JP7035788B2 - Rolling bearings for sliding doors - Google Patents

Description

The present invention relates to a rolling bearing for a sliding door used for a sliding door of a vehicle.

In a rolling bearing for a sliding door used for a sliding door of a vehicle, for example, as described in Patent Document 1 below, a rolling bearing for a sliding door that supports a sliding door that covers a door opening provided on a side surface of a vehicle body so as to be openable and closable. The bearing is assembled to the support shaft provided on the sliding door. The outer circumference of the outer ring that rotates around the support shaft when the slide door is opened and closed is covered with a synthetic resin covering member.

Specifically, as shown in FIG. 11, in the rolling bearing 101 for a sliding door, a concave groove 103 having an axial width L5 is formed in the central portion of the outer peripheral surface of the outer ring 102 having an axial width L1. .. Further, a coating member 105 made of synthetic resin is integrally molded on the outer peripheral surface of the outer ring 102 including the concave groove 103, and the thin-walled portion 105A and the thick-walled portion 105B are formed on the covering member 105. Then, the thin portion 105A of the covering member 105 is positioned on the receiving surface of the guide rail in the closed state of the slide door, and the thick portion 105B of the covering member 105 is placed on the receiving surface of the guide rail in the non-closed state of the sliding door. It is configured to be located.

As a result, it is possible to suppress distortion of the outer shape of the synthetic resin covering member 105 of the rolling bearing 101 for the sliding door due to creep deformation in the closed state of the sliding door. Further, in the non-closed state of the sliding door, the thick portion 105B of the covering member 105 made of synthetic resin is located on the receiving surface of the guide rail and rolls while supporting the load of the sliding door, so that it is durable. It can be improved.

Japanese Unexamined Patent Publication No. 8-276743

However, in the rolling bearing 101 for a sliding door described in Patent Document 1, the axial width L5 of the thick portion 105B of the synthetic resin covering member 105 is larger than the axial width L1 of the outer ring 102 and the inner ring 106. Is also formed in a narrow width. As a result, the contact surface pressure of the thick portion 105B becomes large when the slide door is not closed, so that it is difficult to significantly improve the durability of the synthetic resin covering member 105.

Therefore, the present invention has been devised in view of such a point, and an object of the present invention is to provide a rolling bearing for a sliding door capable of significantly improving the durability of a resin-made covering member.

In order to solve the above problems, the first invention of the present invention is a rolling bearing for a sliding door that supports a sliding door while rolling on a guide rail provided on a vehicle body, and is provided on the sliding door. The inner ring attached to the support shaft and the inner ring are arranged concentrically with respect to the inner ring so that the first width in the axial direction is larger than the second width in the axial direction of the inner ring, and the shaft on the outer peripheral surface is formed. An outer ring in which a concave groove recessed inward in the radial direction is formed in the central portion of the direction in the circumferential direction, a plurality of rolling elements arranged in the circumferential direction between the inner ring and the outer ring, and the concave groove in the outer ring. A resin covering member integrally coated on the outer peripheral surface including the outer peripheral surface thereof is provided, and the bottom surface portion of the concave groove has a width in which a third width in the axial direction is larger than the second width in the axial direction of the inner ring. The covering member is formed to have a width smaller than the first width in the axial direction of the outer ring, and the covering member has a thick portion covering the concave groove and a thin wall portion covering both ends in the axial direction with respect to the concave groove. It is a rolling bearing for sliding doors.

Next, according to the second aspect of the present invention, in the rolling bearing for a sliding door according to the first aspect of the present invention, the outer ring is peripheral to at least one outer peripheral surface of both ends in the axial direction with respect to the concave groove. The covering member is a rolling bearing for a sliding door having a convex portion protruding radially outward along the direction, and a concave portion into which the convex portion is fitted is formed on the inner peripheral surface of the thin-walled portion. ..

Next, according to the third aspect of the present invention, in the rolling bearing for a sliding door according to the second aspect of the present invention, the convex portions are continuous from the radial outer ends of the wall portions on both sides of the concave groove in the axial direction. It is a rolling bearing for a sliding door formed in the above.

