JP2020051515A - Rolling bearing with pulley - Google Patents

Abstract

To enable water droplets to be discharged to the outside smoothly before the water droplets reach a seal of a rolling bearing even if the water droplets enter into a space between the rolling bearing and a dust cover.SOLUTION: A rolling bearing with a pulley includes: a rolling bearing 10 having a seal 17; a pulley 30 having an inner cylinder part 33 into which the rolling bearing 10 is incorporated; and a dust cover 40 which covers both side surfaces of the rolling bearing 10. A water droplets receiving step part 41 which inhibits the water droplets from being guided to the seal 17 is provided on a side surface at the rolling bearing 10 side of the dust cover 40.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a rolling bearing with a pulley.

  In belt transmissions that drive automotive accessories such as alternators and compressors, idler pulleys guide the movement of the belt, or hydraulic tensioners push the tension pulley against the belt to absorb fluctuations in belt tension. The tension is kept constant.

  Since the idler pulley and the tension pulley as described above are assembled to be exposed to the outside, as shown in FIG. 7, a rolling bearing 2 that rotatably supports the pulley 1 is provided with a seal 3 to prevent foreign matter from entering the inside of the bearing. Rolling bearings with seals to prevent intrusion are commonly used.

  However, when foreign matter such as muddy water is prevented from entering the bearing only by the seal 3 incorporated in the sealed rolling bearing, the seal 3 is easily damaged by contact with the foreign matter, and there is a problem in durability. Dust covers 4 are provided on both sides of a rolling bearing to prevent the seal 3 from being damaged and to improve the sealing performance of the rolling bearing (Patent Documents 1 and 2).

JP 2015-17666 A JP-A-2017-26034

  By the way, the dust cover 4 is mounted so as to cover the rolling bearing 2 and both side surfaces of the rolling bearing 2 and has a function of preventing water from splashing on the rolling bearing 2. When water enters between the dust cover 4 and the dust cover 4 as shown by an arrow in the enlarged view of FIG. 8, the water droplets are guided along the side surface of the dust cover 4 toward the seal 3 of the rolling bearing 2, There is a concern that the sealing performance of the rolling bearing 2 is adversely affected.

  In view of the above, the present invention is intended to improve the sealing performance of a rolling bearing by smoothly discharging the water to the outside even if water enters between the rolling bearing and the dust cover.

  In order to solve the above-mentioned problems, the present invention provides a rolling bearing having a seal, a pulley having an inner cylindrical portion in which the rolling bearing is incorporated, and a dust cover including a dust cover that covers both side surfaces of the rolling bearing. The rolling bearing is characterized in that a water drop receiving step is provided on a side surface of the dust cover on a side of the rolling bearing, which obstructs a guide of water drops to the seal.

  As described above, according to the present invention, even if water enters between the rolling bearing and the dust cover, the water droplets are provided on the side surface of the dust cover on the rolling bearing side before reaching the seal of the rolling bearing. The roller bearing temporarily stops when hitting the water drop receiving step portion protruding in the axial direction, and is discharged to the outside along the outer peripheral surface of the water drop receiving step portion, so that the sealing performance of the rolling bearing is improved.

It is a longitudinal section of the rolling bearing with a pulley concerning this invention. FIG. 2 is a partially enlarged longitudinal sectional view of FIG. 1. It is a longitudinal cross-sectional view of the embodiment in which a depression is provided on the outer peripheral surface of the water drop receiving step. It is a longitudinal cross-sectional view of the embodiment in which the ridge is provided on the outer diameter side of the water drop receiving step. It is a longitudinal section of a rolling bearing with a pulley of a conventional example. FIG. 6 is a partially enlarged longitudinal sectional view of FIG. 5.

  Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

  As shown in FIG. 1, the bearing with a pulley includes a double-row rolling bearing 10, a pulley 30 rotatably supported by the double-row rolling bearing 10, and a pair of rolls provided on both sides of the rolling bearing 10. And a dust cover 40.

