An intermediate drive shaft for a servo reducer

Abstract

This utility model discloses an intermediate drive shaft for a servo reducer, including a sleeve shaft. One end of the sleeve shaft is integrally formed with a fixed shaft. The other end of the sleeve shaft away from the fixed shaft has an axially oriented positioning shaft hole. A positioning block is detachably installed inside the positioning shaft hole. A flat keyway is axially oriented on the inner side of the positioning block. A U-shaped groove is axially oriented on the inner wall of the flat keyway away from the torque transmission surface. A thin steel leaf spring is interference-fitted inside the U-shaped groove. This solution significantly improves the overall performance of the intermediate drive shaft of the servo reducer through the synergistic structural design of the sleeve shaft, fixed shaft, positioning block, and thin steel leaf spring. The positioning block is detachable, eliminating the need to replace the entire sleeve shaft after wear, thus reducing maintenance costs. The thin steel leaf spring in the U-shaped groove can compensate for the assembly gap between the flat key and the flat keyway, avoiding torque transmission impact and decreased transmission accuracy caused by excessive gap.

Description

Technical Field

[0001] This utility model relates to the field of transmission shaft technology, and in particular to an intermediate transmission shaft for a servo reducer. Background Technology

[0002] In servo reducer transmission systems, the intermediate drive shaft is the core component for power transmission. It needs to be adapted to high-frequency start-stop and high-precision transmission conditions to achieve stable torque transmission between the external power shaft and the internal mechanism of the reducer. However, existing intermediate drive shafts still have many technical problems: On the one hand, they mostly adopt an integrated keyway structure, and the assembly clearance between the flat key and the keyway is difficult to control precisely. If the clearance is too large, it will cause torque impact and reduce transmission accuracy. If the clearance is too small, it will easily lead to assembly difficulties and aggravate keyway wear. At the same time, after the keyway wears out, the entire drive shaft needs to be replaced, which not only has high maintenance costs but also prolongs the equipment downtime cycle. On the other hand, the contact area between the drive shaft and the external power shaft lacks optimized design, and the unnecessary contact area is large, which can easily shorten the service life of the component due to friction and wear, making it difficult to meet the comprehensive requirements of servo reducers for transmission stability, maintenance convenience, and long service life.

[0003] Therefore, those skilled in the art have provided an intermediate drive shaft for a servo reducer to solve the problems mentioned in the background art. Utility Model Content

[0004] The purpose of this invention is to address the shortcomings of existing technologies by proposing an intermediate drive shaft for a servo reducer.

[0005] To achieve the above objectives, the present invention adopts the following technical solution:

[0006] A servo reducer intermediate drive shaft includes a sleeve shaft. One end of the sleeve shaft is integrally formed with a fixed shaft. The fixed shaft is coaxially arranged with the sleeve shaft and has a smaller diameter than the sleeve shaft. The other end of the sleeve shaft away from the fixed shaft has an axially opened positioning shaft hole in the middle. The positioning shaft hole is used to pass through an external power shaft and transmit torque.

[0007] A positioning block is detachably installed inside the positioning shaft hole. The inner surface of the positioning block is an arc surface that matches the size of the inner wall of the positioning shaft hole, and the arc surface smoothly transitions with the inner wall of the positioning shaft hole. A flat keyway is provided on the inner surface of the positioning block along the axial direction.

[0008] The inner wall of the keyway away from the torque transmission surface is provided with a U-shaped groove along the axial direction, and a thin steel spring is interference-fitted into the inner side of the U-shaped groove.

[0009] Preferably, the side of the thin steel sheet spring away from the bottom of the U-shaped groove protrudes from the inner wall of the flat keyway, and the protrusion from the inner wall is 0.01-0.03mm.

[0010] The thin steel sheet spring has a molybdenum disulfide self-lubricating coating sprayed on the side of the spring away from the U-groove, and the thickness of the molybdenum disulfide self-lubricating coating is 0.05-0.1 mm.

