JP2011085261A - Roller bearing for electric seat reclining - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a roller bearing for electric seat reclining that holds the number of rollers equivalent to that of a full-complement roller type, prevents the occurrence of a rattle feeling or the like when in operation, has excellent feeling characteristics, prevents a deterioration in responsiveness when started, achieves a long service lifetime, low torque, and low vibration, and also, prevents an increase in width dimension. <P>SOLUTION: The roller bearing is used in an electric seat-reclining device and supports a backrest so as to allow the inclination angle of the backrest to be freely adjustable. The roller bearing has two inner and outer retainers 13, 23, and a plurality of rollers 2 held over pockets of the two retainers 13, 23. The inner retainer 13 is configured as follows. A column 5 between each pocket 4 holds the roller 2 between each roller 2 from the inner-diameter side. The outer diameter of the column 5 is smaller than a pitch circle diameter PCD of the roller arrangement. The outer retainer 23 is configured as follows. A column 5 between each pocket 4 holds the roller 2 between each roller 2 from the outer-diameter side. The inner diameter of the column 5 is larger than a pitch circle diameter PCD of the roller arrangement. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a roller bearing for electric seat reclining that is used in an electric seat reclining device in an automobile or the like and supports a backrest so that an inclination angle can be adjusted.

  Conventionally, in a seat reclining device, a rolling bearing or a sliding bearing is used as a bearing that supports the backrest so that the tilt angle can be adjusted. As a rolling bearing, one using a roller bearing having an outer ring, a roller, and a cage has been proposed (for example, Patent Document 1). The roller bearing has an advantage that the reclining mechanism can be configured more compactly than the ball bearing. Sliding bearings are also preferable in terms of compactness.

In the seat reclining device, as shown in FIG. 13, the backrest 32 is supported by the reclining mechanism 33 so that the inclination angle can be adjusted. The reclining mechanism 33 has a function of adjusting the height of the backrest 32 according to the tilt angle, and keeps a person sitting on the seat in a comfortable posture.
In the electric seat reclining device, in such a reclining mechanism 33, as schematically shown in FIG. 14, a bearing fitting hole 35 is provided in the metal fitting 34 fixed to the backrest 32, and the bearing is fitted in the bearing fitting hole 35. 36 is received by a cam 37 having a center P eccentric with respect to the bearing center. The vertical position of the metal fitting 34 and the backrest 32 fixed to the metal fitting 34 is changed by the action of the cam 37 when the inclination angle changes. In the electric seat reclining device, the angle of the backrest 32 is changed by a motor (not shown).

Japanese Patent No. 3324045 JP-A-6-307456 JP-A-7-238940

  In the electric seat reclining mechanism 33 as shown in FIG. 14, when a conventional general roller bearing is used as the bearing 36, a column portion (not shown) of the cage 38 is interposed between the rollers 39. The pitch is large. The cam 37 corresponds to a part in the circumferential direction with respect to the bearing 36, and the roller 39 is intermittently placed on the eccentric cam 37. For this reason, a feeling of crunch and a feeling of poorness are caused during operation.

  If a full roller bearing, which is a cage-less type bearing, is used as the bearing 36, the rollers 39 are densely interposed, so that the feeling of stickiness is eliminated. Also, the load capacity is improved. However, the cam 37 is not on the entire circumference, and in the drop-off type full roller bearing that is not held by the cage 38, the roller 39 that is not placed on the cam surface falls off. Therefore, the conventional drop-off type full complement roller bearing cannot be used.

Although there is a non-drop-off type as a full complement roller bearing, all of them have the following problems when used in an electric seat reclining device.
For example, among non-drop-off type full-roller bearings, the keystone type is difficult to design with 20 or more rollers. If the number of rollers is small, it is impossible to eliminate the above-mentioned feeling of crunch.
Among the non-drop-off type full-roller bearings, the C end face type (for example, Patent Document 2) is provided with a sharp part on the roller end face to prevent the drop-off, but the width dimension is large due to the sharp part. Become. Further, there is a problem that the effective contact length is short and the roller end surface and the contact portion of the outer ring with the roller end surface are worn. In the shape where the roller end face has a sharp point, the wear of the roller end face becomes remarkable particularly in the usage mode in which the induced thrust force is large. In the seat reclining device, in order to widen the seat surface, it is desired to reduce the cross section of the reclining mechanism, and there is a market demand for reducing the width of the bearing. Therefore, it is not preferable to use a C end face type full complement roller bearing.

  As a non-drop-off type full-roller bearing, there is one in which the roller is prevented from dropping with a thermosetting grease (for example, Patent Document 3). This type does not have a problem such as an increase in size, but has a problem that the rotational torque is large. Furthermore, the service temperature of the bearing is limited within the service temperature range of the thermosetting grease, and the means for lubricating the bearing, such as the type of grease and the type of oil, is limited.

