WO2020090484A1

WO2020090484A1 - Rolling bearing with pulley

Info

Publication number: WO2020090484A1
Application number: PCT/JP2019/040786
Authority: WO
Inventors: 櫻井　武仁
Original assignee: Ntn株式会社
Priority date: 2018-10-31
Filing date: 2019-10-17
Publication date: 2020-05-07
Also published as: JP2020070860A

Abstract

The present invention addresses the problem of preventing an increase in the torque of a rolling bearing with a pulley, and preventing the infiltration of muddy water, etc. into the rolling bearing. The roller bearing with a pulley is provided with a slinger (8) that is positioned outside in the axial direction of a seal member (7) installed at both ends of the inner peripheral surface of an outer ring (3) and that is installed at both ends of the outer peripheral surface of an inner ring (4), a seal lip (13) that slidingly contacts the outer peripheral surface of the inner ring (4), and an axial lip that slidingly contacts a side surface of the slinger (8) which faces the seal member (7), wherein: the axial lip comprises a first axial lip (16a) that expands in diameter toward the outside in the axial direction, and a second axial lip (16b) that contracts in diameter toward the outside in the axial direction; the first and second axial lips (16a, 16b) contact the slinger (8) in a state in which the rotation of the outer ring (3) is stopped; and in a state in which the outer ring (3) is rotating at high speed, the first axial lip (16a) is deformed to the outside in the radial direction by a centrifugal force so that the first axial lip does not contact the slinger (8).

Description

Rolling bearing with pulley

The present invention relates to a rolling bearing with a pulley that can prevent foreign matter such as water, mud, and dust from entering the inside of a rolling bearing that rotatably supports a pulley.

Rolling bearings with pulleys are used, for example, to drive automotive engine peripheral accessories such as idler pulleys and tension pulleys.Because it is an assembly that is exposed to the outside, the inside of rolling bearings that rotatably support the pulleys is In addition, in order to prevent foreign matter such as water, mud, and dust from entering, a sealing device that covers the outer ring and the inner ring with an annular seal is provided.

In this type of rolling bearing with pulley, the inner ring and the outer ring rotate relative to each other, so the seal cannot be completely fixed to the outer ring and the inner ring.

Therefore, the outer circumference of the seal is fixed to the outer ring, a seal lip is provided on the inner circumference of the seal, and this seal lip is brought into sliding contact with the inner ring to allow relative rotation of the inner ring and the outer ring.

For rolling bearings with idler pulleys that are used at high speeds, the seal lip must be a light contact type with less interference to prevent heat generation in the sliding parts of the seal. Further, since the seal fixed to the outer ring that rotates at high speed also rotates at high speed, the seal lip is deformed by the centrifugal force of rotation, and the interference of the seal lip is further reduced, and the sealing performance is deteriorated.

Therefore, it cannot be said that the sealing between the outer ring and the inner ring is sufficient to seal against water and dust from the outside, and water and dust are prevented from entering the inside of the bearing from between the seal lip and the inner ring. Therefore, it is difficult to install a shield plate called a slinger on the outside of the seal to prevent water and dust from directly contacting the seal lip and to prevent water and dust from entering between the seal and slinger of the bearing. It is made to fly to the outside by the centrifugal force during rotation.

Also, if the interference between the seal lip and the inner ring is increased in order to increase waterproofness, the torque will increase, which impairs high-speed rotation performance.

Furthermore, if the seal lip bends and deforms toward the outer diameter side due to the centrifugal force due to rotation, the contact state between the seal lip and the inner ring changes, and there is a problem that the waterproofness decreases.

Conventionally, in order to solve such a problem, as shown in FIG. 7, a side surface on the slinger 105 side of a seal body 110 having a seal lip 111 that slides in contact with a portion 105a parallel to the inner peripheral side axis of the slinger 105 is provided. , A ring-shaped axial lip 112 that expands outward in the axial direction is formed, and the axial lip 112 is brought into sliding contact with a portion 105b perpendicular to the axis of the slinger 105 to seal foreign matter such as water or dust. A method has been proposed in which the path reaching the periphery of the lip 111 is closed to improve the waterproof and dustproof properties of the bearing and to improve the sealing performance of the bearing (Patent Document 1).

