communicated with the first buffer cavity; the oil outlet is communicated with the first buffer cavity; the oil inlet is located at one end of the first buffer cavity.

[0007] In some embodiments, the buffer unit further includes a first rectifying cap; the first rectifying cap is located inside one end of the first buffer cavity close to the oil inlet; the first rectifying cap is detachably connected to the buffer housing; the first rectifying cap includes a first fixing part, a first avoiding part and a first sealing part; the first fixing part, the first avoiding part and the first sealing part are integrally formed and connected; the first avoiding part is located between the first fixing part and the first sealing part; the first fixing part is detachably connected to the inner wall of the first buffer cavity; the first sealing part is in interference fit with the inner wall of the first buffer cavity; an annular first avoiding cavity is formed between the first avoiding part and the inner wall of the first buffer cavity; the first fixing part is located on one side of the first sealing part facing the middle of the first buffer cavity; the first avoiding cavity is communicated with the oil inlet; The first fixing part and the first avoiding part are hollow; the inner cavity of the first fixing part is communicated with the inner cavity of the first avoiding part; the inner cavity of the first fixing part is communicated with the first buffer cavity; a plurality of rectifying holes are formed in the first avoiding part; the plurality of rectifying holes are distributed around the inner cavity of the first avoiding part; the first avoiding cavity is communicated with the inner cavity of the first avoiding part through the plurality of rectifying holes.

[0008] In some embodiments, the buffer cavity further includes a second buffer cavity and a first through hole; the second buffer cavity is communicated with the first buffer cavity through the first through hole; the diameter of the second buffer cavity is larger than the diameter of the first through hole; the diameter of the first buffer cavity is larger than the diameter of the first through hole; the first buffer cavity is communicated with the oil outlet through the second buffer cavity; the diameter of the oil outlet is smaller than the diameter of the second buffer cavity.

[0009] In some embodiments, the diameter of the oil inlet is smaller than the diameter of the first through hole.

[0010] In some embodiments, the buffer cavity further includes a third buffer cavity; the third buffer cavity communicates with the second buffer cavity; the length direction of the third buffer cavity is perpendicular to the length direction of the second buffer cavity; one end of the second buffer cavity communicates with the third buffer cavity; the diameter of the third buffer cavity is greater than the diameter of the second buffer cavity.

[0011] In some embodiments, the buffer unit further includes a throttling member; the throttling member is blocked between the third buffer cavity and the oil outlet; the throttling member includes a throttle plate; the throttle plate is detachably connected to the buffer housing; a throttle hole is formed in the throttle plate; the third buffer cavity communicates with the oil outlet through the throttle hole; the minimum diameter of the throttle hole is smaller than the diameter of the oil outlet.

[0012] In some embodiments, the buffer unit further includes a second rectifying cap; the second rectifying cap includes a second avoiding portion, a second sealing portion and a second fixing portion; the second avoiding portion, the second sealing portion and the second fixing portion are integrally formed and connected; the second sealing portion is located between the second avoiding portion and the second fixing portion; the second sealing portion is in interference fit with the buffer housing; the second fixing portion is detachably connected to the buffer housing; a limiting shoulder is provided at the end of the third buffer cavity close to the oil outlet; the throttle plate is clamped between the limiting shoulder and the second avoiding portion; a second avoiding cavity is provided between the second avoiding portion and the buffer housing; the second avoiding cavity communicates with the oil outlet; the second avoiding portion is hollow; a second communication hole is formed in the second avoiding portion; the inner cavity of the second avoiding portion communicates with the second avoiding cavity through the second communication hole; the inner cavity of the second avoiding portion and the third buffer cavity communicate through the throttle hole.

[0013] In some embodiments, in the length direction of the third buffer cavity, the distance from the communicating portion of the second buffer cavity and the third buffer cavity to the throttle plate is a first distance, and the distance from the end of the third buffer cavity far from the throttle plate to the throttle plate is a second distance; the ratio of the first distance to the second distance is between 0.15 and 0.3.

[0014] In some embodiments, the buffer cavity further includes a third buffer cavity and a second through hole; the third buffer cavity communicates with the second buffer cavity through the second through hole; the diameter of the second through hole is smaller than the diameter of the second buffer cavity; the diameter of the second through hole is smaller than the diameter of the third buffer cavity; the second buffer cavity communicates with the oil outlet through the third buffer cavity; the diameter of the oil outlet is smaller than the diameter of the third buffer cavity.