  It is also conceivable to use a sliding bearing as the bearing 36. Examples of the sliding bearing include those made of a sintered material, a combination of a sintered material and a resin coating, and a combination of an iron plate and a resin coating. However, these sliding bearings have a larger rotational torque than the rolling bearings, and the load on the motor increases, resulting in a high current value. Therefore, the motor cannot be downsized. Furthermore, among the plain bearings, those that are coated increase play by peeling off the coating film, and there is a problem that the response at the time of start-up decreases.

  The object of the present invention is to maintain the same number of rollers as a full-fledged roller type, there is no sensation during operation, excellent feeling characteristics, no deterioration in responsiveness at startup, long life, An object of the present invention is to provide a roller bearing for electric seat reclining which can be torque and low vibration and does not cause an increase in width.

The roller bearing for electric seat reclining of the present invention is used in an electric seat reclining device, and is a roller bearing that supports the backrest so that the tilt angle can be adjusted, and is applied to a bearing called a roller with a cage that does not have a bearing ring. It is an example. The roller bearing includes two inner and outer cages each formed in a ring shape having a plurality of pockets arranged in the circumferential direction, and a plurality of rollers held across the pockets of the two cages. The cage of each of the pockets holds the roller from the inner diameter side between the rollers, the outer diameter of the pillar is smaller than the pitch circle diameter of the roller arrangement, the outer cage is A column portion between each pocket holds the roller from the outer diameter side between the rollers, and an inner diameter of the column portion is larger than a pitch circle diameter of the roller arrangement.
According to this configuration, since the inner and outer two cages are provided, the roller can be a non-drop-off type roller bearing in a state where it is not assembled into the device, although it is a roller bearing with a cage that does not have a bearing ring. In this case, the inner and outer cage pillars hold the roller from the inner diameter side and the outer diameter side, the outer diameter of the inner cage pillar part is smaller than the pitch circle diameter of the roller arrangement, and the outer side Since the inner diameter of the retainer column portion is larger than the pitch circle diameter of the roller array, the retainer column portion may not exist on the pitch circle diameter of the roller array. For this reason, the roller arrangement interval is not widened by the column part, and it can be made to have the same number of rollers as the full roller type while using a cage to make the roller non-dropping type. A larger load capacity can be applied compared to the bearing. Therefore, it is possible to solve various problems of the full-roller type, such as assembling with less man-hours without using a drop-off prevention sleeve.

Moreover, since the number of rollers can be the same as that of the full roller type while using the cage to make the roller non-dropping type, the following advantages (1) to (8) can be obtained.
(1) Since the roller pitch is reduced, when used in an electric seat reclining device in which the roller is in contact with a cam provided in a part of the circumferential direction, the roller does not ride on the cam intermittently. The feeling of harshness during operation is reduced and the feeling characteristics are improved.
(2) Feeling characteristics are improved, resulting in low vibration.
(3) Since it can have the same number of rollers as all roller types, the load capacity is increased and the service life is extended.
(4) As the load capacity increases, the contact pressure between the rollers and the cam surface decreases, resulting in a low torque. Of course, compared with the plain bearing, the torque is low because it is a rolling type regardless of whether or not the plain bearing is coated.
(5) Like a resin-coated sliding bearing, the coating does not peel off and wear, and the responsiveness does not deteriorate due to play due to wear.
(6) Even in a bearing using a roller having a flat end face, it can be removed. Since a roller with a flat end face can be used, the roller effective length can be set to the maximum even in a limited width dimension. Accordingly, the width dimension can be reduced. If the outer ring is hooked, the induced thrust force generated on the roller can be received by the flange of the outer ring.
(7) Since the roller can be removed by the cage, it is not necessary to remove the roller by the thermally solidified grease, so the torque can be reduced. Therefore, the type of lubricant is not limited, and the lubricant can be freely selected.
(8) It is easier to assemble than conventional captive roller bearings.

In this invention, it is good also considering the cross-sectional shape of the pillar part of the holder | retainer of an outer diameter side as a shape where the part of an inner diameter side rather than an outer diameter part becomes narrowing to an inner diameter side. For example, a substantially triangular shape may be used.
The gap between adjacent rollers in the roller arrangement is a triangular gap that gradually increases on the outer diameter side. To increase the cross-sectional area of the column without increasing the interval between the rollers, move the column to the inner diameter. It is preferable to have a cross-sectional shape that becomes narrower. However, the outermost diameter part where the width of the column part is most widened is not widened along the roller surface, but the gap between the roller surface and the column part surface is widened to a substantially constant width, thereby inhibiting the flow of the lubricating oil. Can be avoided, and deterioration of lubricity can be prevented.

In this invention, it is good also considering the edge part of the width direction in the internal diameter surface of an outer side holder | retainer as a taper shape or a cross-section arcuate taper shape.
By configuring the tapered shape, the cage can be more smoothly inserted to the outside of the roller array at the time of assembly, and the assemblability is further improved.

  In the present invention, the material of the cage may be made of synthetic resin. If the cage is made of a synthetic resin, the cage can be elastic to some extent. Therefore, the cage can be deformed when the bearing is assembled, and the cage or roller can be easily assembled.

  In the present invention, the number of rollers may be the same as the total roller type or may be reduced by two or less.

