Cycloid rotor mechanical pump

Abstract

The utility model discloses a cycloid rotor mechanical pump which comprises a machine shell, an inner rotor, an outer rotor and a driving shaft. Wherein an inner cavity is formed in the machine shell, the outer rotor is installed in the inner cavity and used for rotating in the inner cavity, the inner rotor is installed in the inner cavity, located on the inner side of the outer rotor and meshed with the outer rotor, and a centering hole and an inner spline communicated with the centering hole are arranged in the center of the inner rotor. The driving shaft is rotationally connected to the machine shell, an outer spline is arranged on the driving shaft, the outer spline comprises a centering spline section and a driving spline section, the centering spline section is inserted into the centering hole in a matched mode and is in interference fit with the centering hole, and the driving spline section is in clearance fit with the inner spline. According to the utility model, deflection during rotation of the inner rotor can be avoided, and the inner rotor can be prevented from being stuck during operation and the driving shaft can be prevented from being broken.

Description

Technical Field

[0001] The utility model relates to a cycloid rotor mechanical pump. Background Art

[0002] At present, a cycloidal rotor pump has an inner rotor and an outer rotor, the inner rotor is an outer gear, the outer rotor is an inner gear, and both gears are cycloidal gears. For example, a gearbox oil pump disclosed in a Chinese patent with publication number CN218882959U belongs to a cycloidal rotor pump.

[0003] The cycloid rotor pump also has a drive shaft for driving the inner rotor to rotate. In order to facilitate assembly, the drive shaft and the inner rotor in some existing cycloid rotor pumps are connected by a spline with a clearance fit. This results in a gap between the drive shaft and the inner rotor. The gap will cause the inner rotor to have a certain degree of deflection during rotation. Because there is also a gap between the inner rotor and the outer rotor and the inner rotor and the outer rotor do not rotate concentrically, when the inner rotor deflects, it is easy to cause the inner rotor to stagnate or even get stuck, which will cause the drive shaft to break. Utility Model Content

[0004] The technical problem to be solved by the utility model is to overcome the defects of the prior art and provide a cycloid rotor mechanical pump, which can avoid the inner rotor from swinging when rotating, and can avoid the inner rotor from getting stuck and the drive shaft from breaking.

[0005] In order to solve the above technical problems, the technical solution of the utility model is: a cycloid rotor mechanical pump, which includes a casing, an inner rotor, an outer rotor and a drive shaft;

[0006] The housing is provided with an inner cavity;

[0007] The outer rotor is installed in the inner cavity and is used to rotate in the inner cavity;

[0008] The inner rotor is installed in the inner cavity and is located inside the outer rotor and meshes with the outer rotor;

[0009] The center of the inner rotor is provided with a centering hole and an internal spline connected to the centering hole;

[0010] The drive shaft is rotatably connected to the housing, and the drive shaft is provided with an external spline;

[0011] The external spline comprises a centering spline segment and a driving spline segment. The centering spline segment is inserted into the centering hole and has an interference fit with the centering hole, and the driving spline segment has a clearance fit with the internal spline.

[0012] Furthermore, the outer diameter of the centering spline segment is greater than the outer diameter of the driving spline segment.

[0013] A specific structure of the drive shaft is further provided, wherein the drive shaft comprises a shaft body and a shaft head;

[0014] The shaft is rotatably connected to the housing;

[0015] The shaft head is connected to the shaft body and is coaxial with the shaft body, and the external spline is arranged on the shaft head.

[0016] A specific structure of the casing is further provided, wherein the casing comprises a shell and a cover plate;

[0017] The cover plate is connected to the shell, the cover plate and the shell surround to form the inner cavity, and the inner rotor and the outer rotor are both located between the shell and the cover plate;

[0018] The cover plate is provided with a mounting hole communicated with the inner cavity, and the shaft head passes through the mounting hole so that the external spline on the shaft head extends into the centering hole and the internal spline.

[0019] To further prevent oil pressure leakage, an oil seal is provided between the mounting hole and the shaft head.

[0020] In order to further prevent the oil seal from being ejected, a boss portion protruding radially inward is provided in the mounting hole, a spring retaining ring is installed in the mounting hole, and the oil seal is located between the boss portion and the spring retaining ring.

[0021] Furthermore, a sealing ring is provided between the cover plate and the shell.

