Elastic press-fitting device for high-precision gear shaft assembly
Through the design of the guide block and limit retaining ring of the elastic pressing device, the problem of improper assembly of the intermediate shaft and gear caused by traditional rigid pressing tools is solved, and high-precision gear shaft assembly assembly is achieved, which improves the stability of the assembly process and gear accuracy.
Patent Information
- Application Number
- CN202422523847.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-10-18
- Publication Date
- 2025-08-12
- Estimated Expiration
- 2034-10-18
AI Technical Summary
When traditional rigid pressing tools press the gear shaft assembly, they cause improper assembly of the intermediate shaft and the gear, resulting in high pressure noise, unstable pressing force, many metal particles, and deformation, which affect the gear accuracy and transmission NVH performance.
An elastic pressing device is adopted, including a pressing base, a press head, a support block, a guide block, a spring and a limit retaining ring. Through the coordination of the positioning boss of the guide block and the limit retaining ring, the intermediate shaft is ensured to be coaxially assembled with the gear, avoid skew and deformation during pressing, and use a spring to provide a buffering guide effect.
The uniform stress assembly of the intermediate shaft and the gear is achieved, which avoids deformation and noise during the pressing process, improves the gear accuracy and NVH performance of the gearbox, and is compact in structure, low in cost and high versatility.
Smart Images
Figure CN223210820U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to a press-fitting device for a gear shaft assembly, in particular to an elastic press-fitting device for a high-precision gear shaft assembly. Background Art
[0002] In electric-powered new energy vehicle reducers, the intermediate shaft assembly is a key component. The primary driven gear and the secondary intermediate shaft are often press-fitted into a gear shaft assembly using either a large-diameter interference fit or a tooth-side interference fit. Due to differences in component structural design, some parts can experience high press-fit noise, unstable press-fitting force, excessive metal particles affecting cleanliness, and deformation during press-fitting due to misaligned intermediate shafts. Traditional rigid tools, in particular, can cause uneven force on the contact surface of the shaft and teeth during press-fitting, leading to gear deformation and excessive helix angle errors or tooth V-values, impacting gear accuracy and, in turn, the NVH performance of the gearbox. To prevent or improve this phenomenon, a new press-fit tool with elastic buffering and good guidance is needed. Utility Model Content
[0003] The purpose of the utility model is to provide an elastic press-fitting device for a high-precision gear shaft assembly, so as to solve the problems existing in the press-fitting of the gear shaft assembly by the existing rigid press-fitting tool.
[0004] To achieve the above objectives, the present invention provides the following technical solutions:
[0005] An elastic press-fitting device for a high-precision gear shaft assembly, comprising
[0006] A press-fit base, the press-fit base having a vertically extending mounting channel;
[0007] A pressing head is arranged above the press-fitting base;
[0008] A support block is provided on the upper portion of the press-fit base and has a first guide channel coaxial with the installation channel;
[0009] A guide block is axially slidably disposed in the first guide channel, the guide block having a support surface parallel to the end surface of the intermediate shaft vertically extending into the gear, and a positioning boss extending upward is provided on the support surface;
[0010] A spring is disposed in the mounting channel, wherein the upper end of the spring is supported on the bottom of the guide block to lift the guide block and allow the positioning boss to be inserted into the shaft hole of the intermediate shaft;
[0011] The limiting retaining ring is arranged on the upper part of the press-fitting base and is coaxial with the positioning boss. The limiting retaining ring has an inner diameter that is adapted to the required assembly gear.
[0012] Preferably, the upper edge of the positioning boss is provided with a guide slope.
[0013] Preferably, a second guide channel is coaxially provided at the bottom of the installation channel, and a vertically extending guide rod is provided at the bottom of the guide block, and the guide rod is slidably fitted through the second guide channel.
[0014] Preferably, the guide rod extends out of the lower end of the press-fit base and is slidably fitted with an adjustment sleeve, and an adjustment bolt can move relatively through the adjustment sleeve and be screwed to the guide rod so that the upper end surface of the adjustment sleeve abuts against the lower surface of the press-fit base.
[0015] Preferably, the fitting clearance between the positioning boss and the inner hole of the intermediate shaft is 0.15 to 0.25 mm on one side.
[0016] Preferably, the fitting clearance between the guide block and the first guide channel of the press-fit base is 0.05 to 0.15 mm on one side.
[0017] Preferably, the support block, the limiting retaining ring and the press-fit base are detachably connected.