  The outer diameter of the outer cage is preferably 0.1 mm or more smaller than the minimum diameter (d2o) of the circumscribed circle diameter of the roller arrangement. The minimum diameter (d2o) of the circumscribed circle diameter of the roller arrangement is a circumscribed circle diameter when the rollers 2 are arranged so as to be in contact with the rolling surface 1a of the inner ring 1. If there is a clearance of 0.1 mm or more with respect to the inner surface of the bearing box to which each roller comes into rolling contact, the cage does not come into strong contact, and an increase in friction torque by the cage is avoided.

  In addition, it is preferable that the inner diameter of the outer cage is 0.1 mm or more larger than the pitch circle diameter of the roller arrangement. Accordingly, it is possible to avoid that the width of the innermost diameter portion in the cross section of the column portion becomes too thin and the strength becomes insufficient without having to widen the interval between the roller arrays.

In this invention, you may provide the slit of the shape notched from the one side edge of this holder | retainer to the vicinity of another side edge in the multiple places of the circumferential direction of each holder | retainer inside and outside.
According to this configuration, when assembling the bearing, it is possible to easily insert the cage into and out of the roller array while increasing the diameter of the insertion side portion of the outer cage and reducing the diameter of the insertion side portion of the inner cage. it can. Thereafter, the cage is naturally restored to its original diameter by the elasticity of the material, so that each roller enters the pocket and the bearing is assembled. In inserting the retainer, since the slit is provided, the retainer can be deformed within the elastic region of the material, and therefore, the retainer is less deformed by deformation and can prevent deterioration in accuracy due to deformation. As a result, the assembling property and accuracy can be improved, and the assembly can be automated.
In addition, you may provide the slit of the shape notched from the one side edge of this holder | retainer to the vicinity of another side edge in the multiple places of the circumferential direction of any one holder | retainer of each inside / outside holder | retainer. Moreover, the said slit may be one place of the circumferential direction.

An assembling method using an inner / outer cage type having no bearing ring will be described. An example will be described in which the outer cage is not provided with a slit, but only the inner cage is provided with a slit. In this case, after the rollers are disposed in the pockets of the outer cage, the inner cage is inserted axially into the roller array. The inner cage is inserted while reducing its diameter, and after insertion, the inner cage is naturally restored to its original diameter due to the elasticity of the material.
When both the inner and outer cages have the above slits, the cage can be easily placed inside and outside the roller array while expanding the insertion side portion of the outer cage during assembly and reducing the diameter of the insertion side portion of the inner cage. Can be inserted into.

The slit may also serve as a pocket for holding rollers. In other words, a removal portion may be provided at the pocket portion on the ring-shaped portion on the side edge of the cage, and the slit may be configured by the removal portion and the pocket.
By disposing the rollers also in the slit, the number of rollers can be increased while providing the slit, and the load capacity of the roller bearing can be increased.

  In this invention, it is preferable that the circumferential positions of the slits of the inner and outer cages are shifted from each other. Thereby, it is possible to sufficiently secure the holding strength of the rollers by the inner and outer cages while providing the slits.

  In the present invention, the inner cage and the outer cage may be integrated with each other. This improves the assemblability.

The electric seat reclining roller bearing according to the present invention has the same number of rollers as the full-roller type while using a cage to make the roller non-dropping type, and therefore operates when used in an electric seat reclining device. There is no harsh feeling at the time, excellent feeling characteristics, no deterioration in responsiveness at start-up, long life, low torque, low vibration, and no problem of increasing width dimensions. .
The inner cage includes two inner and outer cages formed in a ring shape each having a plurality of pockets arranged in the circumferential direction, and a plurality of rollers held across the pockets of the two cages. The column portion between each pocket holds the roller from the inner diameter side between the rollers, the outer diameter of the column portion is smaller than the pitch circle diameter of the roller arrangement, and the outer cage is between the pockets. The column portion holds the roller from the outer diameter side between the rollers, and the inner diameter of the column portion is larger than the pitch circle diameter of the roller arrangement, so that the bearing does not have inner and outer race rings. It can be a drop-off type, can be assembled with less man-hours, and can provide a large load capacity.

(A) is the fragmentary longitudinal cross-sectional view of the roller bearing concerning a proposal example, (B) is the partial cross-sectional view. It is explanatory drawing which shows the relationship between a roller diameter and arrangement | sequence total clearance gap. (A) is a partial cross-sectional view of one embodiment of the present invention, (B) is a partial cross-sectional view thereof, and (C) is a partial cross-sectional view of a modification thereof. (A) is the fragmentary sectional view of other embodiment in this invention, (B) is the fragmentary cross-sectional view. It is a fragmentary sectional view of other embodiment in invention. It is a fragmentary sectional view of other embodiment in invention. It is a partial front view which shows each example of the holder | retainer in other embodiment of this invention. It is a partial front view which shows each example of the roller arrangement | sequence state to the holder | retainer. (A) is the fragmentary sectional view of further another embodiment in this invention, (B) is the fragmentary side view. (A) is a partial side view of still another embodiment of the present invention, and (B) is a partial side view of still another embodiment of the present invention. It is a fragmentary sectional view which shows the holder | retainer of further another embodiment in this invention. It is a fragmentary sectional view which shows the holder | retainer of further another embodiment in this invention. It is a side view of the conventional reclining seat. It is a schematic sectional drawing of the reclining mechanism.

