A ball bearing and its application

Abstract

The present invention discloses a ball bearing and its application. The ball bearing includes an inner ring and an outer ring. There are rolling elements provided between the inner ring and the outer ring, and the inner ring and the outer ring can rotate relative to each other. The inner ring of the ball bearing symmetrically extends towards both sides to have a first convex platform and a second convex platform with respective abutting functions, and the first convex platform and the second convex platform respectively protrude from the left and right sides of the outer ring. Apply two such ball bearings between a rolling element having an installation hole for installing the ball bearing and a clamping plate having a flat installation surface: make the second convex platforms of the two ball bearings abut against each other and install them together into the installation hole of the rolling element. The first convex platforms of the two ball bearings protrude outwards from the rolling element and abut against the installation surface of the clamping plate, and the rolling element and the clamping plate are separated by the first convex platforms. Insert a pin shaft into the ball bearing and lock it with the clamping plate. Compared with the prior art, the influence of the tolerances of the raised steps on the bearing sleeve and the clamping plate on the overall accuracy is eliminated, the rolling element rotates more smoothly, and the straightness is unified.

Description

Technical Field

[0001] The present invention relates to the technical field of bearings, and particularly relates to a ball bearing and its application. Background Art

[0002] Ball bearings are widely used. They have the advantages of high rotational speed and low noise. However, due to their structure, current ball bearings cannot be used individually and must be used in pairs to fulfill their functions. Such ball bearings are often used between rolling elements and clamping plates. The rolling elements are installed on the clamping plates and can rotate relative to the clamping plates, such as in the usage scenarios of various rollers and transmission wheels. The clamping plates often sandwich the rolling elements in the middle to determine the central plane of the rolling elements and limit their movement, preventing the rolling elements from moving back and forth on the shaft. Therefore, a bearing sleeve is generally provided between two ball bearings, and a raised step is provided on the clamping plate to contact the inner ring of the ball bearing, so as to separate the rolling elements from the clamping plate and enable the rolling elements to rotate normally. In this way, the mold opening of the clamping plate becomes complex and troublesome, increasing the mold opening cost. Moreover, the step and the bearing sleeve act on the inner and outer rings of the ball bearing respectively. When the rolling elements are subjected to axial component forces, the step and the bearing sleeve apply forces in opposite directions to the inner and outer rings of the ball bearing respectively, causing relative displacement between the inner and outer rings of the ball bearing, which will change the clearance of the ball bearing, thus resulting in the inability of the rolling elements to rotate smoothly.

[0003] The addition of the step and the bearing sleeve also increases the number of tolerances that need to be noted and considered between the rolling elements and the clamping plate. In specific scenarios, it is necessary to ensure that multiple rolling elements are in the same plane and have a unified straightness, such as roller skates with multiple rollers and a transmission mechanism with front and rear belt pulleys. These unnecessary tolerances are difficult to accurately control, causing slight stagger of each rolling element, thus affecting the operation of the entire mechanism. Summary of the Invention

[0004] In order to solve the above technical problems, the present invention provides a ball bearing. The inner ring of the ball bearing has two bosses. The first boss and the second boss protrude from the outer ring, and both the first and second bosses are used to abut against the components adjacent to the ball bearing.

[0005] Furthermore, an application of the ball bearing is provided. The above two ball bearings are used in rolling elements and clamping plates. In this application, the two ball bearings are adjacent to each other, and the two ball bearings are respectively adjacent to the clamping plate. Therefore, the first bosses of the two ball bearings abut against the clamping plate, and the second bosses of the two ball bearings abut against each other.

[0006] The technical solution of the present invention is realized as follows:

[0007] A ball bearing includes an inner ring and an outer ring. There are rolling elements provided between the inner ring and the outer ring, and the inner ring and the outer ring can rotate relative to each other. The inner ring of the ball bearing symmetrically extends towards both sides with a first boss and a second boss each having an abutting function, and the first boss and the second boss respectively protrude from the left and right sides of the outer ring.

[0008] The ball bearing has bosses with an abutting function, eliminating the need to set up abutting parts between the ball bearing and other adjacent components, thus eliminating the tolerance of the abutting parts. Therefore, the ball bearing can greatly improve the precision of the mechanism to meet the requirements of various smoothness and straightness.

