Optimization design method capable of improving qualified rate of assembled high bearing

Abstract

An optimal design method capable of improving the qualified rate of assembled high bearings is characterized in that when technological design is carried out on bearing parts, on the premise that the width size of the parts is qualified, the height value factor that the two end faces of a ferrule need to be ground at the bearing assembly height is fully considered, the grinding allowance of the ferrule parts is increased in a targeted mode, and the machining precision of the bearing parts is improved. According to the invention, the bearing can be accurately assembled in a manner of grinding the reserved adding end, so that the qualified rate of ferrule parts and products is well ensured, the production cost is reduced, and the product quality is improved. The method is high in operability, good in practicability, easy to design and operate and suitable for being used and popularized in the field of bearings.

Description

Technical Field

[0001] The invention belongs to the technical field of bearings, in particular to an optimization design method capable of improving the qualified rate of high-assembly bearings. Technical Background

[0002] Dimensional tolerance is referred to as tolerance, which refers to the absolute value of the difference between the maximum limit size and the minimum limit size allowed. Over-tolerance means that the product's dimensions exceed the tolerance range specified in the product standard, which is a quality defect of metal plastic processing products. Products have certain shapes and dimensions, and are allowed to fluctuate within a certain range. The range of fluctuation allowed for the dimensions specified in the product standard is called tolerance. Products with dimensions within the tolerance range are qualified products, and those exceeding the tolerance are unqualified products, substandard products or waste products.

[0003] At present, the prior art bearing assembly is achieved by grinding the two end faces of the ring. When the width dimension tolerance of the ring part is more stringent than the tolerance specified in the bearing assembly standard, it is very easy to cause the width of the ring part to exceed the tolerance, so that the bearing product cannot be processed and becomes a waste.

[0004] Therefore, how to optimize the design of bearings with assembly height so that they can accurately achieve the bearing assembly height and have a high product qualification rate is of great significance for reducing the production cost of bearing products and improving product quality. Summary of the invention

[0005] The technical purpose of the present invention is to optimize the structure of the outer ring or inner ring of the bearing, take the qualified width size of the parts as the premise, consider the height value factors of the two end surfaces of the high grinding ring of the bearing assembly, and increase the grinding allowance of the ring in a targeted manner to accurately achieve the high bearing assembly and better ensure the qualified rate of the ring parts and products.

[0006] To achieve the above technical objectives, the technical solution adopted by the present invention is: an optimization design method that can improve the qualified rate of high-quality bearings, wherein the bearing comprises an inner ring, an outer ring, a cage and a rolling element, and the rolling element is installed between the inner ring and the outer ring through the cage. The method comprises the following steps: Step 1: Calculate the theoretical minimum value Tmin of the assembly height after the bearing is assembled according to the formula Tmin=aimin+aomin-Gamax / 2; In the formula, Tmin is the theoretical minimum value of the assembly height after the bearing is assembled, aimin is the minimum value of the inner ring half width centered on the groove bottom, aomin is the minimum value of the outer ring half width centered on the groove bottom, and Gamax is the maximum value of the axial clearance of the bearing; Step 2: Calculate the minimum value Xmin of the grinding amount after the bearing is assembled according to the formula Xmin=Tmin-Smax; In the formula, Xmin is the minimum grinding amount after the bearing is assembled, Tmin is the theoretical minimum assembly height after the bearing is assembled, and Smax is the maximum setting value of the assembly height; Step 3: When the minimum grinding amount Xmin of the bearing after assembly is less than the actual tolerance a of the outer ring, the height value of the outer ring or inner ring is increased by not less than a in the axial direction during design to increase the grinding amount of the bearing with assembly height and improve the qualification rate.

[0007] Furthermore, in step three, the height value is increased in the axial direction of the outer ring by no less than a.

[0008] Furthermore, in step three, the height value increased at the non-grinding end in the axial direction of the outer ring is not less than a.

[0009] Beneficial effects: The invention discloses an optimization design method for improving the qualified rate of bearings with high assembly height. When designing the process of bearing parts, the qualified width size of the parts is taken as a premise, and the height value factor of the two end faces of the rings to be ground for the assembly height of the bearings is fully considered. The grinding reserve of the ring parts is increased in a targeted manner, so that the bearings can accurately achieve the assembly height of the bearings by grinding the reserved increase end, thereby better ensuring the qualified rate of the ring parts and products, reducing production costs, and improving product quality. The method itself has strong operability, good practicality, and simple design and operation, and is suitable for promotion and use in the field of bearings. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1 This is a schematic diagram of the original bearing design structure of Example 1 of the present invention; Figure 2 This is a schematic diagram of the optimized design structure of the outer ring of Example 1 of the present invention; Reference numerals: 1, inner ring; 2, outer ring, 3, cage, 4, rolling element. DETAILED DESCRIPTION

[0011] The present invention is further described in detail below in conjunction with the accompanying drawings and specific embodiments, but the present invention is not limited to the following embodiments. The purpose of disclosing the present invention is to protect all changes and improvements within the scope of the present invention.

[0012] As shown in the figure, the present invention provides an optimization design method that can improve the qualified rate of bearings with high assembly height. When designing the bearing process, it takes the qualified width dimension of the part as a premise, considers the height value of the two end surfaces of the bearing assembly high grinding ring, and increases the grinding allowance of the ring. The process method can accurately realize the bearing assembly height and ensure the qualified rate of the ring parts and products.

