Press fitting tool for simulating straight hole interference fit between pump shaft and transmission gear
By designing the press-fit tooling of simulated pump shaft and transmission gear, the problems of high cost, high risk and lack of simulation test experience in traditional press-fit tests are solved, and safe and reliable simulated press-fit tests are carried out before physical press-fitting, reducing the development cycle and test costs.
Patent Information
- Application Number
- CN202421833776.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-07-31
- Publication Date
- 2025-05-27
- Estimated Expiration
- 2034-07-31
AI Technical Summary
In the direct hole interference matching test of the transmission gear of the diesel engine with pump and the pump shaft, traditional methods require direct use of products or parts for pressing, which leads to high cost, high risk and lack of simulation test experience, which easily leads to the failure of the first piece of pressing.
A press-fit tool for simulated pump shaft and transmission gear is designed to cooperate with straight hole interference, including transmission gear simulation disc, pump shaft simulation rod and compression positioning structure, which is used to conduct simulated compression tests before physical compression.
Through simulated tests, the damage of product parts during the first pressing and delay in development cycle can be effectively avoided, the testing costs are reduced, and the reliability and versatility of the test can be improved.
Smart Images
Figure CN222903134U_ABST
Abstract
Description
Technical Field
[0001] This application relates to the technical field of mechanical manufacturing and assembly, and specifically relates to a press-fitting tooling for simulating the interference fit of a straight hole between a pump shaft and a transmission gear. Background Art
[0002] Diesel engine-driven pumps are very common on ships. Common diesel engine-driven pumps include seawater pumps, fresh water pumps, fuel pumps, lubricating oil pumps, etc. Most pump products on medium and high-speed diesel engines are equipped with transmission gears. With the continuous upgrading of technology, more and more important pump products are designed for light weight, with fewer parts, small volume, light weight, large transmitted torque, and high reliability requirements. Therefore, the connection method between their transmission gears and pump shafts usually adopts straight hole interference fit.
[0003] A newly developed pump product by the applicant has a straight hole interference fit between its transmission gear and pump shaft and requires press-fitting, which is a new situation in the assembly of pump products. For the pump products encountered previously, the connection methods between their transmission gears and pump shafts are mostly key connections (radial clearance fit) and tapered hole connections (interference fit, with a radial interference amount within 0.02 mm); straight hole fits are also mainly assembled by cold fitting and hot fitting. This situation of directly press-fitting a straight hole is extremely rare, and there has been no situation where the press-fitting interference amount reaches 0.042 - 0.07 mm on a diameter of φ20. The radial interference amount between the transmission gear hole and the driving gear shaft is relatively large, and there is no corresponding experience accumulation for reference. It is necessary to avoid directly press-fitting the first piece with the product as much as possible.
[0004] If following the traditional press-fitting test idea and tooling design, it is necessary to directly press-fit with products and product components, and the cost of the press-fitting test is relatively high and the risk is also relatively large. Once a press-fitting error causes partial or complete scrapping of the trial-produced parts, it will further delay the product development cycle. Therefore, it is necessary to conduct a simulation press-fitting test before press-fitting the physical product parts. Summary of the Invention
[0005] This application relates to a press-fitting tooling for simulating the interference fit of a straight hole between a pump shaft and a transmission gear, which is used to conduct a simulation press-fitting test on the transmission gear and pump shaft of a diesel engine-driven pump before physical press-fitting.
[0006] The technical solution of this application is as follows:
[0007] This application provides a press-fitting tooling for simulating the interference fit of a straight hole between a pump shaft and a transmission gear, including: a support and force-bearing structure;
[0008] A transmission gear simulation disc, which is used to simulate the transmission gear of a diesel engine-driven pump;
[0009] A pump shaft simulation rod, which is used to simulate the pump shaft of a diesel engine-driven pump, and one end of the pump shaft simulation rod is assembled on the support and force-bearing structure;
[0010] A press-fitting positioning structure, the press-fitting positioning structure is sleeved on the transmission gear simulation disc, and the press-fitting positioning structure is used to press-fit the transmission gear simulation disc onto the pump shaft simulation rod along the axis direction of the pump shaft simulation rod under the action of the press head of the press;
[0011] Wherein, a first guiding angle is provided at the inner hole edge of the transmission gear simulation disc facing the pump shaft simulation rod, and / or, a second guiding angle is provided at the edge of the pump shaft simulation rod facing the transmission gear simulation disc.