  An example of a proposal that serves as a reference for the present invention will be described with reference to FIGS. The electric seat reclining roller bearing includes an outer ring 1, a plurality of rollers 2 in contact with a rolling surface 1 a formed by an inner diameter surface of the outer ring 1, and a ring-shaped cage 3. The cage 3 has a plurality of pockets 4 arranged in the circumferential direction, and a column portion 5 between the pockets 4 is located between the rollers 2 to hold the rollers 2 from the inner diameter side.

  The outer ring 1 has flanges 1b on both sides. The outer ring 1 is a shell type, that is, a press-formed product of a steel plate. The roller 2 is made of steel such as bearing steel. The cage 3 is made of a synthetic resin such as polyamide (for example, PA66, PA46) or polyacetal. The cage 3 uses these synthetic resins in a non-reinforced state or a state in which a reinforcing fiber such as carbon fiber or glass fiber is added in an amount of 30% or less. It has been given moderate strength and flexibility.

  The cage 3 has ring-shaped portions 6 at both ends in the width direction, and a plurality of column portions 5 are provided at equal intervals in the circumferential direction between the ring-shaped portions 6 on both sides. A space between the pillar portions 5 becomes a pocket 4 in which the roller 2 is inserted. The shape of the pillar portion of the cage 3 is substantially triangular. The inner diameter d3i of the cage 3 is set to be 0.1 mm or more larger than the maximum diameter d2i of the inscribed circle diameter of the roller arrangement. The 0.1 mm dimension is preferably equal to or greater than this value regardless of the bearing size. The outer diameter dimension d3o of the column portions 5 of the cage 3 is set to be smaller than the pitch circle diameter PCD of the roller arrangement. For example, it is smaller than the pitch circle diameter PCD by 0.1 mm or more. The dimension that is smaller than the pitch circle diameter PCD may be a predetermined ratio or more that is designed according to the bearing dimensions and the like. The thickness B of the column portion 5 of the cage 3 is preferably 15 to 30% of the roller diameter.

  As for the cross-sectional shape of the column portion 5 of the cage 3, for example, the innermost diameter portion 5 a (see FIG. 4A) is a portion having a substantially constant width, and the outer diameter side portion 5 b is more than the outer diameter portion. The shape is tapered toward the side. The distal end portion of the outer diameter side portion 5b has, for example, a shape in which a corner portion or the whole is rounded into an arc shape. The side surface 5ba of the outer diameter side portion 5b has, for example, a shape in which the cross section is linear as shown in FIG. 4A, or a concave curved surface shape substantially corresponding to the outer diameter surface of the roller 2 as shown in FIG. Or a convex curved surface shape as shown in FIG. The side surface 5aa of the innermost diameter portion 5a of the column portion 5 may have a shape in which the cross section is a straight shape or a shape that has a convex curved surface such as an arc shape. The innermost diameter portion 5a of the column portion 5 does not necessarily have a substantially constant cross-sectional shape. For example, the innermost portion 5a is curved in an arc shape and the middle portion of the innermost diameter portion 5a protrudes most, or the inner diameter side column. The shape may be narrowed.

According to the roller bearing having the above configuration, the column portion 5 of the cage 3 holds the roller 2 from the inner diameter side, and the shape of the column portion is substantially triangular. Therefore, the cage column portion 5 has a pitch circle diameter PCD of the roller arrangement. It can be absent. Therefore, the arrangement interval of the rollers 2 is not widened by the column portion 5, and the number of rollers can be the same as the total roller type, or the number of rollers can be reduced by one or two. Further, the strength of the column portion 5 is ensured.
In this way, since the roller can be made to be non-drop-off type using the cage 3 and have the same number of rollers as the full-roller type, the following advantages (1) when used in the electric seat reclining device: ~ (8) is obtained.
(1) When the roller 2 is used in an electric seat reclining device in which the roller 2 is in contact with the cam 37 provided in a part of the circumferential direction as described above with reference to FIG. The cam 37 is not ridden intermittently, so that the feeling of harshness during operation is reduced and the feeling characteristics are improved.
(2) Feeling characteristics are improved, resulting in low vibration.
(3) Since it can have the same number of rollers as all roller types, the load capacity is increased and the service life is extended.
(4) As the load capacity increases, the surface pressure between the roller 2 and the cam surface decreases, and the torque becomes low. Of course, compared with the plain bearing, the torque is low because it is a rolling type regardless of whether or not the plain bearing is coated.
(5) Like a resin-coated sliding bearing, the coating does not peel off and wear, and the responsiveness does not deteriorate due to play due to wear.
(6) Even in a bearing using a roller having a flat end face, it can be removed. Since the roller 2 having a flat end face can be used, the roller effective length can be set to the maximum even in a limited width dimension. Accordingly, the width dimension can be reduced. If the outer ring 1 has the flange 1b, the induced thrust force generated on the roller can be received by the flange 1b of the outer ring 1.
(7) Since the roller 2 can be removed without the cage 3, it is not necessary to remove the roller with the heat-setting grease, so that the torque can be reduced. Therefore, the type of lubricant is not limited, and the lubricant can be freely selected.
(8) It is easier to assemble than conventional captive roller bearings.

