Pre-tightening structure, limiting structure and compact sliding disc type plunger pump

Abstract

The invention discloses a pre-tightening structure and a limiting structure which are used for generating pre-tightening and limiting effects on a flow distribution pair and a sliding disc pair of a sliding disc type plunger pump, the flow distribution pair comprises a cylinder body supported on a main shaft and a flow distribution disc supported on a shell, the sliding disc pair comprises a swash plate and a sliding disc supported on the swash plate, the sliding disc is of an integral disc-shaped structure, and the limiting structure is arranged on the sliding disc. The independent pre-tightening limiting structure comprises a pre-tightening structure close to one side of the cylinder body and a limiting structure close to one side of the swash plate, the pre-tightening structure compresses a belleville spring through a pre-tightening bolt connected with the main shaft to generate pre-tightening force, and the pre-tightening force is transmitted to one side of the cylinder body, so that the cylinder body abuts against the valve plate all the time. The limiting structure comprises a fastening piece fixed to the center of the swash plate, a limiting disc used for limiting the sliding disc pair and a limiting pressing piece used for pressing the limiting disc, and the limiting structure limits the sliding disc to move outwards away from the swash plate through the limiting disc. The sliding disc type plunger pump is compact in structure, the variable inclination angle is increased, the size and weight are reduced, and the power density is improved.

Description

Technical Field

[0001] The invention belongs to the technical field of hydraulic transmission and control, and in particular relates to a pre-tightening structure, a limiting structure and a compact sliding disc type plunger pump. Background Art

[0002] Axial piston pumps and motors are one of the most widely used hydraulic components in modern hydraulic transmission, among which hingeless bevel axis pumps and slipper-type swash plate pumps are the two most widely used and main types of axial piston pumps. Swash plate piston pumps and bevel axis piston pumps each have their own advantages and characteristics: for example, the swash plate piston pump has a relatively simple and compact structure, a small size, and a light weight. It can achieve stepless variable through the swing of the swash plate, and the variable is more convenient, with more variable forms, small inertia, and faster variable response speed. However, the speed of the inclined plate piston pump is limited due to the centrifugal force on the sliding shoe, and the lateral force on the piston generates a large overturning moment on the cylinder body, so the inclination angle of the inclined plate is limited, generally less than 20°; the inclined axis pump is superior to the sliding plate piston pump in terms of speed and efficiency, especially in large inclination angles (the maximum inclination angle can reach 40°) and significantly reduced lateral force. But at the same time, since the variable of the inclined axis piston pump relies on driving the cylinder body to swing, it has a large inertia, slow variable response speed, a large bidirectional variable volume, and the bearing needs to withstand huge axial force, which requires very high processing and assembly as well as bearing technology, and therefore the price is high.

[0003] like Figure 1The CY14-1B plunger pump widely used in the industrial field in my country is shown in the figure. Its structure is a non-through-axis slipper-type plunger pump with the following characteristics: (1) It adopts a cylindrical plunger, and the plunger 70 is in surface contact with the plunger hole of the cylinder body, which has a large lateral force; (2) It adopts a slipper structure, and the slipper 75 is supported on the swash plate 40. Under the condition of large centrifugal force and casing pressure, it is easy to overturn and produce a wedge-shaped gap, resulting in eccentric wear and damage to the oil film. In addition, under large high-pressure impact loads, the slipper is easy to deform, and the PV value of a single slipper is large, which affects the use. life; (3) a large-sized third bearing 25 must be provided on the outer circumference of the cylinder body 80 to balance the lateral force transmitted from the plunger 70 to the cylinder body 80, but this structure significantly reduces the running speed of the plunger pump, resulting in a larger radial dimension of the plunger pump, loud movement noise, thick shell, heavy weight, and low reliability; (4) the inlet and outlet ports 32a (32b) of the plunger pump are arranged on the front end of the pump body 30, which, on the one hand, limits the size of the oil inlet and affects the self-priming speed; on the other hand, causes the axial dimension of the plunger pump to be larger, and the suspension of the main shaft 10 is increased. The arm size is long and the structure is not compact; (5) Due to the excessive lateral force and the self-priming speed, the variable tilt angle of the swash plate 40 is generally set to about 18°, and the variable tilt angle cannot be further increased; (6) The oil leakage of the friction pair of the plunger pump into the housing cavity is converted into heat, causing the oil temperature in the housing cavity 35 to be too high. The resulting thermal deformation affects the working performance of the friction pair. At the same time, it is necessary to add an oil leakage pipeline to be led out from the housing oil leakage port 38, making the structure more complicated; (7) The high-pressure oil of the variable mechanism needs to be drawn from The high-pressure oil port 32b of the pump body 30 and the high-pressure hole 37 of the shell are guided, which are difficult to process, have many sealing components and complex structure; (8) The center spring 100 is used for preload and return, and is matched with the steel ball 101, sleeve 102 and outer sleeve 103. The center spring of this structure has a large stiffness and can only provide a same preload force, which cannot meet the different preload force requirements of the sliding shoe pair and the distribution pair. At the same time, the return plate 76 and the sliding shoe are prone to wear, shear damage and cracking of the return plate drilling part, and the reliability is not high.

[0004] It can be seen that there is still room for improvement in the existing technology, and a more reasonable technical solution should be proposed to solve the defects in the existing technology. Summary of the invention

[0005] The purpose of the present invention is to provide a pre-tightening structure, a limiting structure and a compact sliding disc plunger pump to address the above-mentioned problems, which can greatly increase the variable inclination angle of the plunger pump, reduce the volume and weight, improve the power density, increase the self-priming speed and reliability.

[0006] The technical solution of the present invention is implemented as follows:

[0007] A pre-tightening structure is used to pre-tighten the distribution pair of a sliding plate plunger pump, the distribution pair includes a distribution plate supported on a housing and a cylinder body supported on the distribution plate, the pre-tightening structure includes a connecting pre-tightening member connected to the main shaft and used to fit the cylinder body to the main shaft, and also includes an elastic pre-tightening member arranged between the cylinder body and the main shaft, the elastic pre-tightening member generates a pre-tightening force through elastic deformation and transmits it to the cylinder body, so that the cylinder body always abuts against the distribution plate.

[0008] The above disclosed pre-tightening structure connects and pre-tightens the structure at the distribution plate of the sliding plate type plunger pump, and can connect and tighten the cylinder body and the main shaft, so that the cylinder body is always pressed against the main shaft and the distribution plate under the action of the pre-tightening force, which can improve the reliability of operation.

