Angular contact ball bearing and method for manufacturing the same

Abstract

The present invention provides an angular contact ball bearing and a method for manufacturing the same, which achieves weight reduction by using press-formed steel plates for the outer and inner rings, prevents the outer or inner ring from separating from the balls, resulting in good handling and ensuring sealing performance. [Solution] In the angular contact ball bearing 10, the outer ring 21 and the inner ring 22 are press-formed products of steel plate, and at least one of the outer ring 21 and the inner ring 22 has engagement portions 20 and 30. Furthermore, the inner ring 22 has an inner ring extension portion 32 that extends outward from the side opposite to the cylindrical portion 28 of the spherical annular portion 26 and forms a labyrinth seal with the outer ring 21.

Description

Technical Field

[0005] , , , , , ,

[0001] The present invention relates to an angular ball bearing and a method for manufacturing the same, and particularly to an angular ball bearing in which an outer ring and an inner ring are formed by pressing and a method for manufacturing the same.

Background Art

[0002] In recent years, in the automotive industry and the aviation industry, improving fuel efficiency and performance through weight reduction have become important issues, and even for angular ball bearings incorporated in products, lightweight and high-performance ones are required.

[0003] As an angular ball bearing, it is known to manufacture each raceway ring (outer ring and inner ring) by pressing a metal plate material (see, for example, Patent Documents 1 to 3). For example, in the small press bearing described in Patent Document 1, the inner ring is formed by a cylindrical member having recesses for supporting a large number of balls in the circumferential direction of the outer peripheral surface, and the outer ring is formed by a press-worked product made of a single member. The outer ring has a contact portion that contacts each ball from the outside in the radial direction of the bearing and has a protrusion that protrudes inward to prevent the ball from moving in one axial direction of the bearing, and an inner end portion that extends from the other axial direction toward the inside in the radial direction and ends with a small gap left between it and the outer periphery of the inner ring.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

Patent Document 3

Summary of the Invention

Problems to be Solved by the Invention

[0005] Incidentally, in the small press bearing described in Patent Document 1, the movement of the balls is prevented by a protrusion provided on the outer ring, so the outer ring and balls do not separate, resulting in good handling. On the other hand, in this small press bearing, a thin metal sheet suitable for the outer ring is press-formed into a cylindrical shape to form an intermediate molded product, all the balls are fitted into the recess of the inner ring and set inside the cylinder of the intermediate molded product, and a spatula is pressed against the intermediate molded product to form a contact part with a protrusion, thereby forming the outer ring. For this reason, it is difficult to use a press-formed inner ring, and further improvements for weight reduction are required.

[0006] Furthermore, in angular contact ball bearings, sealing performance is sometimes required, such as ensuring lubrication inside the bearing, but attaching sealing components to press-formed parts is difficult.

[0007] The present invention has been made in view of the aforementioned problems, and its purpose is to provide an angular contact ball bearing and a method for manufacturing the same, which can be made lightweight by using press-formed steel plates for the outer ring and inner ring, while preventing the outer ring or inner ring from separating from the balls, thereby providing good handling and ensuring sealing performance. [Means for solving the problem]

[0008] The above objective of the present invention is achieved by the following configuration. [1] comprising an outer ring having an outer ring raceway surface on its inner circumference, an inner ring having an inner ring raceway surface on its outer circumference, and a plurality of balls arranged to roll freely between the outer ring raceway surface and the inner ring raceway surface with a contact angle, The angular contact ball bearing is an angular contact ball bearing in which the outer ring and the inner ring are press-formed products of steel plate, The outer ring and the inner ring each comprise a spherical annular portion with a circular arc cross-section that forms the outer ring raceway surface or the inner ring raceway surface, and a cylindrical portion that extends axially from the spherical annular portion on the side opposite to the outer ring raceway surface or the inner ring raceway surface with respect to the center of the ball. At least one of the outer ring and the inner ring is located radially closer to the center of the ball than the deepest part of the outer ring raceway surface or the inner ring raceway surface, and has an overlapping portion that overlaps with the ball when viewed from the axial direction. The inner ring has an inner ring extension that extends from the side of the spherical annular portion opposite to the cylindrical portion toward the outer diameter, and has an inner ring extension that forms a labyrinth seal with the outer ring. Angular contact ball bearing. [2] The method for manufacturing an angular contact ball bearing as described in [1], The steps include at least heating the outer ring having the aforementioned overlapping portion, A step of shrink-fitting multiple balls between the outer ring raceway surface of the heated outer ring and the inner ring raceway surface of the inner ring having the engagement portion, Equipped with, Manufacturing method for angular contact ball bearings. [Effects of the Invention]

[0009] According to the angular contact ball bearing of the present invention, the outer ring and inner ring are made of press-formed steel plates to reduce weight, while preventing the outer ring or inner ring from separating from the balls, resulting in good handling and ensuring sealing performance.

