A plunger shoe assembly

Abstract

The application discloses a plunger shoe assembly. The spherical head end of the plunger body circumferential surface has a plunger head end arc surface, and the tail end of the plunger body circumferential surface has a plunger tail end arc surface; the inner cavity of the shoe body includes a shoe inner cavity spherical surface and a shoe inner cavity cylindrical surface, and the joint of the shoe inner cavity spherical surface and the shoe inner cavity cylindrical surface is an interface; the shoe inner cavity spherical surface is located above the interface, and the shoe inner cavity cylindrical surface is located below the interface; the diameter of the opening end of the shoe inner cavity spherical surface is smaller than the diameter of the shoe inner cavity cylindrical surface, and the spherical center of the shoe inner cavity spherical surface is located below the interface. The application reduces the plunger pair wear by modifying the plunger body arc, reduces the shoe pair wear by opening the symmetrical circular oil port, reduces the shoe jamming risk by making the diameter of the shoe inner cavity cylindrical surface larger than the diameter of the spherical surface and the spherical center located below the interface, improves the plunger shoe connection strength by making the middle part of the shoe outer wall surface concave, and further improves the working reliability of the plunger pump and prolongs the service life.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of plunger pump, in particular to a plunger shoe assembly. BACKGROUND

[0002] The main problem of plunger pump is low reliability and short service life, and the low reliability and short service life of plunger pump involve the structure, lubrication, strength and other characteristics of three friction pairs. Among them, the wear of plunger pair and shoe pair, shoe jamming and shoe falling are the main reasons for the low reliability and short service life of plunger pump.

[0003] In the process of rotating with the cylinder body, the plunger shoe assembly is inclined along the rotation direction of the cylinder body due to the action of the lateral component of the swash plate and the centrifugal force of itself, so it will cause wear to the plunger hole, especially at the bottom and the opening of the plunger hole. The wear of the plunger hole will cause the leakage to increase and the volumetric efficiency to decrease, and it will even cause the plunger pump to fail. For example, after the durability test of a certain type of plunger pump, the volumetric efficiency decreased by 8%, and it was found that the wear of the opening of each plunger hole reached 0.7mm, the wear of the bottom reached 0.9mm, and the wear of the middle part reached 0.3mm. In addition, the shoe rotates at high speed on the swash plate, and if the lubrication of the working surface of the shoe is not good, it will cause wear and increase the leakage. Furthermore, if the connecting strength is insufficient after the shoe covers the plunger ball head, the shoe will be jammed and the probability of shoe falling will increase.

[0004] For example, the structure of the plunger in the existing plunger shoe assembly is as shown in Figure 6 , the outer wall of the plunger body 01 is a through diameter cylindrical surface. The structure of the shoe is as shown in Figure 7 and Figure 8 , the oil ports 021 and 022 on the inner and outer support belts of the shoe body 02 are rectangular, the diameter of the spherical surface and the cylindrical surface in the inner cavity of the shoe body 02 is the same, and the outer wall surface of the shoe body 02 is composed of a cylindrical surface and a conical surface.

[0005] The above-mentioned technology has the following disadvantages:

[0006] (1) The outer wall of the plunger body is a through diameter cylindrical surface, which causes large wear of the plunger body to the plunger hole;

[0007] (2) The oil ports on the inner and outer support belts of the shoe body are rectangular, the diameter of the spherical surface and the cylindrical surface in the inner cavity of the shoe body is the same, and the outer wall surface of the shoe body is composed of a cylindrical surface and a conical surface, which causes large wear of the working surface of the shoe, small rotation pair gap between the shoe and the plunger ball head, and low connecting strength, and there is a risk of jamming and shoe falling.

[0008] At present, the direction to solve the above-mentioned deficiencies in the field is to carry out research on the materials and heat treatment of the plunger and the shoe, and then find the optimal solution, but this direction has high cost, long cycle and low efficiency. SUMMARY

[0009] To solve the above technical problems, the plunger structure and the shoe structure are improved and optimized, and a plunger shoe assembly is provided.

[0010] The plunger shoe assembly comprises a plunger body and a shoe body, the plunger body has a ball head at one end, and the shoe body has an inner cavity matched with the ball head at one end; the ball head end of the circumferential surface of the plunger body has a plunger ball head end arc surface, and the tail end of the circumferential surface of the plunger body has a plunger tail end arc surface; the inner cavity of the shoe body comprises a shoe inner cavity spherical surface and a shoe inner cavity cylindrical surface, and the joint of the shoe inner cavity spherical surface and the shoe inner cavity cylindrical surface is an interface; the shoe inner cavity spherical surface is located above the interface, and the shoe inner cavity cylindrical surface is located below the interface; the diameter of the opening end of the shoe inner cavity spherical surface is smaller than the diameter of the shoe inner cavity cylindrical surface, and the center of the sphere of the shoe inner cavity spherical surface is located below the interface.