[0015] In some embodiments, the diameter of the first through hole is smaller than the diameter of the second through hole.

[0016] In a second aspect, the present invention provides a hydraulic pump, which comprises: a low-pressure pulsation hydraulic pump flow distribution mechanism as described in any one of the first aspects; a housing, wherein the low-pressure pulsation hydraulic pump flow distribution mechanism is located within the housing; the low-pressure pulsation hydraulic pump flow distribution mechanism is detachably connected to the housing; a rotor, which is located within the housing; the rotor is rotatably connected to the housing; the rotor is coaxial with the flow distribution disc; the rotation direction of the rotor is the direction in which the oil suction area, the pressure boosting transition area, the oil discharge area, and the pressure reducing transition area are arranged in sequence.

[0017] To solve the problem that the effect of suppressing pressure pulsation during the oil discharge and oil outlet processes of the hydraulic pump is not good, the present invention has the following advantages: Through the oil suction area, the pressure boosting transition area, the oil discharge area, and the pressure reducing transition area provided on the flow distribution disc body, combined with the oil liquid outlet communication structure formed by the sequential connection of the first shock absorption hole, the buffer unit, and the oil discharge area located in the pressure boosting transition area, a parallel branch to the oil discharge path is formed during the rotation of the flow distribution disc body. When the plunger cavity approaches the oil discharge area as the rotor rotates, before the plunger cavity communicates with the oil discharge area, the first shock absorption hole is connected in advance, and throttling oil replenishment is carried out through the first shock absorption hole structure with a diameter smaller than the width of the oil discharge area, so that the high-pressure oil liquid in the oil discharge area is pressure buffered through the buffer cavity and then replenishes the oil pressure in the plunger cavity. This process enables the plunger cavity to complete the pressure boosting transition before entering the oil discharge area, establishes pressure balance through the communication path between the buffer housing oil liquid inlet and the oil discharge area, effectively reduces the sudden change in pressure difference at the moment when the plunger cavity communicates with the oil discharge area, thereby effectively suppressing the pressure pulsation problem generated during the transition of the plunger cavity of the hydraulic pump from the oil suction port to the oil discharge port, improving the operation stability of the hydraulic pump, and extending the service life. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 shows a schematic diagram of a low-pressure pulsation hydraulic pump flow distribution mechanism of an embodiment; Figure 2 shows Figure 1 the schematic diagram of the buffer unit in Figure 3 shows Figure 1 the schematic diagram of the flow distribution disc unit in Figure 4 shows Figure 2 the cross-sectional view of the first buffer cavity and the second buffer cavity in Figure 5 shows Figure 2 the cross-sectional view of the third buffer cavity in

[0019] Reference numerals: flow distribution plate unit 10; flow distribution plate body 11; oil suction area 12; oil discharge area 13; boost transition area 14; pressure reduction transition area 15; first shock absorption hole 16; second shock absorption hole 17; buffer unit 20; buffer housing 21; buffer cavity 22; first buffer cavity 221; second buffer cavity 222; first communication hole 223; third buffer cavity 224; second communication hole 225; oil inlet 23; oil outlet 24; first rectifying cap 25; first sealing portion 251; first avoidance portion 252; first fixing portion 253; first avoidance cavity 254; throttling member 26; throttle plate 261; throttle hole 262; second rectifying cap 27; second avoidance portion 271; second sealing portion 272; second fixing portion 273; second avoidance cavity 274. Detailed implementation manners

[0020] The present disclosure will now be described with reference to several exemplary embodiments. It should be understood that these embodiments are described only to enable those of ordinary skill in the art to better understand and thus implement the present disclosure, rather than implying any limitation on the scope of the present disclosure.

