Centering and angular position fixable internal spline gear machining tool and machining method thereof

Abstract

The application discloses a centering and angular position fixing internal spline gear machining tool and a machining method thereof, and relates to the technical field of internal spline gear machining, which comprises a base fixed on a machine tool, wherein the base is formed with a first supporting surface, and a sliding hole is formed in the first supporting surface; a centering shaft is slidably arranged in the sliding hole, and the circumferential surface of the centering shaft is formed with an external spline; the centering shaft is elastically connected to the base, one end of the centering shaft extends out of the sliding hole and is arranged in the spline hole of the internal spline gear, and the external spline is matched with the internal spline of the internal spline gear; a tailstock is adjustably arranged on the machine tool, the tailstock is formed with a second supporting surface, the second supporting surface is formed with a containing hole, and one end of the centering shaft is movably arranged in the containing hole. The application solves the problem that the traditional machining mode of the planetary gear of the RV reducer cannot guarantee the angular phase relationship of the internal and external teeth of different groups of planetary gears.

Description

Technical Field

[0001] This invention relates to the field of internal spline gear machining technology, specifically to a machining fixture and machining method for internal spline gears that can be centered and positioned at a fixed angle. Background Technology

[0002] In RV reducers, planetary gears are a critical component. A group of two or three planetary gears must have a consistent angular relationship between their internal splines and external teeth; otherwise, the transmission accuracy and noise will be significantly affected. Traditional machining methods often use specialized fixtures to process several planetary gears in groups, allowing them to circulate, undergo heat treatment, and precision machining to ensure that the external and internal teeth of the final planetary gear set have a consistent angular phase relationship. However, this method has significant drawbacks. Group circulation greatly increases management and process costs, and gears from different groups cannot be mixed; if one gear fails, the entire group of planetary gears will be scrapped. Summary of the Invention

[0003] To overcome the shortcomings of existing technologies, a machining fixture and machining method for internal spline gears that can be centered and have a fixed angular position are provided to solve the problem that traditional machining methods for planetary gears in RV reducers have difficulty in ensuring the angular phase relationship between the internal and external teeth of different sets of planetary gears.

[0004] To achieve the above objectives, a machining fixture for internal spline gears, capable of being centered and positioned at a fixed angle, is provided, comprising: A base fixed to a machine tool, the base having a first support surface in the middle of one end face of an internal spline gear to be machined, and a sliding channel being formed inside the first support surface; A centering shaft is slidably disposed within the sliding channel. An external spline is formed on the circumferential surface of the centering shaft. The centering shaft is elastically connected to the base. One end of the centering shaft extends out of the sliding channel and passes through the spline hole of the internal spline gear. The external spline is adapted to the internal spline of the internal spline gear. The tailstock is adjustablely mounted on the machine tool. The tailstock has a second support surface for pressing against the middle of the other end face of the internal spline gear. The second support surface has a receiving channel. One end of the centering shaft is movably inserted into the receiving channel.

[0005] Furthermore, the centering shaft is elastically connected to the base via a spring.

[0006] Furthermore, the spring is connected to the bottom of the sliding channel and the other end of the centering shaft.

[0007] Furthermore, a guide groove is formed on the wall of the bottom of the sliding hole, the guide groove is arranged along the axial direction of the sliding channel, and a guide member is installed on the circumferential surface of the centering shaft, the guide member being slidably disposed in the guide groove.

[0008] Furthermore, the external spline has a taper.

[0009] This invention provides a method for machining internal splined gears using a centerable and angleable internal splined gear machining fixture, comprising the following steps: The centering shaft is machined so that the external spline on the centering shaft is adapted to the internal spline of the internal spline gear to be machined; The centering shaft is elastically installed in the sliding channel of the base, such that one end of the centering shaft extends out of the sliding channel; The spline hole of the internal spline gear is fitted onto one end of the centering shaft; Adjust the position of the tailstock so that the tailstock presses against the middle of the other end face of the internal spline gear, so that one end face of the internal spline gear presses against the first support surface of the base, thereby locking the internal spline gear. After the internal spline gear is locked, the external teeth of the internal spline gear are machined.