[0012] Preferably, the pump shaft simulation rod is fixedly connected to the support stress structure by screwing, and the pump shaft simulation rod includes a first section fixedly connected to the support stress structure by screwing and a second section assembled with the transmission gear simulation disc;
[0013] Wherein, for at least two pump shaft simulation rods with different diameters of the second section, the outer diameters of the corresponding first section threads are the same.
[0014] Preferably, the first guiding angle is a chamfer formed at the inner hole edge of the transmission gear simulation disc, and the second guiding angle is a chamfer formed at the end face edge of the pump shaft simulation rod facing the transmission gear simulation disc.
[0015] Preferably, a groove is provided on the press-fitting positioning structure for a section of the pump shaft simulation rod to extend through the transmission gear simulation disc.
[0016] The beneficial effects of this application are as follows:
[0017] The transmission gear simulation disc is used to simulate the transmission gear of the diesel engine-driven pump. The transmission gear simulation disc is manufactured by the same process and production procedures as the transmission gear of the diesel engine-driven pump, but the transmission gear simulation disc does not have the external teeth of the transmission gear, that is, the overall structure of the transmission gear simulation disc is simpler than that of the actual transmission gear of the diesel engine-driven pump; similarly, the pump shaft simulation rod is used to simulate the pump shaft of the diesel engine-driven pump. The pump shaft simulation rod is manufactured by the same process and production procedures as the pump shaft of the diesel engine-driven pump, but the pump shaft simulation rod does not have the external teeth of the pump shaft of the diesel engine-driven pump, that is, the overall structure of the pump shaft simulation rod is simpler than that of the actual pump shaft of the diesel engine-driven pump. Through this press-fitting tooling for direct-hole interference fit between the simulated pump shaft and the transmission gear, it is possible to simulate and verify whether product damage occurs during the direct-hole press-fitting of the pump shaft and the transmission gear under the interference parameter requirements. Description of the Drawings
[0018] Figure 1 It is a schematic diagram of the press-fitting tooling for direct-hole interference fit between the simulated pump shaft and the transmission gear in the embodiment of this application. Detailed Embodiments
[0019] When the pump shaft with interference fit in the straight hole of the medium-speed diesel engine belt-driven pump is press-fitted with the interference fit of the transmission gear, the specific interference press-fitting situation between the shaft and the hole is unknown, and there is a risk of press-fitting failure. Therefore, it is necessary to conduct a press-fitting test. The traditional press-fitting test method for straight-hole interference fit is to directly use the product or its components for press-fitting.
[0020] The traditional press-fitting test tooling is to design a corresponding press-fitting positioning structure 1 according to parameters such as the outer diameter, thickness, and axial press-fitting distance of the product transmission gear; and design a corresponding support force-bearing structure 4 according to the shape, structure, and support points on the back of the product. Then, install the tooling on the bottom of the product and the top of the transmission gear, and use equipment such as a press to press-fit the transmission gear onto the pump shaft. However, this press-fitting test method and tooling require the use of the product or its components for press-fitting during the pressure test, resulting in a relatively high test cost. Moreover, the first batch of trial-produced products is limited in quantity, extremely rare and precious, and has high scientific research value. Once damaged during the pressure test, it will delay the new product development cycle, and direct press-fitting of the first piece with the product should be avoided as much as possible. In addition, a set of traditional gear press-fitting test tooling is almost only applicable to the press-fitting of transmission gears and pump shafts with straight-hole interference fit on specific types of products, belonging to single-matching special tooling with a narrow application range and no interchangeability. That is, for each type of pump product with "straight-hole interference fit", the same number of sets of gear press-fitting test tooling need to be designed and manufactured. And the large number of tooling also brings many inconveniences to their management, maintenance, use, etc., increasing the economic cost of the enterprise.
[0021] Based on this application scenario, the embodiment of the present application specifically designs a press-fitting tooling for simulating the straight-hole interference fit between the pump shaft and the transmission gear; referring to Figure 1 , this tooling is mainly used for simulating the press-fitting test of the straight-hole interference fit of the transmission gear on the medium-high speed diesel engine belt-driven pump. The tooling includes: a press-fitting positioning structure 1 for press-fitting the transmission gear and axial positioning, a transmission gear simulation disk 2 for simulating the inner hole and outer shape of the transmission gear, a pump shaft simulation rod 3 for simulating the outer circle and outer shape of the pump shaft, and a support force-bearing structure 4 for supporting and straightening the simulation rod.