According to the first invention, the bottom surface portion of the concave groove of the outer ring is formed so that the third width in the axial direction is larger than the second width in the axial direction of the inner ring. As a result, the thick portion of the resin covering member that covers the outer peripheral surface of the outer ring is formed so that the width in the axial direction is larger than the second width in the axial direction of the inner ring. As a result, when the rolling bearing for sliding doors rolls on the guide rail, the contact area of the covering member can be made larger than the contact area of the covering member of the conventional rolling bearing for sliding doors. The contact surface pressure of the covering member can be made smaller than the contact surface pressure of the covering member of the conventional rolling bearing for a sliding door, and the durability can be significantly improved.

Further, the axial width of the resin covering member covering the outer peripheral surface of the outer ring can be made wider than the axial width of the covering member of the conventional rolling bearing for a sliding door. As a result, when the slide door is closed, a contact surface in which the covering member comes into contact with the receiving surface of the guide rail is generated in the thick portion, and the cross-sectional area where the maximum shear stress is generated is increased to maximize the covering member. It is possible to reduce the shear stress and improve the creep characteristics of the rolling bearing for sliding doors.

According to the second invention, a convex portion provided on the outer peripheral surface of at least one of both ends in the axial direction of the concave groove of the outer ring and a concave portion formed on the inner peripheral surface of the thin-walled portion of the covering member are provided. Fit. As a result, even if an axial load acts on the outer peripheral surface of the covering member when the slide door is opened and closed, it is possible to prevent the covering member from shifting in the axial direction with respect to the outer ring.

According to the third invention, the convex portion is formed continuously from the radial outer end portion of the wall portion on both sides of the concave groove of the outer ring in the axial direction. As a result, the radial depth of the concave groove can be increased, and even if an axial load acts on the outer peripheral surface of the covering member when the sliding door is opened or closed, the covering member is axially relative to the outer ring. The deviation can be suppressed more effectively.

It is a perspective view which shows the vehicle which provided the sliding door which has the rolling bearing for a sliding door which concerns on this embodiment. It is a perspective view of the upper roller unit connected to the upper guide rail. It is a perspective view of the center roller unit connected to the center guide rail. It is a perspective view of the lower roller unit. It is a schematic diagram which shows the lower roller unit connected to the lower guide rail. It is sectional drawing which shows an example of the load roller (rolling bearing for a sliding door). It is a figure which shows an example of the shear stress distribution of the covering member of the load roller (rolling bearing for a sliding door) shown in FIG. It is a figure which shows an example of the shear stress distribution of the covering member of the rolling bearing for a sliding door of the prior art shown in FIG. It is a figure which shows an example of the contact surface pressure distribution of the covering member of the load roller (rolling bearing for a sliding door) shown in FIG. It is a figure which shows an example of the contact surface pressure distribution of the covering member of the rolling bearing for a sliding door of the prior art shown in FIG. It is sectional drawing which shows an example of the rolling bearing for a sliding door of the prior art.

Hereinafter, a detailed description will be given with reference to the drawings based on an embodiment embodying the rolling bearing for a sliding door according to the present invention. In each figure, the X-axis direction is the vehicle front-rear direction, the Y-axis direction is the vehicle width direction, and the Z-axis direction is the vertical direction, and the axes are orthogonal to each other. The arrow X appropriately shown in each figure indicates the front side of the vehicle, and the arrow Z indicates the upper side of the vehicle. Further, the arrow Y indicates the inside in the vehicle width direction. In the following description, the description regarding the direction of the vehicle shall be made with reference to this direction.

As shown in FIG. 1, the vehicle 10 includes a sliding door 12 that opens and closes a door opening 14 provided on the side surface 11A of the vehicle body 11. In the vehicle 10 of the present embodiment, the sliding door 12 is provided as a rear door of the vehicle 10. The slide door 12 is configured to open by moving to the rear side of the vehicle (right side in FIG. 1) and close by moving to the front side of the vehicle (left side in FIG. 1).