[0021] As used herein, the term "comprising" and its variants are to be construed as open-ended terms meaning "including but not limited to". The term "based on" is to be construed as "at least partially based on". The terms "one embodiment" and "an embodiment" are to be construed as "at least one embodiment". The term "another embodiment" is to be construed as "at least one other embodiment". The orientation or positional relationships indicated by the terms "upper", "lower", "left", "right", "front", "rear", "top", "bottom", "inner", "outer", "vertical", "horizontal", "lateral", "longitudinal", etc. are based on the orientation or positional relationships shown in the drawings. These terms are mainly used to better describe the present application and its embodiments, and are not used to limit that the indicated devices, elements or components must have a specific orientation, or be constructed and operated in a specific orientation. Moreover, in addition to being able to represent orientation or positional relationships, some of the above terms may also be used to represent other meanings. For example, the term "upper" may also be used to represent a certain attachment relationship or connection relationship in some cases. For those of ordinary skill in the art, the specific meanings of these terms in the present application can be understood according to specific circumstances. In addition, the terms "mounted", "arranged", "provided with", "connected", "coupled" should be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, or an integral structure; it may be a mechanical connection or an electrical connection; it may be directly connected, or indirectly connected through an intermediate medium, or there may be internal communication between two devices, elements or components. For those of ordinary skill in the art, the specific meanings of the above terms in the present application can be understood according to specific circumstances. In addition, the terms "first", "second", etc. are mainly used to distinguish different devices, elements or components (the specific types and structures may be the same or different), and are not used to indicate or imply the relative importance and quantity of the indicated devices, elements or components. Unless otherwise specified, the meaning of "a plurality" is two or more.

[0022] In this embodiment, during the operation of the hydraulic pump, when the oil fluid enters the oil discharge area 13 from the oil suction area 12 through the pressure boosting transition area 14, due to the significant pressure difference between the oil discharge area 13 and the oil suction area 12, a pressure mutation is likely to occur at the moment when the plunger chamber is connected to the oil discharge area 13. Therefore, to solve the above problems, the present invention provides a flow distribution mechanism for a low-pressure pulsation hydraulic pump. As Figure 1 shown, the flow distribution mechanism for a low-pressure pulsation hydraulic pump includes a flow distribution disk unit 10 and a buffer unit 20.

[0023] The distribution disk unit 10 includes a distribution disk body 11. The distribution disk body 11 is disc-shaped. Along the circumferential direction of the distribution disk body 11, an oil suction area 12, a pressure boosting transition area 14, an oil discharge area 13, and a pressure reducing transition area 15 are sequentially distributed. The pressure boosting transition area 14 is a transition area where the plunger cavity changes from communicating with the oil suction area 12 to communicating with the oil discharge area 13 during the rotation of the hydraulic pump rotor; the pressure reducing transition area 15 is a transition area where the plunger cavity changes from communicating with the oil discharge area 13 to communicating with the oil suction area 12 during the rotation of the hydraulic pump rotor. Through the disc-shaped structure design of the distribution disk, the sectional control of the oil flow direction is realized, and the oil flow channel is formed by the oil suction area 12 and the oil discharge area 13. The distribution disk body 11 has a first damping hole 16, and the first damping hole 16 is located in the pressure boosting transition area 14. By arranging the first damping hole 16 in the pressure boosting transition area 14, a structural basis can be provided for subsequent pressure buffering. The length of the pressure boosting transition area 14 in the circumferential direction of the distribution disk is the first arc length. In the circumferential direction of the distribution disk, the interval distance between the first damping hole 16 and the oil discharge area 13 is the second arc length, and the second arc length is less than half of the first arc length, that is, the first damping hole 16 is arranged close to the oil discharge area 13, and a pressure transition area is formed by the first damping hole 16. Both the oil suction area 12 and the oil discharge area 13 extend along the circumferential direction of the distribution disk, the width direction of the oil suction area 12 and the oil discharge area 13 is the radial direction of the distribution disk, and the diameter of the first damping hole 16 is smaller than the width of the oil discharge area 13, so that the pressure build-up of the plunger cavity is realized through the first damping hole 16 and the oil discharge area 13 with different sizes. First, the plunger cavity communicates with the first damping hole 16, and the first damping hole 16 with a larger throttling effect is used for slow pressure build-up, so that the oil pressure in the plunger cavity gradually approaches the oil discharge area 13, and then the pressure fluctuation at the moment when the plunger cavity communicates with the oil discharge area 13 is smaller. Until the oil pressure in the plunger cavity is close to the pressure in the oil discharge area 13, then the oil in the plunger cavity can be discharged to the oil discharge area 13 by the sliding of the plunger rod. The present invention uses the first damping hole 16 to perform a small amount of pre-supplementary oil to the plunger cavity, thereby realizing the preliminary pressure build-up of the plunger cavity and achieving the effect of suppressing the pressure pulsation at the moment when the plunger cavity communicates with the oil discharge area 13.

