Deep groove ball bearing

Abstract

The invention provides a deep groove ball bearing which eliminates load on a retainer due to lead and lag of a ball and eliminates interference between the retainer and an outer diameter surface of an inner ring and between the retainer and an inner diameter surface of an outer ring. A deep groove ball bearing (1) is provided with: an inner ring (2) having an inner ring raceway surface (2a) on the outer periphery thereof; an outer ring (3) having an outer ring raceway surface (3a) on the inner periphery thereof; a plurality of balls (4) that roll between the inner ring raceway surface (2a) and the outer ring raceway surface (3a); and a cage (5) that retains the balls (4) at constant intervals in the circumferential direction. The lower limit value of the circumferential pocket gap formed between the ball (4) and the pocket (50) for accommodating the ball (4) of the retainer (5) is set to 0.1 mm, and the upper limit value is set to [0.09 * used ball diameter-0.007] (mm).

Description

Technical Field

[0001] The present invention relates to a deep groove ball bearing, and in particular to a deep groove ball bearing suitable for transmission use. Background Art

[0002] The tracks of the inner and outer rings of deep groove ball bearings are arc-shaped deep grooves, which can bear radial loads, axial loads in two directions, or a combined load of these, and are also suitable for high-speed rotation. Therefore, deep groove ball bearings are the most widely used type of rolling bearings.

[0003] However, due to problems such as compatibility with transmission oil, deep groove ball bearings used in transmissions use a punched retainer that is also used in the deep groove ball bearing of Patent Document 1 to retain balls as rolling elements at equal intervals between the inner and outer rings.

[0004] The revolution speed of the balls, which are rolling elements held in the pockets of the cage, varies from ball to ball.

[0005] Especially when used in transmissions, the retainer is pulled by the faster rotating balls and the slower rotating balls, which is called ball lead-lag. In order to avoid the load on the retainer caused by this phenomenon, it is necessary to ensure sufficient circumferential clearance between the pockets and the balls.

[0006] Prior art literature

[0007] Patent Literature

[0008] Patent Document 1: Japanese Patent Application Publication No. 2013-160376 Summary of the invention

[0009] Problems to be solved by the invention

[0010] However, when the circumferential clearance between the pockets in the cage and the balls is set larger, the radial movement of the cage also increases, so there is a concern that the cage will interfere with the outer diameter surface of the inner ring, or the cage will interfere with the inner diameter surface of the outer ring, and the interference will generate a load on the cage. Since the circumferential clearance between the cage and the balls and the radial movement of the cage are opposite, changing them in a direction that is favorable to one side will produce disadvantageous results for the other side.

[0011] Therefore, depending on the situation, the cage design and bearing dimensions may have to be changed.

[0012] Therefore, the present invention provides a deep groove ball bearing particularly suitable for transmission use, which eliminates the load on the retainer caused by the lead and lag of the balls by stipulating the upper and lower limits of the circumferential pocket gap formed between the retainer pocket and the balls, and eliminates the interference of the inner ring and / or outer ring with the retainer without changing the retainer design and bearing dimensions.

[0013] Technical solutions to solve problems

[0014] In order to solve the above-mentioned problems, the present invention is characterized in that, in a deep groove ball bearing including an inner ring having an inner ring raceway surface on the outer circumference, an outer ring having an outer ring raceway surface on the inner circumference, a plurality of balls rolling between the inner ring raceway surface and the outer ring raceway surface, and a retainer retaining the balls at a certain interval in the circumferential direction, the lower limit value of the circumferential pocket gap formed between the ball-accommodating pocket of the retainer and the balls is set to 0.1 mm, and the upper limit value is set to [0.09×the diameter of the ball used - 0.007] (mm).

[0015] The circumferential pocket clearance formed between the ball-accommodating pocket of the cage and the ball varies depending on the operating temperature. Therefore, in the present invention, the clearance is defined as the clearance at the normal maximum temperature of 100°C.

[0016] Furthermore, the energy with which the ball hits the pocket of the cage varies depending on the mass, and therefore, in the present invention, the size of the circumferential pocket gap is set on the premise that the ball is a steel ball.

[0017] In addition, in the present invention, the size of the circumferential pocket gap is determined by using a punching retainer formed by demolding a cold-rolled steel plate (SPCC), and its material may be metals such as copper (Cu) and silver (Ag) or resin in addition to stainless steel (SUS).

[0018] The belt width of the retainer is set to a range of 0.2×ball diameter (mm) to 0.6×ball diameter (mm). When it is less than 0.2×ball diameter (mm), the movement of the retainer increases, and the retainer contacts the raceway. When it is greater than 0.6×ball diameter (mm), the clearance between the retainer and the outer diameter surface of the inner ring and the clearance between the retainer and the inner diameter surface of the outer ring decreases, and the retainer contacts the inner ring or the retainer contacts the outer ring.