Specifically, the vehicle 10 includes an upper guide rail 16A, a center guide rail 16C, and a lower guide rail 16L extending in the vehicle front-rear direction (X-axis direction in FIG. 1), and these guide rails 16A, 16C, and 16L. An upper roller unit 18A, a center roller unit 18C, and a lower roller unit 18L to be connected are provided. The slide door 12 is supported by the side surface 11A of the vehicle body 11 via the guide rails 16A, 16C, 16L, and the roller units 18A, 18C, 18L, so that the sliding door 12 is supported in the vehicle front-rear direction (in FIG. 1). It is possible to open and close the door opening 14 formed on the side surface 11A of the vehicle body 11 by moving in the X-axis direction).

Specifically, the upper guide rail 16A provided on the upper edge portion 14A of the door opening 14, the center guide rail 16C provided behind the substantially central portion of the door opening 14 in the vertical direction of the vehicle, and the door opening. The lower guide rail 16L provided on the lower edge portion 14B of 14 is provided. Further, the upper roller unit 18A connected to the upper guide rail 16A while being supported by the upper end portion of the slide door 12 on the front side of the vehicle is provided.

Further, a center roller unit 18C connected to the center guide rail 16C is provided at the rear end of the slide door 12 while being supported by a substantially central portion in the vertical direction of the vehicle. A lower roller unit 18L connected to the lower guide rail 16L while being rotatably supported in the front-rear direction of the vehicle is provided at the lower end of the slide door 12 on the front side of the vehicle.

Next, the upper guide rail 16A and the upper roller unit 18A will be described with reference to FIG. As shown in FIG. 2, the upper guide rail 16A includes side wall portions 25A and 25B facing each other in the vehicle width direction, and upper wall portions 25C connecting the upper end portions of both side wall portions 25A and 25B. It has a guide rail portion 25 having a substantially U-shaped cross section that opens downward in the direction. The upper roller unit 18A is provided with a guide roller 27 arranged inside the guide rail portion 25. The guide roller 27 is composed of, for example, a rolling bearing.

The upper roller unit 18A has a side view substantially L-shaped support bracket 28 fixed to the inner side surface of the slide door 12 by bolting or the like at the upper end portion of the slide door 12 on the vehicle front side, and a vehicle width on the support bracket 28. The base end portion on the outer side in the direction is provided with a support arm 29 extending inward in the vehicle width direction in a state of being non-rotatably connected by bolting or the like. Then, the guide roller 27 is pivotally supported by a support shaft 31 extending upward along the vehicle vertical direction at the inner end of the support arm 29 in the vehicle width direction, so that the upper guide rail 16A can rotate. It is configured to be arranged between the side wall portions 25A and 25B constituting the guide rail portion 25.

Therefore, the guide rail portion 25 of the upper guide rail 16A restricts the relative movement of the guide roller 27 in the vehicle width direction by the guide roller 27 coming into contact with any of the side wall portions 25A and 25B. Further, in the guide rail portion 25, one of the side wall portions 25A and 25B with which the guide roller 27 abuts becomes a sliding surface, so that the guide roller 27 moves relative to each other along the extending direction (vehicle front-rear direction). Tolerate. As a result, the upper guide rail 16A is configured to guide the upper roller unit 18A in the front-rear direction of the vehicle.

Next, the center guide rail 16C and the center roller unit 18C will be described with reference to FIG. As shown in FIG. 3, at the rear end of the slide door 12 on the vehicle rear side, the outer end in the vehicle width direction cannot be rotated on the inner surface of the substantially central portion of the slide door 12 in the vertical direction of the vehicle by bolting or the like. It is provided with a long center arm portion 35 connected to the above. The center roller unit 18C is rotatably connected to the inner end of the center arm portion 35 in the vehicle width direction via a rotation shaft 36 inserted in the vehicle vertical direction.

