Rolling bearing device

Abstract

A rolling bearing device 10 includes: a cylindrical housing 11 having an opening on one side in an axial direction; a rotary shaft 12 having a flange 22; a first rolling bearing 13 having a first outer ring 23 and rotatably supporting the rotary shaft 12; a second rolling bearing 14 having a second outer ring 24 and rotatably supporting the rotary shaft 12; a spacer 15; an annular groove 31 provided at a position on one side in an axial direction of the first outer ring 23 on an inner periphery of the housing 11; a mounting hole 32 penetrating the housing 11 in a radial direction from a bottom part of the groove 31; and a stop member 16 inserted into the housing 11 through the mounting hole 32 and regulating movement of the first outer ring 23 to one side in the axial direction. The stop member 16 has a pair of arm parts 41, 42 and a base part 43 connecting the pair of arm parts 41, 42. Respective tip parts of the pair of arm parts 41, 42 are fitted in the groove 31.

Description

Rolling bearing device

[0001] The present invention relates to a rolling bearing device.

[0002] Patent Document 1 discloses a rolling bearing device for an X-ray tube. The rolling bearing device includes a housing having an opening on one axial side, a rotating shaft having a shaft body located within the housing, a pair of rolling bearings supporting the rotating shaft, and a spacer located between the outer rings of the pair of rolling bearings. The rotating shaft has a flange at one axial end of the shaft body. An X-ray target is attached to the flange.

[0003] Japanese Patent Application Publication No. 7-85824

[0004] 8 is a cross-sectional view of a conventional rolling bearing device. A spring 100 is provided at the bottom of a housing 95. The spring 100 presses the outer rings 921, 931 and spacer 94 of a pair of rolling bearings 92, 93 toward one axial direction, i.e., toward the opening side of the housing 95. A C-shaped retaining ring 90 is used as a retaining member to restrict movement of the outer ring 921 and prevent it from falling out of the opening. The C-shaped retaining ring 90 is attached to a groove 91 formed on the inner periphery of the housing 95.

[0005] The rolling bearing device shown in Figure 8 is assembled as follows. A spring 100, a pair of rolling bearings 92, 93 mounted on a rotating shaft 97, and a spacer 94 are installed inside a housing 95. Then, a C-shaped retaining ring 90 is installed in a groove 91 of the housing 95. During installation, the C-shaped retaining ring 90 is held by a tool (pliers) 99, and its diameter is reduced by elastic deformation. The C-shaped retaining ring 90 is installed in the groove 91 through the gap between an end face 96 of the housing 95 and a flange 98 of the rotating shaft 97.

[0006] The distance between the end face 96 of the housing 95 and the flange 98 of the rotating shaft 97 is narrow. Furthermore, great care must be taken during installation not to damage the C-shaped retaining ring 90 or other components. Furthermore, during installation, it is necessary to maintain the rotating shaft 97 pressed toward the bottom (left side in the case of Figure 8) against the spring 100. As described above, the task of installing the C-shaped retaining ring 90 in the housing 95 is extremely difficult.

[0007] SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide a rolling bearing device that allows a retaining member to be easily attached even if the gap between the end face of the housing and the flange of the rotating shaft is narrow.

[0008] The rolling bearing device of the present invention comprises a housing having an opening on one axial side, a shaft body located within the housing, and a rotating shaft having a flange provided at one axial end of the shaft body, a first rolling bearing having a first outer ring located on one axial side of the inner circumference of the housing and supporting the rotating shaft, a second rolling bearing having a second outer ring located on the other axial side of the inner circumference of the housing and supporting the rotating shaft, a spacer located between the first outer ring and the second outer ring, and a stop member that restricts movement of the first outer ring to one axial side, wherein the housing has a groove provided circumferentially at one axial side of its inner circumference, and a mounting hole that penetrates its outer periphery and part of the groove, and the stop member is insertable into the housing through the mounting hole and has portions that fit into multiple locations of the groove.