In the case of the proposed roller bearing, the following advantages are further obtained. For example, since the inner diameter d3i of the cage 3 is set to be 0.1 mm or more larger than the maximum diameter of the inscribed circle diameter d2i of the roller arrangement, a gap of 0.1 mm or more is generated between the shaft and the cage 3. Therefore, the cage 3 does not come into strong contact with the shaft, and it is avoided that the friction torque is increased by the cage 3.
The outer diameter dimension d3o of the arrangement of the column parts 5 of the cage 3 is smaller than the pitch circle diameter PCD of the roller arrangement, and the degree of reduction is, for example, 0.1 mm or more smaller than the pitch circle diameter PCD. It is not necessary to widen the interval between the roller arrangements, and it is avoided that the outermost diameter portion in the cross section of the column portion 5 becomes too thin and the strength becomes insufficient.
Further, the cross-sectional shape of the pillar portion 5 of the cage 3 is such that the innermost diameter portion 5a is a portion having a substantially constant width, and the outer diameter side portion 5b of the innermost diameter portion 5a is tapered toward the outer diameter side. Therefore, the cross-sectional area of the column portion 5 can be increased without increasing the interval between the rollers 2, and the lubricity is excellent. That is, the gap between the adjacent rollers 2 in the roller arrangement is a triangular gap whose inner diameter side is gradually increased. Therefore, in order to increase the cross-sectional area of the column portion 5 without increasing the interval between the rollers 2, the column It is preferable that the portion 5 has a triangular cross-sectional shape that is tapered toward the outer diameter side. However, the innermost diameter portion 5a in which the width of the column portion 5 is widened most is not widened along the roller surface, and the gap between the roller surface and the column portion surface is widened to be substantially constant, thereby inhibiting the flow of the lubricating oil. This can be avoided, and deterioration of lubricity can be prevented. In addition, no waste portion is generated in the column portion 4, and the resin material is saved.

  FIG. 3 shows an embodiment of the present invention. This embodiment is an example applied to a roller bearing having no inner and outer races. The electric seat reclining roller bearing includes two inner and outer cages 13 and 23 and a plurality of rollers 2 held across the pockets 4 of the two cages 13 and 23. Both the inner and outer cages 13 and 23 are formed in a ring shape having a plurality of pockets 4 arranged in the circumferential direction. It is assumed that the inner cage 13 holds the rollers 2 from the inner diameter side between the rollers 2 by the column portions 5 between the pockets 4. It is assumed that the outer retainer 23 holds the roller 2 from the outer diameter side between the rollers 2 by the column portion 5 between the pockets 4.

  The two inner and outer cages 13 and 23 are made of a synthetic resin that can be elastically deformed, such as polyamide (for example, PA66, PA46) or polyacetal. The cages 13 and 23 use these synthetic resins in a non-reinforced state or in a state in which a reinforcing fiber such as carbon fiber or glass fiber is added in an amount of 30% or less. Appropriate strength and flexibility are given.

  The cages 13 and 23 have ring-shaped portions 6 at both ends in the width direction, and a plurality of column portions 5 are provided at equal intervals in the circumferential direction between the ring-shaped portions 6 on both sides. A space between the pillars 5 becomes a pocket 4 in which the roller 2 is inserted.

  As shown in FIG. 3B, the cross-sectional shape of the pillar portion of the inner cage 13 is substantially triangular. The inner diameter d13i of the cage 13 is set to be 0.1 mm or more larger than the maximum diameter d2i of the inscribed circle diameter of the roller arrangement. The 0.1 mm dimension is preferably equal to or greater than this value regardless of the bearing size. The outer diameter dimension d13o of the arrangement of the column portions 5 of the cage 13 is made smaller than the pitch circle diameter PCD of the roller arrangement. For example, it is smaller than the pitch circle diameter PCD by 0.1 mm or more. The dimension to be smaller than the pitch circle diameter PCD may be a predetermined ratio or more designed according to the bearing dimensions and the like. The thickness B of the column portion 5 of the cage 13 is preferably 15 to 30% of the roller diameter.

  Specifically, the cross-sectional shape of the column portion 5 of the inner cage 13 is, for example, the innermost diameter portion 5c having a substantially constant width, and the outer diameter side portion 5d of the innermost diameter portion 5c is the outer diameter side. The shape is narrowed at the tip. The tip of the outer diameter side portion 5d has, for example, a shape in which a corner or the whole is rounded into an arc shape.