[0010] According to the present invention's method for manufacturing angular contact ball bearings, it is possible to construct an all-ball type angular contact ball bearing, which is expected to improve moment performance and increase load capacity. [Brief explanation of the drawing]

[0011] [Figure 1] This is a cross-sectional view of a bearing device to which an angular contact ball bearing according to one embodiment of the present invention is applied. [Figure 2] Figure 2(a) is a cross-sectional view of the outer and inner rings, and Figure 2(b) is an enlarged cross-sectional view of (a). [Modes for carrying out the invention]

[0012] Hereinafter, the angular ball bearing and the bearing device according to an embodiment of the present invention will be described in detail based on the drawings.

[0013] As shown in FIG. 1, the bearing device 1 of the present embodiment is a bearing device for a drone propeller motor, and includes a stator 3 externally fitted to a housing 2 and a rotor 5 fixed to a rotating shaft 4, which constitute a motor 6. The rotating shaft 4 is rotationally driven with respect to the housing 2 via two angular ball bearings 10 and 11. In the present embodiment, the housing 2 is made of aluminum, and the rotating shaft 4 is made of steel of SUJ2.

[0014] Referring also to FIG. 2, the two angular ball bearings 10 and 11 are respectively fitted to the housing 2 by an intermediate fit, and include outer rings 21 and 22 having outer ring raceway surfaces 21a and 22a on their inner peripheral surfaces, inner rings 23 and 24 fitted to the rotating shaft 4 by an intermediate fit and having inner ring raceway surfaces 23a and 24a on their outer peripheral surfaces, and a plurality of balls 41 and 42 arranged to be freely rotatable with a contact angle α between the outer ring raceway surfaces 21a and 22a and the inner ring raceway surfaces 23a and 24a. In the present embodiment, the contact angle α is set to 25 to 40°.

[0015] In FIG. 1, a spacer 50 made of SUJ2 is arranged between the outer rings 21 and 22 of the two angular ball bearings 10 and 11, and a retaining member 51 for preventing the inner ring 24 of the lower angular ball bearing 11 from falling off is provided at the lower end portion of the rotating shaft 4. The two angular ball bearings 10 and 11 are in a back-to-back combination (DB) and are structured to be preloaded.

[0016] The outer rings 21 and 22 and the inner rings 23 and 24 are press-molded products of steel plates such as SK85, and each include a spherical annular portion 25 and 26 having a cross-sectional arc shape forming the outer ring raceway surfaces 21a and 22a or the inner ring raceway surfaces 23a and 24a, and a cylindrical portion 27 and 28 extending axially from the spherical annular portions 25 and 26 to the side opposite to the outer ring raceway surfaces 21a and 22a or the inner ring raceway surfaces 23a and 24a with respect to the center O of the balls 41 and 4...

[0017] In the boundary portion between the spherical annular portions 25 in the cylindrical portions 27 of the outer rings 21 and 22, the inner peripheral surface of the cylindrical portion 27 is partially formed by grinding or barrel finishing so as to be the deepest part of the outer ring raceway surfaces 21a and 22a. Similarly, in the boundary portion between the spherical annular portions 26 in the cylindrical portions 28 of the inner rings 23 and 24, the outer peripheral surface of the cylindrical portion 28 is partially formed by grinding or barrel finishing so as to be the deepest part of the inner ring raceway surfaces 23a and 24a.

[0018] Therefore, the outer rings 21 and 22 and the inner rings 23 and 24 are positioned closer to the centers of the balls 41 and 42 by the bearing widths a in the radial direction than the deepest parts of the outer ring raceway surfaces 21a and 22a and the inner ring raceway surfaces 23a and 24a, and have bearing width portions 29 and 30 that overlap the balls 41 and 42 when viewed in the axial direction. Thereby, it is prevented that the outer rings 21 and 22 and the inner rings 23 and 24 are easily separated from the balls 41 and 42 in the axial direction.

[0019] Note that the bearing width portions 29 and 30 may be formed on at least one of the outer rings 21 and 22 and the inner rings 23 and 24. For example, when the inner rings 23 and 24 do not have the bearing width portions 30, the balls 41 and 42 may be prevented from being easily separated from the inner rings 23 and 24 by providing a cage and holding the balls 41 and 42 at predetermined intervals in the circumferential direction. Also, regarding the above-described configuration, it is common to the two angular ball bearings 10 and 11, and the upper angular ball bearing 10 is described with reference to FIG. 2.