[0018] Compared with the prior art, the beneficial effects of the present invention are:
[0019] Compared with the prior art, the present invention has the following advantages and effects:
[0020] When this solution is used to assemble the shaft and the gear, the front end guide part of the shaft is first inserted into the assembly hole of the gear, and the lower end face abuts against the plane of the guide block to ensure that the shaft can be in a coaxial state with the gear when the pressure head is pressed downward, avoiding the situation where the gear and the shaft are tilted relative to each other when the shaft is pressed downward, resulting in uneven force on the press-fit contact surface. In addition, the guide block in this solution can move downward synchronously with the shaft during the press-fitting process of the shaft and the gear, and can apply an axial buffering and guiding effect to the lower end of the shaft during the downward movement, thereby improving the problem of large rigid impact of traditional press-fitting tools. It should also be noted that this solution has the advantages of compact structure, low production cost, moderate weight, and easy loading and unloading, and the specifications and sizes of the support block and limit ring in this solution can be flexibly replaced according to the specifications of the gears and shafts to be assembled, so that this solution has higher versatility in production. BRIEF DESCRIPTION OF THE DRAWINGS
[0021] Figure 1 This is a schematic diagram of the structure of the utility model when preparing to press-fit gears and shafts;
[0022] Figure 2 It is a structural schematic diagram of the utility model when press-fitting gears and shafts.
[0023] Figure numerals: 1. Press head 2. Guide block 201. Positioning boss 3. Support block 301. First guide channel 4. Spring 5. Limiting retaining ring 6. Press-fit base 601. Mounting channel 602. Second guide channel 7. Guide rod 8. Adjusting sleeve 9. Adjusting bolt 10. Intermediate shaft 11. Gear DETAILED DESCRIPTION
[0024] The following is a clear and complete description of the technical solution of the present invention in conjunction with the accompanying drawings. Obviously, the embodiments described are only some of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts are within the scope of protection of the present invention.
[0025] In the description of this utility model, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicating positions or relationships, are based on the positions or relationships shown in the accompanying drawings and are intended solely to facilitate the description of this utility model and simplify the description. They do not indicate or imply that the devices or components referred to must have a specific orientation, be constructed, or operate in a specific orientation. Therefore, they should not be construed as limitations on this utility model. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.
[0026] In the description of this utility model, it should be noted that, unless otherwise expressly specified or limited, the terms "mounted," "connected," and "connected" should be understood in a broad sense. For example, they can refer to fixed connections, detachable connections, or integral connections; mechanical connections, electrical connections; direct connections, indirect connections through an intermediate medium, and internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in this utility model based on the specific circumstances.
[0027] This solution is used to solve the problem of the intermediate shaft and gear not being able to be aligned during press-fitting (intermediate shaft and gear not being coaxial), which causes the intermediate shaft and gear to be pressed against each other and deform. It also solves the problem of the intermediate shaft being subjected to excessive impact when press-fitting the intermediate shaft into the gear.
[0028] Specifically, such as Figure 1 、 Figure 2 The elastic press-fitting device of a high-precision gear shaft assembly shown in the figure comprises a press-fitting base 6 made of carburized steel and capable of maintaining a stable shape even after bearing the large pressure of the press-fitting intermediate shaft. Figure 1 As shown, a vertically extending installation channel 601 is provided in the press-fit base.
[0029] A pressing head 1 is provided above the press-fitting base, and the pressing head is connected to a servo press (not shown in the figure). When the intermediate shaft needs to be pressed into the gear, the pressing head can apply a downward stable pressure to the intermediate shaft.
[0030] In addition, a support block 3 is provided on the upper portion of the press-fitting base 6 , and a first guide channel 301 is provided through the center of the support block, and the first guide channel is coaxially connected to the installation channel 601 .
[0031] like Figure 1 As shown, a spring 4 is placed in the installation channel 601, and a guide block 2 is slidably fitted in the first guide channel. The lower end of the spring abuts against the bottom of the installation channel, and the upper end abuts against the lower surface of the guide block, so that the guide block can have the ability to slide back and forth elastically in the first guide channel. It should be noted that while ensuring the coaxial sliding of the guide block in the first guide channel 301, it is also necessary to take into account the smoothness of the sliding of the guide block in the first guide channel. For this purpose, the clearance between the guide block and the first guide channel of the press-fit base is specified to be between 0.05 and 0.15 mm. Under this gap, there can be an oil film for lubrication to improve the smoothness of the sliding of the guide block in the first guide channel. It should also be noted that in some embodiments, the diameter of the first guide channel can be the same as the diameter of the installation channel below to facilitate one-piece molding during processing.
