blanks for machining rings of ultra-thin flexible bearings

Abstract

This utility model discloses a blank for machining rings of ultra-thin flexible bearings, comprising a blank body including an outer ring portion, an inner ring portion, and a connecting portion. The outer ring portion and the inner ring portion are connected by the connecting portion. Grooves are provided between the connecting portion and the outer ring portion, and between the connecting portion and the inner ring portion. A positioning groove is provided on the connecting portion, and several mating grooves are formed in the positioning groove. This method is effectively used for machining ultra-thin flexible bearing rings for robots, avoiding clamping deformation problems caused by ultra-thinness, ensuring structural machining accuracy, and exhibiting good performance.

Description

Technical Field

[0001] This utility model relates to a blank for machining the rings of ultra-thin flexible bearings. Background Technology

[0002] With the continuous development of modern industrial robots, their joint designs are increasingly moving towards smaller size and lighter weight, while requiring high precision and high repeatability in functionality. Harmonic reducers, with their compact structure and high transmission accuracy, can meet these requirements and are therefore widely used in the joint designs of modern industrial robots. As a crucial component of harmonic reducers, the precision of ultra-thin flexible bearings is key to the overall quality of the reducer.

[0003] This type of ultra-thin flexible bearing consists of two inner and outer rings with wall thicknesses much smaller than those of standard bearings, making them prone to radial deformation to accommodate the elliptical cam of the wave generator. This deformability leads to various unexpected deformations of the rings during machining. The most obvious example is deformation caused by the pressure of the fixture on the rings during turning. To avoid deformation caused by fixture pressure, common methods on the market involve optimizing the contact surface between the fixture and the ring to minimize uneven pressure. However, because the fixture is always in direct contact with the machined surface of the ring, these methods can only reduce the influence of the fixture, not completely eliminate deformation. Moreover, such tooling often requires more precise assembly, making it inefficient. Utility Model Content

[0004] To address the shortcomings of existing technologies, this utility model provides a blank for machining the rings of ultra-thin flexible bearings. It is effectively used for machining ultra-thin flexible bearing rings for robots, avoiding clamping deformation problems caused by ultra-thinness, ensuring structural machining accuracy, and exhibiting good performance.

[0005] To achieve the above objectives, this utility model provides a blank for machining the rings of an ultra-thin flexible bearing, comprising a blank body, the blank body including an outer ring portion, an inner ring portion and a connecting portion, the outer ring portion and the inner ring portion being connected by the connecting portion, grooves being provided between the connecting portion and the outer ring portion and between the connecting portion and the inner ring portion, a positioning groove being provided on the connecting portion, and a plurality of mating grooves being formed in the positioning groove.

[0006] The advantages of this design are as follows: the blank consists of an outer ring, an inner ring, and a connecting part, with the connecting part becoming the key clamping area during processing. Compared to traditional structures that are prone to deformation due to direct clamping of the outer or inner ring, the connecting part can distribute the clamping force, ensuring the shape stability of the blank during processing, making processing operations more convenient and precise, and avoiding the impact of blank deformation on subsequent accuracy, thus laying the foundation for high-quality processing. The design of the positioning groove and the mating groove further enhances functionality. The positioning groove provides a clear reference, adapting to automated equipment for fast and accurate positioning, while the mating groove, through cooperation with the positioning device components, restricts blank movement from multiple directions, significantly reducing positioning errors, ensuring that the blank has no displacement or rotation during processing, and significantly improving the yield rate. Building upon this foundation, a wealth of technological benefits can be achieved: In terms of processing efficiency, rapid and precise positioning reduces the time required for clamping and adjusting automated equipment, decreases auxiliary processing time, and allows for higher processing parameters due to stable clamping, further enhancing efficiency; in terms of cost control, scrap rate, equipment wear, and tool wear are reduced, achieving cost optimization across the entire process from raw materials and equipment maintenance to tool usage; in terms of automation integration, this structure is compatible with robotic gripping and automatic clamping equipment, creating conditions for fully automated production and facilitating the intelligent upgrading of production lines; in terms of compatibility and expandability, it is compatible with various clamping devices; and stable clamping ensures that the processing state of each blank is similar, reducing quality differences, improving the performance stability and reliability of bearing rings, and enhancing market competitiveness. Overall, this blank structure, through basic design and extended effects, comprehensively empowers the efficient and high-quality production of ultra-thin flexible bearing rings from the processing flow to the final product.

