JP2018054024A - Roller bearing with seal for pulley unit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To attain a roller bearing with seal for a pulley unit used for a car in which foreign matter intrusion into the roller bearing is prevented and even if the foreign matter is intruded, its discharging can be easily carried out.SOLUTION: A roller bearing with a seal for a pulley unit forms a bent part 7c with a peripheral edge of an outward flange 7b being bent inward and a clearance seal that can be contacted to perform a sealing action by a centrifugal force under rotation of an outer ring between its inside surface 7d and an outside surface of a sub-side lip 8d arranged at the outer-most side. The clearance seal prevents passing of liquid foreign matter by a passing resistance at a small clearance and substantially prevents passing of the liquid foreign matter. A sub-side lip 8d arranged at the outer-most side in a radial direction is elastically deformed by a centrifugal force toward outside in a radial direction, forcedly contacted with an inside surface 7d at the bent part 7c of a slinger 7 to close the clearance seal and both end openings in the bearing space are hermetically closed.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a rolling bearing with a pulley unit seal that can prevent entry of foreign matters such as water, mud, and dust into the rolling bearing.

  In general, as an example of contact with foreign matter such as water, mud, and dust when using a rolling bearing, there is a rolling bearing incorporated in a belt transmission near an automobile engine. In addition, foreign matters such as water and muddy water easily enter the inside of the bearing from the outside, and the original function of the rolling bearing may be impaired at an early stage due to the entry of the foreign matter.

  In belt transmissions that drive auxiliary machines such as alternators and compressors near the engine of an automobile, the belt movement is guided by an idler pulley, or the tension pulley is pressed against the belt by a hydraulic auto tensioner to change the belt tension. Absorb. Such an idler pulley or tension pulley is supported by a rolling bearing unitized with the pulley by being incorporated on the inner diameter side of the boss portion.

In order to improve the water resistance of the rolling bearing for the pulley unit, a rolling bearing with a seal is employed.
For example, the basic seal structure employed in a roller bearing with a pulley unit seal is such that the lip provided on the inner periphery of the ring-shaped seal is brought into elastic contact with the groove edge of the annular groove on the outer surface of the inner ring and tightened. The structure prevents the ingress of water from the outside, but if the tightening allowance is increased too much, the rotational torque of the bearing will be increased, so that the tightening allowance cannot be increased sufficiently. It was not possible to completely prevent water from entering the inside.

For example, as described in Patent Documents 1 and 2, there are some which improve water resistance by providing slinger on both sides of a rolling bearing. However, since the outer periphery of the slinger is not in contact with the side surface of the rotating outer ring and has a gap, external water and foreign matter may enter through this gap, and the seal lip contacts the slinger. It is necessary to provide a contact type bearing seal.
In addition, recent automobiles are required to be manufactured under the assumption of various usage conditions outside the country. In particular, there is a high demand for water resistance on rough roads, and an improvement in sealing performance is required.

  The rolling bearing with seal described in Patent Document 2 has a double seal structure in which a main seal lip is elastically contacted with an end portion in an axial direction of a step portion formed at an end portion of an inner ring, and a sub seal lip is also used in combination. The water tightness is improved by increasing the “tightening allowance”.

  That is, in the conventional rolling bearing shown in FIG. 7, the slinger 7 fixed to the inner ring 3 is arranged outside the elastic seal member 20 fixed to the outer ring 2 so that muddy water or the like is not directly applied to the lip. When the elastic seal member 20 is provided with a side lip 21 and brought into contact with the slinger 7 and a strong pressure such as washing water is applied from the outside, the side lip 21 is strongly pressed against the slinger 7 to It has a structure that prevents intrusion.

JP 2009-216138 A JP 2009-216139 A

  However, when the rolling bearing having the above-described conventional seal structure is used for rotating the outer ring via a belt, if a strong centrifugal force acts on the side lip 21 in the direction indicated by the arrow in FIG. No. 21 is elastically deformed so as to approach the outer ring 2 side (indicated by a chain line in the figure), and there is a problem that the “tightening margin” of the seal, that is, the contact area of the lip is reduced and the water resistance is lowered.

  In addition, once foreign matter such as water once enters the inside of the side lip 21, there is a problem that it is difficult to be discharged outside the side lip 21 having an increased contact area.