  As shown in FIG. 3B, the outer cage 23 has a rectangular cross section of the column part 5, or a rectangular or outermost diameter part having a substantially constant width as shown in FIG. The portion on the inner diameter side of the outermost diameter portion is tapered toward the inner diameter side. For example, the inner diameter side has a substantially pentagonal shape with a tapered shape.

  Each dimension about the outer side holder | retainer 23 is demonstrated. The outer diameter dimension d3o of the cage 23 is made 0.1 mm or more smaller than the minimum diameter d2o of the circumscribed circle diameter of the roller arrangement. The 0.1 mm dimension is preferably equal to or greater than this value regardless of the bearing size. The inner diameter dimension d3i of the column portions 5 of the cage 3 is made larger than the pitch circle diameter PCD of the roller arrangement. For example, it is larger than the pitch circle diameter PCD by 0.1 mm or more. The dimension larger than the pitch circle diameter PCD may be a predetermined ratio or more designed according to the bearing dimension or the like.

  According to the roller bearing of this configuration, since the roller 2 is held by the inner and outer cages 13 and 23, the roller 2 is dropped in a state where the roller 2 is not assembled into a device, although it is a roller bearing with a cage that does not have a bearing ring. It can be a non-drop-off type roller bearing. The inner and outer cages 13 and 23 are such that the column portion 5 holds the roller 2 from the inner diameter side and the outer diameter side, and the outer diameter d13o of the column portion 5 of the inner cage 13 is set to the pitch circle diameter of the roller arrangement. Since the diameter is smaller than that of the PCD and the inner diameter d3i of the column portion 5 of the outer cage 23 is larger than the pitch circle diameter PCD of the roller arrangement, each column portion 5 of the cages 13 and 23 has a pitch circle diameter of the roller arrangement. It may not be present on the PCD. Therefore, the arrangement interval of the rollers 2 is not widened by the column portion 5, and the rollers 13 and 23 are used to make the rollers non-dropping type, while having the same number of rollers as the full roller type, and having the same cross-sectional height. Compared with a conventional roller bearing with an outer ring, a larger load capacity can be provided. Therefore, it is possible to solve various problems of the full-roller type, such as assembling with less man-hours without using a drop-off prevention sleeve.

  In addition, since the rollers 13 and 23 are used as a non-drop-off type, the number of rollers can be the same as that of the full roller type. It does not occur, has excellent feeling characteristics, does not deteriorate the response at start-up, has a long life, low torque, and low vibration, and does not cause the problem of an increase in width dimension.

The roller bearing of this embodiment can further obtain the following advantages. For example, since the outer diameter dimension d3o of the outer cage 23 is 0.1 mm or more smaller than the minimum diameter of the circumscribed circle diameter d2o of the roller arrangement, there is a gap of 0.1 mm or more between the bearing box and the cage 3. Arise. Therefore, the cage 23 does not come into strong contact with the bearing box, and it is avoided that the friction torque is increased by the cage 3.
In addition, since the inner diameter d13i of the inner cage 13 is made 0.1 mm or more larger than the maximum diameter of the inscribed circle diameter d2i of the roller arrangement, a gap of 0.1 mm or more is generated between the shaft and the cage 13. . Therefore, the cage 13 does not come into strong contact with the shaft, and it is avoided that the friction torque is increased by the cage 13.

Moreover, the inner diameter dimension d3i of the arrangement of the column portions 5 of the outer cage 23 is larger than the pitch circle diameter PCD of the roller arrangement, and the degree of the increase is, for example, 0.1 mm or more than the pitch circle diameter PCD. Therefore, it is not necessary to increase the interval between the roller arrangements, and it is avoided that the innermost diameter portion in the cross section of the column portion 5 becomes too thin and the strength is insufficient.
Further, the outer diameter dimension d13o of the arrangement of the column portions 5 of the inner cage 13 is made smaller than the pitch circle diameter PCD of the roller arrangement, and the degree of the reduction is, for example, 0.1 mm or more than the pitch circle diameter PCD. Therefore, it is not necessary to widen the interval between the roller arrangements, and it is avoided that the width of the outermost diameter portion in the cross section of the column portion 5 becomes too thin and the strength becomes insufficient.

  Furthermore, the cross-sectional shape of the column portion 5 of the inner cage 13 is such that the innermost diameter portion 5c is a portion having a substantially constant width, and a portion 5d on the outer diameter side of the innermost diameter portion 5c is tapered toward the outer diameter side. Therefore, the cross-sectional area of the column portion 5 can be increased without increasing the interval between the rollers 2, and the lubricity is excellent. That is, since the gap between the adjacent rollers 2 in the roller arrangement becomes a triangular gap whose inner diameter side gradually increases, in order to increase the cross-sectional area of the column portion 5 without increasing the interval between the rollers 2, It is preferable that the portion 5 has a triangular cross-sectional shape that is tapered toward the outer diameter side. However, the innermost diameter portion 5c in which the width of the column portion 5 is widest is not widened along the roller surface, and the gap between the roller surface and the column portion surface is widened to avoid obstruction of the flow of the lubricating oil. It is possible to prevent a decrease in lubricity. In addition, no waste portion is generated in the column portion 5, and the resin material is saved.