  The double row rolling bearing 10 incorporates a plurality of balls 15 between a raceway groove 12 formed on an inner diameter surface of an outer ring 11 and a raceway groove 14 formed on an outer diameter surface of an inner ring 13, and holds the balls 15. A ball bearing with a seal, which is held by a vessel 16 and has openings at both ends of a bearing space formed between opposed portions of the outer ring 11 and the inner ring 13, sealed by a pair of seals 17. It should be noted that the present invention is not limited to the double row rolling bearing, but may be a single row rolling bearing. In the following description, a direction along the central axis of the rolling bearing 10 is referred to as an “axial direction”, a direction orthogonal to the central axis is referred to as a “radial direction”, and a direction along an arc centered on the central axis is referred to as a “circumferential direction”. Call. 1 and 2, the right side of the drawing is referred to as “one side in the axial direction”, and the left side of the drawing is referred to as “the other side in the axial direction”.

  Here, as shown in FIG. 2, the outer peripheral portion of the seal 17 is supported by a seal mounting groove 18 formed at the end of the inner diameter surface of the outer ring 11. An inward lip 19 is formed on an inner peripheral portion of the seal 17, and the inward lip 19 elastically contacts an inner wall of a seal groove 20 formed at an end of an outer diameter surface of the inner ring 13.

  As shown in FIG. 1, the bearing with a pulley is fixed to an engine block 50 by bolts 22.

  A screw hole 51 is formed in the engine block 50, and the sleeve 52 is fixed by tightening the bolt 22 screwed into the screw hole 51.

  The sleeve 52 has a flange 53 at one end. The flange 53 faces the engine block 50, and a washer 54 is incorporated between the facing portions. The bolt 22 is inserted from the inside of the sleeve 52 into the center hole of the washer 54 and is screwed into the screw hole 51.

  A double-row rolling bearing 10 is fitted to the outside of the sleeve 52, and the pulley 30 is rotatably supported by the rolling bearing 10.

  The pulley 30 includes a belt guide wheel 31 around which a belt is wound, an annular plate portion 32 provided at the center of the inner surface of the belt guide wheel 31, and an inner cylindrical portion provided at the inner diameter portion of the annular plate portion 32. A pair of annular spaces 34 are provided between the outer diameter surface of the inner cylindrical portion 33 and the inner peripheral both ends of the belt guide wheel 31 on both axial sides of the annular plate portion 32.

  The inner circumference of the inner cylindrical portion 33 is a bearing fitting surface 35, into which the outer diameter surface of the outer ring of the rolling bearing 10 is press-fitted. Further, an inward flange 36 is provided at one end of the inner cylindrical portion 33, and the amount of press-fit of the double-row rolling bearing 10 is regulated by the inward flange 36.

  The pulley 30 is a metal-turned product here, but may be a metal press-formed product or a resin-formed product.

  Further, as the belt guide wheel 31, a belt guide wheel having an outer diameter surface formed of a cylindrical surface 31a is shown here, but a V-belt guide member having a plurality of V grooves formed on the outer diameter surface is shown. There may be.

  A pair of dust covers 40 is provided on both axial sides of the double-row rolling bearing 10. Each of the pair of dust covers 40 is annular. The dust cover 40 on one side in the axial direction is fixed by being clamped from both sides in the axial direction by the inner peripheral surface of the inner ring 13 and the head 22 a of the bolt 22. The dust cover 40 on the other side in the axial direction is fixed by being sandwiched between the flange 53 of the sleeve 52 and the inner ring 13 of the rolling bearing 10 from both sides in the axial direction. The axially outer side surface 40 a of the dust cover 40 is located axially inward of the axial end surface 31 b of the belt guide wheel 31.

  On the side surface 40b of the dust cover 40 on the side of the rolling bearing 10 (inside in the axial direction), a water droplet receiving step portion 41 protruding in the axial direction is provided. The water drop receiving step portion 41 has a function of obstructing the guide of water drops to the seal 17. Specifically, the water drop step receiving portion 41 protrudes in the axial direction from a portion of the side surface 40b facing the seal 7. The outer diameter surface of the water droplet receiving step portion 41 is desirably an inclined surface that is parallel to the axial direction or has a large diameter on the rolling bearing 10 side and a small diameter toward both sides so that the hitting water droplet is not guided to the rolling bearing 10 side. . In the present embodiment, the outer diameter surface of the water droplet receiving step portion 41 is a flat surface extending parallel to the axial direction.