[0024] The buffer unit 20 includes a buffer shell 21. The buffer shell 21 has a buffer cavity 22, and a pressure regulating space is formed by the volume characteristics of the cavity inside the shell. The buffer shell 21 has an oil outlet 24 and an oil inlet 23. The oil outlet 24 is connected to the buffer cavity 22, the oil inlet 23 is connected to the buffer cavity 22, the first damping hole 16 is connected to the oil inlet 23, and the oil outlet 24 is connected to the oil discharge area 13. The plunger cavity, the first damping hole 16, the oil inlet 23, the buffer cavity 22, the oil outlet 24 and the oil discharge area 13 are connected to form a first communication path, and the direct connection between the oil plunger cavity and the oil discharge area 13 forms a second communication path. The first communication path and the second communication path constitute a parallel pressure buffer channel. This scheme sets a first shock-absorbing hole 16 in the boost transition zone 14 to work together with the buffer chamber to form a pre-boost branch before the plunger cavity is connected to the oil discharge area 13, and uses the shunt pressure compensation method to reduce the pressure mutation gradient, thereby reducing the pressure pulsation generated in the plunger cavity when the oil suction and oil discharge paths are switched.

[0025] In this embodiment, if Figure 4 As shown, the buffer chamber 22 includes a first buffer chamber 221. The diameter of the first buffer chamber 221 is greater than the diameter of the oil inlet 23 to form a volume buffer space, and the diameter of the first buffer chamber 221 is greater than the diameter of the oil outlet 24 to limit the throttling effect, so that the flow rate of the high-pressure oil is reduced when entering the first buffer chamber 221. The oil outlet 24 is connected to the first buffer chamber 221, and the oil inlet 23 is connected to the first buffer chamber 221. The oil inlet 23 is located at one end of the first buffer chamber 221. In this way, when the first damping hole 16 and the plunger cavity are pressurized, the layout of the oil inlet 23 at one end of the first buffer chamber 221, combined with the cross design of the length direction of the first buffer chamber 221 and the direction of the oil outlet 24, extends the flow path of the oil in the first buffer chamber 221. The throttling buffer structure formed by the first buffer chamber 221 causes the oil to produce a velocity attenuation in the first buffer chamber 221, and the pre-pressurization process of the oil being smoothly injected into the plunger cavity is realized in combination with the cavity length.

[0026] In this embodiment, if Figure 4As shown, the buffer unit 20 further includes a first rectifying cap 25. The first rectifying cap 25 is located inside one end of the first buffer chamber 221 close to the oil inlet 23, and the first rectifying cap 25 is detachably connected to the buffer housing 21. The first rectifying cap 25 includes a first fixing portion 253, a first avoiding portion 252, and a first sealing portion 251. The first fixing portion 253, the first avoiding portion 252, and the first sealing portion 251 are connected, and this connection can be a fixed connection or integrally formed. The first avoiding portion 252 is located between the first fixing portion 253 and the first sealing portion 251. The first fixing portion 253 is detachably connected to the inner wall of the first buffer chamber 221, and the first sealing portion 251 is in interference fit with the inner wall of the first buffer chamber 221 to form a pressure seal. There is an annular first avoiding cavity 254 between the first avoiding portion 252 and the inner wall of the first buffer chamber 221. The first fixing portion 253 is located on one side of the first sealing portion 251 facing the middle of the first buffer chamber 221, and the first avoiding cavity 254 communicates with the oil inlet 23.

[0027] The first fixing portion 253 and the first avoiding portion 252 are hollow. Combining the hollow structure of the first fixing portion 253 and the first avoiding portion 252, the interior communicates with the first buffer chamber 221 to construct a multi-stage fluid channel. The inner cavity of the first fixing portion 253 communicates with the inner cavity of the first avoiding portion 252. The inner cavity of the first fixing portion 253 communicates with the first buffer chamber 221. A plurality of rectifying holes are provided on the first avoiding portion 252, and the plurality of rectifying holes are distributed around the inner cavity of the first avoiding portion 252. The first avoiding cavity 254 communicates with the inner cavity of the first avoiding portion 252 through the plurality of rectifying holes. The oil is guided from the inner cavity of the first avoiding portion 252 to the avoiding cavity through the structure of the uniformly distributed plurality of rectifying holes. By utilizing the cooperation of the avoiding cavity and the rectifying holes, the oil experiences path changes of diffusion, contraction, and then diffusion during the flow process. The turbulent intensity is reduced through multi-stage shunting, and finally a smooth transition of the oil flow state is achieved, reducing the pressure pulsation generated when the oil discharge path is switched.