[0022] One end of the pump shaft simulation rod 3 is assembled on the support force-bearing structure 4; the press-fitting positioning structure 1 is sleeved on the transmission gear simulation disk 2, and the press-fitting positioning structure 1 is used to press-fit the transmission gear simulation disk 2 along the axis direction of the pump shaft simulation rod 3 under the action of the press head of the press; wherein, a first guiding angle 21 is provided at the inner hole edge of the transmission gear simulation disk 2 facing the pump shaft simulation rod 3, and / or, a second guiding angle 31 is provided at the edge of the pump shaft simulation rod 3 facing the transmission gear simulation disk 2.
[0023] The press-fitting positioning structure 1 is looped around the transmission gear simulation disc 2, which can keep it radially fixed to the transmission gear simulation disc 2 and prevent it from shifting during press-fitting.
[0024] Before press-fitting, the pump shaft simulation rod 3 and the transmission gear simulation disc 2 form a pre-positioning using the first guiding angle 21 and / or the second guiding angle 31. There is no need for connection between the transmission gear simulation disc 2 and the press-fitting positioning structure 1. The press-fitting positioning structure 1 is just sleeved on the transmission gear simulation disc 2. Since the press-fitting positioning structure 1 is connected to the press head of the press, the press-fitting positioning structure 1 and the pump shaft simulation rod 3 jointly play a positioning role for the transmission gear simulation disc 2, and the transmission gear simulation disc 2 will not fall off. Furthermore, by applying force through the press, the transmission gear simulation disc 2 can be press-fitted onto the pump shaft simulation rod 3 along the axial direction of the pump shaft simulation rod 3.
[0025] Performing simulation press-fitting before actually press-fitting the product parts effectively avoids adverse situations such as part damage during direct press-fitting, repeated disassembly and replacement of parts of the product, and product scrapping. In addition, one pump shaft simulation rod 3 can be used as a simulation part for multiple pump shafts with the same diameter of various mating sections, improving the versatility and expanding the scope of use.
[0026] In the embodiment of the present application, the shape of the transmission gear simulation disc 2 is a round bottom disc shape, and the pump shaft simulation rod 3 is a shaft structure. Both the round bottom disc and the pump shaft simulation rod 3 are easy to obtain materials and process. The separate transmission gear simulation disc 2 does not need to be heat-treated together with the pump shaft simulation rod 3, which greatly reduces the manufacturing difficulty and cost. Moreover, for the press-fitting situations of different products, only the pump shaft simulation rod 3 needs to be replaced each time, and the transmission gear simulation disc 2 can be reused multiple times, thus greatly improving its versatility and further reducing the cost.
[0027] In the embodiment of the present application, the pump shaft simulation rod 3 is fixedly connected to the support stress-bearing structure 4 by screwing, which makes it convenient to disassemble and assemble the transmission gear simulation disc 2 during repeated use. At the same time, the connection screw hole size of the support stress-bearing structure 4 is designed as a fixed value in a range of steps, that is, multiple pump shaft simulation rods 3 with a range of press-fitting section diameters all use the same fixed value of external connection threads. This enables one support stress-bearing structure 4 to assemble multiple pump shaft simulation rods 3 for repeated use many times, greatly improving the versatility. In terms of bearing pressure, the pump shaft simulation rod 3 has a stepped section to bear the pressure, avoiding the thread directly bearing the press-fitting force, which greatly improves the press-fitting load-bearing capacity.
[0028] In the embodiment of the present application, the pump shaft simulation rod 3 matching different pump shafts includes a first section fixedly connected to the support stress-bearing structure 4 by screwing and a second section assembled with the transmission gear simulation disc 2; for at least two pump shaft simulation rods 3 with different diameters of the second section, the outer diameters of the threads of the corresponding first sections are the same.