[0010] The beneficial effects of this invention are that the centerable and angular-positionable internal spline gear machining fixture of this invention enables the universal machining of internal spline gears, eliminating the need for group management and circulation. This invention's centerable and angular-positionable internal spline gear machining fixture uses a centering shaft with external splines to precisely engage with the internal splines of the internal spline gear, and utilizes a base and tailstock to position and clamp the middle of both end faces of the gear, ensuring that each internal spline gear can be machined with the same angular phase reference. During machining, there is no need to bind multiple gears together; a single gear can be machined, circulated, and heat-treated independently, completely breaking the limitations of "group machining and group use" in traditional processes, and significantly reducing production management and process flow costs.

[0011] The centerable and angle-positionable internal spline gear machining fixture of the present invention improves the interchangeability of gear machining and the utilization rate of finished products. Because the external spline of the centering shaft of the centering fixture has a unique and consistent angular phase relationship with the internal spline of the internal spline gear, all gears are machined with external teeth according to the same angular reference, making any single gear interchangeable with other gears. When a gear fails during machining or heat treatment, it is not necessary to scrap other gears in the same group, greatly improving the utilization rate of finished products and reducing the risk of batch loss due to single-piece failure. Attached Figure Description

[0012] Other features, objects, and advantages of this application will become more apparent from the following detailed description of non-limiting embodiments with reference to the accompanying drawings: Figure 1 This is a schematic diagram of the internal spline gear machining fixture that can be centered and positioned at a fixed angle, according to an embodiment of the present invention.

[0013] Figure 2 This is a cross-sectional view of an internal spline gear machining fixture capable of being centered and positioned at a fixed angle, according to an embodiment of the present invention.

[0014] Figure 3 This is a schematic diagram of the external spline structure of the centering shaft according to an embodiment of the present invention.

[0015] Figure label: Base 1, guide groove 10; 2. Centering shaft; 21. External spline; 22. Elastic element; 23. Guide element; Tailstock 3, receiving channel 30; 4. Internal spline gear, one end face a, the other end face b. Detailed Implementation

[0016] The present application will now be described in further detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and not intended to limit it. Furthermore, it should be noted that, for ease of description, only the parts relevant to the invention are shown in the accompanying drawings.

[0017] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. This application will now be described in detail with reference to the accompanying drawings and embodiments.

[0018] Reference Figures 1 to 3 As shown, the present invention provides a machining fixture for internal spline gears that can be centered and positioned at a fixed angle, comprising: a base 1, a centering shaft 2, and a tailstock 3.

[0019] The base and tailstock are arranged opposite each other and coaxially. The base is fixedly mounted on the machine tool. The base 1 has a first support surface. The first support surface is used to support the middle part of one end face a of the internal spline gear 4 to be machined. A sliding channel is formed inside the first support surface.

[0020] In this embodiment, the base and the tailstock are both frustum-shaped. The sliding channel is coaxially arranged with the base.

[0021] The centering shaft 2 is slidably installed within the sliding channel. The centering shaft can move along the axial direction of the sliding channel.

[0022] An external spline 21 is formed on the circumferential surface of the centering shaft 2. The external spline 21 is adapted to the internal spline of the internal spline gear 4 to be machined. In this embodiment, one end of the centering shaft extends to the outside of the sliding channel (i.e., the outside of the first support surface). The external spline is formed on the circumferential surface of one end of the centering shaft.

[0023] The centering shaft 2 is elastically connected to the base 1. In this embodiment, the centering shaft is connected to the base via an elastic element 22. Specifically, the elastic element 22 is a spring. The spring can be a helical spring.

[0024] In a preferred embodiment, the spring is connected to the bottom of the sliding channel and the other end of the centering shaft 2.

[0025] In this embodiment, one end of the centering shaft 2 extends outside the sliding channel and passes through the spline hole of the internal spline gear 4. The other end of the centering shaft slides within the sliding channel.

[0026] For details, please refer to Figure 2 The sliding channel is a variable diameter channel. The diameter of the bottom of the sliding channel is larger than the diameter of the rest of the channel. Correspondingly, a sliding seat is detachably mounted on the other end of the centering shaft. The sliding seat slides within the larger diameter section at the bottom of the sliding channel. The sliding seat is cylindrical. The outer diameter of the sliding seat is adapted to the inner diameter of the larger diameter section. The length of the sliding seat is less than the length of the larger diameter section. The sliding seat is coaxially connected to the centering shaft by bolts.

