Gear pump shaft sleeve assembly press-in device

Abstract

This utility model discloses a gear pump shaft assembly pressing device, including a shaft sleeve and a pump cover. The pump cover has two pump cover seat holes, and also includes a stepped positioning mandrel and a positioning seat. The positioning seat has a positioning structure, and the positioning seat is placed on the pump cover through the positioning structure. The positioning seat has two positioning holes, the diameter of which is slightly larger than the diameter of the pump cover seat holes and coaxial with the pump cover seat holes. The stepped positioning mandrel has a coaxial small section, a middle section, and a large section. The small section can be fitted into the inner hole of the shaft sleeve, and the middle section can be fitted into the positioning holes. This utility model enables precise control of the depth of the shaft sleeve pressed into the pump cover seat hole when the hydraulic press presses down the stepped positioning mandrel to press the shaft sleeve, ensuring assembly quality and avoiding problems caused by the shaft sleeve being pressed too deeply or too shallowly into the pump cover seat hole. At the same time, it improves assembly efficiency, and the operator does not need to be experienced, reducing the skill requirements of the operator.

Description

Technical Field

[0001] This utility model relates to the field of gear pump assembly technology, specifically a gear pump shaft assembly and pressing device. Background Technology

[0002] In the assembly of some gear pump assemblies, bushing assembly is often a challenge. Many gear pump failures on the market are caused by insufficient precision in pressing the bushing into the pump cover seat hole (too deep or too shallow). In existing technology, bushing assembly typically uses a hydraulic press to press a straight cylindrical locating mandrel into the pump cover seat hole. Because the depth of the pump cover seat hole is greater than the length of the bushing (to ensure sufficient clearance for oil to enter the bushing for gear lubrication), the precision of pressing the bushing into the pump cover seat hole relies heavily on the operator's experience. Therefore, the assembled gear pump has potential quality issues. If the bushing is pressed in too deeply, the subsequently assembled figure-eight seal will be ejected and burn out during pump operation, causing gear pump failure. If the bushing is pressed in too shallowly (approximately above the upper plane of the pump cover), the gear pump assembly will interfere. Even if assembly is completed, during factory testing, various data will not meet factory requirements, resulting in product defects. Utility Model Content

[0003] The purpose of this utility model is to provide a gear pump shaft sleeve assembly pressing device that can accurately control the depth of the shaft sleeve pressing into the pump cover seat hole, thereby ensuring assembly quality.

[0004] To achieve the above objectives, this utility model provides the following technical solution:

[0005] A gear pump shaft assembly and pressing device includes a shaft sleeve and a pump cover. The pump cover has two pump cover seat holes. It also includes a stepped positioning mandrel and a positioning seat. The positioning seat has a positioning structure and is placed on the pump cover via the positioning structure. The positioning seat has two positioning holes, the diameter of which is slightly larger than the diameter of the pump cover seat holes and coaxial with them. The stepped positioning mandrel has a coaxial small section, a middle section, and a large section. The small section can be fitted into the inner hole of the shaft sleeve, the middle section can be fitted into the positioning holes, and the diameter of the middle section is larger than the inner diameter of the shaft sleeve and slightly smaller than the outer diameter of the shaft sleeve. The diameter of the large section is larger than the diameter of the positioning hole. During assembly, the shaft sleeve is placed in the positioning hole, the small section of the stepped positioning mandrel is fitted into the shaft sleeve with the large section facing upwards, and the stepped positioning mandrel is used to press the shaft sleeve into the pump cover seat hole using a hydraulic press.

[0006] Furthermore, the positioning structure includes a stop at the bottom of the positioning seat, the shape of which matches the shape of the boss on the pump cover, and the depth of the stop is greater than the height C of the boss.

[0007] Furthermore, the upper end of the positioning hole is chamfered.

[0008] Furthermore, the length of the short segment is slightly less than the length of the bushing.

[0009] Furthermore, the difference between the middle section length A and the positioning seat height B and the boss height C is greater than 0.3-0.5 mm.

[0010] Compared with the prior art, the beneficial effects of this utility model are:

[0011] This utility model is equipped with a stepped positioning mandrel and a positioning seat. The positioning seat has a positioning hole and is placed on the pump cover. The bushing is placed in the positioning hole. The stepped positioning mandrel is inserted into the bushing. By controlling the middle length of the stepped positioning mandrel, the depth of the bushing pressed into the pump cover seat hole can be precisely controlled when the hydraulic press presses down on the stepped positioning mandrel to install the bushing. This ensures the assembly quality and avoids problems caused by the bushing being pressed too deep or too shallow into the pump cover seat hole. At the same time, it improves the assembly efficiency and does not require the operator to be experienced, thus reducing the skill requirements of the operator. Attached Figure Description

[0012] Figure 1 This is an exploded view of the present invention;

[0013] Figure 2 This is a cross-sectional view of the structure of this utility model;

[0014] Figure 3 Schematic diagram of the stepped positioning mandrel;

[0015] Figure 4 This is a schematic diagram of the positioning seat;

[0016] In the diagram: 1-stepped positioning mandrel, 101-small section, 102-middle section, 103-large section, 2-positioning seat, 201-positioning hole, 202-chamfer, 203-stop, 3-shaft sleeve, 4-pump cover, 401-pump cover seat hole, 402-bore. Detailed Implementation

[0017] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments.