[0007] As a further feature of this invention, the positioning groove includes a narrow portion, a smooth portion, and a wide portion, wherein the narrow portion and the wide portion are connected by the smooth portion, and the two sides of the smooth portion are set as smooth bevels.

[0008] The advantages of this design are as follows: The segmented design of the positioning groove—narrow, smooth, and wide sections—combined with a smooth bevel, offers significant advantages in positioning scenarios. The narrow section serves as an initial guide, quickly introducing the positioning element; the smooth section and bevel provide a transition, allowing the positioning element to slide smoothly into the wide section, ensuring accurate positioning while reducing impact during clamping and preventing microscopic deformation of the workpiece due to instantaneous force. The smooth bevel structure reduces friction and wear between the positioning element and the groove, extending their service life and lowering equipment maintenance costs. The segmented structure facilitates compatibility with different types of positioning devices; the narrow section accommodates small, precise positioning pins, while the wide section is compatible with larger or elastic positioning components, improving the workpiece's versatility in multi-process, multi-equipment production. This structure also results in a more uniform distribution of positioning force. When the workpiece is subjected to external forces such as cutting forces during processing, the wide and smooth sections work together to disperse stress, further suppressing workpiece deformation and ensuring stable processing accuracy. This is particularly beneficial for high-precision parts such as ultra-thin flexible bearing rings, helping to improve product consistency and yield.

[0009] As a further feature of this utility model, the mating groove includes a first groove body disposed in the narrow portion and a second groove body disposed in the wide portion. A first platform is formed at the end of the first groove body near the wide portion, and a second platform is formed at the end of the first groove body away from the wide portion. The first platform is shallower than the second platform, and the first platform and the second platform are connected by a guide slope.

[0010] The beneficial effects of this design are as follows: Firstly, the first and second slots, with their narrow and wide sections, create an orderly positioning path. The height difference between the first and second platforms, combined with the guide ramp, allows the positioning element to smoothly transition along the ramp upon insertion, utilizing the height difference to form a pre-position and precisely guide the locking mechanism—a dual constraint. Secondly, the combination of the guide ramp and the stepped platform can accommodate positioning elements with different tolerance ranges, improving the compatibility of the workpiece in multi-batch production and with different equipment, and reducing clamping errors caused by minor differences in the positioning elements. Thirdly, the structure formed by the high and low platforms can suppress minor displacements of the workpiece in a vibration-prone environment through mechanical limiting between the platforms, enhancing the stability of the machining process and contributing to improved dimensional accuracy of the rings.

[0011] As a further feature of this invention, the inner wall of the outer ring portion is connected to the connecting portion by a smooth curved surface, and the outer wall of the inner ring portion is connected to the connecting portion by a smooth curved surface.

[0012] The beneficial effects of this setting are: increasing the fillet radius and draft angle is to ensure smooth forming of the forging and guarantee processing stability. Attached Figure Description

[0013] Figure 1 This is a schematic diagram of the structure of an embodiment of the present utility model;

[0014] Figure 2 This is a cross-sectional structural diagram of an embodiment of the present utility model. Detailed Implementation