Specifically, the center roller unit 18C is a side view (when viewed in the Y-axis direction in FIG. 3) L-shaped first, which is rotatably connected in the vehicle front-rear direction via a rotation shaft 36. It has a sub-arm 37 and a substantially crank-shaped second sub-arm 38 (when viewed in the Y-axis direction in FIG. 3). The bottom 37B of the first sub-arm 37, which is L-shaped when viewed from the side, is rotatably connected to the lower end surface of the inner end of the center arm 35 in the vehicle width direction, and is vertically connected to the inner end of the bottom 37B in the vehicle width direction. A support shaft (support shaft) 41 projecting inward in the vehicle width direction is fixed to the wall portion 37A extending upward, for example, by press fitting. A load roller (rolling bearing for slide door) 42 (see FIG. 6), which will be described later, is rotatably supported on the support shaft 41 to support the load of the slide door 12.

The second sub-arm 38 having a substantially crank-shaped side view is rotatably connected to the upper end surface of the inner end portion of the center arm portion 35 in the vehicle width direction, and a portion vertically facing the load roller 42 is notched. It is formed in a U-shape that is open inward in the width direction of the vehicle. Two support shafts 45 and 46 projecting toward the upper side in the vertical direction of the vehicle are fixed to both ends of the second sub-arm 38 in the vehicle front-rear direction on the inner side in the vehicle width direction, for example, by press fitting. Therefore, the support shafts 45 and 46 extend in a direction intersecting the support shaft 41. Further, a pair of guide rollers 47 are rotatably supported on the support shafts 45 and 46, respectively. The pair of guide rollers 47 are composed of, for example, rolling bearings.

As shown in FIG. 3, the center guide rail 16C is provided in a recess formed on the side surface 11A of the vehicle body 11 along the vehicle front-rear direction. The center guide rail 16C has a center rail portion 48 for rolling the road roller 42 and a guide rail portion 49 for rolling the pair of guide rollers 47. Similar to the guide rail portion 25, the guide rail portion 49 includes side wall portions 49A and 49B facing each other in the vehicle width direction, and an upper wall portion 49C connecting the upper end portions of both side wall portions 49A and 49B. It has a substantially U-shaped cross section that opens downward in the vertical direction of the vehicle. The pair of guide rollers 47 are arranged in a rotatable state between the side wall portions 49A and 49B constituting the guide rail portion 49 along the vehicle front-rear direction.

Therefore, the guide rail portion 49 of the center guide rail 16C regulates the relative movement of the pair of guide rollers 47 in the vehicle width direction by the respective guide rollers 47 coming into contact with any of the side wall portions 49A and 49B. Further, the guide rail portion 49 has a pair of guide rollers 47 along the stretching direction (vehicle front-rear direction) because any of the side wall portions 49A and 49B with which the pair of guide rollers 47 abuts serve as sliding surfaces. Allows relative movement of. As a result, the center guide rail 16C is configured to guide the center roller unit 18C in the front-rear direction of the vehicle.

The center rail portion 48 for rolling the road roller 42 is extended by a predetermined length from the side wall portion 49B located inside in the vehicle width direction to the lower side in the vertical direction of the vehicle, and then extends substantially at a right angle to the outside in the vehicle width direction. It has a lower wall portion 48A. The road roller 42 is arranged so as to be able to roll on the upper side surface of the lower wall portion 48A constituting the center rail portion 48 while supporting the weight of the slide door 12.

Next, the lower guide rail 16L and the lower roller unit 18L will be described with reference to FIGS. 4 and 5. As shown in FIGS. 4 and 5, in the lower roller unit 18L, at the lower end portion of the slide door 12 on the vehicle front side, the end portion on the inner surface of the slide door 12 and the outer end portion in the vehicle width direction are rotated by bolting or the like. It is provided with a long lower arm portion 51 that is immovably connected. The lower roller unit 18L is rotatably connected to the inner end of the lower arm portion 51 in the vehicle width direction via a rotation shaft 52 fitted in the vehicle vertical direction.