  Accordingly, an object of the present invention is to solve the above-described problems in the prior art, and in a rolling bearing with a seal having a contact-type bearing seal that makes a lip contact with a slinger, against foreign matters such as water during non-rotation and low-speed rotation. In addition to having sufficient sealing properties, it is intended to prevent deterioration of water resistance when used in outer ring rotation, and to always prevent intrusion of muddy water and other foreign matters, for example, in the severe use environment of automobiles. Further, in addition to the above effects, a rolling bearing with a pulley unit seal can be easily removed from the rolling bearing even when foreign matter such as water or muddy water enters the inside of the seal lip.

  In order to solve the above-described problems, in the present invention, a seal member that seals both end openings of a bearing space formed between an outer ring and an inner ring of a rolling bearing for outer ring rotation is provided at the outer surface end of the inner ring. A slinger having an outward flange at the outer end of the fixed cylindrical portion and having a substantially L-shaped cross section, and an outer peripheral portion disposed at both ends of the inner diameter surface of the outer ring, which is disposed axially inward from the outward flange of the slinger A roller unit with a pulley unit seal that is provided with two or more annular lips on the surface of the elastic seal member facing the slinger and elastically contacting the slinger. In the bearing, the outer ring rotation of the rolling bearing is between an inner side surface of a bent portion that is bent inward with a peripheral edge of the outward flange and an outer side surface of an annular lip disposed on the outermost side. Than it was in contact sealable gap seal seal rolling bearing for a pulley unit provided with a centrifugal force due. The gap seal may employ a labyrinth that has a protrusion on the outer surface of the annular lip facing the inner surface of the bent portion.

The pulley unit sealed roller bearing of the present invention configured as described above includes an inner surface of a bent portion that is bent inward with a peripheral edge of an outward flange and an outer surface of an annular lip disposed on the outermost side. A gap seal that can be contact-sealed by centrifugal force due to rotation of the outer ring of the rolling bearing is provided between the bent portion of the outward flange and the annular lip when the rolling bearing is in a non-rotating state or a low-speed rotating state. The gap seal exhibits a sealing function in a state without frictional resistance through a small gap while keeping the contactless state.
Moreover, when the said clearance seal has a protrusion on the outer surface of the said annular | circular shaped lip, the said clearance seal fully exhibits sealing performance by a labyrinth.

  In other words, a clearance seal in the form of a non-contact seal has a resistance to allow the passage of liquid foreign substances by a small gap or passage resistance when liquid foreign substances such as water outside the bearing may enter the bearing space. And further prevent the passage of such liquid foreign matter.

In addition, when the rolling bearing with a seal for pulley unit of the present invention increases the rotational speed of the outer ring, an outward centrifugal force acts on the annular lip according to the rotational speed, and the circle disposed on the outermost side thereof The annular lip is elastically deformed outward in the axial radial direction by centrifugal force and is in elastic contact with the inner diameter surface of the peripheral edge of the outward flange of the slinger, whereby the gap of the gap seal is closed, and the rolling bearing Both end openings of the bearing space formed between the outer ring and the inner ring are more completely sealed, and the water resistance is improved as compared with the non-contact seal state.
By being sealed in this way, for example, in a harsh use environment of an automobile, when the rolling bearing is used in a submerged state, entry of water, muddy water and other foreign matters is prevented.

  Among the two or more annular lips, those arranged on the radially outermost side so that the contact sealing action is exhibited as sharply as possible according to the rotational speed of the rolling bearing when the centrifugal force acts. However, it is preferable that the tip lip is thicker than the base. With such a configuration, a large centrifugal force acts on the tip portion having a larger mass than the base portion, so that an elastic sealing action or a labyrinth or gap sealing action is quickly produced according to the rotational speed, and both ends of the bearing space are The opening is always reliably sealed.

  In addition, when the rolling bearing with the pulley unit seal is a tapered roller surface having a tapered inner surface at the outer peripheral edge of the outward flange, the elastic sealing member can be used when the rolling bearing is stopped. A downward flow path is formed in which water and the like that have entered between and the slinger tend to flow out naturally, so that liquid such as water can easily roll and be discharged out of the bearing.

  In addition, at least one of the one or more annular lips is configured to be a side lip that extends outward from the outer surface of the elastic seal member and has a distal end elastically contacting the outward flange of the slinger. Thus, in the state where the centrifugal force due to the outer ring rotation does not act, not only the non-contact seal of the gap seal or the labyrinth seal but also the elastic contact seal can prevent foreign matters such as water from entering the bearing space.

  As described above, the elastic sealing member exhibiting the sealing performance is an elastic made of nitrile rubber, acrylic rubber or fluororubber having excellent flexibility and wear resistance when the annular lip is in sliding contact with the slinger. It is preferable to employ a seal member.