[0011] Further, the working surface of the shoe body in contact with the swash plate has an inner support belt and an outer support belt; two shoe inner support belt oil ports are arranged on the inner support belt and are uniformly distributed around the center of the inner support belt; two shoe outer support belt oil ports are arranged on the outer support belt and are uniformly distributed around the center of the support belt; and the lines connecting the two shoe inner support belt oil ports and the two shoe outer support belt oil ports are perpendicular.

[0012] The shoe inner support belt oil port and the shoe outer support belt oil port are circular; the diameter of the shoe inner support belt oil port is greater than the width of the inner support belt, and the center of the circle of the shoe inner support belt oil port is located between the inner and outer circles of the inner support belt; the radius of the shoe outer support belt oil port is greater than the width of the outer support belt, and the center of the circle of the shoe outer support belt oil port is located on the outer circle of the outer support belt.

[0013] The lower end of the outer wall surface of the shoe body has, from bottom to top, an outer wall lower conical surface, an outer wall middle cylindrical surface, and an outer wall upper cylindrical surface; the two ends of the outer wall middle cylindrical surface are smoothly connected with the outer wall lower conical surface and the outer wall upper cylindrical surface, the diameter of the outer wall middle cylindrical surface is smaller than the diameter of the outer wall upper cylindrical surface, and the outer wall middle cylindrical surface and the outer wall upper cylindrical surface meet above the interface.

[0014] The length of the plunger ball head end arc surface is 7-12 mm, and the distance from the end face of the plunger ball head end arc surface to the circumferential surface of the plunger body is 0.008-0.012 mm.

[0015] The length of the plunger tail end arc surface is 10-14 mm, and the distance from the end face of the plunger tail end arc surface to the circumferential surface of the plunger body is 0.02-0.0025 mm.

[0016] The center of the sphere of the shoe inner cavity spherical surface is located 0.5-1 mm below the interface.

[0017] Compared with the prior art, the plunger shoe assembly has the following beneficial effects:

[0018] (1) By modifying the spherical head end and tail end arc of the plunger body, the contact area between the plunger body and the plunger orifice and the bottom is reduced, the wear of the plunger hole is reduced, and the stability of the plunger pump volume efficiency and mechanical efficiency is ensured;

[0019] (2) By opening symmetrical circular oil ports on the inner and outer support belts of the sliding shoe, compared with the original rectangular oil port, the circular oil port on the outer support belt increases the flow area of the oil entering the oil groove in the shell, and the opening of the circular oil port towards the oil groove is small, so the oil in the oil groove is not easy to leak. In addition, the circular oil port of the inner support belt can store a certain amount of oil pressure while increasing the flow area. This sliding shoe structure strengthens the lubrication of the working surface of the sliding shoe and reduces the wear;

[0020] (3) By making the diameter of the sliding shoe inner cavity column surface greater than the diameter of the sliding shoe inner cavity spherical surface, and the center of the sliding shoe inner cavity spherical surface is located below the interface, the risk of jamming after the sliding shoe wraps the plunger ball head is reduced. In addition, by making the middle part of the outer wall surface of the sliding shoe concave, the connection strength of the plunger sliding shoe is improved, and the risk of shoe separation is reduced;

[0021] (4) The working reliability of the plunger pump is improved, and the service life is prolonged. Moreover, only the plunger structure and the sliding shoe structure are designed, improved and optimized, without involving materials and heat treatment, so the overall cost is low and the cycle is short. BRIEF DESCRIPTION OF DRAWINGS

[0022] Figure 1 is a structure diagram of the plunger body in the present application;

[0023] Figure 2 is Figure 1 is an enlarged view of the position of the plunger ball head end arc surface and the plunger tail end arc surface in

[0024] Figure 3 is a structure diagram of the sliding shoe body in the present application;

[0025] Figure 4 is Figure 3 is a sectional view in the B-B direction in

[0026] Figure 5 is Figure 4 is an enlarged view of the interface position in

[0027] Figures 1 to 5 in which 1 is the plunger body, 11 is the plunger ball head end arc surface, 12 is the plunger tail end arc surface, 2 is the sliding shoe body, 21 is the sliding shoe inner support belt oil port, 22 is the sliding shoe outer support belt oil port, 23 is the sliding shoe inner cavity spherical surface, 24 is the sliding shoe inner cavity column surface, 25 is the interface, 26 is the outer wall upper column surface, 27 is the outer wall middle column surface, 28 is the outer wall lower conical surface, 3 is the ball head, and 4 is the inner cavity.