Specifically, the lower roller unit 18L is a side view (when viewed in the X-axis direction in FIG. 4) L-shaped third, which is rotatably connected in the vehicle front-rear direction via a rotation shaft 52. It has a sub-arm 53 and a substantially crank-shaped fourth sub-arm 55 (when viewed in the X-axis direction in FIG. 4). The bottom 53B of the third sub-arm 53, which is L-shaped when viewed from the side, is rotatably connected to the lower end surface of the inner end of the lower arm 51 in the vehicle width direction, and is vertically upward from the inner end of the bottom 53B in the vehicle width direction. A support shaft (support shaft) 56 projecting inward in the vehicle width direction is fixed to the wall portion 53A extending in the direction of the vehicle by, for example, press fitting. A load roller (rolling bearing for slide door) 42 (see FIG. 6), which will be described later, is rotatably supported on the support shaft 56 to support the load of the slide door 12.

The fourth sub-arm 55 having a substantially crank-shaped side view is rotatably connected to the upper end surface of the inner end portion of the lower arm portion 51 in the vehicle width direction, and a portion vertically facing the load roller 42 is cut out. It is formed in a U-shape that is open inward in the vehicle width direction. Two support shafts 58 and 59 protruding toward the upper side in the vertical direction of the vehicle are fixed to both ends of the fourth sub-arm 55 in the vehicle front-rear direction on the inner side in the vehicle width direction, for example, by press fitting. Therefore, the support shafts 58 and 59 extend in a direction intersecting the support shaft 56. Further, a pair of guide rollers 47 are rotatably supported on the support shafts 58 and 59, respectively. The pair of guide rollers 47 are composed of, for example, rolling bearings.

As shown in FIG. 5, the lower guide rail 16L has a lower rail portion 61 for rolling the road roller 42 and a guide rail portion 62 for rolling the pair of guide rollers 47. Similar to the guide rail portion 49, the guide rail portion 62 includes side wall portions 62A and 62B facing each other in the vehicle width direction, and an upper wall portion 62C connecting the upper end portions of both side wall portions 62A and 62B. It has a substantially U-shaped cross section that opens downward in the vertical direction of the vehicle. The pair of guide rollers 47 are arranged in a rotatable state between the side wall portions 62A and 62B constituting the guide rail portion 62 along the vehicle front-rear direction.

Therefore, the guide rail portion 62 of the lower guide rail 16L restricts the relative movement of the pair of guide rollers 47 in the vehicle width direction by the respective guide rollers 47 coming into contact with any of the side wall portions 62A and 62B. Further, the guide rail portion 62 has a pair of guide rollers 47 along the stretching direction (vehicle front-rear direction) because any of the side wall portions 62A and 62B with which the pair of guide rollers 47 abuts serve as sliding surfaces. Allows relative movement of. As a result, the lower guide rail 16L is configured to guide the lower roller unit 18L in the front-rear direction of the vehicle.

The lower rail portion 61 for rolling the road roller 42 is extended by a predetermined length from the side wall portion 62B located inside in the vehicle width direction to the lower side in the vertical direction of the vehicle, and then extends substantially at a right angle to the outside in the vehicle width direction. It has a lower wall portion 61A. The road roller 42 is arranged so as to be able to roll on the upper side surface of the lower wall portion 61A constituting the lower rail portion 61 while supporting the weight of the slide door 12.

Next, the configuration of the road roller (rolling bearing for sliding door) 42 will be described with reference to FIG. As shown in FIG. 6, the load roller (rolling bearing for sliding door) 42 has a metal inner ring 71 attached to each of the support shafts 41 and 56 and a metal outer ring concentrically arranged with respect to the inner ring 71. A plurality of rolling elements 73 (formed in a spherical shape in FIG. 6) arranged in the circumferential direction between the inner ring 71 and the outer ring 72, and the outer peripheral surface of the outer ring 72 are integrally covered with the 72. It is basically composed of a resin covering member 75.