[0009] An application of a ball bearing is to apply two ball bearings as described above between a rolling element having an installation hole for installing the ball bearing and a clamping plate having a flat installation surface: make the second bosses of the two ball bearings abut against each other and install them together into the installation hole of the rolling element. The first bosses of the two ball bearings protrude outwards from the rolling element and abut against the installation surface of the clamping plate, and the rolling element and the clamping plate are separated by the first bosses; insert a pin shaft into the ball bearing and lock it with the clamping plate.

[0010] The bosses abut against the parts adjacent to the ball bearing. Another identical ball bearing can be used as the part adjacent to this ball bearing, and the clamping plate can also be used as the part adjacent to this ball bearing. In the scenario where two ball bearings are adjacent, the second bosses of the two ball bearings abut against each other, thus eliminating the conventional bearing sleeve and the influence of the tolerance of the bearing sleeve on the overall precision; in the scenario where two ball bearings are adjacent to the clamping plate, the first bosses of the two ball bearings both abut against the clamping plate, canceling the raised steps that would be set on the original clamping plate and eliminating the influence of the tolerance of this step on the overall precision; at the same time, under this application, the inner and outer rings of the ball bearing will not be affected by forces in opposite directions, and the clearance of the ball bearing is not affected; the rotation of the rolling element is excellent in smoothness, and the straightness of each rolling element can be ensured to be unified when there are multiple rolling elements.

[0011] Preferably, the inner rings of the two ball bearings are clamped by the clamping plate and are relatively stationary with respect to the clamping plate.

[0012] Preferably, the outer rings of the two ball bearings are in interference fit with the installation holes of the rolling element and are relatively stationary with respect to the rolling element.

[0013] Preferably, a convex ring extends towards the center on the inner wall of the installation hole, and the two bearings are respectively inserted into the installation hole from both sides of the convex ring.

[0014] Preferably, the thickness of the convex ring is equal to the sum of the lengths of the two second bosses.

[0015] Preferably, the thickness of the rolling element is not greater than the sum of the thicknesses of the two ball bearings.

[0016] The design starting point, concept and beneficial effects of the present invention adopting the above technical solutions are:

[0017] The concept and beneficial effects of the present invention are as follows:

[0018] 1. In the scenario where two ball bearings are adjacent, the second bosses of the two ball bearings abut against each other, thus eliminating the conventional bearing sleeve and the influence of the tolerance of the bearing sleeve on the overall accuracy. In the scenario where two ball bearings are adjacent to the clamping plate, the first bosses of the two ball bearings both abut against the clamping plate, canceling the raised steps that would be provided on the original clamping plate and eliminating the influence of the tolerance of the steps on the overall accuracy. At the same time, in this application, the inner and outer rings of the ball bearing will not be affected by forces in opposite directions, and the clearance of the ball bearing is also not affected. The rolling elements rotate smoothly, and the straightness of multiple rolling elements can be ensured to be unified when there are multiple rolling elements.

[0019] 2. Taking the application of this ball bearing in roller skates as an example: Since the inner ring of the ball bearing has a first boss protruding from the mounting hole, and the first boss can replace the inner ledge on the inner surface of the traditional wheel frame for abutting against the ball bearing, the inner surface of the wheel frame can be made into a flat plane. Compared with the existing traditional wheel frame, the inner ledge for abutting against the inner ring of the traditional bearing is removed from this wheel frame, and this inner ledge is the reason for the high mold opening and processing costs of the traditional wheel frame. The design of the first boss reduces the mold opening and processing costs of the wheel frame sharply. Low-cost processing will cause differences in the convex rings (i.e., inner ledges) on the traditional wheel frame, making it impossible to ensure the straightness of the roller skates. Even during assembly or use, the convex ring excessively squeezes the inner ring of the traditional bearing, causing the inner ring to be misaligned, changing the clearance of the traditional bearing, and making the roller skates rotate smoothly, greatly affecting the use. However, the processing accuracy of the bearing is higher. Therefore, the first boss of the ball bearing has higher accuracy than the inner ledge of the traditional wheel frame, and the straightness of the row of wheels is relatively easy to control, and the roller skating speed is also easy to increase.

[0020] The ball bearing has a protruding second boss. After the two ball bearings are installed in the mounting hole, the second bosses of the two ball bearings abut against each other. Therefore, compared with the traditional bearing, the spacing element, that is, the bearing sleeve, is omitted, the tolerance of the spacing is optimized, ensuring the movement of the steel balls of the ball bearing in the normal clearance, and at the same time ensuring the maximum flexibility of the row of wheels during rotation, and also ensuring the straightness when the row of wheels rotates, greatly increasing the stability and speed advantage during roller skating competitions.