[0011] Preferably, the inner wall of the positioning shaft hole is provided with a positioning groove along the axial direction, the length of the positioning groove is the same as the length of the positioning shaft hole, and the positioning block is slidably inserted into the inner side of the positioning groove;

[0012] The sleeve shaft and the positioning block are fixedly connected by fastening screws, the number of which is 2-4, and the axis of the fastening screws is perpendicular to the axis of the sleeve shaft.

[0013] Preferably, the fastening screw is a hexagonal flathead screw, and the outer wall of the sleeve shaft is provided with a countersunk hole corresponding to the position of each fastening screw, and the size of the countersunk hole is adapted to the size of the head of the hexagonal flathead screw;

[0014] The outer wall of the positioning block is provided with threaded grooves corresponding to the countersunk holes, and one end of the fastening screw is threaded into the corresponding threaded groove.

[0015] Preferably, a clearance hole is provided on the inner side of the sleeve shaft at the end of the positioning shaft hole near the fixed shaft along the axial direction of the sleeve shaft;

[0016] The clearance hole is coaxially arranged with the positioning shaft hole, and the inner diameter of the clearance hole is 2-4mm larger than the inner diameter of the positioning shaft hole.

[0017] The transition between the clearance hole and the positioning shaft hole is provided with a rounded chamfer.

[0018] Preferably, the middle of both sides of the positioning block is integrally formed with a limiting block, the limiting block extends along the axial direction of the positioning block, and the axial length of the limiting block is less than the axial length of the positioning block.

[0019] The inner wall of the positioning groove has a limiting groove on both sides corresponding to the position of the limiting block, and the length of the limiting groove is the same as the length of the limiting block. The limiting block is slidably inserted into the inner side of the limiting groove.

[0020] Compared with the prior art, the beneficial effects of this utility model are:

[0021] This invention significantly improves the overall performance of the intermediate drive shaft of a servo reducer through a collaborative structural design of a sleeve shaft, a fixed shaft, a positioning block, and a thin steel spring. The positioning block is detachable, eliminating the need to replace the entire sleeve shaft after wear; replacing only the block reduces maintenance costs and shortens equipment downtime. Furthermore, positioning blocks with different keyway specifications can be replaced, flexibly matching external power shafts of different sizes and greatly improving the drive shaft's versatility. The thin steel spring within the U-shaped groove precisely compensates for the assembly gap between the key and the keyway, preventing excessive gaps that could cause torque impact and reduced transmission accuracy. The coaxial arrangement of the positioning shaft hole and the clearance hole reduces unnecessary contact between the external power shaft and the sleeve shaft, lowering frictional losses and ultimately ensuring stable transmission under high-frequency start-stop and high-precision operating conditions, meeting the servo reducer's requirements for transmission performance, ease of maintenance, and long service life. Attached Figure Description

[0022] To illustrate the technical solutions in the embodiments of the present invention or the prior art more specifically and intuitively, the accompanying drawings used in the description of the embodiments or the prior art will be briefly introduced below.

[0023] Figure 1 This is a schematic diagram of the intermediate transmission shaft structure for the servo reducer proposed in this utility model;

[0024] Figure 2 This is a schematic diagram of the cross-sectional structure of the sleeve shaft proposed in this utility model;

[0025] Figure 3 This is a schematic diagram of the positioning block installation structure proposed in this utility model;

[0026] Figure 4 The present utility model proposes Figure 3 Enlarged structural diagram at point A in the middle.

[0027] In the diagram: 1. Sleeve shaft; 101. Positioning shaft hole; 102. Alternating hole; 2. Fixed shaft; 3. Positioning block; 4. Flat keyway; 5. U-shaped groove; 6. Thin steel sheet spring; 7. Positioning groove; 8. Fastening screw; 9. Limiting block; 10. Limiting groove. Detailed Implementation

[0028] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present utility model. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments.