[0009] Furthermore, when setting the pre-tightening structure, considering the deformation of the elastic pre-tightening member caused by rotation, the reliability of the pressing structure may be reduced. Here, optimization is performed and one of the feasible options is proposed: a retaining ring is provided between the connection pre-tightening member and the elastic pre-tightening member, a washer is provided between the elastic pre-tightening member and the cylinder body, a pre-tightening groove is provided on the cylinder body, and the elastic pre-tightening member, retaining ring and washer are fitted into the pre-tightening groove. When such a solution is adopted, the retaining ring and the washer both press against the end of the elastic pre-tightening member and provide a stable contact surface, thereby ensuring the stability and reliability of the elastic pre-tightening member.

[0010] In some solutions, the elastic preload member is a butterfly spring.

[0011] The present invention also provides a limiting structure, which is now described:

[0012] A limiting structure is used to limit the sliding plate pair of a sliding plate type piston pump, the sliding plate pair includes a swash plate and a sliding plate supported on the swash plate, the sliding plate is an integral disc-shaped structure, the limiting structure includes a fastening piece connected to the swash plate, a limiting plate for limiting the sliding plate pair, the limiting plate is connected to the fastening piece through a limiting clamping piece, or the limiting plate and the fastening piece are connected and fixed into an integral structure, the limiting plate keeps the supporting surfaces of the sliding plate and the swash plate in contact.

[0013] The above disclosed limiting structure imposes structural restrictions on the sliding plate and the like that cooperate with the swash plate, which can improve the stability of the structure at the swash plate and better cooperate with the plunger during operation.

[0014] Furthermore, the structure of the fastener and the swash plate is not limited to a single one, and an optimization is made here and one of the feasible options is proposed: the fastener and the swash plate are separate structures, the fastener is connected to the swash plate by threads or interference fit, and the fastener includes a support portion that is higher than the swash plate and is used to support the sliding plate. When such a solution is adopted, the fastener is detachably connected to the swash plate, and the support portion for rotatably connecting the sliding plate is retained, and a sliding bearing can be provided between the support portion and the sliding plate to achieve a matching connection.

[0015] Furthermore, another matching structure of the fixing member and the swash plate is provided here: the fixing member and the swash plate are an integrated structure, and the fixing member vertically extends outward from the surface of the swash plate and protrudes to form a supporting portion for supporting the sliding plate. When such a solution is adopted, the supporting portion of the fixing member is also connected to the sliding plate through a sliding bearing.

[0016] Furthermore, when connecting the sliding disc, it is necessary to take into account the flow of oil during the oil inlet and outlet process, so the structure of the fixing piece can also be optimized, and one feasible option is proposed here: at least one first oil drain groove is provided on the supporting part or the sliding disc of the fixing piece, and the first oil drain groove is used to discharge the oil leaked from the sliding disc pair and to lubricate the supporting part, and the first oil drain groove extends along the axial direction of the supporting part and / or extends spirally along the surface of the supporting part. When such a solution is adopted, the first oil drain grooves extending along the axial direction can be evenly spaced on the circumferential side of the supporting part.

[0017] Furthermore, in order to improve the clamping effect on the limit plate, an optimization is made here and one of the feasible options is proposed: the limit plate abuts against the pressure plate and slides with the pressure plate, the pressure plate is provided with a central support surface that cooperates with the limit plate, and an oil leakage structure is provided on the periphery of one side of the limit plate that cooperates with the central support surface. When such a solution is adopted, the pressure plate fits and presses the middle part of the limit plate, so that the limit plate and the sliding plate are kept in close contact.

[0018] Furthermore, another feasible option is that the limit plate abuts against the sliding plate and slidably cooperates with the sliding plate, and an oil leakage structure is provided on the periphery of a side where the limit plate cooperates with the sliding plate.

[0019] Furthermore, in the present invention, the oil leakage structure is optimized and one feasible option is proposed: the oil leakage structure includes a second oil leakage groove or an oil leakage hole.

[0020] The present invention also proposes a plunger pump, which is described below:

[0021] A compact sliding plate type plunger pump, including the preload structure and / or the limit structure described above, specifically: the compact sliding plate type plunger pump includes a main shaft, a housing, a first bearing, a second bearing, a swash plate, a sliding plate, a pressure plate, a plunger, a cylinder body, a distribution plate and a rear end cover, the middle part of the main shaft is supported on the first bearing and the second bearing, the cantilever end of the main shaft enters the housing to support the cylinder body and drive the cylinder body to operate synchronously, the preload is set at the end of the main shaft and is used to connect the cylinder body; the plunger is conical and is connected to the cylinder body The plunger makes reciprocating motion in the plug hole, one end of the plunger slides and fits into the plunger hole, and the other end is connected and fits into the sliding plate. A plunger center hole is provided in the plunger and is connected with the oil chamber provided on the sliding plate to form an oil circuit. The limiting structure is provided at the sliding plate and is used to connect the swash plate; an oil inlet and an oil outlet are provided on the rear end cover, the oil inlet is respectively connected to the housing cavity and the swash plate low-pressure port, and the oil outlet is connected to the swash plate high-pressure port on the swash plate; the swash plate is used to support and connect the sliding plate, and the inclination angle of the supporting surface of the sliding plate is 21°~40°.