[0018] Please see Figures 1-4 One embodiment provided by this utility model:

[0019] A gear pump shaft fitting and pressing device includes a shaft sleeve 3 and a pump cover 4. The pump cover 4 has two pump cover seat holes 401. It also includes a stepped positioning mandrel 1 and a positioning seat 2. The positioning seat 2 has a positioning structure and is placed on the pump cover 4 via the positioning structure. The positioning seat 2 has two positioning holes 201, the diameter of which is slightly larger than the diameter of the pump cover seat holes 401 and coaxial with them. The stepped positioning mandrel 1 has a coaxial small section 101, a middle section 102, and a large section 103. The small section 101 can be fitted into the inner hole of the shaft sleeve 3, and the middle section 102 can be fitted into the positioning holes 203. In section 01, the bushing 3 is made coaxial with the stepped positioning mandrel 1, the positioning hole 201, and the pump cover seat hole 401 to facilitate press fitting. The diameter of the middle section 102 is larger than the inner diameter of the bushing 3 and slightly smaller than the outer diameter of the bushing 3. The middle section 102 is used to press the end face of the bushing 3 so that the bushing 3 can be pressed into the pump cover seat hole 401 by a hydraulic press. The diameter of the large section 103 is larger than the diameter of the positioning hole 201. When assembling the bushing 3, the bushing 3 is placed in the positioning hole 201. The small section 101 of the stepped positioning mandrel 1 is fitted into the bushing 3 with the large section 103 facing upward. The stepped positioning mandrel 1 is pressed into the pump cover seat hole 401 by a hydraulic press.

[0020] The positioning structure includes a stop 203 located at the bottom of the positioning seat 2. The shape of the stop 203 matches the shape of the boss 402 on the pump cover 4. The depth of the stop 203 is greater than the height C of the boss 402, so that the positioning seat 2 can fit tightly against the end face of the pump cover 4, which is convenient for bearing force.

[0021] The positioning hole 201 has a chamfer 202 on the upward-facing end, which serves as a guide when the stepped positioning mandrel 1 enters the positioning hole 201.

[0022] The length of the small segment 101 is slightly less than the length of the bushing 3 to avoid interference between the small segment 101 and the internal structure of the pump cover 4 when the bushing 3 is press-fitted.

[0023] In this embodiment, the difference between the length A of the middle section 102 and the height B of the positioning seat 2 and the height C of the boss 402 is greater than 0.3-0.5mm. This value is 0.5mm. When the hydraulic press presses down the stepped positioning mandrel 1 until the lower end face of the large section 103 contacts the upper surface of the positioning seat 2, the upper end face of the bushing 3 is 0.5mm lower than the upper end face of the boss 402 of the pump cover 4. This precisely controls the depth of the bushing 3 pressed into the pump cover seat hole 401 to be 0.5mm, ensuring the assembly quality and avoiding problems caused by the bushing 3 being pressed too deep or too shallow into the pump cover seat hole 401.

[0024] Although embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A gear pump shaft sleeve fitting and pressing device, comprising a shaft sleeve (3) and a pump cover (4), wherein the pump cover (4) is provided with two pump cover seat holes (401), characterized in that: It also includes a stepped positioning mandrel (1) and a positioning seat (2). The positioning seat (2) is provided with a positioning structure. The positioning seat (2) is placed on the pump cover (4) through the positioning structure. The positioning seat (2) has two positioning holes (201). The diameter of the positioning holes (201) is slightly larger than the diameter of the pump cover seat hole (401) and is coaxial with the pump cover seat hole (401). The stepped positioning mandrel (1) is provided with a coaxial small section (101), a middle section (102) and a large section (103). The small section (101) can be fitted into the inner hole of the bushing (3). The middle section (102) can be fitted into the positioning hole (201). The diameter of the middle section (102) is larger than the inner diameter of the bushing (3) and slightly smaller than the outer diameter of the bushing (3). The diameter of the large section (103) is larger than the hole diameter of the positioning hole (201). When the bushing (3) is assembled, the bushing (3) is placed into the positioning hole (201). The small section (101) of the stepped positioning mandrel (1) is fitted into the bushing (3) with the large section (103) facing upward. The stepped positioning mandrel (1) uses a hydraulic press to press the bushing (3) into the pump cover seat hole (401).

2. The gear pump shaft fitting press-fit device according to claim 1, characterized in that: The positioning structure includes a stop (203) set at the bottom of the positioning seat (2). The shape of the stop (203) matches the shape of the boss (402) of the pump cover (4). The depth of the stop (203) is greater than the height C of the boss (402).

3. The gear pump shaft fitting press-fit device according to claim 1, characterized in that: The positioning hole (201) has a chamfer (202) on the upward-facing end.

4. The gear pump shaft fitting press-fit device according to claim 1, characterized in that: The length of the small segment (101) is slightly less than the length of the bushing (3).

5. The gear pump shaft fitting press-fit device according to claim 1, characterized in that: The difference between the length A of the middle section (102) and the height B of the positioning seat (2) and the height C of the boss (402) is greater than 0.3-0.5mm.

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