[0029] Reference Figure 1-4A servo reducer intermediate drive shaft includes a sleeve shaft 1, one end of which is integrally formed with a fixed shaft 2. The fixed shaft 2 is coaxially arranged with the sleeve shaft 1 and its diameter is smaller than that of the sleeve shaft 1. The other end of the sleeve shaft 1 away from the fixed shaft 2 has an axially formed positioning shaft hole 101. The positioning shaft hole 101 is used to pass through an external power shaft and transmit torque.

[0030] A positioning block 3 is detachably installed inside the positioning shaft hole 101. The inner side of the positioning block 3 is an arc surface that matches the size of the inner wall of the positioning shaft hole 101, and the arc surface smoothly transitions with the inner wall of the positioning shaft hole 101. A flat keyway 4 is provided on the inner side of the positioning block 3 along the axial direction.

[0031] A U-shaped groove 5 is provided on the inner wall of the side of the keyway 4 away from the torque transmission surface along the axial direction, and a thin steel spring 6 is interference-fitted into the inner side of the U-shaped groove 5.

[0032] The above technical solution comprises a sleeve shaft 1, an integrally formed fixed shaft 2, a detachable positioning block 3, a flat keyway 4, a U-shaped groove 5, and a thin steel spring 6 embedded in the U-shaped groove 5. This structure enables the servo reducer to achieve three core functions: precise torque transmission, clearance compensation, and convenient maintenance of the intermediate drive shaft. The positioning shaft hole 101 is used to pass through the corresponding power shaft. The inner surface of the positioning block 3 is an arc surface that matches the inner wall size of the positioning shaft hole 101, and this arc surface smoothly transitions to the inner wall of the positioning shaft hole 101, reducing local stress concentration during power shaft rotation and ensuring the stability of power transmission. The flat keyway 4 cooperates with the flat key to achieve circumferential positioning. The thin steel spring 6, interference-fitted inside the U-shaped groove 5, actively compensates for the assembly clearance between the flat key and the flat keyway 4, effectively solving problems such as torque transmission impact and keyway wear caused by excessive clearance in traditional rigid keyways. This fully meets the high-frequency start / stop and high-precision transmission requirements of servo reducers.

[0033] The side of the thin steel leaf spring 6 away from the bottom of the U-shaped groove 5 protrudes from the inner wall of the flat keyway 4, and the protrusion from the inner wall is 0.01-0.03mm.

[0034] The thin steel leaf spring 6 has a molybdenum disulfide self-lubricating coating sprayed on the side of the spring away from the U-shaped groove 5. The thickness of the molybdenum disulfide self-lubricating coating is 0.05-0.1mm.

[0035] Using the above technical solutions, the thin steel sheet spring 6 protrudes 0.01-0.03mm from the inner wall of the keyway 4, which can accurately match the assembly tolerance of the keyway and the keyway, avoiding torque transmission lag caused by excessive clearance or keyway deformation caused by interference assembly; the molybdenum disulfide self-lubricating coating on the spring surface can reduce the coefficient of friction with the keyway, reduce wear, extend the service life of the keyway 4, and reduce transmission noise.

[0036] A positioning groove 7 is provided on the inner wall of the positioning shaft hole 101 along the axial direction. The length of the positioning groove 7 is the same as the length of the positioning shaft hole 101. The positioning block 3 is slidably inserted into the inner side of the positioning groove 7.

[0037] The sleeve shaft 1 and the positioning block 3 are fixedly connected by fastening screws 8. There are 2-4 fastening screws 8, and the axis of the fastening screws 8 is perpendicular to the axis of the sleeve shaft 1.

[0038] By adopting the above technical solution, the positioning groove 7 and the positioning block 3 slide together, and with the fastening screws 8 evenly distributed around the circumference, the positioning block 3 can be precisely assembled; the fastening screws 8 are detachable, making it easy to replace the worn positioning block 3 individually, and positioning blocks 3 with different keyway specifications can be replaced to match external power shafts of different sizes, thereby improving the versatility of the drive shaft.