The inner ring 71 is formed of, for example, bearing steel, carburized steel, stainless steel, or the like, and has a width L1 in the axial direction of the rotation center axis CA. The rolling element 73 is formed of, for example, bearing steel such as SUJ2, and is held by the cage 76 in a form accommodated between the raceway surfaces of the inner ring 71 and the outer ring 72. The rolling element 73 is not limited to being made of metal, and may be made of, for example, ceramic or the like. A pair of sealing members 77 formed of, for example, nitrile rubber (NBR) are mounted between both end faces in the axial direction of the inner ring 71 and the inner peripheral surfaces of the outer ring 72. The sealing member 77 prevents foreign matter from being mixed between the inner ring 71 and the outer ring 72, and also prevents the lubricant applied between the inner ring 71 and the outer ring 72 from leaking.

The outer ring 72 is formed of, for example, bearing steel, carburized steel, stainless steel, etc., and the axial width of the rotation center axis CA is larger on both sides in the axial direction than the axial width L1 (second width) of the inner ring 71, respectively. It has a total width L3 (first width) protruding by each width L2. On the inner peripheral surface of the outer ring 72, a surface having a width L1 parallel to the axial direction including the raceway surface 72A is formed at the central portion radially facing the outer peripheral surface of the inner ring 71. Further, on the inner peripheral surface of the outer ring 72, the portions of each width L2 on both sides in the axial direction with respect to the width L1 in the central portion are expanded radially outward as they go outward in the axial direction, and then parallel to the axial direction. It is formed on a cylindrical surface. As a result, the portions on both sides in the axial direction are made thinner than the central portion in the axial direction of the outer ring 72.

Further, a concave groove 81 is formed along the outer periphery of the outer ring 72 at the central portion in the axial direction on the outer peripheral surface of the outer ring 72. The bottom surface portion 81A of the concave groove 81 has an axial width L1 (third width) substantially equal to the axial width L1 of the inner ring 71, and is formed parallel to the axial direction. The axial width (third width) of the bottom surface portion 81A is preferably larger than the axial width L1 of the inner ring 71. Further, each side wall portion (wall portion) 81B on both sides of the concave groove 81 in the axial direction is curved outward in the radial direction toward the outer side in the axial direction of the outer ring 72.

Further, a pair of convex portions having a substantially rectangular cross section projecting outward in the radial direction by a predetermined height (for example, a height of about 0.3 mm to 0.7 mm) from both ends 81C in the axial direction of the concave groove 81 in the circumferential direction. 82 is provided. Further, the pair of convex portions 82 continuously protrude outward in the radial direction from the radial outer end portions 81C of the side wall portions (wall portions) 81B on both sides in the axial direction of the concave groove 81.

The covering member 75 is formed of, for example, a resin such as nylon, and is integrally provided along the circumferential direction on the radial outer side of the outer peripheral surface of the outer ring 72 by injection molding. Therefore, the covering member 75 has a thick portion 75A facing the concave groove 81 of the outer ring 72, and a pair of thin-walled portions 75B facing the portions on both sides in the axial direction from the concave groove 81 of the outer ring 72. Further, in the pair of thin-walled portions 75B, a pair of concave portions 85 into which the convex portions 82 of the outer ring 72 are fitted are formed along the circumferential direction at the end portions on the inner side in the axial direction of each inner peripheral surface. Further, the outer peripheral surface of the covering member 75 is slightly curved so as to project slightly radially outward from both ends in the axial direction toward the central portion in the axial direction with a predetermined radius of curvature (for example, a radius of curvature of about 70 mm). ing.

Therefore, a pair of convex portions 82 that project radially outward from the radial outer end 81C of each side wall portion (wall portion) 81B on both sides of the concave groove 81 of the outer ring 72 in the axial direction, and a covering member. A pair of recesses 85 formed at the axially inner end of the inner peripheral surface of the pair of thin-walled portions 75B of the 75 are fitted with each other. As a result, even if an axial load acts on the outer peripheral surface of the covering member 75 when the slide door 12 is opened and closed, it is possible to prevent the covering member 75 from being axially displaced with respect to the outer ring 72.