[0009] Fig. 1 is a cross-sectional view showing an embodiment of a rolling bearing device of the present invention. Fig. 2 is a side view of one axial side portion of the housing. Fig. 3 is a cross-sectional view taken along arrow III in Fig. 2. Fig. 4 shows a state after a retaining member has been inserted into a groove (first mounting state). Fig. 5 is a view showing a state in which the retaining member has been rotated from the first mounting state. Fig. 6 is a cross-sectional view of the rolling bearing device showing a state before the retaining member has been mounted. Fig. 7 is a cross-sectional view showing a state in which a rotating shaft or the like has been displaced to the other axial side against the elastic force of an elastic member from the state shown in Fig. 6. Fig. 8 is a cross-sectional view of a conventional rolling bearing device.

[0010] <Outline of the Embodiments of the Present Invention> The outlines of the embodiments of the present invention will be listed and described below. (1) A rolling bearing device according to an embodiment of the present invention comprises: a cylindrical housing having an opening on one axial side; a rotating shaft arranged within the housing and having a flange on one axial end; a first rolling bearing having a first outer ring located on one axial side of the inner circumference of the housing and rotatably supporting the rotating shaft; a second rolling bearing having a second outer ring located on the other axial side of the inner circumference of the housing and rotatably supporting the rotating shaft; a spacer located between the first outer ring and the second outer ring; an annular groove provided circumferentially on the inner circumference of the housing at a position on one axial side of the first outer ring; a mounting hole extending radially from the bottom of the groove through the housing; and a stop member inserted into the housing through the mounting hole and restricting movement of the first outer ring to one axial side, the stop member having a pair of arms arranged at a distance greater than the outer diameter of the rotating shaft and a base connecting the pair of arms, the tip of each of the pair of arms fitting into the groove.

[0011] In the rolling bearing device according to an embodiment of the present invention, the stop member is not attached through an opening in the housing, but rather through an attachment hole that penetrates the outer periphery of the housing and part of the groove on its inner periphery. Even if the gap between the end face on one axial side of the housing and the flange of the rotating shaft is narrow, the stop member can be attached to the groove more easily than before. By fitting into the groove, the stop member is unable to move in one axial direction, restricting movement of the first outer ring to that side in the axial direction. The stop member (a pair of arms) is attached to the groove of the housing while straddling the rotating shaft. With the stop member fitted into the groove, the stop member remains stable even when pressed by the first outer ring.

[0012] (2) In the rolling bearing device of (1), the base has a protrusion that protrudes from the housing through the mounting hole or is located in the mounting hole, and the retaining member is displaceable along the groove in the circumferential direction around the central axis of the housing. With the retaining member mounted in the housing through the mounting hole, an operator can operate the protrusion to displace (rotate) the retaining member along the groove. This makes it possible to obtain a configuration in which the retaining member does not come off through the mounting hole.

[0013] (3) In the rolling bearing device of (1) or (2), the mounting hole is a long slit-shaped hole extending along the circumferential direction of the housing, and the longitudinal dimension of the mounting hole is no more than two-thirds of the outer diameter of the housing. If the longitudinal dimension of the mounting hole is too large, the strength of the end of the housing on one axial side may be reduced, and the retaining member (part thereof) may become more likely to come off the mounting hole. With this configuration, the strength of the end of the housing is ensured, and the retaining member is less likely to come off.

[0014] (4) In the rolling bearing device of any one of (1) to (3), the diameter of an imaginary circle passing through the tips of the pair of arms and the outer circumferential edge of the base is smaller than the diameter at the bottom of the groove. When the stop member is displaced along the groove, the tips of the arms and the outer circumferential edge of the base are prevented from coming into strong contact with the bottom of the groove. This makes it possible to prevent the stop member from coming into strong contact with the bottom of the groove, thereby preventing the generation of wear powder.

[0015] <Details of the embodiment of the present invention> [Overall configuration of rolling bearing device 10] Fig. 1 is a cross-sectional view showing one embodiment of a rolling bearing device of the present invention. The rolling bearing device 10 shown in Fig. 1 is a bearing device for an X-ray tube used in a medical X-ray device. Although not shown, the X-ray tube has a vacuum vessel, a target manufactured using tungsten or the like, and an electron gun. When the electron gun irradiates the target in the vacuum vessel with electron beams, X-rays are emitted from the target. The temperature of the target rises due to the irradiation of the electron beam. The target rotates to distribute the irradiation position of the electron beam and suppress the temperature rise of the target. For this reason, the X-ray tube has the rolling bearing device 10 shown in Fig. 1.