[0029] Before use, screw the external thread end of the pump shaft simulation rod 3 into the corresponding screw hole of the supporting force-bearing structure 4, and tighten the two with tools such as a wrench, then place it on the supporting platform of the press. Align the inner hole of the transmission gear simulation disc 2 with the outer circular shaft of the pump shaft simulation rod 3 along the first guiding angle 21 and the second guiding angle 31, and then place the press-fitting positioning structure 1 above the transmission gear simulation disc 2. Then, the press head of the press presses down smoothly from above, and the press-fitting test of the straight-hole interference fit can be carried out.
[0030] The screw hole set on the outer circle of the supporting force-bearing structure 4 has a relatively deep depth. Installing a screw in it can easily make it rotate forward and backward in the circumferential direction, playing the role of tightening and loosening. This enables the disc that originally required a wrench and pliers to fix and turn to be operated by hand, simplifying the operation; it also enables it to be used normally under various simple tool conditions, greatly improving the practicability.
[0031] In the embodiment of the present application, the press-fitting positioning structure 1 is provided with a groove 11 for a section of the pump shaft simulation rod 3 passing through the transmission gear simulation disc 2 to extend into. During press-fitting, the protruding section of the pump shaft simulation rod 3 always enters the corresponding groove 11 on the transmission gear simulation disc 2, ensuring the axial press-fitting distance and the stability and reliability of press-fitting. This makes the operation simple and easy to control.
[0032] The tooling in the embodiment of the present application is a general design, which can be popularized and applied, has a wide application range, a high reuse rate, and also reduces costs.
[0033] Compared with the traditional tooling, the tooling in the embodiment of the present application has obvious advantages in the design concept and structure, reducing the production and manufacturing costs; it has certain interchangeability and universality in function, can be used for the press-fitting test of the straight-hole interference fit of various products, expanding the application range and reducing the economic cost; it has good practicability in the assembly and development of water pumps, fuel pumps, and lubricating oil pumps of marine diesel engines.
[0034] The above are only the embodiments of the present invention. It should be noted that for those skilled in the art, without departing from the structure of the present invention, several deformations and improvements can be made, which should also be regarded as the protection scope of the present invention, and these will not affect the implementation effect of the present invention and the practicability of the patent. The protection scope required by this application should be based on the content of its claims, and the specific implementation manners described in the specification can be used to interpret the content of the claims.
Claims
1. A press-fitting tool for simulating the straight hole interference fit between a pump shaft and a transmission gear, characterized in that: include: Supporting structure (4); A transmission gear simulation plate (2), which is used to simulate the transmission gear of a diesel engine belt pump; A pump shaft simulation rod (3) used to simulate a pump shaft of a diesel engine belt pump, one end of the pump shaft simulation rod (3) being assembled on the supporting force structure (4); A press-fitting positioning structure (1), the press-fitting positioning structure (1) being sleeved on the transmission gear simulation disk (2), and the press-fitting positioning structure (1) being used to press-fit the transmission gear simulation disk (2) onto the pump shaft simulation rod (3) along the axial direction of the pump shaft simulation rod (3) under the action of a press head; The inner hole edge of the transmission gear simulation disk (2) facing the pump shaft simulation rod (3) is provided with a first guide angle (21), and / or the edge of the pump shaft simulation rod (3) facing the transmission gear simulation disk (2) is provided with a second guide angle (31).
2. The press-fitting tool for simulating straight hole interference fit between a pump shaft and a transmission gear according to claim 1, characterized in that: The pump shaft simulation rod (3) is screwed and fixed to the supporting force structure (4), and the pump shaft simulation rod (3) comprises a first section screwed and fixed to the supporting force structure (4) and a second section assembled with the transmission gear simulation disk (2); Wherein, for at least two pump shaft simulation rods (3) with different second section diameters, the corresponding first section thread outer diameters are all the same.
3. The press-fitting tool for simulating straight hole interference fit between a pump shaft and a transmission gear according to claim 1, characterized in that: The first guide angle (21) is a chamfer formed by the edge of the inner hole of the transmission gear simulation disk (2), and the second guide angle (31) is a chamfer formed by the edge of the end surface of the pump shaft simulation rod (3) facing the transmission gear simulation disk (2).
4. The press-fitting tool for simulating straight hole interference fit between a pump shaft and a transmission gear according to claim 1, characterized in that: The press-fit positioning structure (1) is provided with a groove (11) for the pump shaft simulation rod (3) to extend through a section of the transmission gear simulation disk (2).