Further, the pair of convex portions 82 continuously protrude outward in the radial direction from the radial outer end portions 81C of the side wall portions (wall portions) 81B on both sides in the axial direction of the concave groove 81. As a result, the radial depth of the concave groove 81 can be increased, and even if an axial load acts on the outer peripheral surface of the covering member 75 when the slide door 12 is opened or closed, the covering member 75 acts on the outer ring 72. On the other hand, it is possible to more effectively suppress the deviation in the axial direction.

Here, regarding the load roller (rolling bearing for sliding door) 42 configured as described above and the conventional rolling bearing 101 for sliding door shown in FIG. 11, the shear stress distribution when the sliding door 12 is fully closed. An example of CAE (Computer Aided Engineering) analysis will be described with reference to FIGS. 7 and 8. In FIGS. 7 and 8, the darker the color, the larger the shear stress.

When the slide door 12 is fully closed, the road roller 42 is positioned in an inclined posture inclined toward the front side in the axial direction with respect to the lower wall portion 61A of the lower rail portion 61 and the lower wall portion 48A of the center rail portion 48. As a result, as shown in FIG. 7, when the slide door 12 is fully closed, in the covering member 75 of the load roller 42, in the thick portion 75A having the width L1 in the axial direction, the maximum is outward in the axial direction of the thick portion 75A. The shear stress portion 91 was generated, and the maximum shear stress value was, for example, "47 MPa".

Similarly, the conventional rolling bearing 101 for a slide door shown in FIG. 11 also has a shaft with respect to the lower wall portion 61A of the lower rail portion 61 and the lower wall portion 48A of the center rail portion 48 when the slide door 12 is fully closed. It is located in an inclined posture that is inclined toward the front side of the direction. As a result, as shown in FIG. 8, when the slide door 12 is fully closed, the covering member 105 of the conventional rolling bearing 101 for the slide door has a thin portion axially outside the thick portion 105B having an axial width L5. In 105A, the maximum shear stress portion 109 was generated inside the thin wall portion 105A in the axial direction, and the maximum shear stress value was, for example, "54 MPa".

Therefore, the axial width L3 of the resin covering member 75 covering the outer peripheral surface of the outer ring 72 of the road roller (rolling bearing for sliding door) 42 is set in the axial direction of the covering member 105 of the conventional rolling bearing 101 for sliding door. By making it larger than the width L1, for example, by making it 1.5 times to 1.7 times, the maximum shear stress portion 91 when the slide door 12 is fully closed can be generated in the thick portion 75A. .. As a result, the cross-sectional area where the maximum shear stress is generated can be increased, the maximum shear stress value of the covering member 75 can be decreased, and the creep characteristics of the load roller (rolling bearing for sliding door) 42 can be improved.

Next, with respect to the load roller (rolling bearing for sliding door) 42 configured as described above and the conventional rolling bearing 101 for sliding door shown in FIG. 11, the contact surface pressure of the sliding door 12 when not closed is applied. An example of CAE (Computer Aided Engineering) analysis of the surface pressure distribution will be described with reference to FIGS. 9 and 10. In FIGS. 9 and 10, the darker the color, the larger the contact surface pressure. Further, a load of 300 N was applied to the load roller 42 and the conventional rolling bearing 101 for a sliding door.

Further, for example, the outer peripheral surface of the covering member 75 of the load roller 42 is curved with a radius of curvature of about 70 mm so as to slightly project outward in the radial direction from both ends in the axial direction toward the central portion in the axial direction. Further, for example, the outer peripheral surface of the covering member 105 of the conventional rolling bearing 101 for a sliding door is curved with a radius of curvature of about 40 mm so as to slightly project outward in the radial direction from both ends in the axial direction toward the central portion in the axial direction. is doing.