[0020] Further, the outer ring 21 of the upper angular ball bearing 10 targeted by the present invention has a flange portion 31 that curves and extends radially outward from the cylindrical portion 27, and the outer ring 21 is axially positioned with respect to the housing 2 by the flange portion 31 abutting against the end face of the housing 2.

[0021] Furthermore, the inner ring 23 of the angular contact ball bearing 10 has an inner ring extension 32 that extends outward from the side opposite to the cylindrical portion 26 of the spherical annular portion 25. The inner ring extension 32 curves in the opposite direction from the cylindrical portion 26 in the axial direction (upward in Figure 2) and also curves outward, so as to generally follow the curved surface 27a between the cylindrical portion 27 and the flange portion 31 of the outer ring 21, and further curves outward, forming a non-contact seal (labyrinth seal) with a narrow passage that becomes a constricted portion from the curved surface 27a of the outer ring 21 to the flange portion 31.

[0022] As a result, the angular contact ball bearing 10 can form a non-contact seal without providing a separate sealing member, thereby suppressing the intrusion of foreign matter into the bearing space and the leakage of lubricant within the bearing space.

[0023] Furthermore, an annular flat surface 33 is formed between the spherical annular portion 25 of the inner ring 23 and the inner ring extension portion 32, such that it can contact the axial end face of the positioning member 7 attached to the rotating shaft 4 in the axial direction, and the inner ring 23 can also be positioned in the axial direction relative to the rotating shaft 4.

[0024] Furthermore, in the above embodiment, the two angular contact ball bearings 10 and 11 are arranged back-to-back (DB), but they may also be arranged in parallel (DT) and a structure in which no preload is applied may be used.

[0025] In the angular contact ball bearings 10 and 11 configured in this way, the outer rings 21 and 22 are heated to expand them, and multiple balls 41 and 42 are fitted between the outer ring raceway surfaces 21a and 22a and the inner ring raceway surfaces 23a and 24a by shrink fitting. This results in a total ball type bearing, which allows for increasing the number of balls to the maximum possible within the bearing space, thereby improving moment performance and increasing load capacity. Furthermore, since the outer rings 21 and 22 and the inner rings 23 and 24 have engagement portions 29 and 30, separation of the balls 41 and 42 from the outer rings 21 and 22 and the inner rings 23 and 24 is prevented.

[0026] As described above, the angular contact ball bearing 10 of this embodiment is lightweight because the outer ring 21 and inner ring 22 are made of press-formed steel plates. Furthermore, since at least one of the outer ring 21 and inner ring 22 has engagement portions 20 and 30, separation of the outer ring 21 or inner ring 22 from the ball 41 can be prevented, resulting in good handling. In addition, the inner ring 22 has an inner ring extension portion 32 that extends outward from the side opposite the cylindrical portion 28 of the spherical annular portion 26 and forms a labyrinth seal with the outer ring 21, so that sealing performance can be ensured without providing a separate sealing member.

[0027] Furthermore, the present invention is not limited to the embodiments and modifications described above, and can be modified, improved, etc., as appropriate. For example, in the above embodiment, the inner ring extension 32 is curved axially from the spherical annular portion 26 and further curved toward the outer diameter side, but it is sufficient that it extends toward the outer diameter side, and it can be appropriately formed according to the position and shape of the outer ring 21 as long as it forms a constricted portion.

[0028] Furthermore, in the above embodiment, the lower angular contact ball bearing 11 has a shape in which the inner ring 24 does not have an inner ring extension 32 like that of the angular contact ball bearing 10, which extends outward from the spherical annular portion to the end so that the retaining ring 51 abuts against it without gap. Also, the outer ring 22 has a shape in which it does not have a flange portion 31 like that of the angular contact ball bearing 10, which extends axially from the spherical annular portion to the end so as not to interfere with the housing 2. However, the angular contact ball bearing of the present invention may be applied as a common part to a pair of upper and lower angular contact ball bearings depending on the shape of the bearing device to which it is applied.