[0016] The rolling bearing device 10 has a housing 11, a rotating shaft 12, a first rolling bearing 13, a second rolling bearing 14, a spacer 15, a stop member 16, and an elastic unit 17. The directions of the rolling bearing device 10 of this embodiment will be described. The rotating shaft 12 is a shaft member that is long in one direction, and the direction along the central axis C of the rotating shaft 12 and the direction parallel to the central axis C are defined as the "axial direction" of the rolling bearing device 10. The direction perpendicular to the central axis C is defined as the "radial direction" of the rolling bearing device 10. The direction along a circle centered on the central axis C is defined as the "circumferential direction" of the rolling bearing device 10. The rotating shaft 12 rotates around the central axis C.

[0017] The housing 11 has a cylindrical shape with a bottom and has an opening 111. The opening side of the housing 11 (the right side in FIG. 1 ) is defined as the "one axial side," and the bottom side (the left side in FIG. 1 ) is defined as the "other axial side." The housing 11 has the opening 111 on one axial side and a bottom wall 112 on the other axial side.

[0018] The housing 11 has a groove 31 on its inner periphery at a position on one axial side of the first rolling bearing 13. The groove 31 is provided along the circumferential direction and is an annular groove in this embodiment. As described above, the housing 11 is cylindrical with a bottom and has a cylindrical pipe wall 110. The housing 11 has one mounting hole 32 penetrating the pipe wall 110 on one axial side. The mounting hole 32 is a hole that radially penetrates the outer periphery of the housing 11 and a part of the groove 31 (a bottom 311 of the groove 31).

[0019] As shown in Fig. 2, the mounting hole 32 is a long slit-shaped hole provided along the circumferential direction of the housing 11. Fig. 2 is a side view of one axial side portion of the housing 11. Fig. 3 is a cross-sectional view taken along arrow III in Fig. 2. Fig. 3 shows a state in which the retaining member 16 has been removed from the housing 11 (a state before the retaining member 16 is attached to the housing 11).

[0020] The longitudinal dimension W of the mounting hole 32 is smaller than the diameter (inner diameter) D2 at the bottom 311 of the groove 31. The longitudinal dimension W of the mounting hole 32 is preferably ⅔ or less of the outer diameter D1 of the housing 11. The mounting hole 32 is a long slit-shaped hole that extends along the circumferential direction of the housing 11, but the longitudinal dimension W is not the dimension along the arc of the outer peripheral surface of the housing 11, but the dimension along a straight line connecting one end 321 and the other end 322 in the longitudinal direction of the mounting hole 32. The longitudinal dimension W is preferably ½ or more of the outer diameter D1 of the housing 11.

[0021] In this embodiment (see FIG. 2), the axial dimension V of the mounting hole 32 is the same as the axial dimension of the groove 31. As will be explained later, the retaining member 16 passes through the mounting hole 32 and fits into the groove 31 (see FIG. 4). The retaining member 16 is formed by stamping out a flat steel plate, for example, by a press, and is a thin, planar member. The axial dimension V of the mounting hole 32 is slightly larger (by about 0.2 mm) than the thickness of the retaining member 16.

[0022] The rotating shaft 12 (see FIG. 1 ) has a shaft body 21 located within the housing 11 and a flange 22 provided at one axial end 211 of the shaft body 21. The flange 22 has a larger outer diameter than the shaft body 21. The flange 22 is located outside the one axial end of the housing 11. The target (not shown) is attached to the flange 22. The first rolling bearing 13 and the second rolling bearing 14 support the rotating shaft 12 rotatably relative to the housing 11.

[0023] The first rolling bearing 13 has a first outer ring 23 and a plurality of first balls 25, which are rolling elements. The plurality of first balls 25 are held at equal intervals in the circumferential direction by an annular cage (not shown). The first outer ring 23 is located on one axial side of the inner circumference of the housing 11. The first outer ring 23 has, on its inner circumference, an outer ring raceway groove 231 with which the first balls 25 roll. In this embodiment, the shaft body 21 has, on part of its outer circumference, an inner ring raceway groove 121 with which the first balls 25 roll. The plurality of first balls 25 are interposed between the outer ring raceway groove 231 and the inner ring raceway groove 121.