[0022] The plunger pump disclosed above adopts a conical plunger structure instead of a cylindrical plunger. The plunger is in line contact with the plunger hole of the cylinder body. The lateral force transmitted by the plunger to the cylinder body is small, which significantly reduces the overturning of the cylinder body and the distribution plate, and the oil film of the distribution pair is more stable. Since the lateral force exerted by the plunger on the cylinder body is very small, the large-sized roller bearings arranged on the outer circumference of the cylinder body can be eliminated, thereby significantly reducing the radial size, movement noise, large shell thickness and weight of the plunger pump, greatly improving the operating speed, reliability and power density of the plunger pump, and making the structure more compact. The pump body at the front end of the plunger pump is eliminated, and the oil inlet and outlet on the pump body are arranged on the rear end cover. On the one hand, the size of the oil inlet can be significantly increased, and the self-priming speed can be increased, and on the other hand, On the one hand, it can significantly reduce the axial size of the plunger pump and the cantilever size of the plunger pump main shaft, thereby significantly improving the compactness of the structure; with a double-end oil distribution structure, the hot oil leaked from the plunger pump friction pair into the shell cavity directly enters the plunger hole, participates in the circulation of the hydraulic system, and takes out the heat in time. The oil in the shell cavity is always cold oil, so the thermal deformation is small, and the working performance of the friction pair is less affected. At the same time, the oil drain pipeline is cancelled, making the structure simpler; integrating the inlet and outlet ports on the rear end cover can greatly simplify the structure, make the size smaller, the structure more compact, and the weight of the pump smaller, thereby improving its unit mass power density; at the same time, the cylinder body is close to the bearing, making the acting on the cantilever The bending moment on the main shaft is reduced, which is more beneficial to the main shaft stress, longer bearing life, and less mechanical noise during operation; the high-pressure oil required by the variable mechanism is directly led from the high-pressure oil port on the rear end cover, the oil hole length is short, the processing difficulty is low, and the structure is simple; the independent pre-tightening structure and limit structure adopted replace the multiple independent sliding shoes and the structure using the return plate return in the prior art, and the connection between the plunger and the sliding plate, and the sliding plate and the pressure plate is more reliable, avoiding the wear and shear damage of the neck and shoulder of the sliding shoe and the cracking of the drilling part of the return plate in the prior art, thereby improving the working reliability of the inclined plate plunger pump; the rotating space of the sliding plate pair and the cylinder pair does not interfere, which can significantly improve the variable inclination angle , the maximum inclination angle can reach more than 30°, which is much larger than the inclination angle of the existing traditional inclined plate type plunger pump, so the displacement and power density of the plunger pump can be significantly improved; it can be set according to the different preload requirements between the sliding plate and the inclined plate, and between the cylinder body and the distribution plate, which solves the problem that the traditional center spring return mechanism can only set one same preload; because the radial radius of the sliding cooperation between the limit plate and the pressure plate is small, the contact line speed between the limit plate and the pressure plate is small, and the wear of the limit plate is also small; the structure of the plunger pump of the present invention is very simple, the number of parts is significantly reduced, the processing technology is significantly reduced, the performance of the entire plunger pump is significantly improved, but the price is significantly reduced, and it has a significant cost-effectiveness advantage;Oil drain holes or grooves are set on the support part, limit plate and sliding bearing in the limit structure, so that the high-pressure oil leaked from the sliding plate pair can be quickly discharged from the gap to prevent the sliding plate pair from detaching due to excessive static pressure support. On the other hand, the sliding parts of the sliding bearing and the fixing parts as well as the limit plate and the pressure plate can be fully lubricated to prevent dry friction, adhesion and burning.

[0023] Furthermore, in some embodiments, the inclination angle of the support surface is set at 24° to 30°.

[0024] Furthermore, an open groove facing the housing cavity is provided on the oil suction side of the swash plate, the open groove is connected with the low-pressure port of the swash plate and the oil inlet on the rear end cover, and the swash plate is also provided with a third oil drain groove connected with the open groove. When such a solution is adopted, the open groove can increase the oil inlet rate.

[0025] Furthermore, a bearing flushing hole connected to the housing cavity is provided on the housing, and the bearing flushing hole continuously injects cold oil in the housing cavity into the gap between the first bearing and the second bearing and takes away the heat during the oil absorption process to achieve cooling and lubrication of the bearing.

[0026] Based on the above technical solution, the beneficial effects of the present invention are:

[0027] The independent preload limit structure adopted in the present invention can meet the requirements of different preload forces of the sliding plate pair and the distribution pair, maintain the sliding plate pair and the distribution pair with better hydrostatic bearing oil film stability and reliability, and at the same time, can greatly improve the variable inclination angle of the plunger pump, reduce the volume and weight, improve the power density, and increase the self-priming speed and reliability. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 It is a schematic diagram of the structure of an axial piston pump in the prior art.

[0029] Figure 2 The figure shows the external structure comparison between the plunger pump of the present invention and the existing plunger pump.

[0030] Figure 3 This is an embodiment of the quantitative plunger pump in the present invention.

[0031] Figure 4 for Figure 3 AA section view in.

[0032] Figure 5 This is another embodiment of the variable displacement piston pump in the present invention.

[0033] Figure 6 It is a structural schematic diagram of one side of the sliding disk in the present invention.

[0034] Figure 7 For the present invention Figure 6Middle CC section.

[0035] Figure 8 It is a structural schematic diagram of the other side of the sliding plate in the present invention.

[0036] Fig. 9 It is a schematic structural diagram of the distribution plate in the present invention.

[0037] Fig.10 It is a schematic structural diagram of one side of the swash plate and the fastener in the present invention.

[0038] Fig.11 For the present invention Fig.10 DD cross-section diagram.

[0039] Fig.12 It is a schematic structural diagram of the other side of the swash plate and the fastener in the present invention.

[0040] Fig.13 It is a cross-sectional view of the structure of the integrated swash plate and the fixing member in the present invention.

[0041] Fig.14 This is another embodiment of the quantitative plunger pump in the present invention.

[0042] Fig.15 This is the third embodiment of the quantitative plunger pump in the present invention.

[0043] Markings in the figure: 1 is a plunger pump of the present invention, 2 is an existing plunger pump, 10 is a main shaft, 10C is a main shaft axis, 11 is a bearing support portion, 12 is a main shaft spline, 13 is a preload bolt, 14 is a retaining ring, 15 is an elastic preload member, 16 is a gasket, 21 is a first bearing, 22 is a second bearing, 23 is a stopper, 24 is a shaft seal, 25 is a third bearing, 30 is a pump body, 31 is a housing, 32 is a rear end cover, 32a is an oil inlet, 32b is an oil outlet, 33 is a screw plug, 34 is a connecting flange, 35 is a housing cavity, 36 is a control valve, 36a is the small chamber of the control valve, 36b is the large chamber of the control valve, 37 is the high-pressure hole of the housing, 38 is the oil drain hole of the housing, 40 is the swash plate, 41 is the supporting surface of the swash plate, 41a is the center hole of the swash plate, 42 is the back of the swash plate, 42a is the positioning hole of the swash plate, 42b is the third oil drain groove, 42c is the bolt connection hole, 42d is the positioning hole of the fastener, 43 is the opening groove, 44 is the low-pressure port of the swash plate, 44a is the triangular groove of the low-pressure port of the swash plate, 45 is the high-pressure port of the swash plate, 45a is the triangular groove of the high-pressure port of the swash plate, 45b is the spacer, 46 is the fastener, 46a is the fastener Supporting part, 46b is the fastener connecting part, 46c is the fastener positioning part, 46d is the fastener oil drain groove, 46e is the inner hexagon hole, 46f is the fastener bolt hole, 47 is the limit plate, 47a is the limit plate oil drain groove, 47b is the limit plate oil drain hole, 48 is the limit pressing part, 50 is the sliding plate, 51 is the sliding plate static pressure bearing surface, 52 is the center through hole, 52a is the sliding bearing, 53 is the sliding plate waist hole, 54 is the outer sealing part, 55 is the inner sealing part, 56 is the interval sealing part, 57 is the auxiliary supporting surface, 57a is the annular oil drain groove, 57b is the is a radial oil drain groove, 58 is a plunger ball socket, 60 is a pressure plate, 61 is a center support surface, 70 is a plunger, 71 is a plunger ball head, 72 is a plunger center hole, 73 is a tapered rod portion, 74 is a plunger portion, 75 is a sliding shoe, 76 is a return plate, 80 is a cylinder body, 81 is a plunger hole, 82 is a waist-shaped hole in the cylinder body, 83 is a spindle assembly hole, 84 is a preload groove, 90 is a distribution plate, 91 is a static pressure support surface, 92 is a low-pressure distribution port, 93 is a distribution plate triangular groove, 100 is a center spring, 101 is a steel ball, 102 is a sleeve, and 103 is a jacket. DETAILED DESCRIPTION