[0019] Effects of the Invention

[0020] As described above, the present invention can eliminate the load on the retainer caused by the lead and lag of the ball by setting the lower limit of the circumferential pocket clearance formed between the ball-accommodating pocket of the retainer in the deep groove ball bearing and the ball to 0.1 mm and the upper limit to [0.09×the diameter of the ball used-0.007] (mm). In addition, in the present invention, by specifying the circumferential pocket clearance in the deep groove ball bearing, the movement amount of the retainer can also be specified, so that the interference between the retainer and the outer diameter surface of the inner ring and between the retainer and the inner diameter surface of the outer ring can be eliminated. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 This is a perspective view showing a partially cutaway deep groove ball bearing according to an embodiment of the present invention.

[0022] Figure 2 yes Figure 1 Longitudinal section of a deep groove ball bearing.

[0023] Figure 3 It means as in Figure 1 A perspective view of a retainer half body which is a component of a retainer used in a deep groove ball bearing.

[0024] Figure 4 Yes Figure 3 A perspective view of a retainer used in a deep groove ball bearing of the present invention, which is obtained by assembling retainer halves of

[0025] Figure 5 This is an enlarged view showing the relationship between the inner diameter of the cage pocket and the diameter of the ball.

[0026] Figure 6 This is an enlarged view showing the circumferential pocket clearance formed between the pocket of the cage and the ball.

[0027] Figure 7 It is a partial longitudinal cross-sectional view showing the procedure for measuring the circumferential pocket clearance.

[0028] Figure 8 This is a side view of a deep groove ball bearing showing a state where the circumferential pocket clearance is measured.

[0029] Fig. 9 This is a graph showing the relationship between ball diameter and circumferential pocket clearance.

[0030] Fig.10 This is a graph showing the relationship between the ball diameter and the clearance at the upper and lower limits of the circumferential pocket clearance.

[0031] Description of Reference Numerals

[0032] 1: Deep groove ball bearing

[0033] 2: Inner circle

[0034] 2a: Outer track surface

[0035] 3: Outer ring

[0036] 3a: Outer raceway surface

[0037] 4: Ball

[0038] 5: Retainer

[0039] 50: Pocket hole

[0040] s: Circumferential pocket clearance

[0041] c, d: clearance. DETAILED DESCRIPTION

[0042] Hereinafter, embodiments of the present invention will be described based on the drawings.

[0043] like Figure 1 and Figure 2 As shown, the deep groove ball bearing 1 includes: an inner ring 2 having an inner ring raceway surface 2a on the outer circumference; an outer ring 3 having an outer ring raceway surface 3a on the inner circumference; and a plurality of balls 4 rolling between the inner ring raceway surface 2a and the outer ring raceway surface 3a. The balls 4 are received in the pockets 50 of the retainer 5 and are retained at a certain interval in the circumferential direction.

[0044] exist Figure 1 and Figure 2 In the illustrated embodiment, a pressed retainer 5 is used which is formed by pressing an iron plate using a die.

[0045] like Figure 3 As shown in the perspective view in FIG. 1 , the stamped retainer 5 is formed by stamping two annular retainer halves 51 as shown in FIG. Figure 4 As shown, the components are formed by overlapping each other in the axial direction and being joined together by rivets 53 inserted into rivet holes 52.

[0046] The retainer half 51 is an annular body formed by alternatingly circumferentially arranging a spherical shell plate portion 51a whose inner surface forms half of the pocket 50 and a flat plate portion 51b located between adjacent pockets 50. Rivet holes 52 are provided in the flat plate portion 51b for making the retainer half 51 overlap in the axial direction and connected by rivets 53.

[0047] In the cage 5 formed by overlapping two cage halves 51 facing each other in the axial direction, pockets 50 for retaining the balls 4 are provided at equal intervals in the circumferential direction, and the inner surface of each pocket 50 is formed in a concave spherical shape.

[0048] like Figure 5As shown, the inner diameter D1 of the pocket 50 of the cage 5 is formed to be larger than the diameter D2 of the ball 4 (D1>D2), and a gap is provided between the inner diameter surface of the pocket 50 and the ball 4.

[0049] In the present invention, the circumferential gap formed between the inner diameter surface of the pocket 50 and the ball 4 is referred to as the circumferential pocket gap s ( Figure 6 ).

[0050] The circumferential pocket clearance s in the present invention can be measured in the following manner.

[0051] First, if Figure 7 As shown in FIG. 1 , a load is applied from one or both sides of the width surface of the inner ring 2 and the outer ring 3 in the direction of the arrow, so that the ball 4 is restrained by the inner ring raceway surface 2a and the outer ring raceway surface 3a. Next, while the ball 4 is restrained, the retainer 5 is moved from the side of the bearing in the circumferential direction ( Figure 8 The circumferential movement of the retainer 5 is measured by moving the retainer 5 in the direction of the arrow. That is, the circumferential pocket clearance s formed between the pocket 50 of the retainer 5 and the ball 4 is as follows: Figure 6 As shown, it can be measured as the amount of movement of the retainer 5 in the opposite direction after it moves to the limit on one side or the left or right side.