[0024] The second rolling bearing 14 has a second outer ring 24 and a plurality of second balls 26, which are rolling elements. The plurality of second balls 26 are held at equal intervals in the circumferential direction by an annular cage (not shown). The second outer ring 24 is located on the other axial side of the inner circumference of the housing 11. The second outer ring 24 has, on its inner circumference, an outer ring raceway groove 241 with which the second balls 26 roll. In this embodiment, the shaft body 21 has, on a portion of its outer circumference, an inner ring raceway groove 122 with which the second balls 26 roll. The plurality of second balls 26 are interposed between the outer ring raceway groove 241 and the inner ring raceway groove 122.

[0025] The spacer 15 has a cylindrical shape. The spacer 15 is located between the first outer ring 23 and the second outer ring 24. A gap is provided between the outer peripheral surface of the spacer 15 and the inner peripheral surface of the housing 11. A gap is provided between the outer peripheral surface of the first outer ring 23 and the inner peripheral surface of the housing 11. A gap is provided between the outer peripheral surface of the second outer ring 24 and the inner peripheral surface of the housing 11. Before the retaining member 16 is attached to the housing 11, the first outer ring 23, the second outer ring 24, and the spacer 15 are able to displace in the axial direction within the housing 11 together with the rotating shaft 12.

[0026] In order for the housing 11 to stably receive the moment acting on the rotating shaft 12, an axial preload is applied to the first rolling bearing 13 and the second rolling bearing 14. For this reason, movement of the first outer ring 23 and the like to one side in the axial direction is restricted by the stop member 16. The preload is applied by the elastic unit 17.

[0027] The elastic unit 17 is provided in the housing 11. The elastic unit 17 is located between the bottom wall 112 of the housing 11 and the rotating shaft 12. The elastic unit 17 has an elastic member 171 such as a steel spring, and a guide 172 attached to the elastic member 171. The guide 172 is an annular member interposed between the elastic member 171 and the second outer ring 24. The guide 172 has an attachment portion 173 attached to the elastic member 171 on the other axial side, and a contact surface 174 on one axial side that comes into contact with the side wall of the second outer ring 24.

[0028] 1, the elastic member 171 is elastically compressed in the axial direction. Therefore, the elastic restoring force of the elastic member 171 acts in the axial direction, and the elastic member 171 pushes the second outer ring 24 toward one axial side via the guide 172. Due to the elastic restoring force, the second outer ring 24 pushes the spacer 15 toward one axial side, and the spacer 15 pushes the first outer ring 23 toward one axial side.

[0029] The elastic unit 17 may be provided in another position, and although not shown, may be provided between the first outer ring 23 and the second outer ring 24. In this case, two spacers 15 may be provided, one on each axial side. As described above, the elastic unit 17 pushes at least the first outer ring 23 to one axial side by elastically compressing and deforming in the installed state. The "installed state" is the state in which the rolling bearing device 10 shown in FIG. 1 is fully assembled. In other words, the elastic unit 17, rotating shaft 12, first rolling bearing 13, second rolling bearing 14, and spacer 15 are installed in the housing 11, and the stop member 16 restricts movement of the first outer ring 23 to one axial side.

[0030] [Regarding the Stop Member 16] As described above, the stop member 16 restricts the movement of the first outer ring 23 to one side in the axial direction against the elastic restoring force of the elastic unit 17. As shown in Fig. 3, the stop member 16 has a pair of arms 41, 42 and a base 43 connecting the pair of arms 41, 42. The stop member 16 of this embodiment has a substantially U-shape.

[0031] The pair of arms 41, 42 are disposed with a gap F therebetween that is larger than the outer diameter d of the rotating shaft 12. The "outer diameter d" is the outer diameter of one axial side of the rotating shaft 12 (see FIG. 1), and is the outer diameter at the same axial position as the attachment position of the retaining member 16. As shown in FIGS. 3 and 4, the retaining member 16 passes through the attachment hole 32 and fits into the groove 31. FIG. 4 is a diagram showing a state after the retaining member 16 has been inserted into the groove 31 (hereinafter referred to as the "first attachment state"). FIG. 5 is a diagram showing a state after the retaining member 16 has been rotated from the first attachment state (hereinafter referred to as the "second attachment state").