[0021] 3. Since the first and second bosses protruding outward on the left and right sides of the ball bearing are symmetrical, when installing the ball bearing into the mounting hole, there is no need to distinguish the front and back of the bearing, and the installation operation is simple and fast. And the mold opening and processing of the bearing with such a special design are also relatively convenient. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a schematic three-dimensional structure diagram of the bearing and the wheel core after assembly in Embodiment 1 of the present invention;

[0023] Figure 2 This is a side view of the bearing and wheel core assembly in Embodiment 1 of the present invention;

[0024] Figure 3 This is a cross-sectional view of the bearing and wheel core assembly in Embodiment 1 of the present invention;

[0025] Figure 4 This is a three-dimensional structural schematic diagram of the bearing and wheel core assembly in Embodiment 1 of the present invention;

[0026] Figure 5 This is a cross-sectional view of the bearing and wheel core assembly in Embodiment 1 of the present invention;

[0027] Figure 6 This is a side view of the wheel core in Embodiment 1 of the present invention;

[0028] Figure 7 This is a three-dimensional structural schematic diagram of the wheel core in Embodiment 1 of the present invention;

[0029] Figure 8 This is a three-dimensional structural cross-sectional view of the wheel core in Embodiment 1 of the present invention;

[0030] Figure 9 This is a three-dimensional structural schematic diagram of the assembly of the wheel core rotating structure and the wheel frame in Embodiment 1 of the present invention;

[0031] Figure 10 This is a top view of the assembly of the wheel core rotating structure and the wheel frame in Embodiment 1 of the present invention;

[0032] Figure 11 This is a cross-sectional view of the assembly of the wheel core rotating structure and the wheel frame in Embodiment 1 of the present invention;

[0033] Figure 12 This is a three-dimensional structural schematic diagram of the roller skate in Embodiment 1 of the present invention;

[0034] Figure 13 This is a cross-sectional view of the combined installation of a traditional bearing and a traditional wheel frame;

[0035] Figure 14 This is a three-dimensional structural schematic diagram of two bearings in Embodiment 1 of the present invention.

[0036] Each reference numeral is: wheel core 1; wheel spoke 101; hub 102; rim 103; fastening structure 2; first ring 201; second ring 202; waist hole 203; rib column 204; wheel frame 3; pin hole 301; wheel frame side plate 302; convex ring 303; PU material 4; bearing 5; inner ring 501; outer ring 502; first boss 503; second boss 504; mounting hole 104; convex ring 105; pin shaft 6; bearing sleeve 7; frame 8; drive shaft 9; driven shaft 10; drive wheel 11; driven wheel 12; actuator 13; mounting groove 14; limiting ring 15. Detailed implementation mode

[0037] In order to more clearly understand the above-mentioned objects, features and advantages of the present invention, the present invention will be further described in detail below in conjunction with the accompanying drawings and specific implementation modes. It should be noted that, without conflict, the embodiments of the present application and the features in the embodiments can be combined with each other.

[0038] In the following description, many specific details are set forth in order to fully understand the present invention. However, the present invention can also be implemented in other ways different from those described herein. Therefore, the protection scope of the present invention is not limited by the specific embodiments disclosed below.

[0039] In the description of the present invention, the term "at least one" means one or more than one, unless otherwise clearly defined. The terms "first", "second", "third", etc. are only used for the purpose of description and cannot be understood as indicating or implying relative importance.

[0040] The specific implementation mode of the present invention is as follows:

[0041] As Figure 14 shown, a ball bearing of the present invention includes an inner ring 501 and an outer ring 502. There are rolling elements between the inner ring 501 and the outer ring 502, and the inner ring 501 and the outer ring 502 can rotate relative to each other. The inner ring 501 of the ball bearing symmetrically extends to both sides with a first boss 503 and a second boss 504 each having a abutting function, and the first boss 503 and the second boss 504 respectively protrude from the left and right sides of the outer ring 502.