[0028] In this embodiment, as Figure 4As shown, the buffer cavity 22 further includes a second buffer cavity 222 and a first through hole. The second buffer cavity 222 communicates with the first buffer cavity 221 through the first through hole. The diameter of the second buffer cavity 222 is greater than the diameter of the first through hole, the diameter of the first buffer cavity 221 is greater than the diameter of the first through hole, the first buffer cavity 221 communicates with the oil outlet 24 through the second buffer cavity 222, and the diameter of the oil outlet 24 is less than the diameter of the second buffer cavity 222. By setting the structural parameter that the diameter of the second buffer cavity 222 is greater than that of the first through hole, a two-stage volume buffer space is formed. The communication path of the first buffer cavity 221 with the oil outlet 24 through the second buffer cavity 222, combined with the size design that the diameter of the oil outlet 24 is less than that of the second buffer cavity 222, constructs a stepped throttling structure. Thus, by using the series layout of the two-stage buffer cavities, the oil fluid passes through the cavity spaces of different sizes in sequence, and the pressure fluctuation energy is attenuated in multiple stages by gradually reducing the flow rate.

[0029] In some other embodiments, the length direction of the second buffer cavity 222 intersects with the length direction of the first communication hole 223, and the length direction of the first buffer cavity 221 intersects with the length direction of the first communication hole 223. Preferably, the length direction of the second buffer cavity 222 is perpendicular to the length direction of the first communication hole 223, and the length direction of the first buffer cavity 221 is perpendicular to the length direction of the first communication hole 223, so as to reduce the processing difficulty of the components. In another embodiment, the first buffer cavity 221 is parallel to the second buffer cavity 222, the length of the second buffer cavity 222 is greater than the length of the first communication hole 223, and the length of the first buffer cavity 221 is greater than the length of the first communication hole 223. The distribution disk body 11 has a second shock-absorbing hole 17; the second shock-absorbing hole 17 is located in the pressure-reducing transition area 15.

[0030] In this embodiment, as Figure 4 shown, the diameter of the oil inlet 23 can be set to be less than the diameter of the first through hole. By controlling the diameter relationship between the oil inlet 23 and the first through hole, a differential throttling gradient is formed, so that on the basis of the two-stage buffer structure, the oil pressure can achieve a smoother transition during the gradual attenuation process.

[0031] In this embodiment, as Figure 5 shown, the buffer cavity 22 further includes a third buffer cavity 224. The third buffer cavity 224 communicates with the second buffer cavity 222. The length direction of the third buffer cavity 224 is perpendicular to the length direction of the second buffer cavity 222. One end of the second buffer cavity 22 communicates with the third buffer cavity 224, and the diameter of the third buffer cavity 224 is greater than the diameter of the second buffer cavity 222. By setting the vertically distributed third buffer cavity 224 and the second buffer cavity 222 to form a vertical space layout, the independent hole-opening step in the processing procedure is reduced.

[0032] When the length direction of the third buffer cavity 224 is parallel to the length direction of the second buffer cavity 222, a parallel space layout is formed by arranging the first buffer cavity 221 and the second buffer cavity 222 in parallel distribution, thereby effectively optimizing the utilization rate of the internal space of the device.

[0033] In this embodiment, as Figure 5 shown, the buffer unit 20 further includes a throttling member 26. The throttling member 26 is blocked between the third buffer cavity 22 and the oil outlet 24. The throttling member 26 includes a throttle plate 261. The throttle plate 261 is detachably connected to the buffer housing 21. A throttle hole 262 is formed in the throttle plate 261. The third buffer cavity 22 communicates with the oil outlet 24 through the throttle hole 262. The minimum diameter of the throttle hole 262 is smaller than the diameter of the oil outlet 24. A secondary throttling effect is formed by the diameter difference between the throttle hole 262 and the oil outlet 24. A replaceable blocking structure is formed between the third buffer cavity 22 and the oil outlet 24, and a stepped attenuation of the oil pressure is realized through hierarchical throttling control. The diameter of the throttle hole 262 on the side facing the oil outlet 24 is larger than the diameter of the throttle hole 262 on the side facing the third buffer cavity 224 chamber, so as to guide the oil through the stepped throttle hole 262.