However, in a rolling bearing with a pulley that rotates the outer ring, the seal fixed to the outer ring rotates with the outer ring, and therefore receives centrifugal force due to rotation. In the configuration in which the axial lip 112 expands toward the outer diameter side toward the outside of the bearing as described in Patent Document 1, centrifugal force pulls the axial lip 112 toward the outer diameter side during high speed rotation of the bearing. As a result, a gap may be formed between the axial lip 112 and the vertical portion 105b of the slinger 105, and it is conceivable that foreign matter such as water or dust may enter the inside of the bearing through this gap.

Patent Document 2 discloses a rolling bearing sealing device that prevents deterioration of sealing performance due to a gap between the axial lip 112 and the vertical portion 105b of the slinger 105 during high-speed rotation.

In the rolling bearing sealing device disclosed in Patent Document 2, as shown in FIG. 8, an axial lip 122 is formed on the side surface 121 of the rolling bearing seal 120 toward the slinger 130. Then, at the tip of the axial lip 122, a cone-shaped first sliding contact portion 123 that expands in diameter toward the outside of the bearing and is brought into contact with the slinger 130 when the rotation of the bearing is stopped, and faces the outside of the bearing. And a second slidable contact portion 124 having an inverted conical shape that is in non-contact with the slinger 130 when the bearing is in a rotation stopped state. The second slidable contact portion 124 of the axial lip 122 is In the high speed rotation state, it is brought into contact with the convex portion 131 of the slinger 130 by the action of centrifugal force. In FIG. 8, reference numeral 140 indicates the outer ring of the rolling bearing, and reference numeral 150 indicates the inner ring of the rolling bearing.

Japanese Patent Laid-Open No. 2004-11732 JP, 2010-25251, A

The rolling bearing sealing device disclosed in Patent Document 2 has a second sliding contact with the slinger 130 even if the sealing property is deteriorated by the centrifugal force acting on the first sliding contact portion 123 at the time of high speed rotation and muddy water enters. The portion 124 can prevent the infiltration of muddy water into the interior.

However, in the rolling bearing sealing device disclosed in Patent Document 2, the second sliding contact portion 124 is not in contact with the slinger when the operation of the bearing is stopped, so that the first sliding contact portion 123, The muddy water that has entered the space surrounded by the 2 sliding contact portion 124 and the slinger 130 enters the inside of the bearing, which causes rusting, seizure, and other troubles in the bearing.

Therefore, an object of the present invention is to prevent the intrusion of muddy water or the like into the inside of the rolling bearing while preventing the torque of the rolling bearing with a pulley from increasing.

In order to solve the above problems, the present invention has an outer ring raceway surface on an inner peripheral surface, an outer ring having a pulley mounted on an outer peripheral surface, an inner ring having an inner ring raceway surface on an outer peripheral surface, and the outer ring raceway surface. A plurality of rolling elements that are rotatably arranged between the inner ring raceway surface, a seal member attached to both end portions of the inner peripheral surface of the outer ring, and located on the outer side in the axial direction of the seal member, A slinger attached to both ends of the outer peripheral surface of the inner ring, the seal member, a seal lip slidingly contacting the outer peripheral surface of the inner ring, and an axial lip slidingly contacting the side surface of the slinger facing the seal member. In the rolling bearing with a pulley, the axial lip includes a first axial lip that expands outward in the axial direction and a second axial lip that decreases outward in the axial direction. The allip and the second axial lip contact the slinger in a state where the rotation of the outer ring is stopped, and when the outer ring is rotating at a high speed, the first axial lip is deformed radially outward by a centrifugal force. Characterized by being in non-contact with the slinger.

A state in which the slinger is inclined such that a radially outer portion thereof extends outward in the axial direction from a contact position with the second axial lip, and the first axial lip has a rotation of the outer ring stopped at this inclined portion. It can be configured to contact with each other.

By making the thickness of the first axial lip 0.2 to 1 times the thickness of the second axial lip, the first axial lip is easily deformed radially outward by centrifugal force.

Further, it is desirable that the angle θ between the first axial lip and the seal member be specified in the range of 10 ° to 80 °.