[0042] At the same time, an application of a ball bearing is provided. Two such ball bearings are applied between a rolling element having a mounting hole 104 for mounting the ball bearing and a clamping plate having a flat mounting surface: the first bosses 503 of the two ball bearings are abutted against each other and are together installed into the mounting hole 104 of the rolling element. The second bosses 504 of the two ball bearings protrude outwards from the rolling element and abut against the mounting surface of the clamping plate. The rolling element and the clamping plate are separated by the first boss 503; a pin shaft 6 is inserted into the ball bearing and locked with the clamping plate. Embodiment

[0043] In this embodiment, the ball bearing is applied to roller skates. The ball bearing is bearing 5, the rolling element is wheel core 1, the clamping plate is wheel frame side plate 302, and the mounting surface is the side surface of the wheel frame side plate 302 facing the bearing 5. In this embodiment, the length in the axial direction of the bearing 5 is called the thickness.

[0044] The roller skating industry has gradually matured and the product has become stable; this has resulted in all roller skates being the same. Although the appearance is constantly changing, their core, such as the thickness of the roller skate wheels and the bearings used, have not had major improvements for a long time.

[0045] The qualification verification of roller pulleys needs to go through a whole set of specific tests to check whether their key performance such as life and wear resistance meet the requirements. Due to the limited technology in the past, in order to pass the test, standard roller pulleys are all 24mm thick. Under the same structure, thicker pulleys are stronger than thinner pulleys. However, most manufacturers may not have considered how to reduce the thickness of the wheels, and set the thickness of the wheels at 24mm during production. Therefore, reducing the thickness of roller pulleys will be a major improvement to the roller skating industry, which is of great significance to both production and roller skating competitions.

[0046] In order to improve the quality of the wheel pulley, under the premise that the used materials, wheel test conditions and test results remain unchanged, the globally accepted thickness of 24mm is reduced to 16mm, and the weight of a single wheel is reduced by more than 30%; the present invention is based on the thinning of the wheel pulley, and further improves the bearing 5.

[0047] Specifically, if Figures 1-6 As shown, a mounting hole 104 for mounting a bearing 5 is provided at the center of the wheel core 1, and a convex ring 105 extends toward the center on the inner wall of the mounting hole 104, and the thickness of the convex ring 105 is 3.2 mm; the bearing 5 includes an inner ring 501 and an outer ring 502, and a rolling body is provided between the inner ring 501 and the outer ring 502. The rolling body can be a steel ball or a needle roller, etc. The rolling body provided between the inner ring 501 and the outer ring 502 is not limited, and the outer ring 502 is connected and fixed to the mounting hole 104, that is, the bearing 5 and the mounting hole 104 are interference fit, and the bearing 5 is pressed into the mounting hole 104, and the two can be fixedly connected by friction.

[0048] The inner ring 501 extends a first boss 503 and a second boss 504 to the left and right sides along the axial direction, and the first boss 503 and the second boss 504 both protrude from the outer ring 502. In this embodiment, since the thickness of the convex ring 105 is 3.2 mm, in order to allow the first bosses 503 of the two bearings 5 ​​to abut against each other after assembly, the thickness of the first boss 503 and the second boss 504 are both set to 1.6 mm, and the thickness of the outer ring 502 is the same as that of the traditional bearing 5, which is 7 mm. Therefore, the total thickness of the inner ring 501 is 10.2 mm; the two bearings 5 ​​are respectively installed in the mounting hole 104 from both sides of the convex ring 105, as shown in FIG. Figure 4 , 5As shown, at this time, the outer rings 502 of the two bearings 5 are in contact with the convex ring 105, and at the same time, the first convex platforms 503 of the two bearings 5 are in contact with each other, and the second convex platforms 504 protrude from the wheel core 1. The bearings 5 are in interference fit with the mounting holes 104.

[0049] As Figure 13 shown, compared with traditional bearings, the inner and outer rings of traditional bearings have the same thickness, and a spacing element, i.e., a bearing sleeve 7, needs to be provided between the two bearings to ensure the spacing between the two bearings so that the bearings can work properly. Now, the thickness of the inner ring 501 of the bearing 5 is increased bidirectionally until after the bearing 5 is assembled into the mounting hole 104, the inner rings 501 of the two bearings 5 can be in contact with each other to replace the spacing element, thereby optimizing the tolerance of the spacing, ensuring straightness, and ensuring that the steel balls of the bearing 5 move in the normal clearance. At the same time, the maximum flexibility of the pulley rotation is also guaranteed.