[0034] In this embodiment, as Figure 5 shown, the buffer unit 20 further includes a second rectifying cap 27. The second rectifying cap 27 includes a second avoiding portion 271, a second sealing portion 272 and a second fixing portion 273. The second avoiding portion 271, the second sealing portion 272 and the second fixing portion 273 are connected, and this connection can be a fixed connection or an integrally formed one. The second sealing portion 272 is located between the second avoiding portion 271 and the second fixing portion 273. Placing the detachable second fixing portion 273 at an outer position can avoid damaging the sealing part and prevent debris from entering the oil during disassembly and assembly. The second sealing portion 272 is in interference fit with the buffer housing 21 to form a pressure seal; the second fixing portion 273 is detachably connected to the buffer housing 21, which can be a threaded connection; a limiting shoulder is provided at the end of the third buffer cavity 22 close to the oil outlet 24; the throttle plate 261 is clamped between the limiting shoulder and the second avoiding portion 271. A second avoiding cavity 274 is formed between the second avoiding portion 271 and the buffer housing 21. The second avoiding cavity 274 communicates with the oil outlet 24. The second avoiding portion 271 is hollow, and a second communication hole 225 is formed in the second avoiding portion 271. The inner cavity of the second avoiding portion 271 communicates with the second avoiding cavity 274 through the second communication hole 225; the inner cavity of the second avoiding portion 271 and the third buffer cavity 22 communicate through the throttle hole 262. By using the cooperation of the hollow structure of the second avoiding portion 271 and the communication hole to form an auxiliary flow channel, combined with the constraint effect of the limiting shoulder, a functional structure with multiple seals and fluid guiding is constructed.

[0035] In this embodiment, asFigure 5 As shown, in the longitudinal direction of the third buffer chamber 224, the distance from the communication part between the second buffer chamber 222 and the third buffer chamber 224 to the throttle plate 261 is the first distance, and the distance from the end of the third buffer chamber 224 away from the throttle plate 261 to the throttle plate 261 is the second distance; the ratio of the first distance to the second distance is between 0.15 and 0.3. In this way, a pre-buffer area with a specific length is formed, so as to precisely control the residence time of the oil in the third buffer chamber 224 by using the distance ratio, and make the pressure fluctuation energy complete gradient attenuation within a specific space range.

[0036] In this embodiment, as Figure 5 shown, the buffer cavity 22 further includes a third buffer chamber 224 and a second through hole; the third buffer chamber 224 communicates with the second buffer chamber 222 through the second through hole; the diameter of the second through hole is smaller than the diameter of the second buffer chamber 222; the diameter of the second through hole is smaller than the diameter of the third buffer chamber 224; the second buffer chamber 222 communicates with the oil outlet 24 through the third buffer chamber 224; the diameter of the oil outlet 24 is smaller than the diameter of the third buffer chamber 224. By providing a second through hole to connect buffer cavities with different diameters, a three-stage throttling buffer structure is formed, so as to construct a gradually enhanced throttling effect by using the decreasing relationship of the diameters of the second through holes, and make the oil experience different intensity flow rate limiting processes in sequence, realizing the layered attenuation of pressure pulsation. In this embodiment, the communication part between the second buffer chamber 222 and the third buffer chamber 224 is at the end of the second buffer chamber 222, and in another embodiment, it is the second communication hole 225.

[0037] In this embodiment, as Figure 4 、 5 shown, the diameter of the first through hole is smaller than the diameter of the second through hole, so as to establish an asymmetric flow control channel between adjacent buffer cavities by using the combined relationship of through holes with decreasing diameters, and enhance the hierarchical effect of pressure buffering.

[0038] In this embodiment, the present invention provides a hydraulic pump, which includes a low-pressure pulsation hydraulic pump flow distribution mechanism, a housing, and a rotor as described in any one of the above embodiments.

[0039] The low-pressure pulsation hydraulic pump flow distribution mechanism is located in the housing, and the low-pressure pulsation hydraulic pump flow distribution mechanism is detachably connected to the housing.