FIG. 4 shows another embodiment of the present invention. In the embodiment shown in FIG. 3, this roller bearing has a slit 7 having a shape in which the inner and outer cages 13, 23 are cut out from one side edge to the vicinity of the other side edge as shown in FIG. 7D, for example. This is an example of having. Here, the circumferential position of the slit 7 of the outer retainer 23 and the circumferential position of the slit 7 of the inner retainer 13 facing the slit 7 are set to be shifted from each other. Yes. The slit structures of the cages 13 and 23 are not limited to the example of FIG. 7D, but may be those of the examples of FIGS. 7A to 7C.
Further, the slit 7 does not necessarily have to be provided in both the inner and outer holders 13 and 23. For example, as shown in FIG. 5, the slit 7 may be provided only in the inner holder 13, as shown in FIG. Thus, the slit 7 may be provided only in the outer cage 23.

The slits 7 and 7A in FIGS. 7A to 7D will be described. 7A to 7D are examples of the inner cage 13, but the outer cage 23 is the same as the inner cage 13.
FIG. 7A shows an example of the cage 13 in which the slit 7 is only cut out from one side edge (left side in the drawing).
In FIG. 7B, there are slits 7 cut out from one side edge and those cut out from the other side edge, and the slits 7 on both sides are arranged in a staggered pattern in the circumferential direction. The example of the holder | retainer 3 provided in is shown.
FIG. 7C is an example in which only the slits 7 and 7A are cut from one side edge, but there are two types of slits 7 and 7A. One kind of the slit 7 is formed as a slit 7 by a portion obtained by removing substantially the entire portion between the adjacent column portions 5 in the ring-shaped portion 6 and a portion also serving as a pocket. Another type of slit 7A is constituted by a portion in which part 6a of a portion between adjacent column portions 5 in ring-shaped portion 6 is removed and a portion that also serves as a pocket. The two types of slits 7 and 7A are alternately provided in the circumferential direction.
FIG. 7D shows a holding in which the slits 7 cut out from one side edge and the slits 7 cut out from the other side edge are arranged in a staggered manner in the circumferential direction, as in FIG. 7B. In this case, the dedicated pocket 4 is omitted, and the slits 7 cut out from one side edge and the slits 7 cut out from the other side edge are alternately arranged in the circumferential direction. To be lined up.

7A, 7 </ b> B, and 7 </ b> D, the retainer 13 in the example of FIG. 7A is a portion obtained by removing substantially the entire portion between the adjacent column portions 5 in the ring-shaped portion 6, and the adjacent column portion 5. A slit 7 is formed by a portion that also serves as a pocket between them.
7A and 7B, the pockets 4 and the slits 7 are alternately formed in each example, and the column portion 5 is provided between the pocket 4 and the slit 7 that also serves as a pocket. It is supposed to be provided.
In the example of FIG. 7C, the slit 7A is provided by opening a plurality of pockets 4 and the column portion 5 is provided between the pocket 4 and the slit 7 that also serves as a pocket. Although not shown in the figure, a dedicated pocket 4 is also provided in an adjacent part. 7A and 7B, the slit 7 may be provided by arranging a plurality of pockets 4 in an array.
The cross-sectional shape of the column portion 5 is the shape described above with reference to FIG. 3B both for the space between the pocket 4 and the slit 7 and between the adjacent dedicated pockets 4.

FIG. 8 shows a state in which the rollers 2 are held by the cages 3. FIG. 6 (A) shows a case where a cage 13 (example of FIG. 7 (A)) having a slit 7 only on one side is used. Here, the roller 2 is arranged not only in the pocket 4 but also in the slit 7. ing. Thereby, the load capacity of the roller bearing can be increased. FIG. 8B shows a case where the cage 3 having the slits 7 on both sides (example of FIG. 7B) is used. In this case, the roller 2 is arranged not only in the pocket 4 but also in the slit 7. ing. FIG. 8C shows a case where the cage 13 having only the slit 7 (example of FIG. 7D) is used. In this case, the rollers 2 are arranged in all the slits 7.

Thus, by making the inner and outer cages 13 and 23 have the slits 7, the diameter of the insertion side portion of the outer cage 3 is increased during assembly, and the insertion side portion of the inner cages 13 and 23 is expanded. The cages 13 and 23 can be inserted inside and outside the roller array while reducing the diameter. Therefore, the cages 13 and 23 can be deformed within the elastic region of the material, the cages 13 and 23 are less bent and deformed, accuracy deterioration due to the deformation can be prevented, and assembling property and accuracy are improved. be able to.
In addition, when the circumferential positions of the slits 7 of the inner and outer cages 13 and 23 are shifted from each other, the holding strength of the rollers 2 by the inner and outer cages 13 and 3 can be sufficiently secured.