[0027] The tailstock 3 is mounted on the machine tool in an adjustable position. The tailstock is mounted on the machine tool via a hydraulic cylinder. The hydraulic cylinder drives the tailstock to move axially along the base. The tailstock 3 has a second support surface. The second support surface is used to press against the middle of the other end face b of the internal spline gear 4. The second support surface has a receiving channel 30. One end of the centering shaft 2 is movably inserted into the receiving channel 30.

[0028] When machining the internal spline gear, the internal spline gear is clamped by the first support surface of the base and the second support surface of the tailstock, so that the internal spline gear is coaxial with the base and the tailstock, and the internal spline gear is coaxial with the sliding channel and the centering shaft.

[0029] In this embodiment, flanges are formed on the outer edges of the first and second support surfaces, respectively. The flanges are arranged in a ring along the circumferential direction of the base and the tailstock. The diameter of the ring-shaped flange is smaller than the outer diameter of the internal spline gear, so that the outer edge of the internal spline gear protrudes beyond the sides of the base and the tailstock to facilitate the machining of the external teeth.

[0030] As a preferred implementation method, see [reference]. Figure 3 As shown, the external spline 21 has a taper. When the centering shaft passes through the spline hole of the internal spline gear, it can be easily and conveniently inserted into the spline hole of the internal spline gear.

[0031] See Figure 3 As shown, the taper of the external spline at the end furthest from the base is greater than the taper of the end closest to the base. The taper at the end furthest from the base serves a guiding function, facilitating workpiece installation. The taper at the end closest to the base is smaller, allowing it to fit internal splines on workpieces with slight dimensional differences in their internal splines. Therefore, the tapered external spline provides tight positioning (centering and angular fixation).

[0032] To prevent the centering shaft from rotating when it moves axially along the sliding channel, a guide groove 10 is formed in the bottom wall of the sliding channel. The guide groove is set along the axial direction of the sliding channel, and a guide member 23 is installed on the circumferential surface of the centering shaft 2. The guide member 23 is slidably disposed in the guide groove 10.

[0033] In this embodiment, there are two guide members. The two guide members are spaced apart along the axial direction of the centering shaft. The two guide members slide simultaneously in a guide groove.

[0034] This invention provides a method for machining internal splined gears using a centerable and angleable internal splined gear machining fixture, comprising the following steps: S1. Machining the centering shaft 2 so that the external spline 21 on the centering shaft 2 is adapted to the internal spline of the internal spline gear 4 to be machined.

[0035] S2. The centering shaft 2 is elastically installed in the sliding channel of the base 1, so that one end of the centering shaft 2 extends out of the sliding channel.

[0036] S3. Fit the spline hole of the internal spline gear 4 onto one end of the centering shaft 2.

[0037] S4. Adjust the position of the tailstock 3 so that the tailstock 3 presses against the middle of the other end face of the internal spline gear 4, so that one end face of the internal spline gear 4 presses against the first support surface of the base 1, thereby locking the internal spline gear 4.

[0038] S5. After the internal spline gear 4 is locked, the external teeth of the internal spline gear 4 are machined.

[0039] In this embodiment, the machine tool has a spindle orientation function. After the internal spline gear is clamped and locked by the first and second support surfaces, the angle of the external teeth of the internal spline gear (i.e., planetary gear) is adjusted so that the angle between the external and internal teeth of the internal spline gear is 0. All planetary gears are machined at this angle, regardless of whether they are roughing or finishing. Ultimately, it is ensured that the angle between the external and internal teeth of the planetary gears is 0, realizing that the process does not require group control and that all gears are interchangeable.

[0040] The centerable and angular-positionable internal spline gear machining fixture of this invention enables the universal machining of internal spline gears, eliminating the need for group management and circulation. This fixture achieves this by precisely engaging a centering shaft with external splines with the internal splines of the gear, and using a base and tailstock to position and clamp the midpoints of both end faces of the gear. This ensures that each internal spline gear can be machined with the same angular phase reference. During machining, there is no need to bind multiple gears together; each gear can be machined, circulated, and heat-treated independently, completely breaking the limitations of traditional "group machining and group use," and significantly reducing production management and process flow costs.