[0040] The rotor is located in the housing, the rotor is rotatably connected to the housing, the rotor is coaxial with the distribution disk, and the rotation direction of the rotor is the direction in which the oil suction area 12, the pressure boost transition area 14, the oil discharge area 13, and the pressure reduction transition area 15 are arranged in sequence. Through the detachable connection design between the low-pressure pulsation hydraulic pump flow distribution mechanism and the housing, the maintainability is realized, and by using the spatial correspondence relationship between the rotor rotation direction and the functional partition of the distribution disk, it is ensured that the oil forms a continuous pressure transition when switching between partitions, so as to construct a complete hydraulic energy conversion system.

[0041] Those of ordinary skill in the art can understand that the above embodiments are specific examples for implementing the present disclosure, and in actual applications, various changes can be made to them in form and details without departing from the scope of the present disclosure.

Claims

1. A flow distribution mechanism for a low-pressure pulsation hydraulic pump, characterized in that, The flow distribution mechanism of the low-pressure pulsation hydraulic pump includes: A flow distribution disc unit, the flow distribution disc unit includes a flow distribution disc body; the flow distribution disc body is in a disc shape; the flow distribution disc body is sequentially provided with an oil suction area, a pressure boosting transition area, an oil discharge area, and a pressure reducing transition area along its circumferential direction; the flow distribution disc body has a first shock absorption hole; the first shock absorption hole is located in the pressure boosting transition area; the length of the pressure boosting transition area in the circumferential direction of the flow distribution disc is a first arc length; in the circumferential direction of the flow distribution disc, the interval distance between the first shock absorption hole and the oil discharge area is a second arc length; the second arc length is less than half of the first arc length; both the oil suction area and the oil discharge area extend along the circumferential direction of the flow distribution disc; the width direction of the oil suction area and the oil discharge area is the radial direction of the flow distribution disc; the diameter of the first shock absorption hole is less than the width of the oil discharge area. A buffer unit, the buffer unit includes a buffer housing; a buffer cavity is provided inside the buffer housing; the buffer housing has an oil inlet and an oil outlet; the oil inlet is communicated with the buffer cavity; the oil outlet is communicated with the buffer cavity; the first shock absorption hole is communicated with the oil inlet; the oil outlet is communicated with the oil discharge area.

2. The flow distribution mechanism of a low-pressure pulsation hydraulic pump according to claim 1, wherein The buffer cavity includes a first buffer cavity; the diameter of the first buffer cavity is larger than the diameter of the oil inlet; the diameter of the first buffer cavity is larger than the diameter of the oil outlet; the oil inlet is communicated with the first buffer cavity; the oil outlet is communicated with the first buffer cavity; the oil inlet is located at one end of the first buffer cavity.

3. The flow distribution mechanism of a low-pressure pulsation hydraulic pump according to claim 2, wherein The buffer unit further includes a first rectifying cap; the first rectifying cap is located inside the first buffer cavity near the oil inlet end; the first rectifying cap is detachably connected to the buffer housing; the first rectifying cap includes a first fixing portion, a first avoiding portion, and a first sealing portion; the first fixing portion, the first avoiding portion, and the first sealing portion are integrally formed and connected; the first avoiding portion is located between the first fixing portion and the first sealing portion; the first fixing portion is detachably connected to the inner wall of the first buffer cavity; the first sealing portion is in interference fit with the inner wall of the first buffer cavity; there is an annular first avoiding cavity between the first avoiding portion and the inner wall of the first buffer cavity. The first fixing portion is located on the side of the first sealing portion facing the middle of the first buffer cavity; the first avoiding cavity is communicated with the oil inlet. The first fixing portion and the first avoiding portion are hollow; the inner cavity of the first fixing portion is communicated with the inner cavity of the first avoiding portion; the inner cavity of the first fixing portion is communicated with the first buffer cavity; a plurality of rectifying holes are provided on the first avoiding portion; the plurality of rectifying holes are distributed around the inner cavity of the first avoiding portion; the first avoiding cavity is communicated with the inner cavity of the first avoiding portion through the plurality of rectifying holes.

