JP2020165444A - Pulley with dust cover - Google Patents

Abstract

To provide a pulley with a dust cover which makes water less likely to enter into a rolling bearing rotatably supporting a pulley body.SOLUTION: A pulley with a dust cover has a pulley body 4, a rolling bearing 5 which is provided fitting in an inner periphery of the pulley body 4, and a dust cover 6. The dust cover 6 has: an outer ring part 23 which is connected to an axial side surface 15 of the pulley body 4 so as to rotate integrally with the pulley body 4; and a cover body 24 which extends from the outer ring part 23 to the radial inner side, faces the rolling bearing 5 in an axial direction, and has an annular plate shape. The outer ring part 23 is formed with a dust discharge hole 26 which allows an interior and an exterior of the dust cover 6 to communicate so that dust is discharged from the inner side to the outer side of the outer ring part 23 by centrifugal force.SELECTED DRAWING: Figure 1

Description

The present invention relates to a pulley with a dust cover used by winding a transmission belt.

Auxiliary machinery of automobiles, such as alternators, car air conditioners, and water pumps, has a rotating shaft connected to the crankshaft of an engine by a transmission belt and is driven via the transmission belt. Here, the transmission belt is wound around each pulley such as the auxiliary machine pulley attached to the rotating shaft of the auxiliary machine and the idler pulley provided to secure the winding angle of the belt with respect to the auxiliary machine pulley, and these pulleys. By traveling between them, the rotation is transmitted from the crankshaft to the auxiliary equipment.

As the idler pulley, for example, the one shown in FIG. 4 of Patent Document 1 is known. This idler pulley has an annular pulley body having a belt receiving surface around which a transmission belt is wound, and a rolling bearing provided by being fitted to the inner circumference of the pulley body.

By the way, muddy water may infiltrate into the engine room of an automobile, or water injected by a high-pressure washer may infiltrate. At this time, if water enters the inside of the rolling bearing of the idler pulley, there arises a problem that the life of the rolling bearing is shortened.

Therefore, in order to prevent water from entering the rolling bearing of the idler pulley, a pulley with a dust cover may be used as the idler pulley. FIG. 7 shows an example of a conventional pulley with a dust cover. The pulley with a dust cover includes an annular pulley body 52 having a belt receiving surface 51 around which a transmission belt 51 is wound, a rolling bearing 53 fitted on the inner circumference of the pulley body 52, and a rolling bearing. It has a dust cover 54 provided so as to face the 53 in the axial direction. The dust cover 54 is fixed to a sleeve 56 inserted into the inner ring 55 of the rolling bearing 53.

JP-A-2015-64036

However, in the conventional pulley with a dust cover shown in FIG. 7, the dust cover 54 is connected to the side of the inner ring 55 of the pulley main body 52 and the inner ring 55, and the dust cover 54 is separated from the side of the pulley main body 52. The space sandwiched between the dust cover 54 and the rolling bearing 53 is open to the outside in the radial direction over the entire circumference. Therefore, when water is splashed from the outside in the radial direction, the water easily enters the inside of the dust cover 54. Further, in the conventional pulley with a dust cover shown in FIG. 7, when the pulley main body 52 is rotating, the dust cover 54 does not rotate and remains stationary, so that water once flows into the dust cover 54 and the rolling bearing 53. There is a problem that it is difficult for the water to be discharged when entering the space sandwiched between the bearings.

An object to be solved by the present invention is to provide a pulley with a dust cover that prevents water from entering the rolling bearing that rotatably supports the pulley body.

In order to solve the above problems, the present invention provides a pulley with a dust cover having the following configuration.
An annular pulley body with a belt receiving surface around which the transmission belt is wound, and
Rolling bearings fitted to the inner circumference of the pulley body and
In a pulley with a dust cover having a dust cover provided so as to face the rolling bearing in the axial direction.
The dust cover is
An outer ring portion connected to the axial side surface of the pulley body so as to rotate integrally with the pulley body,
It has an annular plate-shaped cover body that extends inward in the radial direction from the outer ring portion and faces the rolling bearing in the axial direction.
The outer ring portion is formed with dust discharge holes that communicate with each other inside and outside the dust cover so that dust is discharged from the inside to the outside of the outer ring portion by centrifugal force.
A pulley with a dust cover that is characterized by this.