[0050] In addition, the wheel core rotation structure further includes a polymer material provided outside the wheel core 1. The polymer material is a PU material 4, and the PU material 4 forms a tread outside the wheel core 1. The wheel core 1 further includes a wheel spoke 101, a hub 102 at the center of the wheel core 1, and a rim 103 at the outermost side of the wheel core 1. The wheel spokes 101 radiate outward from the hub 102 in a branch-like shape and are connected to the inner surface of the rim 103. A fastening structure 2 for preventing the PU material 4 from peeling off due to lateral force is provided outside the rim 103. The fastening structure 2 is arranged along the axial direction of the wheel core 1, and the fastening structure 2 is integrally formed with the wheel core 1.

[0051] As Figures 6-8 shown, the fastening structure 2 is provided on the basis of thinning the pulley to consider how to prevent the tread from peeling off the wheel core 1 when the tread is subjected to a large lateral force, such as braking, turning during racing, etc., so as to avoid major accidents. The fastening structure 2 is a double-layer waist-hole structure, including a first ring 201 close to the rim 103 and a second ring 202 far from the rim 103. The first ring 201 and the second ring 202 are arranged at the middle position outside the rim 103 and are distributed layer by layer outward in the radial direction of the wheel core 1. A plurality of waist holes 203 are evenly distributed in the circumferential direction of the wheel core 1 between the first ring 201 and the rim 103 and between the second ring 202 and the first ring 201. When the PU material 4 is poured outside the rim 103, the PU material 4 is poured and combined with the fastening structure 2 to form a tread. Due to the existence of the double-layer waist holes, the bonding area between the wheel core 1 and the polymer material is greatly increased, and the anti-peeling performance is improved, making the pulley more stable when changing the angle with the ground.

[0052] Between two kidney-shaped holes 203 on the same layer, there is a rib column 204 formed, that is, the rib column 204 separates the kidney-shaped holes 203 on the same layer; and the rib columns 204 between the first ring 201 and the second ring 202 are staggeredly arranged circumferentially with the rib columns 204 between the first ring 201 and the rim 103, that is, the rib column 204 between the first ring 201 and the second ring 202 corresponds to the kidney-shaped hole 203 between the first ring 201 and the rim 103 towards the center of the circle. This makes each angle of the fastening structure 2 have a compressible or deformable space, so that the wheel core 1 has physical structure elasticity. If the rib columns 204 of the upper and lower layers are opposite to each other, this place becomes a solid structure that is difficult to deform, resulting in uneven overall elasticity. When the user is using it, they are likely to feel an abnormal feeling during travel.

[0053] As Figure 8 shown, in order to implement the principle of lightweight to the end, the thickness of the rim 103 is greater than the thickness of the first ring 201, and the thickness of the first ring 201 is greater than the thickness of the second ring 202, so as to reduce the weight of the fastening structure 2 as much as possible and prevent the fastening structure 2 from becoming an obstacle to lightweight.

[0054] As Figure 13 shown, the problem derived from the same thickness of the inner and outer rings of the traditional bearing is that a convex ring 303 for abutting against the inner ring of the traditional bearing must be provided on the inner surface of the traditional wheel frame, that is, the inner ledge. This convex ring 303 is the reason for the high mold opening and processing costs of the traditional wheel frame. Low-cost processing will cause differences in the convex rings 303 on the same wheel frame, and it is impossible to ensure the straightness of the wheel core rotation structure; even during assembly, the convex ring 303 excessively presses the inner ring of the traditional bearing, causing the inner ring to be misaligned, changing the clearance of the traditional bearing, resulting in unsmooth rotation of the wheel, which greatly affects the use.

[0055] Therefore, as Figures 9-12 shown, furthermore, a roller skate is provided, including a wheel frame 3 and the above-mentioned wheel core rotation structure, and the wheel is rotatably connected to the wheel frame 3; the inner surface of the wheel frame 3 is flat, and the second boss 504 of the bearing 5 abuts against the inner surface of the wheel frame 3. In this way, the processing cost of the wheel frame 3 is greatly reduced, the straightness of the rotation of the roller is relatively easy to control, and the roller skating speed is also easy to increase.

[0056] After assembling the bearing 5 and the roller skate, install them on the wheel frame 3: a pin hole 301 is provided at the lower part of the wheel frame 3. After aligning the bearing hole with the pin hole 301, they are connected and fixed by inserting a pin shaft 6. The pin shaft 6 is a pair of locking screws; since the bearing 5 has a second boss 504, at this time, the second boss 504 of the bearing 5 abuts against the inner surface of the wheel frame 3 to prevent the roller from rubbing against the wheel frame 3 when rotating.