[0032] The pair of arms 41, 42 are arranged opposite each other. In this embodiment, the pair of arms 41, 42 are arranged parallel to each other. Each of the arms 41, 42 has a shape that is long in one direction. The base 43 has a shape that is long (curved) in a direction perpendicular to the longitudinal direction (the one direction) of the arms 41, 42. With respect to the stop member 16 (see FIG. 3 ), the longitudinal direction (the one direction) of the arms 41, 42 is defined as the "first direction," and the direction perpendicular to the first direction is defined as the "second direction." The base 43 has a shape that is long in the second direction.

[0033] The maximum dimension Q1 of the pair of arms 41, 42 in the second direction is smaller than the longitudinal dimension W of the mounting hole 32. In this embodiment, the maximum dimension Q2 of the base 43 in the second direction is the same as the maximum dimension Q1. Therefore, the longitudinal direction (first direction) of the arms 41, 42 becomes the insertion direction, allowing the stop member 16 to pass through the mounting hole 32.

[0034] The dimension X in the first direction of the retaining member 16, including the pair of arms 41, 42 and the base 43 (see FIG. 3), is greater than the longitudinal dimension W of the mounting hole 32 (X>W). Note that the dimension X is the dimension from tips 41e, 42g of tip ends 411, 421 of the arms 41, 42, described below, to the outer periphery of the base main body 432, described below, and does not include the protrusion 44. When the retaining member 16 is in the second attached state (see FIG. 5), the structure of X>W prevents the retaining member 16 from falling off the mounting hole 32.

[0035] In the first attachment state (see FIG. 4 ) and the second attachment state (see FIG. 5 ), the tip ends 411, 421 of the pair of arm portions 41, 42 fit into the groove 31, and the entire outer peripheral edge portion 431, which is the radially outer portion of the base portion 43, fits into the groove 31. It is sufficient that at least a portion of the radially outer side of the base portion 43 fits into the groove 31.

[0036] As described above, the retaining member 16 is sized and shaped to be insertable into the housing 11 through the mounting hole 32, and has portions that fit into multiple locations (three locations in this embodiment) of the groove 31 in the first mounting state and the second mounting state.

[0037] The retaining member 16, which is in the first attachment state (see FIG. 4), can be rotated to a second attachment state (see FIG. 5). That is, the retaining member 16 can be displaced circumferentially around the central axis C of the housing 11 along the groove 31. The retaining member 16 is rotated by an operator assembling the rolling bearing device 10. The base 43 has a protrusion 44 for rotating the retaining member 16. The base 43 has a curved base body 432 that connects the pair of arms 41, 42. The protrusion 44 extends radially outward from the base body 432.

[0038] The worker rotates the retaining member 16 by manipulating the protrusion 44 by hand or using a tool. In this embodiment, the protrusion 44 protrudes from the mounting hole 32 to the outside of the housing 11. Alternatively, the protrusion 44 may be shorter than the shape shown in FIG. 4 and may be shaped to fit within the mounting hole 32. The retaining member 16 can be rotated until the protrusion 44 contacts the end (one end 321) of the mounting hole 32 (see FIG. 5). In the second mounting state shown in FIG. 5, the retaining member 16 passes through the mounting hole 32 and cannot be removed.

[0039] The protrusion 44 is located at the end of the base body 432 of the base 43. Therefore, in the second attachment state, almost the entire base 43 is misaligned from the attachment hole 32. This makes it possible to more effectively prevent the retaining member 16 from passing through the attachment hole 32 and becoming detached.

[0040] The retaining member 16 is made of metal. The protruding portion 44 of the retaining member 16 may be thinner than the other portions. In this case, for example, after the retaining member 16 is in the second attachment state, the protruding portion 44 (at least the portion protruding from the housing 11) may be bent and cut.

[0041] The retaining member 16 (see FIG. 1 ) is pressed against the side surface 312 of the groove 31 by the elastic restoring force (elastic force) of the elastic unit 17. Even if the retaining member 16 is in the first attachment state, the frictional force between the retaining member 16 and the side surface 312 of the groove 31 makes it unlikely that the retaining member 16 will fall off from the attachment hole 32.

