Impact mechanism transmission

Abstract

The application relates to the technical field of electric impact wrenches, in particular to an impact mechanism transmission device which comprises an impact shell and a rear end cover buckled on the impact shell, a transmission structure is arranged on the rear end cover; the transmission mechanism comprises a planet carrier rotatably arranged on the rear end cover, rotation gears are rotatably arranged in the planet carrier at equal intervals, an inner gear ring part meshing with the rotation gears is arranged on the rear end cover, an output shaft is arranged on the planet carrier, a driving shaft is rotatably arranged on the rear end cover and inserted into the planet carrier, and a driving gear part meshing with the rotation gears is arranged on the driving shaft. The application has the effects of guaranteeing assembly convenience and structural strength.

Description

Technical Field

[0001] This application relates to the technical field of electric impact wrenches, and in particular to an impact mechanism transmission device. Background Technology

[0002] An electric impact wrench is a common power tool that uses high-torque impact to tighten or loosen bolts and nuts. It is widely used in automotive repair, construction engineering, heavy equipment assembly, and other fields. Its core function is to convert the high-speed, low-torque rotation of the motor into a low-frequency, high-torque output that can generate a huge impact force through an internal drive mechanism.

[0003] Currently, mainstream electric impact wrench drive mechanisms typically include a motor, a gear reduction assembly, and an impact mechanism. Among these, the gear reduction assembly plays a crucial role in increasing torque and reducing speed. To achieve a high reduction ratio within a limited space, planetary gear reduction mechanisms are widely used by those skilled in the art due to their compact structure, high transmission efficiency, and strong load-bearing capacity.

[0004] A typical planetary gear reducer consists of a sun gear, a planet carrier (on which at least three planetary gears are mounted), and an internal ring gear. During operation, the motor's output shaft drives the sun gear to rotate, causing the planetary gears to revolve and rotate under the constraint of the internal ring gear, thereby outputting a reduced speed and increased torque through the planet carrier.

[0005] However, during in-depth research and practice, the inventors discovered a long-neglected but seriously problematic assembly process in existing drive mechanisms using planetary gear sets, which significantly impacts production efficiency and product reliability. Specifically, during assembly, the internal gear ring needs to be precisely positioned and fixed within the tool housing or a dedicated gearbox. Subsequently, the assembler must insert the planetary carrier assembly, with the sun gear and planetary gears already installed, axially into the fixed internal gear ring.

[0006] This assembly process has inherent flaws: Extremely high precision is required: multiple planetary gears on the planet carrier must simultaneously mesh with the internal teeth of the internal gear ring. This demands extremely high circumferential and radial alignment accuracy of the internal gear ring's fixed position within the housing. Any minute deviation can prevent the planetary gears from meshing properly.

[0007] High risk of assembly interference: During the insertion of the planetary carrier into the internal gear ring, due to the initial phase difference between the planetary gears and the internal gear ring, the tooth tips of the planetary gears are very prone to interference and collision with the tooth tips of the internal gear ring, a phenomenon known as "tooth collision." This not only hinders the smooth assembly process but may even damage the gear tooth surfaces, affecting transmission smoothness and generating noise.

[0008] Inconvenient and inefficient operation: To avoid the aforementioned interference, assembly workers typically need to repeatedly fine-tune the angle of the planetary carrier to find the correct meshing phase. This process relies on the operator's experience and feel, making it difficult to automate, severely restricting the improvement of assembly efficiency and increasing production costs.

[0009] Potential quality risks: Even if assembly is barely completed with human intervention, initial interference or misalignment may cause the gear pair to wear out more quickly during long-term operation, affecting the lifespan and reliability of the entire drive mechanism.

[0010] Therefore, there is an urgent need in this field for a new type of electric impact wrench drive mechanism that can fundamentally solve the problems of complex assembly process, strict centering requirements, and easy assembly interference while retaining the advantages of planetary gear transmission, thereby achieving a more convenient, efficient and reliable assembly process. Utility Model Content

[0011] To solve the above-mentioned technical problems, this application provides an impact mechanism transmission device, which has the advantages of ensuring both ease of assembly and structural strength.