  As a suitable application in which the rolling bearing with a seal for pulley unit exhibits a desired effect, it is a rolling bearing with a seal for pulley unit in a belt transmission device of an automobile engine.

  According to the present invention, in the rolling bearing with a pulley unit seal in which two or more annular lips are brought into elastic contact with the slinger, a clearance seal is provided between the outward flange of the slinger and the annular lip. When rotating or at low speed, the flange and the annular lip have a sufficient sealing function in a non-contact state. When the outer ring of the rolling bearing is rotating, the annular lip is elastically deformed by centrifugal force. As a result, the gap of the gap seal is closed, so that both the non-rotation and the rotation are good in sealing properties and excellent in water resistance. This is suitable for a rolling bearing with a pulley unit seal that can always prevent intrusion of muddy water and other foreign matters, for example, in the severe use environment of an automobile.

  In addition, in the case where the inner surface of the bent portion is a tapered surface with a bending angle of less than 90 degrees, in addition to the above effects, even if foreign matter such as water or muddy water enters the inside of the seal lip, the foreign matter is outside the rolling bearing. There is also an advantage that a rolling bearing with a pulley unit seal is easily removed.

Sectional drawing of the rolling bearing with a seal for pulley units of 1st Embodiment The principal part expanded sectional view of FIG. 1 explaining the use condition of 1st Embodiment. The principal part expanded sectional view of 2nd Embodiment The principal part expanded sectional view of 3rd Embodiment The principal part expanded sectional view of 4th Embodiment The principal part expanded sectional view of 5th Embodiment Expanded cross-sectional view of the main part of a rolling bearing with seal for explaining the prior art

Embodiments of the present invention will be described below with reference to the accompanying drawings.
As shown in FIGS. 1 and 2, a rolling bearing 1 with a seal according to the first embodiment is composed of an outer ring 2, an inner ring 3, and ball bearings having balls 10 as rolling elements incorporated between these two rings. A seal member is incorporated outside the ball 10, and both end openings of the bearing space formed between the opposing surfaces of the outer ring 2 and the inner ring 3 are sealed by the seal member.

  The illustrated rolling bearing 1 with a seal is used in a pulley unit, and is incorporated in a state in which an outer ring rotates inside a boss portion 6 provided inside a belt guide wheel 5 of the pulley 4, and between the outer ring 2 and the inner ring 3. It has a seal structure that seals each opening at both ends of the formed bearing space.

  The sealing member includes a slinger 7 having a substantially L-shaped cross section provided with an outward flange 7b extending radially outward from the outer end of the cylindrical portion 7a fixed to the outer diameter surface end of the inner ring 3, and an outward flange. An annular elastic seal member 8 is disposed on the inner side in the axial direction from 7b and the outer peripheral portion is fixed to both ends of the inner diameter surface of the outer ring 2. The slinger 7 is made of a press-formed product of a steel plate, and the cylindrical portion 7 a is fixed in a state where it is press-fitted into the outer diameter surface end portion of the inner ring 3.

  The elastic seal member 8 is made of a rubber material having an annular shape and substantially rubber-like elasticity, and is reinforced in a state where an annular cored bar 9 sharing an axis is embedded. A fitting portion 8 a is provided on the outer peripheral portion of the elastic seal member 8 so as to cover the cylindrical portion 9 a of the core metal 9, and the fitting portion 8 a is a seal mounting groove formed at the inner diameter surface end portion of the outer ring 2. It is press-fitted into 2 a and is fixed to the outer ring 2.

  In addition, a radial lip 8b inclined inward is formed on the inner peripheral portion of the elastic seal member 8, and a side lip 8c inclined in the outer radial direction extends outwardly, and its distal end elastically acts on the outward flange 7b. It contacts and seals the gap between the elastic seal member 8 and the outward flange 7b. In the present embodiment, the radial lips 8b and 8c are inclined at the same angle. However, the radial lips 8b and 8c are not limited to this, and may be inclined at different angles.

  Further, the radial lip 8b provided on the surface of the elastic seal member 8 facing the slinger 7 has a tip portion arranged at a small interval on the outer diameter surface of the cylindrical portion 7a of the slinger 7 and is non-contact. A gap seal is formed.

  As shown in FIGS. 1 and 2, the slinger 7 of the above-described pulley-rolled roller bearing 1 has a bent portion 7c formed by bending the outer peripheral edge of the outward flange 7b inward in the axial direction. Yes. The bent portion 7 c overlaps with the outer ring 2 in the radial direction of the rolling bearing 1. A sub-side lip 8d is provided on the radially outer side of the elastic seal member 8 on the radially inner side of the bent portion 7c.