[0042] However, as described above, by rotating the retaining member 16 to the second attachment state, the retaining member 16 cannot pass through the attachment hole 32. In other words, the retaining member 16 in the second attachment state cannot fall off from the attachment hole 32. Due to the frictional force between the retaining member 16 and the side surface 312 of the groove 31, the retaining member 16 in the second attachment state is unlikely to rotate due to vibration or the like. As a means for preventing the retaining member 16 from falling off and rotating, a portion of the retaining member 16 (e.g., the protrusion 44) may be fixed to the housing 11 by caulking. Alternatively, although not shown, a cover may be attached to the attachment hole 32, or the attachment hole 32 may be filled with a fixing member such as an adhesive.

[0043] The shape of the retaining member 16 will be further described. An imaginary circle K indicated by a two-dot chain line in Fig. 4 is a circle that passes through the tips 41e, 42e of the pair of arm portions 41, 42 and the outer peripheral edge 43e of the base portion 43. When the retaining member 16 is attached to the groove 31 (the first attachment state or the second attachment state), the tips 41e, 42e, and outer peripheral edge 43e of the first arm portion 41, the second arm portion 42, and the base portion 43, respectively, are located at the farthest positions from the central axis C of the housing 11.

[0044] The diameter D3 of the imaginary circle K is slightly (by about 0.3 mm) smaller than the diameter (inner diameter) D2 at the bottom 311 of the groove 31 (D3<D2). With this configuration, a gap e is formed between the retaining member 16 and the bottom 311 of the groove 31. Due to the gap e, when the retaining member 16 is displaced along the groove 31, each portion of the retaining member 16 (tips 41 e, 42 e, outer peripheral end 43 e) is less likely to get caught on the bottom 311 of the groove 31.

[0045] In other words, when the stop member 16 rotates, the tips 41 e, 42 e of the arms 41, 42 and the outer peripheral end 43 e of the base 43 are prevented from coming into strong contact with the bottom 311 of the groove 31. This makes it possible to prevent wear powder from being generated due to the stop member 16 coming into strong contact with the bottom 311 of the groove 31. As a result, wear powder is prevented from entering the first rolling bearing 13.

[0046] The tip surface including the tip 41 e of the first arm 41 and the tip surface including the tip 42 e of the second arm 42 each have an arc shape, and these tip surfaces have a shape that follows a common imaginary circle (the imaginary circle K). The base body 432 of the base 43 has an arc shape. A radially outer edge 43 f of the base body 432 also has an arc shape. The edge 43 f may have a shape that follows the imaginary circle (the imaginary circle K), but in this embodiment, it has a curved shape that is located closer to the central axis C of the housing 11 than the imaginary circle.

[0047] [Method of attaching the retaining member 16] As described above, the elastic unit 17 provided in the housing 11 elastically compresses and deforms in the attached state shown in Fig. 1, thereby pushing at least the first outer ring 23 to one side in the axial direction. Therefore, before the retaining member 16 is attached to the groove 31 (see Fig. 6), if the elastic member 171, such as a spring, is in its natural state, the first outer ring 23 is positioned further to one side in the axial direction than in the attached state shown in Fig. 1, and covers the groove 31 and the attachment hole 32. In this state, the retaining member 16 cannot be attached to the groove 31 through the attachment hole 32. Fig. 6 is a cross-sectional view of the rolling bearing device 10, showing the state before the retaining member 16 is attached.

[0048] Therefore, when attaching the retaining member 16, it is necessary to maintain the rotating shaft 12 pressed toward the bottom side (to the left in the case of FIG. 6 ) against the elastic force of the elastic member 171. For this reason, the rolling bearing device 10 of this embodiment has a means for elastically compressing and deforming the elastic member 171 to restrain it toward the bottom side. This means will be described below.

[0049] As shown in Fig. 6, the housing 11 has through holes 35 penetrating its outer and inner circumferences. In this embodiment, the through holes 35 are provided in two locations in the pipe wall 110. The two through holes 35 are located 180 degrees apart from each other with respect to the central axis C. The number of through holes 35 and the number of pins 176, which will be described later, may be two or more.