As described above, according to the present invention, since the first axial lip and the second axial lip are in contact with the slinger in a state where the rotation of the outer ring is stopped, water, dust, etc. may be present between the seal member and the slinger. Is hard to enter. Then, during high speed operation, the first axial lip is deformed radially outward due to centrifugal force and does not come into contact with the slinger. However, even if muddy water enters between the first axial lip and the slinger, it does not contact the second axial lip. The contact of the slinger prevents further infiltration of muddy water. Further, since the seal member is rotating at a high speed, the muddy water attached to the seal member is blown outward in the radial direction by the centrifugal force and discharged to the outside of the bearing. At this time, even if the second axial lip is deformed by the centrifugal force and the pressing force against the slinger increases, the first axial lip is not in contact with the slinger, so that the torque increase is suppressed.

It is a longitudinal section of a rolling bearing with a pulley concerning this invention. It is an expanded longitudinal cross-sectional view which shows the rolling bearing part of FIG. 1 in the state where rotation of the outer ring has stopped. FIG. 2 is an enlarged vertical sectional view showing a rolling bearing portion of FIG. 1 in a state where the outer ring is rotating at a high speed. FIG. 2 is an enlarged vertical sectional view showing a seal member and a slinger of FIG. 1. It is a reference drawing which shows the case where the angle with respect to the seal member of a 1st axial lip is small. It is a reference drawing showing a case where the angle of the 1st axial lip to a seal member is large. It is a partially enlarged view of a prior art example. It is a partially expanded view of another conventional example.

Embodiments of the present invention will be described below with reference to the accompanying drawings.

As shown in FIG. 1, a rolling bearing with a pulley has a rolling bearing 1 and a pulley 2 rotatably supported by the rolling bearing 1.

As shown in FIGS. 1 to 3, the rolling bearing 1 has an outer ring raceway surface 3a on the inner circumferential surface, an outer ring 3 on which a pulley 2 is mounted on the outer circumferential surface, and an inner ring raceway surface 4a on the outer circumferential surface. 4, a plurality of rolling elements 5 rotatably arranged between the outer ring raceway surface 3a and the inner ring raceway surface 4a, and a cage 6 for holding the plurality of rolling elements 5 at predetermined intervals. Become. Although the embodiment shown in FIGS. 1 to 3 is a deep groove ball bearing that uses balls as the rolling elements 5, it may be a cylindrical roller bearing that uses cylindrical rollers as the rolling elements 5. In the following description, in the rolling bearing 1, the direction along the central axis of the rolling bearing 1 is “axial direction”, the direction orthogonal to the central axis is “radial direction”, and the arc around the central axis is The direction is called “circumferential direction”.

Both end openings of the bearing opening formed between the facing portions of the outer ring 3 and the inner ring 4 are located on the seal member 7 mounted on both end portions of the inner peripheral surface of the outer ring 3 and on the outer side in the axial direction of the seal member 7. However, the inner ring 4 is sealed by the slinger 8 mounted on both ends of the outer peripheral surface of the inner ring 4.

As shown in FIGS. 2 to 4, the seal member 7 is an annular member in which the outer side of the bearing of a metal cored bar 9 is covered with a rubber covering portion 10. A fixing portion 11 for attaching the seal member 7 to the outer ring 3 is formed. Then, the fixed portion 11 is mounted in the seal groove 12 provided on the inner diameter surface of the outer ring 3, and the seal member 7 is fixed to the inner diameter surface of the outer ring 3.

A seal lip 13 is formed on the inner peripheral edge of the seal member 7 inside the bearing, and the seal lip 13 elastically contacts the inner side wall 14a of the seal groove 14 formed at the end of the outer diameter surface of the inner ring 4. ing. When the seal member 7 rotates at high speed together with the outer ring 3, the seal lip 13 rotates at high speed while slidingly contacting the inner side wall 14 a of the seal groove 14. Therefore, the seal lip 13 is in light contact with the inner wall 14a.

A cylindrical land portion 15 is formed outside the seal groove 14 formed at the end of the outer diameter surface of the inner ring 4, and the slinger 8 is attached to the land portion 15.