[0012] To achieve the above objectives, the technical solution of this utility model is as follows: An impact mechanism transmission device includes an impact housing and a rear end cover fastened to the impact housing, wherein a transmission structure is provided on the rear end cover. The transmission mechanism includes a planetary carrier rotatably mounted on the rear end cover, rotating gears rotatably mounted at equal intervals inside the planetary carrier, an internal gear ring portion meshing with the rotating gears on the rear end cover, an output shaft on the planetary carrier, and a drive shaft rotatably mounted on the rear end cover and inserted into the planetary carrier, with a drive gear portion meshing with the rotating gears on the drive shaft.

[0013] The above technical solution involves using a motor to drive a drive shaft, which in turn drives a drive gear on the drive shaft to simultaneously mesh with several rotating gears. When these rotating gears rotate, they mesh with an internal gear ring, which is integrally formed with the rear end cover. When the internal gear ring cannot rotate, the rotating gears rotate around it, synchronously driving the planetary carrier to rotate. This causes the output shaft on the planetary carrier to rotate. In other words, the drive shaft adjusts its output torque through the planetary gear set consisting of the drive gear, rotating gears, and internal gear ring, thus ensuring impact force. The internal gear ring's integration into the rear end cover ensures its structural strength. Furthermore, during assembly, the planetary carrier and rotating gears can be assembled in an unrestricted external environment and then inserted into the rear end cover. Only alignment calibration is required, facilitating assembly.

[0014] As a preferred embodiment of this application, the top end of the internal gear ring is inclined downward toward the central axis of the internal gear ring.

[0015] The above technical solution enables the top of the internal gear ring to be set in a "conical" shape, which serves as a guide and correction function, thereby facilitating the centering process after the planetary carrier is inserted as a whole, and thus making it easier for personnel to assemble.

[0016] As a preferred embodiment of this application, the rear end cover further includes an arc-shaped inner guide portion connected to the internal gear ring, and an arc-shaped outer guide portion is provided on the outer side wall of the rear end cover. The arc-shaped inner guide portion and the arc-shaped outer guide portion are offset from each other along the axial direction of the rear end cover.

[0017] To achieve the above technical solution, the arc-shaped inner guide can reduce stress concentration at the connection between the inner gear ring and the part, thereby ensuring its structural strength. The arc-shaped outer guide can ensure the structural strength of the overall shell of the end cover while reducing the material used in the end cover, thereby reducing costs. The arc-shaped inner guide and the arc-shaped outer guide are offset along the axial direction of the rear end cover, thereby ensuring that the minimum thickness of the rear end cover is not too small. At the same time, the stress concentration points on the inner and outer sides are offset, thereby ensuring structural strength.

[0018] As a preferred embodiment of this application, a thrust bearing is provided between the rear end cover and the planetary carrier.

[0019] The above technical solution ensures the normal rotation of the planetary carrier.

[0020] As a preferred embodiment of this application, a sealing groove is provided on the outer wall of the rear end cover, and a sealing ring for sealing with the outer shell is provided in the sealing groove.

[0021] The above technical solution ensures the sealing between the rear end cover and the impact shell, thereby preventing leakage of internal lubricating oil.