[0015] This utility model provides an embodiment of a blank for machining the rings of an ultra-thin flexible bearing, such as... Figures 1 to 2As shown, the workpiece includes a blank comprising an outer ring portion 1, an inner ring portion 2, and a connecting portion 3. The outer ring portion 1 and the inner ring portion 2 are connected by the connecting portion 3. Grooves are provided between the connecting portion 3 and the outer ring portion 1, and between the connecting portion 3 and the inner ring portion 2. A positioning groove is provided on the connecting portion 3, and several mating grooves are formed in the positioning groove. The beneficial effect of this design is that the blank is composed of the outer ring portion 1, the inner ring portion 2, and the connecting portion 3, with the connecting portion 3 becoming a key clamping area during processing. Compared to traditional structures that are prone to deformation due to direct clamping of the outer or inner ring, the connecting portion 3 can disperse the clamping force, ensuring the shape stability of the blank during processing, making processing operations more convenient and precise, avoiding the impact of blank deformation on subsequent accuracy, and laying the foundation for high-quality processing. The design of the positioning groove and the mating groove further enhances the functionality. The positioning groove provides a clear reference, enabling rapid and precise positioning by automated equipment. The mating groove, in conjunction with positioning device components, restricts workpiece movement from multiple directions, significantly reducing positioning errors and ensuring no displacement or rotation of the workpiece during processing, thus significantly improving yield. Building upon this, it offers a wealth of additional technical benefits: in terms of processing efficiency, rapid and precise positioning shortens the clamping and adjustment time of automated equipment, reduces auxiliary processing time, and stable clamping allows for higher processing parameters, further enhancing efficiency; in terms of cost control, scrap rate, equipment wear, and tool wear are reduced, achieving cost optimization across the entire process from raw materials and equipment maintenance to tool usage; in terms of automation integration, this structure is compatible with robotic gripping and automatic clamping equipment, creating conditions for fully automated production and facilitating intelligent upgrades to production lines; in terms of compatibility and expandability, it is compatible with various clamping devices; and stable clamping ensures that the processing state of each workpiece is similar, reducing quality differences, improving the performance stability and reliability of bearing rings, and enhancing market competitiveness. Overall, this workpiece structure, through its basic design and extended effects, comprehensively empowers the efficient and high-quality production of ultra-thin flexible bearing rings, from the processing flow to the final product.In practice, the inner and outer ring tower components are designed, and the weight and volume of the material required for the bearing forging blank are calculated. A high-speed upsetting forging machine is used to sequentially perform blanking, upsetting, tower forging, and punching processes to obtain the inner and outer ring tower-shaped blanks of the bearing. The inner and outer ring tower-shaped blanks are then clamped in a CNC lathe for turning, removing the pre-reserved turning and cutting portions of the outer ring to obtain the finished ultra-thin flexible bearing outer ring and the remaining tower component. The remaining tower component after turning is then clamped in a CNC lathe for turning, removing the pre-reserved turning and cutting portions of the inner ring to obtain the ultra-thin flexible bearing outer ring. The specific method for obtaining the material weight and volume of the forged tower part of the thin flexible bearing inner ring is as follows: based on the dimensions of the finished outer and inner rings of the ultra-thin flexible bearing used in robots, turning and cutting allowances are increased. Combining the characteristics of high-speed forging, and considering the clamping parts required for the machining process, the dimensions of the inner and outer ring tower-shaped blanks suitable for machining are designed. The dimensional parameters of the inner and outer ring tower-shaped blanks include: outer ring portion 1: outer diameter D1, inner diameter d1, height h1; inner ring portion 2: 3.3 outer diameter D2, inner diameter d2, height h2; connecting... The height of section 3 is B, and the total height of the inner and outer ring tower-shaped blanks is H. All parameters are in mm. The outer ring 1-point outer diameter D1 is the maximum outer diameter of the inner and outer ring tower-shaped blanks; the outer ring 1-point inner diameter d1 is the maximum inner diameter of the inner and outer ring tower-shaped blanks; the inner ring 2-point outer diameter D2 is the minimum outer diameter of the inner and outer ring tower-shaped blanks; the inner ring 2-point inner diameter d2 is the minimum inner diameter of the inner and outer ring tower-shaped blanks; the outer ring 1-point height h1 is the axial distance from the large end face of the inner and outer ring tower-shaped blanks to the end face at the inner diameter step; the inner ring 2-point height h2 is the distance between the inner and outer ring tower-shaped blanks. The axial distance from the small end face of the blank to the end face at the outer diameter step; the height B of the connecting part 3 is the axial distance from the end face at the inner diameter step of the inner and outer ring tower-shaped blanks to the end face at the outer diameter step; the total height of the inner and outer ring tower-shaped blanks is the axial distance from the large end face to the small end face; all machining allowances are single-sided allowances. The design is based on the finished dimensions of the inner and outer rings of the ultra-thin bearing. The dimensional parameters of the ultra-thin flexible bearing include: the outer diameter Dt1, inner diameter dt1, and height ht1 of the finished outer ring; and the outer diameter Dt2, inner diameter dt2, and height ht2 of the finished inner ring. The single-sided machining allowance for the outer ring portion 1 and inner ring portion 2 of the inner and outer ring tower-shaped blanks, based on the dimensions of the ultra-thin flexible bearing, needs to be at least 0.6mm, and the cutting allowance at least 2.5mm. Simultaneously, the minimum wall thickness of the outer ring portion 1 and inner ring portion 2 of the blank must be at least 4mm.The specific design is as follows: The outer diameter D1 of the outer ring portion 1 of the blank is increased by at least 0.6*2 based on the outer diameter Dt1 of the finished outer ring 1 of the ultra-thin flexible bearing. The inner diameter d1 of the outer ring portion 1 of the blank is decreased by at least 0.6*2 based on the inner diameter dt1 of the finished outer ring 1 of the ultra-thin flexible bearing. The wall thickness (D1-d1) / 2 of the outer ring portion 1 of the blank is guaranteed to be ≥4. Then, based on the height ht1 of the finished outer ring 1 of the ultra-thin flexible bearing, the end face machining allowance of 0.6*2 and the cutting allowance of at least 2.5mm are added to obtain the height h1 of the outer ring portion 1 of the blank. Similarly, the outer diameters D2, d2, and h2 of the inner ring portion 2 of the blank are determined in the same way. Then, based on the length required for machining and clamping, the height B of the clamping portion is determined, generally at least 5mm. Thus, the total height H of the blank is determined: H = h1 + h2 + B. By adding core thickness, transition fillet radius, and draft angle to the inner and outer ring tower-shaped blanks obtained from S10 using conventional methods, the upsetting shape can be obtained. The core is a discarded portion of material that is necessary for high-speed forging. Based on the weight and volume of the required material for the inner and outer ring tower-shaped blanks, a suitable diameter bar and blank length are selected according to the principle of a length-to-diameter ratio of 0.8-1.2. The specific method for the upsetting process is as follows: the upsetting diameter is obtained by subtracting 1 mm from the outer diameter D1 of the outer ring portion of the inner and outer ring tower-shaped blanks. Then, the diameter and thickness of the upset disc are calculated based on the required material weight and volume. The calculation of blanking and upsetting is based on the principle of constant volume. The obtained inner and outer ring tower-shaped blanks are clamped in a CNC machine tool, with the base surface positioned on the end face of the inner ring portion of the inner and outer ring tower-shaped blanks, and the jaws clamped on the connecting part 3 of the inner and outer ring tower-shaped blanks. The CNC turning program is started to machine the outer ring portion 1 of the inner ring tower-shaped blank. First, the inner and outer diameters and the excess material on the outward-facing end face are removed. After roughing and finishing, the inward-facing end face is cut off. At the same time as the end face is machined, the outer ring is separated from the tower-shaped blank to obtain the finished ultra-thin flexible bearing outer ring. The connecting part 3 of the inner and outer ring tower-shaped blanks and the inner ring portion 2 of the blank are left in the chuck. The remaining parts of the inner and outer ring tower-shaped blanks left in the CNC machine tool chuck are removed. The remaining parts of the inner and outer ring tower-shaped blanks are reversed and clamped in another CNC machine tool, with the base surface positioned on the flat end face left after the previous turning. The chuck is still clamped on the connecting part 3 of the inner and outer ring tower-shaped blanks. Start the CNC turning program to process the remaining parts of the inner and outer ring tower-shaped blanks left on the CNC machine tool jaws. The process of removing the designed allowance and cutting off the part is similar to the previous process and will not be described again here. Finally, the ultra-thin flexible bearing inner ring is obtained.