[0032] It should be noted that after the guide block is placed in the first guide channel, the upper surface of the guide block and the lower end surface of the intermediate shaft inserted into the gear are parallel to each other. When the transition section of the intermediate shaft is inserted into the assembly hole of the gear, the surface of this transition section is not subject to radial constraints from the gear mounting hole, and the intermediate shaft is very likely to tip over and become skewed. In this case, if a traditional rigid press-fitting tool is used, the contact portion between the intermediate shaft and the gear is prone to crushing and damage. At this time, if the upper surface of the guide block can abut against the lower end surface of the intermediate shaft, it can provide a guiding support for the intermediate shaft to guide it upright, ensuring that the intermediate shaft and the gear mounting hole are parallel to each other during press-fitting. This avoids the occurrence of localized uneven force during press-fitting caused by the skew of the intermediate shaft.
[0033] It should be noted that to better guide the intermediate shaft, an upwardly projecting positioning boss 201 is provided on the upper surface of the guide block. This positioning boss maintains a coaxial position with the gear mounting hole as it slides within the first guide channel. Once the intermediate shaft's transition section is inserted into the gear, the positioning boss slides into the intermediate shaft's axial hole, ensuring the intermediate shaft and the gear mounting hole remain coaxial. This prevents edge deformation caused by misalignment between the intermediate shaft and gear during press-fitting. To facilitate the positioning boss's entry into the intermediate shaft's axial hole, a sloped guide ramp is preferably provided on its upper edge.
[0034] It should be noted that in the above method, in order to be able to more efficiently guide the position of the gear and the shaft assembly when installing, a limit ring 5 is also provided on the upper part of the press-fit base. Specifically, the inner circle of the limit ring maintains a coaxial relationship with the first guide channel opened on the support block. Moreover, the inner diameter of the limit ring is adapted to the tooth top circle of the gear (a single-sided gap of 1mm is left between the tooth top circle of the gear and the limit ring) to ensure that the gear can be slidably fitted into the limit ring. In addition, as the above-mentioned preference, that is, when the limit boss is inserted into the shaft hole of the intermediate shaft, the accuracy of positioning and guiding can be guaranteed, and the limit boss can also be smoothly inserted into the shaft hole of the intermediate shaft. The fitting clearance between the limit boss 201 and the inner hole of the intermediate shaft is between 0.15 and 0.25mm on one side.
[0035] Furthermore, based on the above embodiment, a further improvement can be made. Specifically, a second guide channel 602 is coaxially disposed at the bottom of the mounting channel 601 and extends through the guide channel. A guide rod 7 is slidably inserted into the second guide channel 602. It should be noted that the upper end of the guide rod is fixedly connected to the bottom of the guide block, thereby providing an auxiliary sliding guide function for the guide block.
[0036] It should also be noted that the portion of the guide rod 7 extending from the bottom of the press-fit base can also be used to adjust the compression length of the spring 4 and the height of the guide block. Specifically, an adjustment sleeve 8 is slidably mounted on the lower end of the guide rod extending from the press-fit base 6. The lower end of the adjustment sleeve is sealed and has a through hole. Simultaneously, an adjustment bolt 9 is coaxially threaded onto the lower end of the guide rod. This adjustment bolt passes through a through hole in the adjustment cap to prevent the adjustment cap from sliding off the guide rod. At this time, since the spring is in a compressed state, the guide rod tends to be pulled upward, and the upper end surface of the adjustment cap presses against the lower surface of the press-fit base to prevent the guide rod from being pulled into the installation channel by the spring. To adjust the height of the guide block extending from the first guide channel 301, the operator simply adjusts the depth of the bolt in the guide rod. Specifically, as the adjustment bolt penetrates the guide rod further, the guide block's height decreases, while as the adjustment bolt penetrates the guide rod further, the guide block's height increases.
[0037] It should also be noted that in actual assembly, intermediate shafts and gears come in a variety of sizes. To enhance the adaptability of this solution, the retaining rings and support blocks used to constrain the gears and intermediate shafts are removably bolted to the press-fit base. This allows for replacement of the support blocks and retaining rings if the gear or intermediate shaft size changes.