[0022] In summary, this application includes at least one of the following beneficial technical effects: 1. The drive shaft is rotated by a motor, which in turn drives a drive gear on the drive shaft to drive several rotating gears to mesh and rotate synchronously. When the rotating gears rotate, they mesh with the internal gear ring. Since the internal gear ring is integrally formed with the rear end cover, the internal gear ring cannot rotate. Instead, the rotating gears rotate around the internal gear ring, which in turn drives the planetary carrier to rotate. This causes the output shaft on the planetary carrier to rotate. In other words, the drive shaft adjusts its output torque through the planetary gear set that works with the drive gear, rotating gears, and internal gear ring, thereby ensuring the impact force. The internal gear ring is integrated into the rear end cover, which ensures the structural strength of the internal gear ring. During assembly, the planetary carrier and rotating gears can be assembled in an environment with no external space restrictions, and then the whole assembly can be inserted into the rear end cover. At this time, only the centering calibration of the whole assembly is required, which facilitates personnel assembly. Attached Figure Description

[0023] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0024] Figure 1 This is a schematic diagram of the overall structure of an embodiment of this application.

[0025] Figure 2 This is a cross-sectional view of an embodiment of this application.

[0026] Figure 3 This is a schematic diagram of the structure of the rear cover in an embodiment of this application.

[0027] Reference numerals: 1. Impact housing; 2. Rear end cover; 21. Arc-shaped inner guide; 22. Arc-shaped outer guide; 23. Internal gear ring; 24. Sealing groove; 3. Transmission structure; 31. Planetary carrier; 32. Rotating gear; 34. Output shaft; 35. Drive shaft; 36. Drive gear; 37. Thrust bearing. Detailed Implementation

[0028] The following is in conjunction with the appendix Figure 1-3 This application will be described in further detail.

[0029] This application discloses a transmission device for an impact mechanism. (Refer to...) Figure 1 The impact mechanism transmission device includes an impact housing 1 and a rear end cover 2 fastened to the impact housing 1, and a transmission structure 3 is provided on the rear end cover 2.

[0030] Combination Figure 2-3The transmission mechanism includes a planetary carrier 31 rotatably mounted on the rear end cover 2, rotating gears 32 rotatably mounted at equal intervals inside the planetary carrier 31, an internal gear ring portion 23 meshing with the rotating gears 32 on the rear end cover 2, an output shaft 34 mounted on the planetary carrier 31, and a drive shaft 35 rotatably mounted on the rear end cover 2 and inserted into the planetary carrier 31, with a drive gear portion 36 meshing with the rotating gears 32 on the drive shaft 35. The drive shaft 35 is rotated by a motor, which in turn causes the drive gear 36 on the drive shaft 35 to drive several rotating gears 32 to mesh and rotate synchronously. When the rotating gears 32 rotate, they mesh with the internal gear ring 23, which is integrally formed with the rear end cover 2. When the internal gear ring 23 cannot rotate, the rotating gears 32 rotate around the internal gear ring 23, which in turn drives the planetary carrier 31 to rotate. This causes the output shaft 34 on the planetary carrier 31 to rotate. In other words, the drive shaft 35 adjusts its output torque through the planetary gear set consisting of the drive gear 36, rotating gears 32, and internal gear ring, thereby ensuring the impact force. The internal gear ring 23 is integrated into the rear end cover 2, which ensures the structural strength of the internal gear ring 23. During assembly, the planetary carrier 31 and rotating gears 32 are assembled in an environment without external space restrictions, and then the whole assembly is inserted into the rear end cover 2. At this time, only the centering calibration of the whole assembly is required, which facilitates personnel assembly.

[0031] Preferably, the top of the internal gear ring 23 is inclined downward toward the central axis of the internal gear ring 23, so that the top of the internal gear ring is "conical", which plays a guiding and correcting role, thereby facilitating the centering process after the planet carrier 31 is inserted as a whole, and thus facilitating personnel assembly.

[0032] The rear end cover 2 also includes an arc-shaped inner guide portion 21 connected to the internal gear ring, and an arc-shaped outer guide portion 22 is provided on the outer wall of the rear end cover 2. The arc-shaped inner guide portion 21 reduces stress concentration at the connection point between the internal gear ring and the internal gear ring, thus ensuring structural strength. The arc-shaped outer guide portion 22 ensures the overall structural strength of the end cover while reducing material usage, thereby reducing costs. The arc-shaped inner guide portion 21 and the arc-shaped outer guide portion 22 are offset along the axial direction of the rear end cover 2, ensuring that the minimum thickness of the rear end cover 2 is not too small, and that the stress concentration points on the inner and outer sides are offset, thus ensuring structural strength. The axial distance h between the arc-shaped inner guide portion 21 and the arc-shaped outer guide portion 22 is not less than 10 mm, thus ensuring structural strength.