In this way, since the dust cover is connected to the pulley body, the space between the dust cover and the rolling bearing is opened inward in the radial direction, and when water is splashed from the outside in the radial direction, The water does not easily get inside the dust cover. In addition, since the dust cover rotates when the pulley body is rotating, even if water once enters the space between the dust cover and the rolling bearing, the water moves radially outward due to centrifugal force. , It is discharged through the dust discharge hole formed in the outer ring portion of the dust cover. Therefore, it is possible to effectively prevent water from entering the rolling bearing.

The outer ring portion is formed in a cylindrical shape in which one end in the axial direction is connected to the axial side surface of the pulley body and the other end in the axial direction is connected to the cover body.
It is preferable to adopt a configuration in which the dust discharge hole is a through hole that penetrates the outer ring portion in the radial direction.

In this way, water that has moved radially outward in the space sandwiched between the dust cover and the rolling bearing can be reliably discharged by centrifugal force.

It is preferable to adopt a configuration in which the dust discharge holes have a pair of circumferential facing surfaces facing each other in the circumferential direction, and the pair of circumferential facing surfaces are all inclined to the same side with respect to the radial direction.

In this way, one of the pair of circumferentially opposed surfaces of the dust discharge holes prevents water from passing straight through the dust discharge holes in the radial direction, so that the pulley body is stopped. Occasionally, it is possible to prevent water from passing through the dust discharge holes from the radial outer side to the radial inner side and entering the inside of the dust cover.

In this case, the direction of inclination of the pair of circumferential facing surfaces is such that the circumferential facing surface on the rear side in the rotation direction of the pair of circumferential facing surfaces faces radially outward and the circumferential facing surface on the front side in the rotation direction. Is preferably oriented inward in the radial direction.

In this way, when the pulley body is rotating, water causes the dust discharge holes to flow in the radial direction by the guiding action of the circumferential facing surfaces on the rear side in the rotation direction of the pair of circumferential facing surfaces of the dust discharge holes. It is possible to effectively prevent the dust cover from entering the inside of the dust cover by passing through from the outside to the inside in the radial direction.

It is preferable that the dust cover further has a cylindrical inner ring portion extending from the radial inner end of the cover body toward the rolling bearing side.

By doing so, the gap between the dust cover and the rolling bearing is narrowed, so that it is possible to effectively prevent water from entering the inside from the outside of the dust cover.

The rolling bearing is incorporated into an outer ring fitted to the inner circumference of the pulley body, an inner ring provided coaxially inside the outer ring in the radial direction, and an annular space formed between the outer ring and the inner ring. It is preferable to employ a sealed bearing having a plurality of rolling elements and an annular sealing member fixed to the inner circumference of the outer ring so as to close the end opening on the dust cover side of the annular space.

In this way, it is possible to more effectively prevent water from entering the rolling bearing.

In the pulley with a dust cover of the present invention, since the dust cover is connected to the pulley body, the space between the dust cover and the rolling bearing is opened radially inward, and water is splashed from the radial outside. At that time, it is difficult for the water to get inside the dust cover. In addition, since the dust cover rotates when the pulley body is rotating, even if water once enters the space between the dust cover and the rolling bearing, the water moves radially outward due to centrifugal force. , It is discharged through the dust discharge hole formed in the outer ring portion of the dust cover. Therefore, it is possible to effectively prevent water from entering the rolling bearing.

Sectional drawing which shows the pulley with the dust cover of 1st Embodiment of this invention Sectional view taken along line II-II of FIG. Enlarged view of the vicinity of the dust discharge hole in FIG. Sectional drawing which shows the pulley with the dust cover of 2nd Embodiment of this invention. Sectional view along the VV line of FIG. Enlarged view of the vicinity of the dust discharge hole in FIG. Cross-sectional view showing a conventional pulley with a dust cover The figure which shows an example of the belt transmission device which incorporated the pulley with the dust cover of FIG.

FIG. 1 shows a pulley 1 with a dust cover according to a first embodiment of the present invention. The pulley 1 with a dust cover has an annular pulley body 4 having a belt receiving surface 3 around which a transmission belt 2 is wound, and a rolling bearing 5 provided by being fitted to the inner circumference of the pulley body 4. It has a bearing 5 and a dust cover 6 provided so as to face each other in the axial direction.