[0022] Furthermore, the shaft is rotatably connected to the shell through a bearing, a first step hole and a second step hole are provided in the shell, the first step hole is connected to the second step hole, the cover plate is installed in the first step hole, and the bearing is assembled in the second step hole.

[0023] Furthermore, an oil suction chamber and an oil pressure chamber are provided on the chamber wall of the inner chamber, and the oil suction chamber and the oil pressure chamber are both provided in the housing and are respectively communicated with the inner chamber;

[0024] The shell is also provided with an oil inlet hole communicating with the oil suction chamber and an oil outlet hole communicating with the oil pressure chamber.

[0025] Furthermore, the inner rotor is an external gear, the outer rotor is an internal gear, both the inner rotor and the outer rotor are cycloid gears, and the inner rotor has one less tooth than the outer rotor.

[0026] After adopting the above technical solution, when the drive shaft rotates, the inner rotor is driven to rotate by the cooperation of the driving spline segment and the inner spline, and the inner rotor then drives the outer rotor to rotate, thereby pumping oil. Among them, the interference fit between the centering spline segment and the centering hole can play a centering role on the inner rotor, so that the inner rotor always remains concentric with the drive shaft during rotation and will not swing relative to the drive shaft, thereby eliminating the swing of the inner rotor during rotation, thereby avoiding the inner rotor from getting stuck or even stuck during operation, and thus will not cause the drive shaft to break. In addition, the centering hole only contacts with the tooth top of the centering spline segment, and the contact area is small, so it is relatively easy to insert the centering spline segment into the centering hole, making assembly easy and convenient. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 It is an exploded view of the assembly of the cycloid rotor mechanical pump of the utility model;

[0028] Figure 2 It is a cross-sectional view of the cycloid rotor mechanical pump of the utility model;

[0029] Figure 3 It is a schematic diagram of the structure of the inner rotor and the outer rotor of the utility model;

[0030] Figure 4 It is a structural schematic diagram of the drive shaft of the utility model;

[0031] Figure 5 It is an exploded view of the assembly of the shaft head and the inner rotor of the utility model;

[0032] Figure 6 It is a cross-sectional view of the shaft head and the inner rotor of the utility model when assembled;

[0033] Figure 7 is a cross-sectional view of the casing of the utility model;

[0034] Figure 8 It is a structural schematic diagram of the shell of the utility model. DETAILED DESCRIPTION

[0035] In order to make the content of the utility model more clearly understood, the utility model is further described in detail below based on specific embodiments and in conjunction with the accompanying drawings.

[0036] like Figures 1 to 8 As shown, a cycloid rotor mechanical pump comprises a casing 1, an inner rotor 2, an outer rotor 3 and a drive shaft 4;

[0037] The housing 1 is provided with an inner cavity 5;

[0038] The outer rotor 3 is installed in the inner cavity 5 and is used to rotate in the inner cavity 5;

[0039] The inner rotor 2 is installed in the inner cavity 5 and is located inside the outer rotor 3 and meshes with the outer rotor 3;

[0040] The center of the inner rotor 2 is provided with a centering hole 6 and an internal spline 7 connected to the centering hole 6;

[0041] The drive shaft 4 is rotatably connected to the housing 1, and an external spline 8 is provided on the drive shaft 4;

[0042] The outer spline 8 includes a centering spline segment 9 and a driving spline segment 10. The centering spline segment 9 is inserted into the centering hole 6 and has an interference fit with the centering hole 6, and the driving spline segment 10 has a clearance fit with the inner spline 7. Specifically, when the drive shaft 4 rotates, the inner rotor 2 is driven to rotate by the cooperation of the driving spline segment 10 and the inner spline 7, and the inner rotor 2 then drives the outer rotor 3 to rotate, thereby pumping oil; wherein, the centering spline segment 9 and the centering hole 6 have an interference fit, which can play a centering role for the inner rotor 2, so that the inner rotor 2 always remains concentric with the drive shaft 4 during the rotation process and will not deflect relative to the drive shaft 4, thereby eliminating the deflection of the inner rotor 2 during rotation, thereby preventing the inner rotor 2 from getting stuck or even stuck during operation, and thereby preventing the drive shaft 4 from breaking. Furthermore, the centering hole 6 is only in contact with the tooth top of the centering spline segment 9, and the contact area is small, so it is relatively easy to insert the centering spline segment 9 into the centering hole 6, making assembly easy and convenient.

[0043] like Figures 4 to 6 As shown, the outer diameter of the centering spline segment 9 is greater than the outer diameter of the driving spline segment 10 .