[0052] The revolution speed of the balls 4 accommodated in the pockets 50 of the retainer 5 varies according to the individual balls 4. There are balls 4 that rotate faster and balls 4 that rotate slower, and a phenomenon called lead-lag of the balls 4 may occur in which the retainer 5 is pulled by the balls 4 that rotate faster and the balls 4 that rotate slower.

[0053] This phenomenon called lead-lag of the balls 4 is caused by the phase difference between the balls 4 caused by the movement of the balls 4 in the direction of reducing the circumferential pocket gaps s during the rotation of the bearing.

[0054] When there is a circumferential pocket clearance s between the pockets 50 of the retainer 5 and the balls 4 accommodated in the pockets 50 , the retainer 5 moves in the radial direction during the bearing rotation due to the circumferential pocket clearance s.

[0055] When the retainer 5 moves in the radial direction, the clearance c between the retainer 5 and the outer diameter surface of the inner ring 2 and the clearance d between the retainer 5 and the inner diameter surface of the outer ring 3 are reduced.

[0056] Therefore, when the circumferential pocket clearance s is set larger, the clearances c and d disappear, and the retainer 5 comes into contact with the outer diameter surface of the inner ring 2 or the inner diameter surface of the outer ring 3 , so that a load is applied to the retainer 5 .

[0057] On the other hand, when the circumferential pocket clearance s is too small, a load is applied to the cage 5 due to the lead and lag of the balls 4 .

[0058] Therefore, in the present invention, the load on the retainer 5 caused by the lead and lag of the ball 4 is eliminated by setting the lower limit value and the upper limit value of the circumferential pocket gap s. Even if the retainer 5 moves radially due to the circumferential pocket gap s, the clearance c between the retainer 5 and the outer diameter surface of the inner ring 2 and the clearance d between the retainer 5 and the inner diameter surface of the outer ring 3 can be ensured.

[0059] The lower limit of the circumferential pocket clearance s in the present invention is 0.1 mm. This lower limit is a value that does not cause a load on the cage 5 due to lead / lag of the ball 4 in consideration of manufacturing tolerance and safety factor.

[0060] In addition, the bandwidth W ( Figure 1 ) is set to the range of 0.2×ball diameter to 0.6×ball diameter (mm). When it is less than 0.2×ball diameter (mm), the movement amount of retainer 5 becomes large, and retainer 5 contacts outer ring 3 or inner ring 2. When it is more than 0.6×ball diameter (mm), the clearance c between retainer 5 and the outer diameter surface of inner ring 2 and the clearance d between retainer 5 and the inner diameter surface of outer ring 3 become small, and retainer 5 and inner ring 2 or retainer 5 and outer ring 3 contact.

[0061] For various sizes of balls 4 (1 / 4 to 19 / 32 inches) suitable for use in transmission bearings, the relationship between the retainer 5 and the circumferential pocket clearance s required to ensure the clearances c and d is as follows: Fig. 9 As shown, according to the Fig. 9 The approximate formula is obtained from the plotted points, and the upper limit value of the circumferential pocket clearance s is calculated by [0.09×ball diameter used-0.007] (mm).

[0062] The clearance c and d are applicable to various sizes of the ball 4 for the transmission bearing when the upper and lower limits of the circumferential pocket clearance s are as follows: Fig.10 shown.

[0063] In the above embodiment, it is specified to use the punching retainer 5 formed by demoulding a cold rolled steel sheet (SPCC), but as its material, in addition to stainless steel (SUS), metals such as copper (Cu) and silver (Ag) can be used. In addition, as the retainer 5, it can also be made of resin.

[0064] The present invention is not limited to the above-described embodiments, and can of course be implemented in various forms without departing from the spirit of the present invention. The scope of the present invention also includes equivalent meanings and all modifications within the scope.

Claims

1. A deep groove ball bearing, characterized in that: include: An inner ring having an inner ring raceway surface on the outer circumference; an outer ring having an outer ring raceway surface on the inner circumference; a plurality of balls rolling between the inner ring raceway surface and the outer ring raceway surface; and a retainer for retaining the balls at a certain interval in the circumferential direction, wherein: The lower limit of the circumferential pocket clearance formed between the ball-accommodating pocket of the cage and the ball is set to 0.1 mm, and the upper limit is set to [0.09×the diameter of the ball used-0.007] (mm).

2. The deep groove ball bearing according to claim 1, characterized in that: The balls are made of steel.

3. The deep groove ball bearing according to claim 1, characterized in that: The material of the retainer is metal material.

4. The deep groove ball bearing according to claim 1 or 2, characterized in that: The belt width of the retainer is (0.2×ball diameter to 0.6×ball diameter) mm.

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