  The inner diameter side plate portion 42 on the inner diameter side than the water droplet receiving step portion 41 extends in parallel in the radial direction and is sandwiched between the inner ring 13 and the bolt 22. The outer diameter side plate portion 43 on the outer diameter side from the water drop receiving step portion 41 extends in parallel to the radial direction. The outer diameter side plate portion 43 extends to a position where the outer diameter side edge of the outer diameter side plate portion 43 faces (in substantially the radial center of) the annular plate portion 32 in the axial direction. The outer diameter side plate portion 43 is opposed to the inner peripheral surface of the belt guide wheel 31 with a small gap therebetween, so that water does not easily enter between the pair of dust covers 40 and the rolling bearing 10.

  The width of the water droplet receiving step portion 41 provided on the inner diameter portion of the pair of dust covers 40, which protrudes in the axial direction, is such that water droplets that have entered between the pair of dust covers 40 and the rolling bearings 10 as shown in FIG. Is formed to be longer than the thickness of the pair of dust covers 40 so that the dust cover can be sufficiently received. The water droplets that have hit the water drop receiving step 41 are discharged to the outside along the outer diameter surface of the water drop receiving step 41.

  In order to enhance the effect of discharging water droplets, it is preferable that the radial position of the water droplet receiving step portion 41 be set as far as possible on the outer diameter side of the dust cover 40, and specifically, the pitch circle of the balls 15 of the rolling bearing 10 It is preferable that the diameter is set to be equal to or larger than the diameter (a position overlapping the pitch circle diameter of the ball 15 or a position outside the pitch circle diameter).

  FIG. 3 shows a dust cover 40 used in another embodiment of the present invention.

  The dust cover 40 of this embodiment is provided with a depression 44 on the outer peripheral surface of the water drop receiving step 41.

  By providing the depression 44 on the outer peripheral surface of the water droplet receiving step 41, the effect of receiving the water droplet is improved by this depression, and the effect of discharging the water along the depression 44 to the outside is also improved.

    FIG. 4 shows a dust cover 40 used in another embodiment of the present invention.

  The dust cover 40 of this embodiment is provided with an annular ridge 45 that protrudes in the axial direction at a position on the outer diameter side of the water drop receiving step 41 on the side surface on the rolling bearing 10 side.

  By providing an annular ridge 45 projecting in the axial direction at a position on the outer diameter side of the water drop receiving step 41, the amount of water entering between the rolling bearing 10 and the dust cover 40 can be reduced. Therefore, the sealing performance of the rolling bearing 10 can be further improved.

  The present invention is not limited to the above-described embodiment at all, and it is needless to say that the present invention can be embodied in various forms without departing from the gist of the present invention. And further includes the equivalent meaning described in the claims and all the changes within the scope.

10: Rolling bearing 17: Seal 30: Pulley 40: Dust cover 41: Water drop receiving step 44: Depression 45: Convex ridge

Claims (4)

Rolling bearing having a seal, a pulley having an inner cylindrical portion incorporating the rolling bearing, and a rolling bearing with a pulley including a dust cover that covers both side surfaces of the rolling bearing,
A rolling bearing with a pulley, characterized in that a water drop receiving step is provided on a side surface of the dust cover on the side of the rolling bearing, which inhibits the guide of water drops to the seal.   The bearing with a pulley according to claim 1, wherein the water drop receiving step has a flat surface extending parallel to the axial direction.   The rolling bearing with a pulley according to claim 1, wherein a depression is provided on an outer peripheral surface of the water drop receiving step.   The pulley according to any one of claims 1 to 3, wherein a convex portion is provided on a side surface of the dust cover on the rolling bearing side, the convex portion being located on an outer diameter side of the water drop receiving step portion. With rolling bearing.

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