The rolling bearing 5 surrounds an outer ring 7 fitted to the inner circumference of the pulley body 4, an inner ring 8 coaxially provided inside the outer ring 7 in the radial direction, and an annular space formed between the outer ring 7 and the inner ring 8. On the inner circumference of the outer ring 7 so as to close the end opening on the side (left side in the figure) of the annular space between the outer ring 7 and the inner ring 8 and the plurality of balls 9 incorporated at intervals in the direction. On the inner circumference of the outer ring 7 so as to close the end opening on the side (right side in the figure) opposite to the dust cover 6 of the annular space between the outer ring 7 and the inner ring 8 and the fixed annular seal member 10. It is a bearing with a seal having an annular seal member 11 provided fixedly. The radial inner ends of the seal members 10 and 11 are in sliding contact with the outer circumference of the inner ring 8. Here, the ball 9 is used as a rolling element, but a cylindrical roller or a tapered roller may be used instead of the ball 9.

The pulley body 4 has a tubular rim portion 12 having a belt receiving surface 3 on the outer circumference, a tubular boss portion 13 that fits on the outer circumference of the outer ring 7, and a connecting portion 14 that connects the rim portion 12 and the boss portion 13. It consists of. The rim portion 12, the connecting portion 14, and the boss portion 13 are integrally molded with resin without any seams. The belt receiving surface 3 is a cylindrical surface (for example, a surface that receives the outer peripheral surface of the V-ribbed belt) here, but it can also be a surface having a plurality of peripheral grooves so as to receive the inner peripheral surface of the V-ribbed belt. The axial thickness of the connecting portion 14 is smaller than the axial width dimension of the rim portion 12 and smaller than the axial width dimension of the boss portion 13. The axial side surface 15 of the connecting portion 14 forms a recess recessed inward in the axial direction from the axial end portion of the rim portion 12 and the axial end portion of the boss portion 13.

A sleeve 16 is press-fitted into the inner circumference of the inner ring 8. The sleeve 16 is formed in a hollow tubular shape with both ends open. The sleeve 16 has a small outer diameter portion 17 that fits on the inner circumference of the inner ring 8 and a large outer diameter portion 19 that is provided on the small outer diameter portion 17 via the step portion 18. The step portion 18 supports the axial end surface of the inner ring 8. A headed bolt 20 is inserted into the sleeve 16. The headed bolt 20 has a screw shaft 21 and a head portion 22 having a diameter larger than that of the screw shaft 21 provided at one end of the screw shaft 21. The head 22 presses the axial end surface on the side opposite to the side supported by the sleeve 16 of the inner ring 8.

The dust cover 6 has an outer ring portion 23 connected to the axial side surface 15 of the pulley main body 4 so as to rotate integrally with the pulley main body 4, and a rolling bearing 5 and a shaft extending radially inward from the outer ring portion 23. It has an annular plate-shaped cover main body 24 facing in the direction, and a cylindrical inner ring portion 25 extending from the radial inner end of the cover main body 24 toward the rolling bearing 5. The outer ring portion 23, the cover main body 24, and the inner ring portion 25 are integrally molded with resin without any seams.

The outer ring portion 23 is formed in a cylindrical shape in which one end in the axial direction is connected to the axial side surface 15 of the connecting portion 14 of the pulley main body 4 and the other end in the axial direction is connected to the cover main body 24. The outer ring portion 23 is arranged between the rim portion 12 of the pulley main body 4 and the radial facing surfaces of the boss portion 13. The outer ring portion 23 and the pulley main body 4 can be connected by resin welding (heat welding, ultrasonic welding, vibration welding, etc.).

The cover body 24 faces the boss portion 13 of the pulley body 4 in the axial direction, and further faces the outer ring 7 and the seal member 10 of the rolling bearing 5 in the axial direction. Further, the cover main body 24 is arranged so as to be accommodated in the axial direction inside the rim portion 12 of the pulley main body 4. The cover body 24 has a structure in which dust such as water does not pass through (a structure in which there is no through hole for passing dust).

As shown in FIG. 2, in the outer ring portion 23, a dust discharge hole 26 communicating with the inside and outside of the dust cover 6 is provided in the circumferential direction so that dust is discharged from the inside to the outside of the outer ring portion 23 by centrifugal force. Multiple pieces are formed at intervals. The dust discharge hole 26 is a through hole that penetrates the outer ring portion 23 in the radial direction.

As shown in FIG. 3, the dust discharge hole 26 has a pair of circumferential facing surfaces 27 and 28 facing each other in the circumferential direction. The pair of circumferential facing surfaces 27 and 28 are both inclined to the same side with respect to the radial direction. In the direction of inclination of the pair of circumferential facing surfaces 27, 28, the circumferential facing surface 27 on the rear side in the rotation direction (left side in the figure) of the pair of circumferential facing surfaces 27, 28 is radially outside (upper side in the figure). ), And the circumferential facing surface 28 on the front side (right side in the figure) in the rotation direction faces the inside in the radial direction (lower side in the figure). The rotation direction of the pulley body 4 and the dust cover 6 is a counterclockwise direction when the dust cover 6 is viewed from the front (see FIG. 8).