[0050] As described above, the elastic unit 17 has an elastic member 171 and a guide 172 located on one axial side of the elastic member 171. The guide 172 has an engaging portion 175. In this embodiment, the engaging portion 175 is a recessed portion provided on the outer periphery of the guide 172. The recessed portion is formed long in the circumferential direction (continuous in the circumferential direction), and the engaging portion 175 is a recessed groove.

[0051] Figure 7 is a cross-sectional view showing a state in which the rotating shaft 12 and the like are displaced axially toward the other side against the elastic force of the elastic member 171 from the state shown in Figure 6. Figure 7 shows a state in which the elastic member 171 is elastically compressed and deformed more than in the attached state shown in Figure 1. In the state shown in Figure 7, a member passing through the through hole 35 can engage with an engaging portion 175 consisting of a recess. The member passing through the through hole 35 is, for example, a steel pin 176. In other words, when the elastic member 171 is elastically compressed and deformed more than in the attached state shown in Figure 1, the pin 176 passing through the through hole 35 fits into the engaging portion 175.

[0052] The pin 176 is inserted into the through-hole 35 of the housing 11, and the tip of the pin 176 engages with the engaging portion 175 of the guide 172. The pin 176 prevents the guide 172 from being displaced in the axial direction, and the elastic unit 17 (elastic member 171) is maintained in a state where it is more elastically compressed and deformed than in the mounted state shown in Fig. 1. In this state, the action of the elastic unit 17 to push the first outer ring 23 to one side in the axial direction disappears.

[0053] Therefore, the first outer ring 23 does not cover the groove 31 and the mounting hole 32. As a result, it becomes easier to attach the retaining member 16 through the mounting hole 32. After the retaining member 16 is attached to the groove 31, the pin 176 is removed, resulting in the state shown in FIG. 1, and the action of the elastic unit 17 is exerted to push the first outer ring 23 to one side in the axial direction.

[0054] In this way, the elastic unit 17 has an engagement portion 175 on a part thereof (guide 172) with which a member (pin 176) passing through the through hole 35 can engage when the elastic unit 17 is in a state of elastic compression deformation greater than the mounted state shown in Figure 1.

[0055] Regarding the rolling bearing device 10 of this embodiment (see FIG. 1 ), as described above, the rolling bearing device 10 of this embodiment (see FIG. 1 ) comprises a cylindrical housing 11 with a bottom that has an opening on one axial side, a rotating shaft 12, a first rolling bearing 13, a second rolling bearing 14, a spacer 15, and a retaining member 16. The rotating shaft 12 has a shaft body 21 located within the housing 11, and a flange 22 provided on one axial end 211 of the shaft body 21.

[0056] The first rolling bearing 13 has a first outer ring 23 located on one axial side of the inner periphery of the housing 11, and supports the rotating shaft 12. The second rolling bearing 14 has a second outer ring 24 located on the other axial side of the inner periphery of the housing 11, and supports the rotating shaft 12. The spacer 15 is located between the first outer ring 23 and the second outer ring 24. The stop member 16 restricts movement of the first outer ring 23 to one axial side.

[0057] The housing 11 has a groove 31 provided along the circumferential direction at one axial position on the inner periphery of the housing 11, and an attachment hole 32 penetrating the outer periphery of the housing 11 and part of the groove 31. The retaining member 16 can be inserted into the housing 11 through the attachment hole 32. The retaining member 16 has portions that fit into the groove 31 at multiple locations.

[0058] According to the rolling bearing device 10 having the above-described configuration, the stop member 16 is not attached through the opening 111 of the housing 11, but rather through a mounting hole 32 that penetrates the outer periphery of the housing 11 and part of the groove 31 on its inner periphery. This makes it possible to easily attach the stop member 16 to the groove 31 even if the gap between the end face 113 on one axial side of the housing 11 and the flange 22 of the rotating shaft 12 is narrow. The stop member 16 is fitted into multiple locations in the groove 31, making it unable to move in one axial direction, and restricting movement of the first outer ring 23 to one axial side.