[0044] The present invention will be described in detail below in conjunction with the accompanying drawings.

[0045] Although the present invention is susceptible of different forms of embodiments, this specification and the accompanying drawings only disclose some specific forms as examples of the present invention. However, the present invention is not intended to be limited to the described embodiments. The scope of the present invention is given in the appended claims.

[0046] For the convenience of description, an embodiment of the present invention is shown in a typical orientation, which is such that when the central axis of the main shaft of the axial piston pump is placed horizontally, the side of the coupling end of the main shaft is on the left and the rear end cover is on the right. The terms "longitudinal", "transverse", "upper", "lower", "front", "rear", "left", "right", "horizontal", "bottom", "inside" and "outside" used in the description are all used with reference to this position, only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, and a specific orientation structure and operation. It should be understood that the present invention can be manufactured, stored, transported, used and sold in orientations different from the described position.

[0047] Example 1

[0048] like Figures 1 to 12 As shown, an embodiment of the sliding plate type plunger pump of the present invention is shown. In the embodiment shown, the plunger pump is a non-through-axis plunger pump, including a main shaft 10, a housing 31, a first bearing 21, a second bearing 22, a swash plate 40, a sliding plate 50, a pressure plate 60, a plunger 70, a cylinder body 80, a distribution plate 90 and a rear end cover 32. The main shaft axis 10C of the main shaft 10 coincides with the cylinder body axis of the cylinder body 80. One end of the main shaft 10 extends out of the housing 31. The bearing support portion 11 in the middle of the main shaft is supported on the first bearing 21 and the second bearing 22. The main shaft 10 is a cantilever structure, and its end cantilever supports the cylinder body 80 and is connected to the cylinder body 80 through the main shaft spline 12. The main shaft 10 drives the cylinder body 80 to rotate synchronously, and the plunger 70 reciprocates in the plunger hole 81 of the cylinder body 80 to realize the oil suction and discharge work of the pump.

[0049] Preferably, Figure 2 As shown, the overall structure of the plunger pump 1 of the present invention is smaller than the structural dimensions of the existing plunger pump 2.

[0050] The casing of the plunger pump includes a hollow shell 31 with openings at both ends, and a rear end cover 32 connected to the shell 31. The shell 31 and the rear end cover 32 are fixedly connected by bolts. The shell 31 is also provided with a screw plug 33 and a connecting flange 34. The shell 31 has a shell cavity 35 for accommodating the rotor assembly. The rear end cover 32 is provided with an oil inlet 32a and an oil outlet 32b of the pump. In order to reduce the temperature of the first bearing 21 and the second bearing 22 during long-term operation, a bearing flushing hole 39 connected to the shell cavity 35 is provided on the shell 31. The bearing flushing hole 39 continuously injects the cold oil in the shell cavity 35 into the bearing gap and takes away the heat generated by the bearing during the oil absorption process, so that the bearing has a longer service life.

[0051] When the plunger pump is a variable displacement pump, a variable displacement mechanism for variable displacement swing may be provided on the rear end cover 32. The variable displacement mechanism includes a control valve 36 that can slide in the end seat, a small control valve chamber 36a located at the upper part of the control valve, and a large control valve chamber 36b located at the lower part of the control valve. Generally, the small control valve chamber is provided with a spring and is always connected to the high-pressure oil. The oil pressure of the large control valve chamber 36b changes with external factors to adjust the variable displacement mechanism. The variable displacement mechanism may include but is not limited to constant pressure variable, constant flow, constant power, and load sensitive control modes according to the working conditions. One end of the spherical surface of the fastener 46 is connected to the slide valve 36 in a state of relative tilting. Under the action of the variable displacement mechanism, the swash plate 40 together with the slide plate 50 can rotate in the housing cavity 35 through the action of the fastener 46. A shaft seal 23 and a retaining ring are provided on one side of the shaft extension to prevent oil leakage from the housing.

[0052] Preferably, in this embodiment, the fastener 46 is a pin.

[0053] The sliding plate pair is a key core component of the sliding plate type plunger pump, including a swash plate 40 and a sliding plate 50 supported on the swash plate 40. In this embodiment, the sliding plate 50 is an integral disc-shaped structure, and there is a hydrostatic support between the sliding plate 50 and the swash plate 40. The end surface of the sliding plate 50 opposite to the swash plate 40 is provided with a hydrostatic support surface 51, and the hydrostatic support surface 51 is provided with a sliding plate waist-shaped hole 53. The hydrostatic support surface 51 maintains a sliding fit with the swash plate 40 and forms a hydrostatic oil film support with a clearance fit. A plurality of waist-shaped sliding plate waist-shaped holes 53 are provided on the hydrostatic support surface 51. Preferably, the sliding plate waist-shaped holes 53 are evenly distributed on the hydrostatic support surface 51 with the sliding plate axis as the center. The sliding plate waist-shaped holes 53 are connected with the plunger ball socket 58. Preferably, the number of the sliding plate waist-shaped holes 53 and the plunger ball socket 58 is set to 7 or 9. Figure 6 , Figure 7 , Figure 8 shown.