[0028] Figure 6A schematic view of the structure of a plunger in the prior art;

[0029] Figure 7 A schematic view of the structure of a sliding shoe in the prior art;

[0030] Figure 8 A Figure 7 A sectional view of the sliding shoe A-A direction in the prior art;

[0031] Figures 6 to 8 In the drawings, 01 is a plunger body; 02 is a sliding shoe body, 021 is a sliding shoe inner support oil port, and 022 is a sliding shoe outer support oil port. DETAILED DESCRIPTION

[0032] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative work fall within the scope of protection of the present application.

[0033] The present application is described in detail in combination with the schematic view. In the detailed description of the embodiments of the present application, the sectional view of the part structure will be partially enlarged without the general proportion for the convenience of description, and the schematic view is only an example, which should not limit the scope of protection of the present application. In addition, the three-dimensional spatial dimensions of length, width and depth should be included in the actual manufacture. Meanwhile, in the description of the present application, it should be noted that the directions or positional relationships of the terms such as "upper", "lower", "cavity" and "outer wall" are based on the directions or positional relationships shown in the drawings, which are only for the convenience of describing the present application and simplifying the description, and therefore cannot be understood as the limitation of the present application.

[0034] A plunger sliding shoe assembly, comprising a plunger body 1 and a sliding shoe body 2,

[0035] In combination with Figure 1 And Figure 2As shown, the plunger body 1 has a ball head 3 at one end. The ball head end of the plunger body 1 circumferential surface has a plunger ball head end arc surface 11, and the tail end of the plunger body 1 circumferential surface has a plunger tail end arc surface 12. In this embodiment, the total length of the plunger body 1 is 57, and the unmodified surface is φ24.5. The length of the plunger ball head end arc surface 11 is L3=7-12mm, the distance from the plunger ball head end arc surface 11 end face to the plunger body 1 circumferential surface is L5=0.008-0.012mm, the distance from the plunger ball head end arc surface 11 end face to the plunger body 1 ball head end face is L1=0.6mm, and the modified surface is Ra0.2. The length of the plunger tail end arc surface 12 is L4=10-14mm, the distance from the plunger tail end arc surface 12 end face to the plunger body 1 circumferential surface is L6=0.02-0.0025mm, the distance from the plunger tail end arc surface 12 end face to the plunger body 1 tail end face is L1=0.7mm, and the modified surface is Ra0.2.

[0036] In combination Figures 3 to 5 As shown, the lower end of the shoe body 2 has an inner cavity 4 matched with the ball head 3, and the upper end of the shoe body 2 is a working surface in contact with the swash plate. The inner cavity 4 of the shoe body 2 includes a shoe inner cavity spherical surface 23 and a shoe inner cavity cylindrical surface 24, and the joint between the shoe inner cavity spherical surface 23 and the shoe inner cavity cylindrical surface 24 is a junction surface 25. The shoe inner cavity spherical surface 23 is located above the junction surface 25, and the shoe inner cavity cylindrical surface 24 is located below the junction surface 25. The diameter of the shoe inner cavity spherical surface 23 is smaller than that of the shoe inner cavity cylindrical surface 24, and the center of the sphere of the shoe inner cavity spherical surface 23 is located 0.5-1mm below the junction surface 25. Preferably, in this embodiment, the center of the sphere of the shoe inner cavity spherical surface 23 is located 0.7mm below the junction surface 25, the diameter of the shoe inner cavity spherical surface 23 is Sφ18, and the diameter of the shoe inner cavity cylindrical surface 24 is φ18.045.

[0037] The lower end of the outer wall surface of the shoe body 2 has, from bottom to top, an outer wall lower conical surface 28, an outer wall middle cylindrical surface 27, and an outer wall upper cylindrical surface 26. The diameter of the outer wall middle cylindrical surface 27 is φ21.7, the diameter of the outer wall upper cylindrical surface 26 is φ22, the angle between the outer wall lower conical surface 28 and the central axis of the shoe body 2 is 15°, and the transition round angle is R1.5. The outer wall middle cylindrical surface 27 smoothly transitions with the outer wall lower conical surface 28 and the outer wall upper cylindrical surface 26 at both ends, and the outer wall middle cylindrical surface 27 and the outer wall upper cylindrical surface 26 meet at 0.8mm above the junction surface 25.

[0038] The inner support band and the outer support band are provided on the working surface of the sliding shoe body 2 in contact with the swash plate. Two sliding shoe inner support band oil ports 21 are provided on the inner support band and are uniformly distributed around the center of the inner support band. Two sliding shoe outer support band oil ports 22 are provided on the outer support band and are uniformly distributed around the center of the outer support band. The line connecting the two sliding shoe inner support band oil ports 21 and the line connecting the two sliding shoe outer support band oil ports 22 are perpendicular. In this embodiment, the sliding shoe inner support band oil ports 21 and the sliding shoe outer support band oil ports 22 are circular and have a diameter of φ4. The diameter of the sliding shoe inner support band oil ports 21 is greater than the width of the inner support band, and the center of the circle of the sliding shoe inner support band oil ports 21 is located in the middle of the inner and outer rings of the inner support band. The radius of the sliding shoe outer support band oil ports 22 is greater than the width of the outer support band, and the center of the circle of the sliding shoe outer support band oil ports 22 is located on the outer ring of the outer support band.