[0033] Combination Figure 2-3 A thrust bearing 37 is provided between the rear end cover 2 and the planetary carrier 31 to ensure the normal rotation of the planetary carrier 31.

[0034] A sealing groove 24 is provided on the outer wall of the rear end cover 2, and a sealing ring is provided in the sealing groove 24 for sealing with the outer shell, thereby ensuring the sealing between the rear end cover 2 and the impact outer shell 1, and preventing the leakage of internal lubricating oil.

[0035] The implementation principle of the impact mechanism transmission device in this application embodiment is as follows: the drive shaft 35 is driven to rotate by a motor, which in turn causes the drive gear 36 on the drive shaft 35 to drive several rotating gears 32 to mesh and rotate synchronously. When the rotating gears 32 rotate, they mesh with the internal gear ring 23. Since the internal gear ring 23 is integrally formed with the rear end cover 2, the internal gear ring 23 cannot rotate. Therefore, the rotating gears 32 rotate around the internal gear ring 23, which in turn drives the planetary carrier 31 to rotate synchronously. This causes the output shaft 34 on the planetary carrier 31 to rotate. In other words, the drive shaft 35 adjusts its output torque through the planetary gear set consisting of the drive gear 36, rotating gears 32, and internal gear ring, thereby ensuring the impact force. After the internal gear ring 23 is integrated into the rear end cover 2, the structural strength of the internal gear ring 23 is ensured. During assembly, the planetary carrier 31 and rotating gears 32 are assembled in an environment with no external space restrictions, and then the whole assembly is inserted into the rear end cover 2. At this time, only the centering calibration of the whole assembly is required, which facilitates personnel assembly.

[0036] The above are all preferred embodiments of this application, and are not intended to limit the scope of protection of this application. Therefore, all equivalent changes made in accordance with the structure, shape and principle of this application should be covered within the scope of protection of this application.

Claims

1. An impact mechanism transmission device, characterized in that: It includes an impact housing (1) and a rear end cover (2) fastened to the impact housing (1), wherein a transmission structure (3) is provided on the rear end cover (2); The transmission structure includes a planetary carrier (31) rotatably mounted on the rear end cover (2), rotating gears (32) rotatably mounted at equal intervals inside the planetary carrier (31), an internal gear ring (23) meshing with the rotating gears (32) on the rear end cover (2), an output shaft (34) on the planetary carrier (31), and a drive shaft (35) rotatably mounted on the rear end cover (2) and inserted into the planetary carrier (31), with a drive gear part (36) meshing with the rotating gears (32) on the drive shaft (35).

2. The impact mechanism transmission device according to claim 1, characterized in that: The top of the internal gear ring (23) is inclined downward toward the central axis of the internal gear ring (23).

3. The impact mechanism transmission device according to claim 1, characterized in that: The rear end cover (2) also includes an arc-shaped inner guide portion (21) connected to the internal gear ring, and an arc-shaped outer guide portion (22) is provided on the outer side wall of the rear end cover (2). The arc-shaped inner guide portion (21) and the arc-shaped outer guide portion (22) are offset from each other along the axial direction of the rear end cover (2).

4. The impact mechanism transmission device according to claim 1, characterized in that: A thrust bearing (37) is provided between the rear end cover (2) and the planetary carrier (31).

5. The impact mechanism transmission device according to claim 1, characterized in that: A sealing groove (24) is provided on the outer wall of the rear cover (2), and a sealing ring for sealing with the outer shell is provided in the sealing groove (24).

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