[0044] like Figure 1 , 2 As shown in , 4, 5, and 6, the drive shaft 4 may include a shaft body 11 and a shaft head 12;

[0045] The shaft 11 is rotatably connected to the housing 1;

[0046] The shaft head 12 is connected to the shaft body 11 and is coaxial with the shaft body 11, and the external spline 8 is arranged on the shaft head 12; specifically, when the shaft body 11 is driven to rotate, the shaft head 12 is driven to rotate, and the shaft head 12 then drives the inner rotor 2 to rotate through the cooperation of the driving spline segment 10 and the internal spline 7, and the inner rotor 2 then drives the outer rotor 3 to rotate. Because the centering spline segment 9 is interference-fitted with the centering hole 6, the inner rotor 2 is always concentric with the shaft head 12 during the rotation process, and the inner rotor 2 will not deflect during the rotation process, so it can avoid the inner rotor 2 from being stuck or stuck during operation, thereby avoiding the shaft head 12 from breaking.

[0047] like Figure 1 , 2 As shown in , 7 and 8, the housing 1 may include a shell 13 and a cover plate 14;

[0048] The cover plate 14 is connected to the housing 13, and the cover plate 14 and the housing 13 surround and form the inner cavity 5, and the inner rotor 2 and the outer rotor 3 are both located between the housing 13 and the cover plate 14;

[0049] The cover plate 14 is provided with a mounting hole 15 communicating with the inner cavity 5 , and the shaft head 12 passes through the mounting hole 15 so that the external spline 8 on the shaft head 12 extends into the centering hole 6 and the internal spline 7 .

[0050] like Figure 1 , 2 As shown in FIG. 7 , an oil seal 16 is provided between the mounting hole 15 and the shaft head 12; specifically, the oil seal 16 can ensure the sealing between the shaft head 12 and the cover plate 14, thereby preventing oil pressure leakage, so as to meet the expected lubrication flow requirement.

[0051] like Figure 7 As shown, the mounting hole 15 is provided with a boss portion 17 protruding radially inward, a spring retaining ring 18 is installed in the mounting hole 15, and the oil seal 16 is located between the boss portion 17 and the spring retaining ring 18, thereby preventing the oil seal 16 from being ejected from the mounting hole 15 due to excessive oil pressure.

[0052] Specifically, a sealing ring may be provided between the cover plate 14 and the housing 13 ; in this embodiment, the cover plate 14 is fastened to the housing 13 by bolts.

[0053] like Figure 1 , 2 As shown in , 7 and 8, the shaft body 11 can be rotatably connected to the shell body 13 through a bearing 19. The shell body 13 can be provided with a first step hole 20 and a second step hole 21. The first step hole 20 is connected to the second step hole 21. The cover plate 14 is installed in the first step hole 20, and the bearing 19 is assembled in the second step hole 21.

[0054] like Figure 7 , 8 As shown, an oil suction chamber 22 and an oil pressure chamber 23 are provided on the cavity wall of the inner cavity 5, and the oil suction chamber 22 and the oil pressure chamber 23 are both provided in the housing 13 and communicated with the inner cavity 5 respectively;

[0055] The housing 13 is also provided with an oil inlet hole 24 connected to the oil suction chamber 22 and an oil outlet hole 25 connected to the oil pressure chamber 23; specifically, when the inner rotor 2 and the outer rotor 3 rotate in coordination, the oil flows into the oil suction chamber 22 from the oil inlet hole 24, and then flows into a plurality of closed working volumes between the inner rotor 2 and the outer rotor 3, and then the oil in the closed working volumes flows into the oil pressure chamber 23 and is discharged from the oil outlet hole 25.

[0056] like Figure 3 As shown, the inner rotor 2 is an external gear, the outer rotor 3 is an internal gear, the inner rotor 2 and the outer rotor 3 are both cycloid gears, and the inner rotor 2 has one less tooth than the outer rotor 3; in this embodiment, the inner rotor 2 has 6 teeth, and the outer rotor 3 has 7 teeth.