[0038] Working Principle: When assembling the gear and intermediate shaft assembly, workers select the appropriate retaining ring and support block and install them on the press-fit base. The worker then places the gear into the retaining ring. The outer edge of the gear is guided and aligned by the retaining ring's inner diameter, and the middle end face of the gear abuts the end face of the support block. The gear is now coaxial with the first guide channel in the support frame. The intermediate shaft's transition section is then inserted into the gear. It should be noted that the support block height in this solution is calculated to ensure that after the intermediate shaft's transition section (the lower half that guides the intermediate shaft's splined portion into the gear) is inserted into the gear's axial hole (spline groove), the lower end face of the intermediate shaft abuts the upper surface of the guide block, maintaining a vertical position. The retaining boss also simultaneously enters the intermediate shaft's axial hole to ensure coaxiality between the intermediate shaft and the gear. Once these preparatory steps are complete, the press head, driven by the servo press, presses downward, and the intermediate shaft is pressed into the gear in the correct position. It should be noted that during the downward pressing process, the intermediate shaft is clamped by the pressing head and the guide blocks at both ends to prevent the intermediate shaft from tilting during the press-fit process and ensure that all parts of the intermediate shaft and gear are evenly stressed during press-fit. It should be noted that the spring-supported guide blocks during this downward pressing process provide a cushioned assembly process, avoiding the problems of collision and deformation between the intermediate shaft and gear that can easily occur with existing rigid press-fit methods.
[0039] In addition, in this solution, the height to which the guide block is raised can be flexibly adjusted according to the height to which the transition section of the intermediate shaft can be lowered during assembly, so as to ensure that the upper surface of the guide block is in close contact with the lower end surface of the intermediate shaft, and the limiting boss on the guide block can be inserted into the axial hole of the intermediate shaft, ensuring that the intermediate shaft is in a coaxial state with the gear during press assembly.
[0040] Although the 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 variations may be made to these embodiments without departing from the principles and spirit of the present invention, and the scope of the present invention is defined by the appended claims and their equivalents.
Claims
1. An elastic press-fitting device for a high-precision gear shaft assembly, characterized in that: include A press-fit base (6), the press-fit base (6) having a vertically extending mounting channel (601); A pressing head (1) is arranged above the press-fitting base (6); A support block (3) is arranged on the upper portion of the press-fit base (6) and has a first guide channel (301) coaxial with the installation channel (601); A guide block (2) is axially slidably disposed in the first guide channel (301), the guide block (2) having a support surface parallel to the end surface of the intermediate shaft vertically extending into the gear, and a positioning boss (201) extending upward is provided on the support surface; A spring (4) is arranged in the installation channel (601), and the upper end of the spring (4) is supported on the bottom of the guide block (2) to lift the guide block (2) and allow the positioning boss (201) to be inserted into the shaft hole of the intermediate shaft; A limit ring (5) is arranged on the upper part of the press-fit base (6) and is coaxial with the positioning boss (201). The limit ring (5) has an inner diameter that is adapted to the required assembled gear.
2. The elastic press-fitting device for a high-precision gear shaft assembly according to claim 1, characterized in that: The upper edge of the positioning boss (201) is provided with a guide slope.
3. The elastic press-fitting device for a high-precision gear shaft assembly according to claim 2, characterized in that: A second guide channel (602) is coaxially provided at the bottom of the installation channel (601), and a vertically extending guide rod (7) is provided at the bottom of the guide block (2), and the guide rod (7) is slidably fitted through the second guide channel (602).
4. The elastic press-fitting device for a high-precision gear shaft assembly according to claim 3, characterized in that: The guide rod (7) extends out of the lower end of the press-fit base (6) and is slidably fitted with an adjustment sleeve (8). An adjustment bolt (9) is capable of relative movement and passes through the adjustment sleeve (8) and is screwed onto the guide rod (7) so that the upper end surface of the adjustment sleeve (8) abuts against the lower surface of the press-fit base (6).
5. The elastic press-fitting device for a high-precision gear shaft assembly according to claim 4, characterized in that: The matching clearance between the positioning boss (201) and the inner hole of the intermediate shaft is 0.15 to 0.25 mm per side.
6. The elastic press-fitting device for a high-precision gear shaft assembly according to claim 5, characterized in that: The fitting clearance between the guide block (2) and the first guide channel (301) of the press-fit base (6) is 0.05 to 0.15 mm per side.
7. The elastic press-fitting device for a high-precision gear shaft assembly according to claim 6, characterized in that: The support block (3), the limiting retaining ring (5) and the press-fit base (6) are detachably connected.