This slinger 8 is an annular metal plate. The slinger 8 is formed with a cylindrical portion 8a on the inner peripheral side, the inner peripheral end of which is bent into a cylindrical shape toward the inside of the rolling bearing 1. The slinger 8 is fixed to the inner ring 4 by press-fitting the cylindrical portion 8 a into the land portion 15 on the outer diameter side of the inner ring 4.

The outer end of the cylindrical portion 8a of the slinger 8 is bent toward the outer diameter side to form a flange 8b that faces the side surface of the seal member 7 in the axial direction. The flange 8b includes a vertical portion 8c that extends perpendicularly from the outer end of the cylindrical portion 8a to the outer side in the radial direction from the outer side in the radial direction, and an axial outer side and a radial outer side from the outer end of the vertical portion 8c. And an inclined portion 8d extending obliquely toward.

The covering portion 10 for covering the core metal 9 of the seal member 7 is formed in a flat surface at a portion facing the flange 8b of the slinger 8, and is formed at a substantially central portion in the radial direction of the flat surface toward the outer side in the axial direction. A first axial lip 16a that expands in diameter and a second axial lip 16b that decreases in diameter axially outward are formed on the inner diameter side of the first axial lip 16a. The first axial lip 16a extends from the axially outer end surface of the covering portion 10 slightly inward of the ball PCD toward the axially outer side and the radially outer side. The first axial lip 16a is in contact with the inclined portion 8d when the bearing is not rotating. The second axial lip 16b extends inward in the axial direction and inward in the radial direction from a portion of the axially outer end surface of the covering portion 10 that axially faces the boundary portion between the vertical portion 8c and the inclined portion 8d. .. When the bearing is not rotating, the second axial lip 16b is in contact with the vertical portion 8c.

The first axial lip 16a and the second axial lip 16b contact the inclined portion 8d of the flange 8b of the slinger 8 in a state where the rotation of the outer ring 3 is stopped, and when the outer ring 3 rotates at a high speed, The first axial lip 16a is formed so as to be radially outwardly deformed by centrifugal force so as not to come into contact with the flange 8b of the slinger 8. Then, the first axial lip 16a is deformed radially outward by centrifugal force when the outer ring 3 is rotating at a high speed, and is not in contact with the flange 8b of the slinger 8.

The flange 8b of the slinger 8 is formed such that the inner diameter side thereof is formed in a vertical surface perpendicular to the axis of the rolling bearing 1, the second axial lip 16b contacts the vertical surface, and the second axial lip 16b contacts the vertical surface. The radially outer portion of the surface is formed as an inclined surface that spreads outward in the axial direction, and the outer diameter end of the first axial lip 16a contacts the inclined surface.

The angle θ between the first axial lip 16a and the flat surface of the covering portion 10 of the seal member 7 is set to 10 ° to 80 °, preferably 40 ° to 60 °. When the angle is smaller than 40 °, the contact portion between the first axial lip 16a and the inclined surface of the flange 8b of the slinger 8 is on the outer diameter side of the inclined surface of the flange 8b, as shown in FIG. The slinger 8 and the outer ring 3 may interfere with each other. When the angle is larger than 60 °, the contact portion between the first axial lip 16a and the inclined surface of the flange 8b of the slinger 8 is on the inner diameter side of the inclined surface of the flange 8b, as shown in FIG. The flange 8b of the slinger 8 has to be formed so as to spread outward in the axial direction, and the size in the axial direction increases.

As described above, the first axial lip 16a is in contact with the inclined surface of the flange 8b of the slinger 8 that is inclined outward in the radial direction, and during high speed rotation, the first axial lip 16a does not hit and smoothly. The flange 8b is not in contact with the flange 8b. That is, during high speed operation, the first axial lip 16a is deformed radially outward by the centrifugal force and is not in contact with the flange 8b of the slinger 8. The second axial lip 16b does not come into non-contact with the flange 8b of the slinger 8 even if it is deformed radially outward by the centrifugal force. Therefore, even if muddy water enters between the first axial lip 16a and the flange 8b of the slinger 8, contact of the second axial lip 16b and the flange 8b of the slinger 8 prevents muddy water from further entering the inside. Further, since the seal member 7 is rotating at a high speed, the muddy water attached to the seal member 7 is blown outward in the radial direction by the centrifugal force and discharged to the outside of the bearing. At this time, even if the second axial lip 16b is deformed by the centrifugal force and the pressing force of the slinger 8 against the flange 8b increases, the first axial lip 16a does not contact the flange 8b of the slinger 8. Torque increase is suppressed.