[0057] Therefore, the improved wheel pulley and roller skates greatly save production and processing costs and materials. In terms of performance, the thinner wheel pulley reduces the overall weight of the roller skates, thus enhancing the user experience and increasing the speed advantage during competitions. The advantages of using this bearing 5 are as follows: unnecessary tolerances are eliminated, the installation is more precise, the clearance of the bearing 5 and the straightness of the wheel pulley on the wheel frame 3 are ensured, so that the wheel pulley rotates more smoothly on the wheel frame 3, thereby increasing competitiveness in competitions. The design of the double-layer waist hole increases the bonding area between the tread and the wheel core 1, making the wheel pulley more stable when changing the angle with the ground, and at the same time increasing the structural elasticity of the wheel pulley.

[0058] It should be clear that the core of the present invention lies in thinning the thickness of the wheel pulley from 24 mm to 16 mm, but this does not mean that wheel pulleys of other thicknesses are not applicable. Although the above technical features are developed for the purpose that the wheel pulley can still be used normally after thinning, they are also applicable to 24-mm-thick wheel pulleys and wheel pulleys of other thicknesses.

[0059] A method for improving the rotation smoothness of roller skates is provided for the above-mentioned wheel core rotation structure and roller skates:

[0060] The first step is to pre-manufacture the said bearing 5. Generally, the production of the bearing 5 is entrusted to a bearing factory. The requirements for the bearing 5 are as follows: it includes an inner ring 501 and an outer ring 502, with balls provided between the inner ring 501 and the outer ring 502. The inner ring 501 extends out the first boss 503 and the second boss 504 respectively on both sides along the axial direction. The thickness of the outer ring 502 is 7 mm, the thickness of the inner ring 501 (including the thicknesses of the first and second bosses) is 10.2 mm, and the thicknesses of the first and second bosses are both 1.6 mm.

[0061] The second step is to symmetrically install the two said bearings 5 into the mounting holes 104 of the wheel core 1 from left to right. When installing the bearings 5, since the first and second bosses of the bearings 5 are symmetrical, there is no need to distinguish the front and back of the bearings. The second bosses 504 of the two bearings 5 in the mounting holes 104 both protrude out of the mounting holes 104, and the first bosses 503 both face inward and are in contact with each other.

[0062] The third step is to install the wheel core 1 between two pre-formed wheel frame side plates 302. The wheel frame side plates 302 can be formed by stamping or by turning and milling. The second boss 504 is in contact and cooperation with the inner surface of the wheel frame side plate 302, and a pin shaft 6 is inserted into the bearing 5 and assembled with the wheel frame side plate 302.

Claims

1. Application of a ball bearing, Characterized in that: The ball bearing includes an inner ring and an outer ring. There are rolling elements provided between the inner ring and the outer ring, and the inner ring and the outer ring can rotate relative to each other. The inner ring of the ball bearing symmetrically extends towards both sides with a first boss and a second boss each having a abutting function, and the first boss and the second boss respectively protrude from the left and right sides of the outer ring; Two ball bearings as described above are applied between a rolling element having an installation hole for installing the ball bearing and a clamping plate having a flat installation surface, so that the second bosses of the two ball bearings are abutted against each other and are installed together into the installation hole of the rolling element. The first bosses of the two ball bearings protrude outwards from the rolling element and abut against the installation surface of the clamping plate, and the rolling element and the clamping plate are separated by the first bosses; A pin shaft is inserted into the ball bearing and locked with the clamping plate; The inner rings of the two ball bearings are clamped by the clamping plate and are relatively stationary with respect to the clamping plate; The outer rings of the two ball bearings are in interference fit with the installation holes of the rolling element and are relatively stationary with respect to the rolling element.

2. The application of the ball bearing according to claim 1, Characterized in that: A convex ring extends towards the center on the inner wall of the installation hole, and the two bearings are respectively inserted into the installation hole from both sides of the convex ring.

3. The application of the ball bearing according to claim 2, Characterized in that: The thickness of the convex ring is equal to the sum of the lengths of the two second bosses.

4. The application of the ball bearing according to claim 1, Characterized in that: The thickness of the rolling element is not greater than the sum of the thicknesses of the two ball bearings.

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