In addition, in each embodiment shown in FIGS. 3-8, the cross-sectional shape of the outer holder | retainer 23 is good also as a cross-sectional shape shown in FIG. 11 or FIG.
In the example of FIG. 11, both the left and right edge portions 23 c of the inner diameter surface of the cage 23 are tapered. Other configurations are the same as those of the embodiment shown in FIGS.
Thus, by making the edge portion 23c of the inner diameter surface of the cage 23 into a tapered tapered shape, the cage 23 can be smoothly inserted to the outside of the roller array at the time of assembly. Is further improved. In addition, since both edge portions 23c of the inner diameter surface of the cage 23 are tapered and tapered, even if the cage 23 is inserted from any side edge to the outside of the roller arrangement, the insertion can be performed smoothly. Can do.

In the example of FIG. 12, the cage 23 has a shape in which the ring-shaped parts 6 on both sides are thicker toward the inner diameter side than the column part 5.
Other configurations are the same as those of the embodiment shown in FIGS. Also in this configuration, the functions and effects shown in the embodiments of FIGS. 13 to 8 can be obtained.

  In this way, by connecting the inner and outer cages 13 and 23 at one side thereof and integrating them with each other, it is easy to insert the inner and outer cages 13 and 23 into and out of the roller array during assembly. This can be done and the assembly is improved. Further, the side edges 13a, 23a opposite to the connecting portion 10 of the inner and outer cages 13, 23 are tapered and tapered, so that both the retainers 13, 23 are arranged in a roller arrangement from the opposite side to the connecting portion 10. The insertion can be performed smoothly when inserted to the outside.

  FIGS. 10A and 10B show still another embodiment of the present invention. The roller bearing of FIG. 10 (A) is the one in which the connecting portions 10 are provided at intervals of one roller 2 in the circumferential direction in the embodiment of FIG. 9, and the connecting portions 10 and the inner and outer cages 13, The window portion 11 surrounded by the ring-shaped portion 6 is a rectangle. Further, the roller bearing of FIG. 10 (B) is provided with a connecting portion 10 at intervals of two rollers 2 arranged in the circumferential direction in the embodiment of FIG. 9, and the connecting portion 10 is an inner cage. It is formed in a fan shape that tapers from the ring-shaped part 6 toward the outer cage ring-shaped part 6. Moreover, it is good also as a fan shape used as an expansion.

DESCRIPTION OF SYMBOLS 2 ... Roller 3 ... Cage 4 ... Pocket 5 ... Column part 7, 7A ... Slit 10 ... Connection part 13 ... Inside cage 23 ... Outside cage

Claims (14)

  A roller bearing that is used in an electric seat reclining device and supports a backrest so that an inclination angle can be adjusted, and includes two inner and outer cages each formed in a ring shape having a plurality of pockets arranged in the circumferential direction. A plurality of rollers held across the pockets of the cage, the inner cage holds the rollers from the inner diameter side between the rollers, and the outer diameter of the pillars is between the rollers. The outer cage has a smaller diameter than the pitch circle diameter of the roller arrangement, and the column portion between the pockets holds the rollers from the outer diameter side between the rollers, and the inner diameter of the column portion is a pitch circle of the roller arrangement. An electric seat reclining roller bearing having a larger diameter than a diameter.   2. A roller bearing for electric seat reclining according to claim 1, wherein the cross-sectional shape of the column portion of the outer cage is such that a portion on the inner diameter side of the outer diameter portion becomes a rectangle or a shape that narrows toward the inner diameter side.   The roller bearing for electric seat reclining according to claim 1 or 2, wherein the cage is made of synthetic resin.   The roller bearing for an electric seat reclining according to any one of claims 1 to 3, wherein the number of rollers is the same as that of the full roller type or is reduced by two or less. 5. The electric seat reclining roller bearing according to claim 1, wherein an outer diameter of the outer cage is 0.1 mm or more smaller than a minimum circumscribed circle diameter of the roller arrangement.
  The roller bearing for electric seat reclining according to any one of claims 1 to 5, wherein an inner diameter dimension of an outer cage is larger by 0.1 mm or more than a pitch circle diameter of a roller arrangement.   The roller bearing for electric seat reclining according to any one of claims 1 to 6, wherein an edge in a width direction on an inner diameter surface of an outer cage is tapered or tapered in a cross-section arc shape.   The electric seat according to any one of claims 1 to 7, wherein each of the inner and outer cages has a slit cut out from one side edge of each cage to the vicinity of the other side edge. Reclining roller bearing.   The electric seat reclining according to any one of claims 1 to 8, wherein either the inner or outer retainer has a slit cut out from one side edge to the vicinity of the other side edge. Roller bearing.   The roller bearing for electric seat reclining according to claim 9, wherein the slit is provided at a plurality of locations in a circumferential direction of the cage.   The roller bearing for electric seat reclining according to claim 9, wherein the slit is provided at a plurality of locations in a circumferential direction of the cage.   The roller bearing for electric seat reclining according to claim 10 or 11, wherein the circumferential positions of the slits of the inner and outer cages are shifted from each other.   The roller bearing for an electric seat reclining according to any one of claims 8 to 12, wherein the slit also serves as a pocket for holding the roller.   The roller bearing for an electric seat reclining according to any one of claims 1 to 13, wherein the inner cage and the outer cage are integrated with each other.

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