[0016] As a further feature of this invention, the positioning groove includes a narrow portion 5, a smooth portion 6, and a wide portion 4. The narrow portion 5 and the wide portion 4 are connected by the smooth portion 6, and the two sides of the smooth portion 6 are set as smooth bevels. The advantages of this design are: this segmented design of the positioning groove—narrow portion 5, smooth portion 6, and wide portion 4—combined with the smooth bevels, offers significant advantages in positioning scenarios. The narrow portion 5 can serve as an initial guide, quickly introducing the positioning element; the smooth portion 6 and the bevels provide a transition, allowing the positioning element to slide smoothly into the wide portion 4, ensuring accurate positioning while reducing the impact force during clamping and preventing microscopic deformation of the workpiece due to instantaneous force. The smooth bevel structure reduces friction and wear between the positioning element and the groove, extending their service life and lowering equipment maintenance costs. The segmented structure facilitates compatibility with different types of positioning devices; the narrow section 5 is suitable for small, precise positioning pins, while the wide section 4 is compatible with larger or elastic positioning components, improving the versatility of the workpiece in multi-process, multi-equipment production. This structure makes the positioning force distribution more uniform. When the workpiece is affected by external forces such as cutting forces during processing, the wide section 4 and the smooth section 6 can work together to disperse stress, further suppressing workpiece deformation and ensuring the stability of processing accuracy. Especially for high-precision parts such as ultra-thin flexible bearing rings, this structure can help improve product consistency and yield.