At the time of high speed rotation, the thickness of the first axial lip 16a is smaller than that of the second axial lip 16b so that the first axial lip 16a can be easily deformed radially outward by centrifugal force. It is desirable to form it to 0.2 to 1 times the thickness.

The inner ring 4 of the rolling bearing 1 is non-rotatably supported by screwing a bolt 19 inserted therein into a screw hole 18 formed on the shaft end surface of the pulley shaft 17.

Here, as shown in FIG. 1, the bolt 19 is provided with a large-diameter shaft portion 19b at an end portion of a screw shaft 19a, a flange 19c at an end portion of the large-diameter shaft portion 19b, and an end surface of the flange 19c. A head portion 19d is provided, the large-diameter shaft portion 19b is fitted to the inner ring 4 of the rolling bearing 1, and the screw shaft 19a is screwed into the screw hole 18 of the pulley shaft 17 to tighten the inner ring. 4 is clamped and fixed from both sides by the flange 19c and the shaft end surface of the pulley shaft 17.

The pulley 2 has a belt guide wheel 22 on its outer peripheral portion, an annular flange 23 is formed on the inner diameter surface of the belt guide wheel 22, and a boss portion 24 is provided on the inner diameter portion of the annular flange 23. Further, an inward flange 25 is provided at one end of the boss portion 24, and an outer surface of the inward flange 25 is a tapered surface 26.

The pulley 2 is made of resin and is integrally molded with the outer diameter surface of the outer ring 3. In order to prevent relative rotation between the outer ring 3 and the pulley 2, the outer diameter surface of the outer ring 3 is knurled. I am giving it. Further, the pulley 2 may be a metal molded product or a metal turned product.

The present invention is not limited to the embodiments described above, and it is needless to say that the present invention can be implemented in various forms without departing from the gist of the present invention. And the equivalent meanings set forth in the claims, and all modifications within the scope.

1: Rolling bearing 2: Pulley 3: Outer ring 3a: Outer ring raceway surface 4: Inner ring 4a: Inner ring raceway surface 5: Rolling element 6: Retainer 7: Seal member 8: Slinger 13: Seal lip 16a: First axial lip 16b: 2nd axial lip 17: Pulley shaft

Claims

An outer ring having an outer ring raceway surface on the inner peripheral surface and a pulley attached to the outer peripheral surface, and an inner ring having an inner ring raceway surface on the outer peripheral surface,
A plurality of rolling elements that are rollably arranged between the outer ring raceway surface and the inner ring raceway surface,
Sealing members attached to both ends of the inner peripheral surface of the outer ring,
A slinger that is located on the outer side in the axial direction of the seal member and that is attached to both ends of the outer peripheral surface of the inner ring,
In the rolling bearing with a pulley, wherein the seal member is provided with a seal lip slidably contacting an outer peripheral surface of the inner ring, and an axial lip slidably contacting a side surface of the slinger facing the seal member,
The axial lip includes a first axial lip whose diameter increases outward in the axial direction and a second axial lip whose diameter decreases outward in the axial direction.
The first axial lip and the second axial lip come into contact with the slinger in a state where the rotation of the outer ring is stopped, and when the outer ring is rotating at a high speed, the first axial lip is radially outward by a centrifugal force. A rolling bearing with a pulley, which is deformed to be out of contact with the slinger.
A state in which the slinger is inclined such that a radially outer portion thereof extends outward in the axial direction from a contact position with the second axial lip, and the first axial lip has a rotation of the outer ring stopped at this inclined portion. The rolling bearing with a pulley according to claim 1, wherein the rolling bearings are in contact with each other.
The rolling bearing with a pulley according to claim 1 or 2, wherein the thickness of the first axial lip is 0.2 to 1 times the thickness of the second axial lip.
The rolling bearing with a pulley according to any one of claims 1 to 3, wherein an angle θ between the first axial lip and the seal member is defined in a range of 10 ° to 80 °.