[0054] An effective static oil film support is formed between the static pressure bearing surface 51 and the bearing surface of the swash plate 40. A sealing part for sealing the oil is provided on the static pressure bearing surface 51. The sealing part is provided on the inner and outer peripheries of the sliding plate waist-shaped hole 53 in a state of surrounding the sliding plate waist-shaped hole 53. The sealing part includes an inner sealing part 55 and an outer sealing part 54 distributed radially inside and outside the sliding plate waist-shaped hole 53, and a spacing sealing part 56 distributed between adjacent sliding plate waist-shaped holes 53. The inner sealing part 55 is a region surrounded by the inner edge of the sliding plate waist-shaped hole 53 and the inner diameter R1 of the static pressure bearing surface 51, the outer sealing part 54 is a region surrounded by the outer edge of the sliding plate waist-shaped hole 53 and the outer diameter R2 of the static pressure bearing surface 51, and the spacing sealing part 56 is a spacing boss surface region between adjacent sliding plate waist-shaped holes 53. A certain reasonable gap is always maintained between the sealing part of the static pressure bearing surface 51 and the bearing surface of the swash plate 40 so that the oil film leakage is at a reasonable level. The static pressure bearing surface 51 of the sliding plate 50 can be configured as a plane or a spherical structure.

[0055] In order to reduce the support force on the sliding disc support surface and reduce wear, a plurality of auxiliary support surfaces 57 can be provided radially on the outer circumference of the sliding disc 50 on the basis of providing the sliding disc waist-shaped hole 53 on the static pressure support surface 51, such as Figure 6 As shown, radial oil drain grooves 57 b are provided between the auxiliary support surfaces 57 , and an annular oil drain groove 57 a is also provided between the auxiliary support surface 57 and the outer sealing portion 54 , and the radial oil drain grooves 57 b and the annular oil drain grooves 57 a are communicated with each other.

[0056] like Figures 10-12 As shown, the swash plate 40 has a swash plate support surface 41 matched with the sliding plate static pressure support surface 51, and a swash plate low pressure port 44 and a swash plate high pressure port 45 are arranged on the swash plate support surface 41. The swash plate low pressure port 44 and the swash plate high pressure port 45 are divided into two sides by the central axis of the swash plate. The swash plate low pressure port 44 and the swash plate high pressure port 45 can be arranged in a symmetrical or asymmetrical structure relative to the central axis. For example, the swash plate high pressure port 45 is arranged as a plurality of waist-shaped windows with baffles 45b. In order to make the swash plate have a certain pre-boost and pre-stress, To reduce the pressure, the swash plate low pressure port 44 and the swash plate high pressure port 45 can be rotated along the central axis of the swash plate by a certain angle; or in particular, a swash plate low pressure port triangular groove 44a can be set at the end of the swash plate low pressure port 44 in the direction of transition from the swash plate low pressure port 44 to the swash plate high pressure port 45, and a swash plate high pressure port triangular groove 45a or hole can be set at the end of the swash plate high pressure port 45 in the direction of transition from the swash plate high pressure port 45 to the swash plate low pressure port 44, so as to play the role of pre-reducing the pressure from high pressure to low pressure or pre-increasing the pressure from low pressure to high pressure. In addition, a swash plate positioning hole 42a, a bolt connection hole 42c and a fastener positioning hole 42d for installation and positioning are also set on the back side 42 of the swash plate opposite to the rear end cover 32.

[0057] In addition, a plurality of plunger ball sockets 58 are provided at positions opposite to the plunger 70 in the circumferential direction of the end surface of the sliding plate 50 facing the cylinder body, such as Figure 7 , Figure 8 As shown, the plunger ball socket 58 forms a concave portion with an opening roughly in the shape of a hemisphere on the end surface of the sliding plate 50, and the plunger ball socket 58 supports the plunger in a state of being evenly spaced and distributed on the common circumference of the sliding plate axis 50C. After the plunger 70 is installed on the plunger ball socket 58, it is fixed to the end surface of the sliding plate 50 by the pressure plate 60, so that the movement of the plunger 70 away from the end surface of the sliding plate 50 is restricted. In particular, the method for fixing the plunger 70 to the end surface of the sliding plate 50 is not limited to the method of using the pressure plate. For example, a shape-locking clamping device can also be provided on the sliding plate 50, and the clamping device can fix the plunger ball head 71 by covering it more than 180 degrees.

[0058] The plunger 70 includes a plunger ball head 71, one end of which is supported on the plunger ball socket 58 of the sliding disk 50 and fixed to the end surface of the sliding disk via a pressure plate 60, a plunger center hole 72 for connecting the plunger hole 81 and the plunger ball socket 58, a tapered rod portion 73 with a conical outer circumference, and a plunger portion 74 that is fitted with a clearance with the cylinder plunger hole wall and can reciprocate thereon. The plunger ball head 71 is spherical and can be slidably supported on the plunger ball socket 58 of the sliding disk 50; the plunger center hole 72 is a large-diameter through-hole structure, which serves as an oil suction and / or discharge channel; at least one sealing ring is often provided on the plunger portion 74 for sealing the liquid, and the tapered rod portion 73 is a tapered shape that gradually increases from the plunger ball end to the plunger portion 74. When the plunger 70 moves to a certain position, the tapered rod portion 74 contacts the inner circumferential surface of the plunger hole 81 to play a force transmission role. However, it should be noted that the plunger 70 is not limited to a tapered plunger type, and may also include a connecting rod-plunger with ball heads at both ends or a spherical plunger with a universal joint.

[0059] The distribution pair includes a distribution plate 90 supported on the housing 31 and a cylinder body 80 supported on the distribution plate 90. Fig. 9 As shown, the distribution plate structure of this embodiment is shown. The low-pressure side of the distribution plate 90 is provided with a low-pressure distribution port 91 and the end of the low-pressure distribution port 91 transitioning from the high-pressure area to the low-pressure area is provided with a distribution plate triangular groove 93 or hole. The high-pressure area of ​​the distribution plate is not provided with a distribution port, but a closed plane structure. When the cylinder waist-shaped hole 82 runs to the low-pressure distribution port 91, oil is sucked from the shell cavity. When the cylinder waist-shaped hole 82 runs to the high-pressure area, when the cylinder waist-shaped hole 82 is closed by the distribution plate, the cylinder 80 and the distribution plate 90 are supported by an oil film.

[0060] The cylinder body 80 has a cylindrical configuration with a circular radial cross-section and is accommodated in the shell cavity 35 of the shell 31. The cylinder body 80 has a plurality of plunger holes 81, a plunger waist hole 82 and a spindle assembly hole 83 at the center for accommodating the spindle, which are evenly distributed in the circumferential direction around the cylinder body axis. The number of plunger holes in the cylinder body 80 is generally set to 7 or 9; the spindle 10 passes through the spindle assembly hole 83 of the cylinder body 80, and the spindle spline 12 is connected to the cylinder body 80. The cylinder body 80 is cantilever supported on the spindle 10 in a manner that it moves synchronously with the spindle 10.