[0029] As described above, the following matters are disclosed in this specification: (1) comprising an outer ring having an outer ring raceway surface on its inner circumferential surface, an inner ring having an inner ring raceway surface on its outer circumferential surface, and a plurality of balls arranged to roll freely between the outer ring raceway surface and the inner ring raceway surface with a contact angle, The angular contact ball bearing is an angular contact ball bearing in which the outer ring and the inner ring are press-formed products of steel plate, The outer ring and the inner ring each comprise a spherical annular portion with a circular arc cross-section that forms the outer ring raceway surface or the inner ring raceway surface, and a cylindrical portion that extends axially from the spherical annular portion on the side opposite to the outer ring raceway surface or the inner ring raceway surface with respect to the center of the ball. At least one of the outer ring and the inner ring is located radially closer to the center of the ball than the deepest part of the outer ring raceway surface or the inner ring raceway surface, and has an overlapping portion that overlaps with the ball when viewed from the axial direction. The inner ring has an inner ring extension that extends from the side of the spherical annular portion opposite to the cylindrical portion toward the outer diameter, and has an inner ring extension that forms a constricted portion between it and the outer ring. Angular contact ball bearing. This configuration allows for weight reduction by using press-formed steel plates for the outer and inner rings, while preventing the outer or inner ring from separating from the ball, resulting in good handling and ensuring a secure seal.

[0030] (2) The outer ring has a flange portion that curves outward radially from the cylindrical portion and forms the constricted portion between itself and the inner ring extension, (1) The angular contact ball bearing described above. With this configuration, the outer ring can be easily positioned using the flange portion, and a constricted portion can be formed between it and the inner ring extension portion of the inner ring.

[0031] (3) The holder further comprises a holder that holds the plurality of balls at predetermined intervals in the circumferential direction. (1) The angular contact ball bearing described above. With this configuration, even if the outer ring or inner ring does not have a engagement portion, it is possible to prevent the ball from separating from the outer ring or inner ring.

[0032] (4) The constricted portion forms a non-contact seal. (1) The angular contact ball bearing described above. This configuration ensures the sealing performance of the angular contact ball bearing.

[0033] (5) For motor support, (1) The angular contact ball bearing described above. This configuration allows for the use of lightweight angular contact ball bearings for motor support.

[0034] (6) A method for manufacturing an angular contact ball bearing as described in any of (1) to (5), The steps include at least heating the outer ring having the aforementioned overlapping portion, A step of shrink-fitting multiple balls between the outer ring raceway surface of the heated outer ring and the inner ring raceway surface of the inner ring having the engagement portion, Equipped with, Manufacturing method for angular contact ball bearings. This configuration allows for the creation of an all-ball type angular contact ball bearing, which is expected to improve moment performance and increase load capacity. [Explanation of symbols]

[0035] 1. Bearing device 2 Housing 3 stata 4 rotation axes 5 rotors 6 motors 10,11 Angular Contact Ball Bearings 21,22 Outer ring 21a, 22a Outer ring raceway surface 23,24 Inner circle 23a, 24a Inner ring raceway surface 25,26 Spheroidal annular section 27,28 Cylindrical part 29.30 Expense portion 31 Flange section 32 Inner ring extension α contact angle

Claims

1. The device comprises an outer ring having an outer ring raceway surface on its inner circumference, an inner ring having an inner ring raceway surface on its outer circumference, and a plurality of balls arranged to roll freely between the outer ring raceway surface and the inner ring raceway surface at a contact angle, The angular contact ball bearing is an angular contact ball bearing in which the outer ring and the inner ring are press-formed products of steel plate, The outer ring and the inner ring each comprise a spherical annular portion with a circular arc cross-section that forms the outer ring raceway surface or the inner ring raceway surface, and a cylindrical portion that extends axially from the spherical annular portion on the side opposite to the outer ring raceway surface or the inner ring raceway surface with respect to the center of the ball. At least one of the outer ring and the inner ring is located radially closer to the center of the ball than the deepest part of the outer ring raceway surface or the inner ring raceway surface, and has an overlapping portion that overlaps with the ball when viewed from the axial direction. The inner ring has an inner ring extension that extends from the side of the spherical annular portion opposite to the cylindrical portion toward the outer diameter, and has an inner ring extension that forms a constricted portion between it and the outer ring. Angular contact ball bearing.

2. The outer ring extends radially outward from the cylindrical portion and has a flange portion that forms the constricted portion between it and the inner ring extension. The angular contact ball bearing according to claim 1.

3. The device further comprises a holder that holds the plurality of balls at predetermined intervals in the circumferential direction. The angular contact ball bearing according to claim 1.

4. The constricted portion forms a non-contact seal. The angular contact ball bearing according to claim 1.

5. It is for motor support. The angular contact ball bearing according to claim 1.

6. A method for manufacturing an angular contact ball bearing according to any one of claims 1 to 5, The steps include at least heating the outer ring having the aforementioned overlapping portion, A step of shrink-fitting multiple balls between the outer ring raceway surface of the heated outer ring and the inner ring raceway surface of the inner ring having the engagement portion, Equipped with, Manufacturing method for angular contact ball bearings.

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