[0013] A specific scheme for an optimization design method that can improve the qualified rate of bearings with high assembly height is as follows: the bearing is composed of an inner ring 1, an outer ring 2, a retainer 3 and a rolling element 4. The assembly height of the bearing is achieved by grinding the height of the end face of the outer ring (width is C) or the inner ring (width is B). When it is found that the width size of the outer ring or the inner ring is out of tolerance, or the width sizes of the inner ring and the outer ring are both out of tolerance, assuming that the tolerance is a, then in the bearing process design, at least the width value a is increased at the non-grinding end of the ring, so that the width of the ring becomes C+a or B+a. After grinding, the bearing assembly height can be accurately achieved, and the qualified rate of the ring parts and products is guaranteed.

[0014] The process method of the present invention adopts a method of increasing the width of the ferrule, and ensures the qualified rate of the ferrule parts and products under the premise of accurately achieving high bearing assembly.

[0015] Example 1 An optimization design method of this embodiment can improve the qualified rate of high-quality bearings. Taking 7212 bearings as an example, the attached Figure 1 This is a schematic diagram of the original parts design structure of the 7212 bearing. In the figure, the 7212 bearing consists of an inner ring 1, an outer ring 2, a retainer 3 and a rolling element 4. The units of the dimensions in the figure and below are all mm.

[0016] As attached Figure 1 As shown in the figure, the required value of the 7212 bearing assembly height is 21.97~22mm, that is, the height between the large end face of the outer ring and the end face of the inner ring. The width (height) requirement of the inner ring is 22-0.015mm, the width (height) requirement of the outer ring is 22-0.1mm, and the half-width requirement of the outer ring is 11.32±0.02mm.

[0017] According to Figure 1 According to the structural dimensions shown, the theoretical minimum value Tmin of the assembly height after the bearing is assembled is calculated to be 22.07. The specific calculation process is as follows: Tmin=aimin+aomin-Gamax / 2=11-0.015+11.32-0.02-0.431 / 2=22.07. Among them, ai is the inner ring half width centered on the groove bottom, ao is the outer ring half width centered on the groove bottom, and Ga is the axial clearance of the bearing; the maximum axial clearance of the 7212 bearing is 0.431mm and the minimum is 0.358mm. Then the minimum inner ring half width aimin is 11-0.015, the minimum outer ring half width aomin is 11.32-0.02, and the maximum axial clearance Gamax is 0.431. The theoretical minimum value Tmin of the assembly height after the bearing is assembled is 22.07.

[0018] The theoretical minimum value Tmax of the assembly height after the bearing is assembled is calculated to be 22.16. The specific calculation process is as follows: Tmax=aimax+aomax-Gamin / 2=11+11.32+0.02-0.358 / 2=22.16. Among them, ai is the inner ring half width centered on the groove bottom, ao is the outer ring half width centered on the groove bottom, and Ga is the axial clearance of the bearing; the maximum inner ring half width aimax is 11, the maximum outer ring half width aomax is 11.32+0.02, and the minimum axial clearance Gamin is 0.358. The theoretical maximum assembly height Tmax of the bearing after assembly is calculated to be 22.16.

[0019] Therefore, in order to meet the requirement of bearing assembly height of 21.97~22, the maximum value of grinding amount is 0.19 and the minimum value is 0.07. Considering that the tolerance range of outer ring is 21.9~22, when the minimum value of grinding amount Xmin is less than the actual tolerance of outer ring 0.1, it is easy to cause the outer ring parts to be out of tolerance, which greatly reduces the product qualification rate.

[0020] For this reason, the bearing parts process design adopts the following Figure 2 The outer ring process dimensions shown are Figure 2 This is a schematic diagram of the optimized design structure of the outer ring of Example 1 of the present invention; considering the maximum and minimum values ​​of the grinding amount, and the width dimension of the inner ring is relatively strict and insufficient to support the grinding amount, the width of the outer ring is increased by 0.1, that is, it becomes 22~22.1, which not only ensures the high requirements of the bearing assembly, but also ensures the qualification rate of the outer ring parts and products.

[0021] Finally, it should be noted that the above is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art can still modify the technical solutions described in the aforementioned embodiments or replace some of the technical features therein by equivalents. Any modification, equivalent replacement, improvement, etc. made within the scope of the present invention shall be included in the scope of protection of the present invention.

Claims

1. An optimization design method for improving the qualified rate of high-quality bearings, wherein the bearing comprises an inner ring, an outer ring, a cage and a rolling element, wherein the rolling element is installed between the inner ring and the outer ring through the cage, and wherein: The method comprises the following steps: Step 1: Calculate the theoretical minimum value Tmin of the assembly height after the bearing is assembled according to the formula Tmin=aimin+aomin-Gamax / 2; In the formula, Tmin is the theoretical minimum value of the assembly height after the bearing is assembled, aimin is the minimum value of the inner ring half width centered on the groove bottom, aomin is the minimum value of the outer ring half width centered on the groove bottom, and Gamax is the maximum value of the axial clearance of the bearing; Step 2: Calculate the minimum value Xmin of the grinding amount after the bearing is assembled according to the formula Xmin=Tmin-Smax; In the formula, Xmin is the minimum grinding amount after the bearing is assembled, Tmin is the theoretical minimum assembly height after the bearing is assembled, and Smax is the maximum setting value of the assembly height; Step 3: When the minimum grinding amount Xmin of the bearing after assembly is less than the actual tolerance a of the outer ring, the height value of the outer ring or inner ring is increased by not less than a in the axial direction during design to increase the grinding amount of the bearing with assembly height and improve the qualification rate.

2. The optimization design method for improving the qualified rate of high-quality bearings according to claim 1, characterized in that: In step three, the height value is increased in the axial direction of the outer ring by no less than a.

3. The optimization design method for improving the qualified rate of high-quality bearings according to claim 2, characterized in that: In step three, the height value increased at the non-grinding end in the axial direction of the outer ring is not less than a.

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