[0061] It should be noted that, unlike the existing CY14-1 B structure, the outer periphery of the cylinder body 80 of the present invention is not provided with a third bearing 25, but is directly supported on the cantilever end of the main shaft. The main reason is that due to the use of a tapered plunger or connecting rod plunger structure, the lateral force of the plunger 70 is not transmitted to the cylinder body through the plunger, and the cantilever main shaft is mainly subjected to the centrifugal force of the plunger and the cylinder body, which is much smaller than the lateral hydraulic pressure of the plunger. Therefore, the structure of the present invention can significantly reduce the radial size of the plunger pump, and avoid the problems of excessive noise, reduced reliability, and limited speed limit caused by the large bearings provided on the outer periphery of the cylinder body.

[0062] In this embodiment, the pump body at the front end of the plunger pump is eliminated, and the oil inlet and outlet ports on the pump body are arranged on the rear end cover. On the one hand, the size of the oil inlet port can be significantly increased, and the self-priming speed can be improved. On the other hand, the axial dimension of the plunger pump and the cantilever dimension of the main shaft of the plunger pump can be significantly reduced, especially the axial cantilever length of the main shaft can be further reduced, so that the flexural deformation of the cantilever end of the main shaft is significantly reduced, thereby improving the compactness of the structure and the support strength of the main shaft.

[0063] In order to ensure that the distribution pair and the sliding plate pair establish oil pressure when the plunger pump starts to move and prevent the pulling force when the oil is sucked during movement, it is necessary to apply a certain preload force and return force to the distribution pair and the sliding plate pair. The present invention achieves this function by setting an independent preload limit structure.

[0064] The independent pre-tightening and limiting structure includes a pre-tightening structure close to one side of the cylinder body 80 and a limiting structure close to one side of the swash plate 40. The pre-tightening structure and the limiting structure function independently to meet the different pre-tightening force requirements of the sliding plate pair and the distribution plate pair. The pre-tightening structure generates a pre-tightening force by compressing the butterfly spring 15 through a pre-tightening bolt 13 connected to the main shaft 10, and transmits it to one side of the cylinder body 80, so that the cylinder body 80 is always in contact with the distribution plate 90. The limiting structure includes a fixing member 46 fixed on the center of the swash plate 40, a limiting plate 47 that slides with the pressure plate 60, and a limiting pressing member 48 that presses the limiting plate 47 onto the pressure plate 60. The limiting structure limits the sliding plate 50 from moving outward away from the swash plate 40 through the limiting plate 47.

[0065] Preferably, the fastener 46 is provided with a fastener bolt hole 46 f and a hexagon socket hole 46 e for matching with the position limiting and pressing member 48 .

[0066] In a preferred embodiment of the limiting structure, the fixing member 46 and the swash plate 40 are separated structures. The fixing member 46 is provided with a fixing member support portion 46a extending out of the swash plate 40, a fixing member connecting portion 46b connected to the swash plate center hole 41a, and a fixing member positioning portion 46c. The fixing member 46 is connected to the swash plate center hole 41a through a threaded structure, or the fixing member 46 can also be fixed on the swash plate 40 through an interference fit with the swash plate center hole 41a. A central through hole 52 is provided in the middle of the sliding plate 50. The sliding plate 50 is supported on the fixing member support portion 46a through a sliding bearing 52a on the sliding plate center through hole 52. Generally, the sliding bearing 52a and the sliding plate center through hole 52 are set to be interference fit. In addition, in order to ensure the accuracy of the connection between the fixing member and the swash plate, a fixing member positioning hole 42d is provided on the swash plate. When the fixing member 46 is connected to the swash plate 40, the fixing member positioning portion 46c is inserted into the fixing member positioning hole 42d.

[0067] In order to ensure that the high-pressure oil leaking from the sealing belt inside the sliding plate can be quickly discharged from the gap between the sliding plate and the inclined plate to prevent the oil film from being destroyed due to the accumulation of high pressure, at least one fastener oil drain groove 46d is provided on the fastener support portion 46a of the fastener 46. The fastener oil drain groove 46d can be arranged in a radial or spiral configuration. In addition, an oil drain groove is also provided on the sliding bearing 52a. It can be easily understood that this structure in which the oil drain groove is also provided on the fastener support portion 46a and / or on the sliding bearing 52a is also conducive to lubricating the sliding bearing 52a and bringing heat out of the bearing, thereby playing a role in actively lubricating the sliding bearing 52a and significantly improving the service life of the sliding bearing 52a.

[0068] In order to enhance the reliability of the contact between the sliding plate 50 and the swash plate 40, a limiting plate 47 is arranged at the center of the pressure plate 60 and connected and fixed with the fixing member 46 through the limiting pressing member 48 to form a forced gap limiting structure, wherein a central bearing surface 61 that is slidably matched with the limiting plate 47 is arranged at the center of the pressure plate 60, and the limiting plate 47 and the pressure plate 60 form a pair of friction pairs. In order to provide a better lubrication condition for the pair of friction pairs when the sliding plate is matched, a plurality of limiting plate oil drain grooves 47a and / or limiting plate oil drain holes 47b are arranged on the outer periphery of one side of the limiting plate 47 that is matched with the central bearing surface 61. At the same time, the oil leaked from the gap between the sliding plate and the swash plate is further discharged from the limiting plate oil drain grooves 47a and / or the limiting plate oil drain holes 47b into the housing cavity 35.

[0069] Another embodiment of the limiting structure is as follows: Fig.13As shown, the fastener 46 and the swash plate 40 are an integral structure, the fastener support portion 46a of the fastener 46 is an outward extension of the center of the swash plate, the sliding plate 50 is supported on the fastener support portion 46a through a sliding bearing 52a, and at least one fastener oil drain groove 46d is provided on the fastener support portion 46a for lubricating the sliding bearing 52a and leaking oil, and the fastener oil drain groove 46d can be set to a radial or spiral configuration.

[0070] One preferred embodiment of the pre-tightening structure includes a pre-tightening bolt 13, a retaining ring 14, a butterfly spring 15, and a washer 16. The central end of the cylinder 80 is provided with a pre-tightening groove 84 for accommodating the pre-tightening structure. The pre-tightening bolt 13 is connected to the main shaft 10 and compresses the butterfly spring 15. The main shaft 10 is supported on a first bearing 21 and a second bearing 22. The first bearing 21 is configured to withstand an axial load in the direction of the cylinder 80 to ensure that there is no axial play. For example, the first bearing 21 can be configured to include but not limited to a tapered roller bearing, a cylindrical roller bearing with a rib, and other bearing types. At the same time, the second bearing 22 has lower or no requirements for bearing axial force than the first bearing 21. It can also be configured to include but not limited to a tapered roller bearing, a cylindrical roller bearing with a rib, and other bearing types.