  The auxiliary side lip 8 d overlaps the bent portion 7 c in the axial direction of the rolling bearing 1. Specifically, one axial end portion (end portion on the slinger 7 side) of the secondary side lip 8d overlaps the bent portion 7c in the axial direction. Then, between the inner side surface 7d of the bent portion 7c and the outer side surface of the sub-side lip 8d arranged on the outermost side, a contact seal state (shown by a one-dot chain line in FIG. 2) is obtained by centrifugal force due to rotation of the outer ring of the rolling bearing. A gap seal (labyrinth seal) is formed.

  The gap seal prevents liquid foreign substances such as water outside the bearing from passing through the gap between the slinger 7 and the outer ring 2 due to the passage resistance of the small gap. It substantially prevents the passage of liquid foreign substances, and the gap size depends on the shaft diameter and material of the rolling bearing, but for example, the narrowest part is preferably a gap of about 0.2 to 1.0 mm. .

  As shown in FIG. 2, when the rolling bearing 1 with a pulley unit seal of the present embodiment increases the rotational speed of the outer ring 2 in use, both the side lip 8c and the auxiliary side lip 8d have centrifugal force. As shown by the arrows in the figure, it acts at a magnitude corresponding to the rotational speed, but the secondary side lip 8d disposed on the radially outermost side is elastically deformed so as to bend radially outward by centrifugal force, The gap seal is closed by pressing against the inner surface 7d of the bent portion 7c of the slinger 7, and the both end openings of the bearing space are sealed.

  As a result, the side lip 8c, which is another annular lip provided in a state capable of elastic contact with the slinger 7, receives the centrifugal force due to the rotation of the outer ring of the rolling bearing and is elastic in the state shown by the one-dot chain line in FIG. Even in the case of deformation, the deterioration of the sealing performance can be compensated by the sealing performance of the secondary side lip 8d.

  In this way, the rolling bearing with a pulley unit seal of the first embodiment can prevent the ingress of water, muddy water, and other foreign matters from the outside even when the rolling bearing is submerged in a severe use environment of an automobile, for example. The contact seal by 8d is surely protected.

  The material of the elastic seal member that exhibits the sealing performance of the annular lip is considered that the annular lip is elastically pressed against the slinger 7 and used in a sliding state. In addition, it is preferable to employ a material having excellent flexibility and wear resistance. For example, an elastic seal member made of nitrile rubber, acrylic rubber or fluororubber can be employed.

  Moreover, 2nd Embodiment shown in FIG. 3 illustrates as another form of the clearance seal of the smooth surfaces of the outer peripheral surface of the sub side lip 8d in 1st Embodiment, and the inner peripheral surface of the bending part 7c, A plurality of rows (four in the figure) of protrusions 11 extending in the circumferential direction are formed on the outer side surface of the auxiliary side lip 8d, and a labyrinth passage 12 is formed between them to form a labyrinth seal. is there.

  Further, the third embodiment shown in FIG. 4 is also exemplified as another form of the gap seal in the first embodiment, and an inner side surface 7d of the bent portion 7c of the outward flange 7b and an annular shape disposed on the outermost side. A square groove portion 13 and a square protrusion 14 are arranged to be opposed to each other with two gaps facing each other on the outer surface of the secondary side lip 8d, which is a lip, to form a four-line labyrinth passage 16 The labyrinth seal which was made is shown.

  The labyrinth seals of the second and third embodiments described above are contact-sealed by centrifugal force due to rotation of the outer ring of the rolling bearing 1 in the same manner as in the first embodiment, and the rolling bearing 1 is either rotated or not rotated. However, the sealing performance equivalent to or better than that of the first embodiment can be exhibited.

  Further, in the rolling bearing with a pulley unit seal of the fourth embodiment shown in FIG. 5, among the one or more annular lips, the sub-side lip 15 disposed on the radially outermost side has a tip portion 15b rather than a base portion 15a. The tip portion 15b is formed thicker than the base portion 15a. The tip portion 15b is thicker than the base portion 15a.

  In the fourth embodiment configured as described above, a large centrifugal force acts on the tip portion 15b having a larger thickness and a larger mass than the base portion 15a of the sub-side lip 15 in the rotating state of the rolling bearing. The tip portion 15b is easily elastically deformed so as to close the labyrinth gap even when rotating at a relatively low speed, and both end openings of the bearing space are elastically deformed corresponding to the rotational speed, thereby reliably exhibiting a sealing action.

  Moreover, in the rolling bearing with a pulley unit seal of the fifth embodiment shown in FIG. 6, the inner surface of the bent portion 7c of the outward flange 7b is formed with a tapered surface with a bending angle θ of less than 90 °. .