[0059] In this embodiment (see FIG. 3 ), the retaining member 16 has a pair of arms 41, 42 and a base 43 connecting the pair of arms 41, 42. The pair of arms 41, 42 are disposed with a gap F between them that is larger than the outer diameter d of the rotary shaft 12. As shown in FIGS. 4 and 5 , the tip ends 411, 421 of the pair of arms 41, 42 and at least a portion of the base 43 are fitted into the groove 31. The retaining member 16 (the pair of arms 41, 42) is attached to the groove 31 of the housing 11 while straddling the rotary shaft 12. Three points, namely the tip ends 411, 421 of the arms 41, 42 and the radially outer portion 431 of the base 43, are fitted into the groove 31. The retaining member 16 remains stable even when pressed by the first outer ring 23.

[0060] As shown in Fig. 4, the base 43 has a protrusion 44. When the retaining member 16 is attached to the housing 11 through the attachment hole 32, an operator can operate the protrusion 44 to displace (rotate) the retaining member 16 along the groove 31. In the second attachment state shown in Fig. 5, the retaining member 16 does not come off through the attachment hole 32.

[0061] If the longitudinal dimension W of the mounting hole 32 (see FIGS. 2 and 3) is too large, the strength of one axial end of the housing 11 may be reduced, and the retaining member 16 (part thereof) may become more likely to come off from the mounting hole 32. In the present embodiment, as described above, the longitudinal dimension W of the mounting hole 32 is equal to or less than two-thirds of the outer diameter D1 of the housing 11. This configuration ensures the strength of the end of the housing 11, and also makes it difficult for the retaining member 16 to come off.

[0062] [Others] The above-described embodiments are illustrative in all respects and are not limiting. The scope of the present invention is defined by the claims, not the above-described embodiments, and includes all modifications within the scope of equivalents to the configurations described in the claims.

[0063] REFERENCE SIGNS LIST 10 Rolling bearing device 11 Housing 12 Rotating shaft 13 First rolling bearing 14 Second rolling bearing 15 Spacer 16 Stop member 17 Elastic unit 21 Shaft body 211 End 22 Flange 23 First outer ring 24 Second outer ring 31 Groove 311 Bottom 32 Mounting hole 35 Through hole 41, 42 Arm portion 41e, 42e Tip 411, 421 Tip portion 43 Base 43e Outer peripheral end 44 Convex portion 111 Opening 175 Engagement portion 176 Pin (member passing through through hole) C Central axis D1 Outer diameter dimension of housing D2 Diameter at bottom of groove D3 Diameter of imaginary circle d Outer diameter of rotating shaft F Spacing K Imaginary circle W Longitudinal dimension

Claims

1. A rolling bearing device comprising: a cylindrical housing having an opening on one axial side; a rotating shaft arranged within the housing and having a flange on one axial end; a first rolling bearing having a first outer ring located on one axial side of the inner periphery of the housing and rotatably supporting the rotating shaft; a second rolling bearing having a second outer ring located on the other axial side of the inner periphery of the housing and rotatably supporting the rotating shaft; a spacer located between the first outer ring and the second outer ring; an annular groove provided circumferentially on the inner periphery of the housing at a position on one axial side of the first outer ring; a mounting hole extending radially from the bottom of the groove through the housing; and a stop member inserted into the housing through the mounting hole and restricting movement of the first outer ring to one axial side, wherein the stop member has a pair of arms arranged at a distance greater than the outer diameter of the rotating shaft, and a base connecting the pair of arms, wherein the tip of each of the pair of arms fits into the groove.

2. A rolling bearing device as set forth in claim 1, wherein the base has a protrusion that protrudes from the mounting hole to the outside of the housing or is located in the mounting hole, and the stop member is displaceable in the circumferential direction around the central axis of the housing along the groove.

3. A rolling bearing device as set forth in claim 1 or claim 2, wherein the mounting hole is a long slit-shaped hole that extends along the circumferential direction of the housing, and the longitudinal dimension of the mounting hole is 2 / 3 or less of the outer diameter dimension of the housing.

4. A rolling bearing device according to claim 1 or 2, wherein the diameter of an imaginary circle passing through the tips of the pair of arms and the outer circumferential edge of the base is smaller than the diameter at the bottom of the groove.

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