4. The flow distribution mechanism of a low-pressure pulsation hydraulic pump according to claim 2, characterized in that the buffer cavity further includes a second buffer cavity and a first through hole; the second buffer cavity is communicated with the first buffer cavity through the first through hole; the diameter of the second buffer cavity is larger than that of the first through hole; the diameter of the first buffer cavity is larger than that of the first through hole; the first buffer cavity is communicated with the oil outlet through the second buffer cavity; the diameter of the oil outlet is smaller than that of the second buffer cavity.

5. The flow distribution mechanism of a low-pressure pulsation hydraulic pump according to claim 4, characterized in that the diameter of the oil inlet is smaller than that of the first through hole.

6. The flow distribution mechanism of a low-pressure pulsation hydraulic pump according to claim 5, characterized in that the buffer cavity further includes a third buffer cavity; the third buffer cavity is communicated with the second buffer cavity; the length direction of the third buffer cavity is perpendicular to the length direction of the second buffer cavity; one end of the second buffer cavity is communicated with the third buffer cavity; the diameter of the third buffer cavity is larger than that of the second buffer cavity.

7. The flow distribution mechanism of a low-pressure pulsation hydraulic pump according to claim 6, characterized in that the buffer unit further includes a throttling member; the throttling member is blocked between the third buffer cavity and the oil outlet; the throttling member includes a throttle plate; the throttle plate is detachably connected to the buffer housing; a throttle hole is formed in the throttle plate; the third buffer cavity is communicated with the oil outlet through the throttle hole; the minimum diameter of the throttle hole is smaller than that of the oil outlet.

8. The flow distribution mechanism of a low-pressure pulsation hydraulic pump according to claim 7, characterized in that the buffer unit further includes a second rectifying cap; the second rectifying cap includes a second avoiding portion, a second sealing portion and a second fixing portion; the second avoiding portion, the second sealing portion and the second fixing portion are integrally formed and connected; the second sealing portion is located between the second avoiding portion and the second fixing portion; the second sealing portion is in interference fit with the buffer housing; the second fixing portion is detachably connected to the buffer housing; a limiting shoulder is arranged at the end of the third buffer cavity close to the oil outlet; the throttle plate is clamped between the limiting shoulder and the second avoiding portion; a second avoiding cavity is formed between the second avoiding portion and the buffer housing; the second avoiding cavity is communicated with the oil outlet; the second avoiding portion is hollow; a second communication hole is formed in the second avoiding portion; the inner cavity of the second avoiding portion is communicated with the second avoiding cavity through the second communication hole; the inner cavity of the second avoiding portion and the third buffer cavity are communicated through the throttle hole.

9. The flow distribution mechanism of a low-pressure pulsation hydraulic pump according to claim 8, characterized in that In the longitudinal direction of the third buffer chamber, the distance from the communication part of the second buffer chamber and the third buffer chamber to the throttle plate is a first distance, and the distance from the end of the third buffer chamber away from the throttle plate to the throttle plate is a second distance; the ratio of the first distance to the second distance is between 0.15 and 0.

3.

10. A flow distribution mechanism for a low-pressure pulsation hydraulic pump according to claim 5, characterized in that the buffer chamber further includes a third buffer chamber and a second through hole; the third buffer chamber communicates with the second buffer chamber through the second through hole; the diameter of the second through hole is smaller than the diameter of the second buffer chamber; the diameter of the second through hole is smaller than the diameter of the third buffer chamber; the second buffer chamber communicates with the oil outlet through the third buffer chamber; the diameter of the oil outlet is smaller than the diameter of the third buffer chamber.

11. A flow distribution mechanism for a low-pressure pulsation hydraulic pump according to claim 10, characterized in that the diameter of the first through hole is smaller than the diameter of the second through hole.

12. A hydraulic pump, characterized in that the hydraulic pump includes: a flow distribution mechanism for a low-pressure pulsation hydraulic pump according to any one of claims 1 to 11; a housing, wherein the flow distribution mechanism for the low-pressure pulsation hydraulic pump is located in the housing; the flow distribution mechanism for the low-pressure pulsation hydraulic pump is detachably connected to the housing; a rotor, wherein the rotor is located in the housing; the rotor is rotatably connected to the housing; the rotor is coaxial with the flow distribution disk; the rotation direction of the rotor is the direction in which the oil suction area, the boost transition area, the oil discharge area, and the pressure reduction transition area are arranged in sequence.

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