  In the fifth embodiment configured as described above, when the rolling bearing stops rotating, liquid such as water that has entered and accumulated between the elastic seal member 8 and the slinger 7 causes the bent portion 7c and the sub-side lip. The labyrinth gap with 8d flows down as a downward flow path, and can be efficiently discharged out of the rolling bearing.

  In order to ensure the drainage action, the bending angle θ is preferably a small angle that does not bend the flow path as much as possible. On the other hand, in order to improve the sealing performance, centrifugal force due to rotation of the outer ring of the rolling bearing is: Even if it is relatively small, the contact sealability needs to be improved efficiently, and for that purpose, it is preferable that the folding angle θ is 45 °, for example, about 30 to 60 °.

  In the first to fifth embodiments described above, the non-contact radial lip 8b is formed on the outer diameter surface of the cylindrical portion 7a of the slinger 7. However, the annular lip made of such a radial lip 8b is shown. Also, the cylindrical portion 7a may be elastically contacted.

  In the above-described embodiment, the case of a single-row ball bearing is shown as the ball bearing. However, as long as the sealability is not hindered, a plurality of double-row ball bearings or a plurality of single-row ball bearings, For example, a form used in two rows may be adopted.

  Each of the above-described embodiments can solve the problem in the prior art that “water resistance is reduced by centrifugal force” such as a pulley unit, and a reduction in tightening allowance due to centrifugal force of a rolling bearing used in outer ring rotation. Nevertheless, it becomes a rolling bearing with a pulley unit seal that can reliably prevent the intrusion of muddy water and other foreign matters in the harsh environment of automobiles.

DESCRIPTION OF SYMBOLS 1 Rolling bearing with seal 2 Outer ring 2a Seal mounting groove 3 Inner ring 4 Pulley 5 Belt guide wheel 6 Boss part 7 Slinger 7a, 9a Cylindrical part 7b Outward flange 7c Bending part 7d Inner side face 8, 20 Elastic seal member 8a Fitting part 8b Radial lip 8c, 21 Side lip 8d, 15 Sub-side lip 9 Core 10 Ball 11, 14 Projection 12, 16 Labyrinth passage 13 Square groove 15a Base 15b Tip

Claims (7)

Sealing members for sealing both ends of the bearing space formed between the outer ring (2) and the inner ring (3) of the rolling bearing (1) for rotating the outer ring are fixed to the outer diameter surface end of the inner ring (3). An outward flange (7b) is provided at the outer end of the cylindrical portion (7a), and a slinger (7) is disposed on the inner side in the axial direction from the outward flange (7b) of the slinger (7). 2) an annular elastic seal member (8) having outer peripheral portions fixed to both ends of the inner diameter surface of 2), and 2 on the surface of the elastic seal member (8) facing the slinger (7). In the rolling bearing (1) with a pulley unit seal provided with the above annular lip and elastically contacting the slinger (7),
The rolling bearing (1) is provided between an inner surface (7d) of a bent portion (7c) bent inward with a peripheral edge of the outward flange (7b) and an outer surface of an annular lip disposed on the outermost side. Roller bearing with seal for pulley unit (1), characterized in that a clearance seal that can be contacted by centrifugal force due to rotation of the outer ring is provided.   The labyrinth is formed by the gap seal having protrusions (11, 14) on the outer surface of the annular lip facing the inner surface (7d) of the bent portion (7c). The rolling bearing with a seal for the pulley unit described (1).   The rolling bearing (1) with a pulley unit seal according to claim 1 or 2, wherein the annular lip disposed on the outermost side is an annular lip having a tip (15b) thicker than a base (15a).   The rolling bearing (1) with a pulley unit seal according to any one of claims 1 to 3, wherein an inner side surface (7d) of the bent portion (7c) is a tapered surface having a bending angle of less than 90 degrees.   At least one of the two or more annular lips extends outward from the outer surface of the elastic seal member (8), and the tip thereof elastically contacts the outward flange (7b) of the slinger (7). It is a side lip (8c), The rolling bearing (1) with a pulley unit seal in any one of Claims 1-4.   The rolling bearing (1) with a pulley unit seal according to any one of claims 1 to 5, wherein the elastic seal member (8) is an elastic seal member made of nitrile rubber, acrylic rubber or fluororubber.   The rolling bearing (1) with a pulley unit seal according to any one of claims 1 to 6, wherein the rolling bearing (1) is a rolling bearing with a pulley unit seal in a belt transmission of an automobile engine.

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