As shown in FIG. 9, when the slide door 12 is not closed, the outer peripheral surface of the covering member 75 of the load roller 42 is curved with a radius of curvature of about 70 mm in the axial direction, so that the maximum contact surface pressure portion 93 is thick. It occurs widely from the outer end portion in the axial direction of the outer peripheral surface of the meat portion 75A toward the central portion in the axial direction. The maximum contact surface pressure was "about 102 MPa". On the other hand, as shown in FIG. 10, in the covering member 105 of the conventional rolling bearing 101 for a sliding door, the outer peripheral surface is curved with a radius of curvature of about 40 mm in the axial direction, so that the maximum contact surface pressure portion 111 is a thin portion. It occurs from the central portion in the axial direction of 105A to the central portion in the axial direction of the thick portion 105B. The maximum contact surface pressure was "about 119 MPa".

Therefore, when the road roller (rolling bearing for a slide door) 42 rolls on the lower wall portion 61A of the lower rail portion 61 and the lower wall portion 48A of the center rail portion 48, the contact area of the covering member 75 is slid by the conventional slide. It can be made larger than the contact area of the covering member 105 of the rolling bearing 101 for a door. As a result, the contact surface pressure of the resin covering member 75 can be made smaller than the contact surface pressure of the covering member 105 of the conventional rolling bearing 101 for sliding doors, and the durability can be significantly improved.

It should be noted that the present invention is not limited to the above-described embodiment, and it goes without saying that various improvements, modifications, additions, and deletions can be made without departing from the gist of the present invention. In the following description, the same reference numerals as the configuration of the road roller (rolling bearing for sliding door) 42 shown in FIG. 6 may be the same as the configuration of the road roller (rolling bearing for sliding door) 42 according to the embodiment. It shows a considerable part.

For example, the convex portion 82 may project at a predetermined height outward in the radial direction along the circumferential direction only from one of the axial end portions of the concave groove 81 in the axial direction. As a result, even if an axial load acts on the outer peripheral surface of the covering member 75 when the slide door 12 is opened and closed, it is possible to prevent the covering member 75 from being axially displaced with respect to the outer ring 72.

11 Body 12 Sliding door 16C Center guide rail 16L Lower guide rail 41, 56 Support shaft (support shaft)
42 Road roller (rolling bearing for sliding door)
71, 106 Inner ring 72, 102 Outer ring 73 Rolling element 75, 105 Covering member 75A, 105B Thick part 75B, 105A Thin part 81, 103 Concave groove 81A Bottom part 81B Side wall part (wall part)
82 Convex 85 Concave 101 Rolling bearing for sliding door

Claims (3)

A rolling bearing for a sliding door that supports the sliding door while rolling on the guide rail provided on the vehicle body.
An inner ring attached to a support shaft provided on the slide door, and an inner ring.
Arranged concentrically with respect to the inner ring, the first width in the axial direction is formed to be larger than the second width in the axial direction of the inner ring, and the outer peripheral surface is radially inward at the central portion in the axial direction. An outer ring with a concave groove formed in the circumferential direction,
A plurality of rolling elements arranged in the circumferential direction between the inner ring and the outer ring, and
A resin-made covering member integrally coated on the outer peripheral surface of the outer ring including the concave groove,
Equipped with
The bottom surface portion of the concave groove is formed so that the third width in the axial direction is larger than the second width in the axial direction of the inner ring and smaller than the first width in the axial direction of the outer ring.
The covering member has a thick portion that covers the concave groove and a thin portion that covers both ends in the axial direction of the concave groove.
Rolling bearings for sliding doors. In the rolling bearing for a sliding door according to claim 1,
The outer ring has a convex portion protruding radially outward along the circumferential direction on the outer peripheral surface of at least one of both ends in the axial direction with respect to the concave groove.
In the covering member, a concave portion into which the convex portion is fitted is formed on the inner peripheral surface of the thin-walled portion.
Rolling bearings for sliding doors. In the rolling bearing for a sliding door according to claim 2.
The convex portion is continuously formed from the radial outer ends of the wall portions on both sides of the concave groove in the axial direction.
Rolling bearings for sliding doors.

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