[0039] The fastening screw 8 is a hexagonal flat-head screw. The outer wall of the sleeve 1 has a countersunk hole corresponding to the position of each fastening screw 8. The size of the countersunk hole is adapted to the size of the head of the hexagonal flat-head screw.

[0040] The outer wall of the positioning block 3 is provided with threaded grooves corresponding to the positions of each countersunk hole, and one end of the fastening screw 8 is threaded into the corresponding threaded groove.

[0041] Using the above technical solution, the internal hexagonal flat head screw 8 is matched with the countersunk hole of the sleeve shaft 1, which can avoid the screw head protruding and interfering with the internal components of the reducer, and is suitable for the compact structure requirements; the screw is connected to the threaded groove of the positioning block 3, which can not only achieve rigid fixation of the positioning block 3 to prevent transmission loosening, but also facilitate disassembly and maintenance without damaging the structure of the sleeve shaft 1.

[0042] A clearance hole 102 is provided on the inner side of the sleeve shaft 1 at the end of the positioning shaft hole 101 near the fixed shaft 2 along the axial direction of the sleeve shaft 1.

[0043] The clearance hole 102 is coaxially arranged with the positioning shaft hole 101, and the inner diameter of the clearance hole 102 is 2-4mm larger than the inner diameter of the positioning shaft hole 101.

[0044] The transition between the clearance hole 102 and the positioning shaft hole 101 is provided with a rounded chamfer.

[0045] By adopting the above technical solution, this structural design ensures that after the external power shaft is inserted, it only contacts the positioning shaft hole 101, avoiding unnecessary contact between the power shaft and other areas of the sleeve shaft 1. Calculations show that this reduces the contact area by more than 60%, thereby significantly reducing friction and wear during power shaft rotation and extending the service life of the power shaft and shaft body. Furthermore, the transition between the clearance hole 102 and the positioning shaft hole 101 is provided with a rounded chamfer. This chamfer design eliminates the sharp edges of the inner wall of the positioning shaft hole 101, preventing the power shaft from being scratched by sharp edges during insertion. It also reduces stress concentration at the shaft hole transition, effectively improving the fatigue strength of the sleeve shaft 1.

[0046] Both sides of the positioning block 3 are integrally formed with limiting blocks 9. The limiting blocks 9 extend along the axial direction of the positioning block 3, and the axial length of the limiting blocks 9 is less than the axial length of the positioning block 3.

[0047] On both sides of the inner wall of the positioning groove 7, corresponding to the position of the limiting block 9, a limiting groove 10 adapted to the limiting block 9 is provided, and the length of the limiting groove 10 is the same as the length of the limiting block 9. The limiting block 9 is slidably inserted into the inner side of the limiting groove 10.

[0048] Using the above technical solution, the limiting block 9 and the limiting groove 10 slide together, which can accurately position the assembly position of the positioning block 3, ensuring that the positioning block 3 is inserted into the positioning groove 7 and will not slide further into the area of ​​the avoidance hole 102.

[0049] Working principle:

[0050] After the external power shaft passes through the positioning shaft hole 101 of the sleeve shaft 1, it only contacts the positioning shaft hole 101. The positioning block 3 is precisely fixed inside the positioning shaft hole 101 by the positioning groove 7 and the fastening screw 8. Its keyway 4 cooperates with the key to achieve circumferential positioning of the power shaft and the transmission shaft. When the key is assembled, the thin steel spring 6 in the U-shaped groove 5 undergoes slight deformation due to compression, which compensates for the assembly gap between the key and the keyway 4. The molybdenum disulfide coating on the surface of the spring reduces friction with the key. At the same time, the clearance hole 102 of the sleeve shaft 1 avoids unnecessary contact between the power shaft and the shaft body, and finally achieves precise and low-wear transmission of the power shaft torque to the transmission shaft.