[0071] The above structural analysis shows that the independent pre-tightening and limiting structure adopted by the present invention replaces the multiple independent sliding shoes and the structure using the return plate return in the prior art, and has the following significant features: the connection between the plunger and the sliding plate, and the sliding plate and the pressure plate is more reliable, avoiding the wear and shear damage of the neck and shoulder of the sliding shoe and the cracking of the drilling part of the return plate in the prior art, thereby improving the working reliability of the inclined plate plunger pump; due to the use of the independent pre-tightening and limiting structure, the rotation space of the sliding plate pair and the cylinder pair does not interfere, so the variable inclination angle can be further significantly improved, and the maximum inclination angle is controlled between 21 and 40 degrees, and further preferably controlled between 24 and 30 degrees. °, which is much larger than the inclination angle of the existing traditional inclined plate type plunger pump, so the displacement and power density of the plunger pump can be significantly improved; it can be set according to the different preload requirements between the sliding plate and the inclined plate, and between the cylinder body and the distribution plate 90, which solves the problem that the traditional center spring return mechanism can only set one preload; a limit structure is set in the center of the pressure plate, the contact line speed between the limit plate and the pressure plate is small, and the limit plate wear is small; oil drain holes or grooves are set on the fixing support part, the limit plate and the sliding bearing in the limiting structure, so that the sliding parts of the sliding bearing and the fixing part and the sliding parts of the limit plate and the pressure plate can be fully lubricated to prevent dry friction, adhesion and burning.

[0072] Since the structure of the sliding plate plunger pump is very compact, according to the above structural analysis, the variable inclination angle can be increased by 40% to 60%, the volume and weight can be reduced by about 40% to 50%, the power density can be increased by 100% to 150%, and the self-priming speed can be increased by about 40% to 50%. Figure 2 As shown, 1 is a compact sliding disc type plunger pump of the present invention, Figure 2 Compared with the existing CY14-1 B plunger pump, under the same displacement conditions, the sliding disc plunger pump of the present invention is much smaller than the existing CY14-1 B plunger pump. As we all know, compared with the electric field, although the related products in the electric field have been constantly eroding the related similar products in the hydraulic field in recent years, they are mainly concentrated in the product field with low pressure and low power density. Under the conditions of high power density and high pressure, the components and systems related to the hydraulic field always maintain active vitality.

[0073] Combine the following Figure 4 To further illustrate the double-end oil distribution structure adopted by the present invention, a low-pressure oil inlet 32a and a high-pressure oil outlet 32b are provided on the rear end cover 32, and the low-pressure oil inlet 32a is communicated with the housing cavity 35 and the swash plate low-pressure port 44. At the same time, an open groove 43 facing the housing cavity 35 is provided on the oil suction side of the swash plate 40, and the open groove 43 is communicated with the swash plate low-pressure port 44 and the low-pressure oil inlet 32a on the rear end cover 32. A third oil drain groove 42b is also provided on the swash plate 40, and the oil drain groove 42b is communicated with the open groove 43. The plunger 70 is a conical structure and is provided with a large-diameter plunger center hole 72 connecting the plunger ball socket 58 and the plunger hole 81. The sliding plate 50 is provided with an oil chamber 53 connecting the plunger center hole 72. When sucking oil, low-pressure oil enters from the low-pressure oil inlet 32a and enters the cylinder plunger hole 81 in two ways. One way enters the cylinder plunger hole 81 through the housing cavity 35 and the distribution plate low-pressure port 92, and the other way enters the cylinder plunger hole 81 through the swash plate swash plate low-pressure port 44, the sliding plate oil chamber 53, and the plunger center hole 72; when pressing oil, high-pressure oil is discharged from the cylinder plunger hole 81 through the plunger center hole 72, the sliding plate oil chamber 53, the swash plate high-pressure port 45, and the high-pressure oil outlet 32b. The double-end oil distribution structure is adopted. The hot oil leaked from the piston pump friction pair into the shell cavity directly enters the plunger hole and participates in the circulation of the hydraulic system to take out the heat in time. The oil in the shell cavity is always cold oil. Therefore, the thermal deformation is small and the working performance of the friction pair is less affected. At the same time, the oil leakage pipeline is cancelled, making the structure simpler.

[0074] Example 2

[0075] like Fig.14 As shown, another embodiment of the present invention is shown, which is different from the embodiment 1 in that the limiting structure on one side of the swash plate is different. For other matters, reference may be made to the structure described in the embodiment 1.

[0076] The limiting plate 47 is abutted against the center of the sliding plate 60 through the limiting pressing member 48 and limits the sliding plate pair to be away from the swash plate support surface to form a forced clearance limiting structure. The limiting plate 47 is slidably matched with the sliding plate end face on one side of the ball socket. The limiting plate 47 and the sliding plate 50 form a pair of friction pairs. The center of the pressure plate 60 is provided with a center hole for accommodating the limiting plate 47. The pressure plate 60 and the limiting plate 47 do not contact each other. The size of the center hole is larger than the outer diameter of the limiting plate 47. Similarly, in order to make the pair of friction pairs have better lubrication conditions when the sliding plates are matched, a plurality of limiting plate oil drain grooves 47a and / or limiting plate oil drain holes 47b are provided on the outer periphery of one side of the limiting plate 47 matched with the sliding plate. At the same time, the oil leaked from the gap between the sliding plate and the swash plate is further discharged from the limiting plate oil drain grooves 47a and / or the limiting plate oil drain holes 47b into the housing cavity 35.

[0077] Example 3

[0078] like Fig.15 As shown, another embodiment of the present invention is shown, which is different from the embodiment 1 in that the limiting structure on one side of the swash plate is different. For other matters, reference may be made to the structure described in the embodiment 1.

[0079] The fastening member 46 and the limiting plate 47 are connected and fixed into an integral structure, for example, the limiting plate 47 is an extension of the end of the fastening member 46, or the limiting plate 47 is connected to the fastening member 46 and the limiting plate 47 into a whole by welding, sintering, gluing, etc. The advantage of this structure is that the limiting pressing member 48 is omitted and the reliability of the work of the parts is improved.

[0080] It can be predicted that the fastener 46 and the limit plate 47 can be integrally processed and formed with the same material, for example, made of copper alloy material, which can not only meet the end face matching requirements of the limit plate 46 and the pressure plate 60 or the sliding plate 50, but also meet the requirements of the fastener 46 and the center hole support of the sliding plate, which can further eliminate the need for the sliding bearing 52a.