[0057] In summary, when the drive shaft 4 rotates, the inner rotor 2 is driven to rotate through the cooperation of the driving spline segment 10 and the inner spline 7, and the inner rotor 2 then drives the outer rotor 3 to rotate, thereby pumping oil. Among them, the interference fit between the centering spline segment 9 and the centering hole 6 can play a centering role for the inner rotor 2, so that the inner rotor 2 always remains concentric with the drive shaft 4 during the rotation process and will not swing relative to the drive shaft 4, thereby eliminating the swing of the inner rotor 2 during rotation, thereby avoiding the inner rotor 2 from getting stuck or even stuck during operation, and thus will not cause the drive shaft 4 to break. In addition, the centering hole 6 only contacts with the tooth top of the centering spline segment 9, and the contact area is small, so it is relatively easy to insert the centering spline segment 9 into the centering hole 6, making assembly easy and convenient.

[0058] The specific embodiments described above further illustrate the technical problems, technical solutions and beneficial effects solved by the present invention. It should be understood that the above are only specific embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A cycloid rotor mechanical pump, characterized in that: It comprises a casing (1), an inner rotor (2), an outer rotor (3) and a drive shaft (4); The housing (1) is provided with an inner cavity (5); The outer rotor (3) is installed in the inner cavity (5) and is used to rotate in the inner cavity (5); The inner rotor (2) is installed in the inner cavity (5) and is located inside the outer rotor (3) and meshes with the outer rotor (3); A centering hole (6) and an internal spline (7) communicating with the centering hole (6) are provided at the center of the inner rotor (2); The drive shaft (4) is rotatably connected to the housing (1), and the drive shaft (4) is provided with an external spline (8); The external spline (8) comprises a centering spline segment (9) and a driving spline segment (10); the centering spline segment (9) is inserted into the centering hole (6) and has an interference fit with the centering hole (6); and the driving spline segment (10) has a clearance fit with the internal spline (7).

2. The cycloid rotor mechanical pump according to claim 1, characterized in that: The outer diameter of the centering spline segment (9) is greater than the outer diameter of the driving spline segment (10).

3. The cycloid rotor mechanical pump according to claim 1, characterized in that: The driving shaft (4) comprises a shaft body (11) and a shaft head (12); The shaft (11) is rotatably connected to the housing (1); The shaft head (12) is connected to the shaft body (11) and is coaxial with the shaft body (11), and the external spline (8) is arranged on the shaft head (12).

4. The cycloid rotor mechanical pump according to claim 3, characterized in that: The casing (1) comprises a shell (13) and a cover plate (14); The cover plate (14) is connected to the shell (13), the cover plate (14) and the shell (13) surround and form the inner cavity (5), and the inner rotor (2) and the outer rotor (3) are both located between the shell (13) and the cover plate (14); The cover plate (14) is provided with a mounting hole (15) which is in communication with the inner cavity (5); the shaft head (12) passes through the mounting hole (15) so that the external spline (8) on the shaft head (12) extends into the centering hole (6) and the internal spline (7).

5. The cycloid rotor mechanical pump according to claim 4, characterized in that: An oil seal (16) is provided between the mounting hole (15) and the shaft head (12).

6. The cycloid rotor mechanical pump according to claim 5, characterized in that: The mounting hole (15) is provided with a boss portion (17) protruding radially inward, a spring retaining ring (18) is installed in the mounting hole (15), and the oil seal (16) is located between the boss portion (17) and the spring retaining ring (18).

7. The cycloid rotor mechanical pump according to claim 4, characterized in that: A sealing ring is provided between the cover plate (14) and the housing (13).

8. The cycloid rotor mechanical pump according to claim 4, characterized in that: The shaft body (11) is rotatably connected to the housing (13) via a bearing (19); a first step hole (20) and a second step hole (21) are provided in the housing (13); the first step hole (20) is communicated with the second step hole (21); the cover plate (14) is installed in the first step hole (20); and the bearing (19) is assembled in the second step hole (21).

9. The cycloid rotor mechanical pump according to claim 4, characterized in that: An oil suction chamber (22) and an oil pressure chamber (23) are provided on the chamber wall of the inner chamber (5); the oil suction chamber (22) and the oil pressure chamber (23) are both provided in the housing (13) and are respectively communicated with the inner chamber (5); The housing (13) is also provided with an oil inlet hole (24) communicating with the oil suction chamber (22) and an oil outlet hole (25) communicating with the oil pressure chamber (23).

10. The cycloid rotor mechanical pump according to claim 1, characterized in that: The inner rotor (2) is an external gear, the outer rotor (3) is an internal gear, the inner rotor (2) and the outer rotor (3) are both cycloid gears, and the inner rotor (2) has one less tooth than the outer rotor (3).

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