[0051] The above description is only a preferred embodiment of the present utility model, but the protection scope of the present utility model is not limited thereto. Any equivalent substitutions or changes made by those skilled in the art within the technical scope disclosed in the present utility model, based on the technical solution and the inventive concept of the present utility model, should be included within the protection scope of the present utility model.

Claims

1. An intermediate drive shaft for a servo reducer, comprising a sleeve shaft (1), characterized in that, One end of the sleeve shaft (1) is integrally formed with a fixed shaft (2). The fixed shaft (2) is coaxially arranged with the sleeve shaft (1) and its diameter is smaller than that of the sleeve shaft (1). The other end of the sleeve shaft (1) away from the fixed shaft (2) is provided with a positioning shaft hole (101) along the axial direction. The positioning shaft hole (101) is used to pass through an external power shaft and transmit torque. A positioning block (3) is detachably installed inside the positioning shaft hole (101). The inner side of the positioning block (3) is an arc surface that matches the size of the inner wall of the positioning shaft hole (101), and the arc surface smoothly transitions with the inner wall of the positioning shaft hole (101). A flat keyway (4) is provided on the inner side of the positioning block (3) along the axial direction. The inner wall of the keyway (4) away from the torque transmission surface is provided with a U-shaped groove (5) along the axial direction, and a thin steel spring (6) is interference-fitted into the inner side of the U-shaped groove (5).

2. The intermediate drive shaft for a servo reducer according to claim 1, characterized in that, The thin steel sheet spring (6) protrudes from the inner wall of the flat keyway (4) on the side away from the bottom of the U-shaped groove (5), and the protrusion from the inner wall is 0.01-0.03mm. The thin steel sheet spring (6) is coated with a molybdenum disulfide self-lubricating coating on the side away from the U-groove (5), and the thickness of the molybdenum disulfide self-lubricating coating is 0.05-0.1 mm.

3. The intermediate drive shaft for a servo reducer according to claim 1, characterized in that, The inner wall of the positioning shaft hole (101) is provided with a positioning groove (7) along the axial direction. The length of the positioning groove (7) is the same as the length of the positioning shaft hole (101). The positioning block (3) is slidably inserted into the inner side of the positioning groove (7). The sleeve shaft (1) and the positioning block (3) are fixedly connected by fastening screws (8). The number of fastening screws (8) is 2-4, and the axis of the fastening screws (8) is perpendicular to the axis of the sleeve shaft (1).

4. The intermediate drive shaft for a servo reducer according to claim 3, characterized in that, The fastening screw (8) is an internal hexagonal flathead screw. The outer wall of the sleeve (1) is provided with countersunk holes corresponding to the position of each fastening screw (8). The size of the countersunk holes is adapted to the size of the head of the internal hexagonal flathead screw. The outer wall of the positioning block (3) is provided with threaded grooves corresponding to the countersunk holes, and one end of the fastening screw (8) is threaded into the corresponding threaded groove.

5. The intermediate drive shaft for a servo reducer according to claim 1, characterized in that, A clearance hole (102) is provided on the inner side of the sleeve (1) at the end of the positioning shaft hole (101) near the fixed shaft (2) along the axial direction of the sleeve (1). The clearance hole (102) is coaxially arranged with the positioning shaft hole (101), and the inner diameter of the clearance hole (102) is 2-4 mm larger than the inner diameter of the positioning shaft hole (101). The transition between the clearance hole (102) and the positioning shaft hole (101) is provided with a rounded chamfer.

6. The intermediate drive shaft for a servo reducer according to claim 3, characterized in that, The positioning block (3) has a limiting block (9) integrally formed in the middle of both sides of the middle wall. The limiting block (9) extends along the axial direction of the positioning block (3), and the axial length of the limiting block (9) is less than the axial length of the positioning block (3). The inner walls of the positioning groove (7) are provided with positioning grooves (10) that are adapted to the positioning block (9) on both sides, and the length of the positioning groove (10) is the same as the length of the positioning block (9). The positioning block (9) is slidably inserted into the inner side of the positioning groove (10).

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