[0039] In this embodiment, the plunger sliding shoe assembly reduces the wear of the plunger pair by modifying the circular arcs at the head end and the tail end of the plunger body, reduces the wear of the sliding shoe pair by providing symmetrical circular oil ports on the inner and outer support bands of the sliding shoe, reduces the risk of sliding shoe jamming by making the diameter of the cylindrical surface of the sliding shoe inner cavity greater than the diameter of the spherical surface and locating the spherical center below the interface, and improves the connection strength of the plunger and the sliding shoe and reduces the risk of shoe separation by making the middle part of the outer wall surface of the sliding shoe concave. Thus, the working reliability of the plunger pump is improved, and the service life is prolonged.

[0040] The preferred embodiments disclosed above are only used to help explain the present application. The preferred embodiments do not describe all the details and do not limit the present application to the specific embodiments described. Obviously, many modifications and changes can be made according to the content of the present application. The present application selects and specifically describes these embodiments in order to better explain the principles and practical applications of the present application, so that those skilled in the art can well understand and utilize the present application. The present application is limited only by the claims and their entire scope and equivalents.

Claims

1. A plunger slipper assembly, comprising a plunger body (1) and a slipper body (2), wherein one end of the plunger body (1) has a ball head (3) and one end of the slipper body (2) has an inner cavity (4) that mates with the ball head (3). Its features are: The ball end of the circumferential surface of the plunger body (1) has a plunger ball end arc surface (11), and the tail end of the circumferential surface of the plunger body (1) has a plunger tail end arc surface (12). The inner cavity (4) of the slipper body (2) includes a spherical inner cavity surface (23) and a cylindrical inner cavity surface (24). The joint between the spherical inner cavity surface (23) and the cylindrical inner cavity surface (24) is an interface (25). The spherical inner cavity surface (23) is located above the interface (25), and the cylindrical inner cavity surface (24) is located below the interface (25). The diameter of the opening end of the spherical inner cavity surface (23) is smaller than the diameter of the cylindrical inner cavity surface (24), and the center of the spherical inner cavity surface (23) is located below the interface (25). The working surface of the slipper body (2) in contact with the swashplate has an inner support belt and an outer support belt; the inner support belt has two slipper inner support belt oil ports (21) evenly distributed around the center of the inner support belt; the outer support belt has two slipper outer support belt oil ports (22) evenly distributed around the center of the outer support belt; the line connecting the two slipper inner support belt oil ports (21) and the line connecting the two slipper outer support belt oil ports (22) are perpendicular; The inner support belt oil port (21) and the outer support belt oil port (22) of the skate shoe are circular; the diameter of the inner support belt oil port (21) is greater than the width of the inner support belt, and the center of the inner support belt oil port (21) is located in the middle of the inner and outer rings of the inner support belt; the radius of the outer support belt oil port (22) is greater than the width of the outer support belt, and the center of the outer support belt oil port (22) is located on the outer ring of the outer support belt.

2. The plunger slipper assembly according to claim 1, characterized in that: The lower end of the outer wall of the slipper body (2) has a lower conical surface (28), a middle cylindrical surface (27), and an upper cylindrical surface (26) from bottom to top. The two ends of the outer wall middle cylindrical surface (27) are smoothly transitioned to the outer wall lower conical surface (28) and the outer wall upper cylindrical surface (26). The diameter of the outer wall middle cylindrical surface (27) is smaller than the diameter of the outer wall upper cylindrical surface (26). The outer wall middle cylindrical surface (27) and the outer wall upper cylindrical surface (26) meet above the interface (25).

3. The plunger slipper assembly according to claim 1, characterized in that: The length of the arc surface (11) at the end of the plunger ball head is 7-12 mm, and the distance from the end face of the arc surface (11) at the end of the plunger ball head to the circumferential surface of the plunger body (1) is 0.008-0.012 mm.

4. A plunger slipper assembly according to claim 1, characterized in that: The length of the arc surface (12) at the tail end of the plunger is 10-14 mm, and the distance from the end face of the arc surface (12) at the tail end of the plunger to the circumferential surface of the plunger body (1) is 0.02-0.0025 mm.

5. A plunger slipper assembly according to claim 1, characterized in that: The center of the spherical surface (23) of the inner cavity of the slipper is located 0.5-1 mm below the interface (25).

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