The circumferential facing surface 27 on the rear side in the rotation direction (left side in the figure) is the opening on the radial outer side of the dust discharge hole 26 when the radial outer opening of the dust discharge hole 26 is projected straight inward. The entire inclination is such that it is projected onto the circumferential facing surface 27 on the rear side in the rotation direction (left side in the figure) (that is, the dust discharge hole 26 is straightly radially inward from the radial outside of the dust discharge hole 26). The region on the inner side in the radial direction from the outer ring portion 23 is inclined so as to be hidden by the circumferential facing surface 27 on the rear side in the rotation direction (left side in the figure).

In this pulley 1 with a dust cover, as shown in FIG. 1, since the dust cover 6 is connected to the pulley main body 4, the space sandwiched between the dust cover 6 and the rolling bearing 5 is opened radially inward. When water is splashed from the outside in the radial direction, it is difficult for the water to enter the inside of the dust cover 6. Further, since the dust cover 6 rotates when the pulley main body 4 is rotating, even if water once enters the space sandwiched between the dust cover 6 and the rolling bearing 5, the water is radially due to centrifugal force. It moves to the outside and is discharged through the dust discharge hole 26 formed in the outer ring portion 23 of the dust cover 6. Therefore, it is possible to effectively prevent water from entering the rolling bearing 5.

Further, in the pulley 1 with a dust cover, since the dust discharge hole 26 is a through hole that penetrates the outer ring portion 23 of the dust cover 6 in the radial direction, it is sandwiched between the dust cover 6 and the rolling bearing 5. Water that has moved outward in the radial direction can be reliably discharged by centrifugal force.

Further, as shown in FIG. 3, the pulley 1 with a dust cover discharges dust because the pair of peripheral facing surfaces 27 and 28 of the dust discharge holes 26 are all inclined to the same side with respect to the radial direction. One of the pair of circumferentially opposed surfaces 27, 28 of the holes 26 prevents water from passing straight through the dust discharge holes 26 in the radial direction. Therefore, when the pulley body 4 is stopped, it is possible to prevent water from passing through the dust discharge hole 26 from the outside in the radial direction to the inside in the radial direction and entering the inside of the dust cover 6.

Further, as shown in FIG. 3, the direction of inclination of the pair of circumferential facing surfaces 27, 28 is such that the circumferential facing surface 27 on the rear side in the rotation direction faces the radial outside, and the circumferential facing surface 28 on the front side in the rotation direction. When the pulley body 4 is rotating, water flows through the dust discharge hole 26 from the outside in the radial direction by the guiding action of the circumferential facing surface 27 on the rear side in the rotation direction. It is possible to effectively prevent the dust cover 6 from entering the dust cover 6 through the inside in the radial direction.

Further, in the pulley 1 with a dust cover, as shown in FIG. 1, the dust cover 6 has a cylindrical inner ring portion 25 extending from the radial inner end of the cover main body 24 toward the rolling bearing 5. The gap between the dust cover 6 and the rolling bearing 5 is narrow, and it is possible to effectively prevent water from entering the inside of the dust cover 6 from the outside.

Further, in the pulley 1 with a dust cover, as shown in FIG. 1, since the inner ring portion 25 of the dust cover 6 and the head portion 22 of the headed bolt 20 form a labyrinth, water flows into the rolling bearing 5. It is hard to take.

Further, since the pulley 1 with a dust cover employs a bearing with a seal as the rolling bearing 5, it is possible to more effectively prevent water from entering the rolling bearing 5.

4 to 6 show a pulley with a dust cover according to a second embodiment of the present invention. The parts corresponding to the first embodiment are designated by the same reference numerals, and the description thereof will be omitted.

The dust cover 6 is made of metal. Specifically, the outer ring portion 23, the cover main body 24, and the inner ring portion 25 of the dust cover 6 are integrally molded seamlessly by press molding a metal plate. One end of the outer ring portion 23 of the dust cover 6 in the axial direction is connected to the axial side surface 15 of the connecting portion 14 of the pulley body 4. This connection can be made by dissimilar material bonding (chemical bonding, laser bonding, plasma bonding, etc.).