[0081] In order to achieve oil leakage, a plurality of oil leakage grooves 46 d may be provided on the sliding plate center hole 52 or on the supporting portion 46 a of the fastener 46 .

[0082] The above contents are further detailed descriptions of the present invention in combination with specific preferred technical solutions, and it cannot be determined that the specific implementation of the present invention is limited to these descriptions. For ordinary technicians in the technical field to which the present invention belongs, several simple deductions or substitutions can be made without departing from the concept of the present invention, and all technical solutions and improvements thereof that do not depart from the spirit and scope of the present invention should be included in the scope of the claims of the present invention.

Claims

1. A pre-tightening structure for pre-tightening a distribution pair of a sliding plate type plunger pump, wherein the distribution pair comprises a distribution plate (90) supported on a housing (31) and a cylinder body (80) supported on the distribution plate (90), characterized in that: The pre-tightening structure comprises a connecting pre-tightening member (13) connected to the main shaft (10) and used to fit the cylinder body (80) to the main shaft (10), and also comprises an elastic pre-tightening member (15) arranged between the cylinder body (80) and the main shaft (10), wherein the elastic pre-tightening member (15) generates a pre-tightening force through elastic deformation and transmits it to the cylinder body (80), so that the cylinder body (80) always abuts against the distribution plate (90).

2. The pre-tightening structure according to claim 1, characterized in that: A retaining ring (14) is provided between the connecting preload member (13) and the elastic preload member (15), a washer (16) is provided between the elastic preload member (15) and the cylinder body (80), a preload groove (84) is provided on the cylinder body (80), and the elastic preload member (15), the retaining ring (14) and the washer (16) are fitted into the preload groove (84).

3. A limiting structure for limiting the position of a sliding plate pair of a sliding plate type piston pump, wherein the sliding plate pair comprises a swash plate (40) and a sliding plate (50) supported on the swash plate (40), wherein the sliding plate (50) is an integral disc-shaped structure, and is characterized in that: The limiting structure comprises a fastening member (46) connected to the swash plate (40) and a limiting plate (47) for limiting the sliding plate pair. The limiting plate (47) is connected to the fastening member (46) via a limiting pressing member (48), or the limiting plate (47) and the fastening member (46) are connected and fixed to form an integral structure. The limiting plate (47) enables the sliding plate (50) to maintain contact with the supporting surface (41) of the swash plate (40).

4. The limiting structure according to claim 3, characterized in that: The fastener (46) and the swash plate (40) are of separate structures. The fastener (46) is connected to the swash plate (40) by means of threads or interference fit. The fastener (46) includes a supporting portion (46a) that is higher than the swash plate (40) and is used to support the sliding plate (50).

5. The limiting structure according to claim 3, characterized in that: The fastening piece (46) and the swash plate (40) are an integrated structure. The fastening piece (46) vertically extends outward from the surface of the swash plate (40) and protrudes to form a supporting portion (46a) for supporting the sliding plate (50).

6. The limiting structure according to claim 4 or 5, characterized in that: At least one first oil drain groove (46d) is provided on the support portion (46a) or the sliding disk of the fastener (46). The first oil drain groove (46d) is used to discharge oil leaked from the sliding disk pair and to lubricate the support portion (46a). The first oil drain groove (46d) extends axially along the support portion (46a) and the sliding disk, and / or extends spirally along the surface of the support portion (46a) and the sliding disk.

7. The limiting structure according to claim 4 or 5, characterized in that: The limit plate (47) abuts against the pressure plate (60) and slidably cooperates with the pressure plate (60); the pressure plate (60) is provided with a central support surface (61) that cooperates with the limit plate (47); and an oil leakage structure is provided on the periphery of one side of the limit plate (47) that cooperates with the central support surface (61).

8. The limiting structure according to claim 4 or 5, characterized in that: The limiting plate (47) abuts against the sliding plate (50) and is slidably matched with the sliding plate (50), and an oil leakage structure is provided on the outer periphery of the side where the limiting plate (47) matches the sliding plate (50).

9. The limiting structure according to claim 7 or 8, characterized in that: The oil leakage structure comprises a second oil leakage groove (47a) and / or an oil leakage hole (47b).

10. A compact sliding disc plunger pump, comprising the pre-tightening structure according to any one of claims 1 to 2, and / or the limiting structure according to any one of claims 3 to 9, characterized in that: The compact sliding plate type plunger pump comprises a main shaft (10), a housing (31), a first bearing (21), a second bearing (22), a swash plate (40), a sliding plate (50), a pressure plate (60), a plunger (70), a cylinder body (80), a valve plate (90) and a rear end cover (32); the middle part of the main shaft (10) is supported on the first bearing (21) and the second bearing (22); the cantilever end of the main shaft (10) enters the housing (31) to support the cylinder body (80) and drive the cylinder body (80) to operate synchronously; the pre-tightening structure is arranged at the end of the main shaft (10) and is used to connect the cylinder body (80); the plunger (70) is conical and is inserted into the plunger hole of the cylinder body (80). When making reciprocating motion, one end of the plunger (70) slides into the plunger hole, and the other end is connected to the sliding plate (50). A plunger center hole (72) is provided in the plunger (70) and is connected to an oil chamber (53) provided on the sliding plate (50) to form an oil circuit. The limit structure is provided at the sliding plate (50) and is used to connect the swash plate (40). An oil inlet (32a) and an oil outlet (32b) are provided on the rear end cover (32). The oil inlet (32a) is connected to the housing cavity (35) and the swash plate low pressure port (44) respectively, and the oil outlet (32b) is connected to the swash plate high pressure port (45) on the swash plate (40). The swash plate (40) is used to support and connect the sliding plate (50).

11. The compact sliding plate type plunger pump according to claim 10, characterized in that: An open groove (43) facing the housing cavity (35) is provided on the oil suction side of the swash plate (40); the open groove (43) is connected to the swash plate low-pressure port (44) and the oil inlet (32a) on the rear end cover (32); and the swash plate (40) is also provided with a third oil drain groove (42b) connected to the open groove (43).

12. The compact sliding plate type plunger pump according to claim 10, characterized in that: A bearing flushing hole (39) connected to the housing cavity (35) is provided on the housing (31). The bearing flushing hole (39) continuously injects cold oil from the housing cavity (35) into the gap between the first bearing (21) and the second bearing (22) and takes away heat during the oil absorption process to achieve cooling and lubrication of the bearings.

Images