[0017] As a further feature of this invention, the mating groove includes a first groove 71 disposed in the narrow portion 5 and a second groove 72 disposed in the wide portion 4. A first platform is formed at the end of the first groove 71 near the wide portion 4, and a second platform is formed at the end of the first groove 71 away from the wide portion 4. The first platform is shallower than the second platform, and the first and second platforms are connected by a guide ramp. The beneficial effect of this configuration is that, with the narrow portion 5 and the wide portion 4, the first groove 71 and the second groove 72 form an orderly positioning path. The height difference between the first and second platforms, combined with the guide ramp, allows the positioning element to smoothly transition along the ramp when inserted, utilizing the height difference to form a pre-position and precisely guide the locking mechanism—a dual constraint. The combination of guide ramp and stepped platform can accommodate positioning elements with different tolerance ranges, improve the compatibility of blanks in multi-batch production and when adapted to different equipment, and reduce clamping errors caused by slight differences in positioning elements; secondly, the structure formed by the high and low platforms can suppress the small displacement of blanks through mechanical limiting between the platforms in the processing vibration environment, enhance the stability of the processing process, and help improve the dimensional accuracy of the ring.

[0018] As a further feature of this invention, the inner wall of the outer ring portion 1 and the connecting portion 3 are connected by a smooth curved surface, and the outer wall of the inner ring portion 2 and the connecting portion 3 are also connected by a smooth curved surface. The beneficial effect of this design is that by increasing the fillet radius and draft angle, the forging can be formed smoothly, ensuring processing stability.

[0019] The above examples are merely one preferred embodiment of this utility model. Ordinary variations and substitutions made by those skilled in the art within the scope of this utility model's technical solution are all included within the protection scope of this utility model.

Claims

1. A blank for machining the rings of an ultra-thin flexible bearing, characterized in that: The material includes a blank body, which includes an outer ring portion, an inner ring portion, and a connecting portion. The outer ring portion and the inner ring portion are connected by the connecting portion. Grooves are provided between the connecting portion and the outer ring portion and between the connecting portion and the inner ring portion. A positioning groove is provided on the connecting portion, and several mating grooves are formed in the positioning groove.

2. A blank for race machining for ultra-thin flexible bearings according to claim 1, characterized in that: The positioning groove includes a narrow section, a smooth section, and a wide section. The narrow section and the wide section are connected by the smooth section, and the two sides of the smooth section are set as smooth bevels.

3. A blank for race machining for ultra-thin flexible bearings according to claim 2, characterized in that: The mating groove includes a first groove body disposed in the narrow part and a second groove body disposed in the wide part. A first platform is formed at the end of the first groove body near the wide part, and a second platform is formed at the end of the first groove body away from the wide part. The first platform is shallower than the second platform, and the first platform and the second platform are connected by a guide slope.

4. The blank for machining the rings of an ultra-thin flexible bearing according to claim 3, characterized in that: The inner wall of the outer ring and the connecting part are connected by a smooth curved surface, and the outer wall of the inner ring and the connecting part are connected by a smooth curved surface.

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