FIG. 8 shows a belt transmission device incorporating the pulley 1 with a dust cover of the above embodiment. This belt transmission device includes a crank pulley 31 attached to the crankshaft 30 of the engine, a water pump pulley 33 attached to the rotating shaft 32 of the water pump, and an alternator pulley 35 attached to the rotating shaft 34 of the alternator. The pulley 1 with a dust cover, the power steering pulley 37 attached to the rotating shaft 36 of the power steering pump, the air conditioner pulley 39 attached to the rotating shaft 38 of the compressor of the air conditioner, and the transmission hung on each of these pulleys. It has a belt 2 and a tension adjusting device 40 that keeps the tension of the transmission belt 2 within an appropriate range.

The crank pulley 31 is driven clockwise, and the transmission belt 2 also travels clockwise accordingly. The transmission belt 2 has a V-ribbed belt (a plurality of V-shaped ridges extending in the traveling direction of the belt are formed adjacent to the inner peripheral surface of the belt in a direction orthogonal to the traveling direction of the belt, and the outer peripheral surface of the belt is flat. It is a face). The pulley 1 with a dust cover is an idler pulley provided to secure the winding angle of the belt with respect to the alternator pulley 35, and the outer peripheral surface of the transmission belt 2 is wound around the pulley 1.

It should be considered that the embodiments disclosed this time are exemplary in all respects and not restrictive. The scope of the present invention is shown by the scope of claims rather than the above description, and is intended to include all modifications within the meaning and scope equivalent to the scope of claims.

1 Pulley with dust cover 2 Transmission belt 3 Belt receiving surface 4 Pulley body 5 Rolling bearing 6 Dust cover 7 Outer ring 8 Inner ring 9 Ball 10 Sealing member 15 Axial side surface 23 Outer ring part 24 Cover body 25 Inner ring part 26 Dust discharge hole 27 , 28 Circumferential facing surface

Claims (6)

An annular pulley body (4) having a belt receiving surface (3) around which the transmission belt (2) is wound, and an annular pulley body (4).
A rolling bearing (5) fitted to the inner circumference of the pulley body (4) and
In a pulley with a dust cover having a dust cover (6) provided so as to face the rolling bearing (5) in the axial direction.
The dust cover (6) is
An outer ring portion (23) connected to the axial side surface (15) of the pulley body (4) so as to rotate integrally with the pulley body (4).
It has an annular plate-shaped cover body (24) extending inward in the radial direction from the outer ring portion (23) and facing the rolling bearing (5) in the axial direction.
The outer ring portion (23) has a dust discharge hole (26) communicating with the inside and outside of the dust cover (6) so that dust is discharged from the inside to the outside of the outer ring portion (23) by centrifugal force. Is formed,
A pulley with a dust cover that is characterized by this. The outer ring portion (23) is formed in a cylindrical shape in which one end in the axial direction is connected to the axial side surface (15) of the pulley body (4) and the other end in the axial direction is connected to the cover body (24). Being done
The dust discharge hole (26) is a through hole that penetrates the outer ring portion (23) in the radial direction.
The pulley with a dust cover according to claim 1. The dust discharge hole (26) has a pair of circumferential facing surfaces (27, 28) facing each other in the circumferential direction, and the pair of circumferential facing surfaces (27, 28) are the same in the radial direction. Inclined to the side,
The pulley with a dust cover according to claim 1 or 2. In the direction of inclination of the pair of circumferential facing surfaces (27, 28), the circumferential facing surface (27) on the rear side in the rotational direction of the pair of circumferential facing surfaces (27, 28) is radially outside. The pulley with a dust cover according to claim 3, wherein the circumferential facing surface (28) on the front side in the direction and rotation direction faces inward in the radial direction. Any of claims 1 to 4, wherein the dust cover (6) further has a cylindrical inner ring portion (25) extending from the radial inner end of the cover body (24) toward the rolling bearing (5). Pulley with dust cover described in Cylinder. The rolling bearing (5) includes an outer ring (7) fitted to the inner circumference of the pulley body (4), an inner ring (8) coaxially provided inside the outer ring (7) in the radial direction, and the outer ring. A plurality of rolling elements (9) incorporated in the annular space formed between the inner ring (7) and the inner ring (8) and the end opening on the dust cover (6) side of the annular space are closed. A bearing with a seal having an annular sealing member (10) fixed to the inner circumference of the outer ring (7).
The pulley with a dust cover according to any one of claims 1 to 5.

Images