[0041] The centerable and angle-positionable internal spline gear machining fixture of the present invention improves the interchangeability of gear machining and the utilization rate of finished products. Because the external spline of the centering shaft of the centering fixture has a unique and consistent angular phase relationship with the internal spline of the internal spline gear, all gears are machined with external teeth according to the same angular reference, making any single gear interchangeable with other gears. When a gear fails during machining or heat treatment, it is not necessary to scrap other gears in the same group, greatly improving the utilization rate of finished products and reducing the risk of batch loss due to single-piece failure.

[0042] The centerable and angle-positionable internal spline gear machining fixture of this invention ensures high precision and consistency of angular phase between the internal spline and the external teeth. In this fixture, the centering shaft is elastically connected to the base and can adaptively adjust its position during tailstock clamping, ensuring a clearance-free fit between the internal spline gear and the centering shaft while avoiding clamping deformation caused by rigid over-positioning. Combined with the spindle orientation function of the machine tool, precise angular positioning of the external teeth relative to the internal spline can be achieved, ensuring that the angular phase of the external teeth and internal spline of all gears is highly consistent, thereby effectively improving the transmission accuracy of transmission systems such as RV reducers and reducing transmission noise.

[0043] The internal spline gear machining fixture of the present invention offers high reliability and convenient operation for clamping internal spline gears to be processed, making it suitable for mass production. One end of the centering shaft of this fixture features a tapered external spline structure, which guides the gear as it passes through the spline hole, facilitating quick and easy clamping. The tailstock position is adjustable and hydraulically driven, enabling stable clamping of the gear. Simultaneously, the centering shaft engages with a guide groove in the base via a guide component, effectively preventing rotation during clamping and further ensuring the repeatability and positioning accuracy of the spline fit. This makes it suitable for high-volume, high-cycle automated machining scenarios.

[0044] The above description is merely a preferred embodiment of this application and an explanation of the technical principles employed. Those skilled in the art should understand that the scope of the invention involved in this application is not limited to technical solutions formed by specific combinations of the above-described technical features, but should also cover other technical solutions formed by arbitrary combinations of the above-described technical features or their equivalents without departing from the inventive concept. For example, technical solutions formed by substituting the above features with (but not limited to) technical features with similar functions disclosed in this application.

Claims

1. A machining fixture for internal spline gears capable of being centered and positioned at a fixed angle, characterized in that, include: A base fixed to a machine tool, the base having a first support surface in the middle of one end face of an internal spline gear to be machined, and a sliding channel being formed inside the first support surface; A centering shaft is slidably disposed within the sliding channel. An external spline is formed on the circumferential surface of the centering shaft. The centering shaft is elastically connected to the base. One end of the centering shaft extends out of the sliding channel and passes through the spline hole of the internal spline gear. The external spline is adapted to the internal spline of the internal spline gear. The tailstock is adjustablely mounted on the machine tool. The tailstock has a second support surface for pressing against the middle of the other end face of the internal spline gear. The second support surface has a receiving channel. One end of the centering shaft is movably inserted into the receiving channel.

2. The machining fixture for internal spline gears capable of centering and angular positioning according to claim 1, characterized in that, The centering shaft is elastically connected to the base by a spring.

3. The machining fixture for internal spline gears capable of centering and angular positioning according to claim 2, characterized in that, The spring is connected to the bottom of the sliding channel and the other end of the centering shaft.

4. The machining fixture for internal spline gears capable of being centered and positioned at a fixed angle according to claim 1, characterized in that, The bottom wall of the sliding hole is formed with a guide groove, which is arranged along the axial direction of the sliding channel. A guide member is installed on the circumferential surface of the centering shaft, and the guide member is slidably disposed in the guide groove.

5. The machining fixture for internal spline gears capable of being centered and positioned at a fixed angle according to claim 1, characterized in that, The external spline has a taper.

6. A method for machining internal splined gears using a centerable and angularly positionable internal splined gear machining fixture as described in any one of claims 1 to 5, characterized in that, Includes the following steps: The centering shaft is machined so that the external spline on the centering shaft is adapted to the internal spline of the internal spline gear to be machined; The centering shaft is elastically installed in the sliding channel of the base, such that one end of the centering shaft extends out of the sliding channel; The spline hole of the internal spline gear is fitted onto one end of the centering shaft; Adjust the position of the tailstock so that the tailstock presses against the middle of the other end face of the internal spline gear, so that one end face of the internal spline gear presses against the first support surface of the base, thereby locking the internal spline gear. After the internal spline gear is locked, the external teeth of the internal spline gear are machined.

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