Fulcrum bearing device for pulley arm

Patent metadata

Field	Value
Publication number	US-9581199-B2
Application number	US-201314438233-A
Country	US
Kind code	B2
Filing date	Oct 23, 2013
Priority date	Oct 25, 2012
Publication date	Feb 28, 2017
Grant date	Feb 28, 2017

Abstract

In a fulcrum bearing device for a pulley arm, a sleeve is inserted in a shaft hole formed in a boss portion of a pulley arm, washers are fitted on the outer peripheries of small diameter tube portions formed at the respective end portions of the sleeve, and the sleeve is fixed to an engine block by means of a bolt inserted through the sleeve and tightened, so that the pulley arm is pivotally supported. The shaft hole is formed at its respective end portions with seal receiving recesses having large diameters. Each seal member includes a cylindrical portion provided on its outer peripheral portion and press-fitted in the seal receiving recess, and a radial lip extending obliquely inwardly and provided on the inner periphery of the seal member. The distal end portions of the radial lips are kept in elastic contact with the outer diameter surface of the sleeve.

First claim

The invention claimed is:

1. A fulcrum bearing device for a pulley arm,
wherein a sleeve is inserted in a shaft hole formed in a boss portion of the pulley arm,
wherein washers are attached to two respective end portions of the sleeve so as to be opposed to two respective end surfaces of the boss portion in an axial direction,
wherein the sleeve is fixed in position by means of a bolt which is inserted through the sleeve, screwed into a member to which the pulley arm is attached, and tightened, whereby the pulley arm is pivotally supported,
wherein the shaft hole of the boss portion is formed, at two respective end portions of the shaft hole, with seal receiving recesses having diameters larger than a diameter of the shaft hole,
wherein seal members are incorporated in the respective seal receiving recesses, so as to prevent a foreign object from going into the boss portion from outside,
wherein each of the seal members is made of an elastic material, and comprises a cylindrical portion press-fitted on an inner diameter surface of the seal receiving recess, an inwardly extending annular portion integrally connected with an outer side end of the cylindrical portion, and a tapered radial lip extending obliquely inwardly from an inner periphery of the annular portion inside of the cylindrical portion, and having a distal end portion kept in elastic contact with an outer diameter surface of the sleeve,
wherein the annular portion of each of the seal members has an outer side surface provided, on an inner peripheral portion of the outer side surface with an axial lip extending obliquely outwardly and having a distal end portion kept in elastic contact with an inner side surface of a corresponding one of the washers,
wherein each of the washers is formed with an annular recessed step in the inner side surface of the washer at an outer peripheral portion thereof opposed to a corresponding one of the end surfaces of the boss portion, the annular recessed step defining, inside the annular recessed step, a circular protrusion fitted in a corresponding one of the seal receiving recesses,
wherein the annular recessed step has a side surface opposed to the respective end surface of the boss portion with a gap defined between the respective side surface and the respective end surface of the boss portion, and configured to restrict an axial movement of the pulley arm, and
wherein the axial lip is kept in elastic contact with a side surface of the respective circular protrusion.

2. The fulcrum bearing device according to claim 1 , wherein the seal members are each reinforced by a seal metal core having an L-shaped section, and including a cylindrical portion having an outer diameter surface and an end surface which are covered by the cylindrical portion of a corresponding one of the seal members, and an inwardly extending flange provided at one end of the cylindrical portion of the seal metal core, and having an outer side surface covered by the annular portion of the corresponding one of the seal members.

3. The fulcrum bearing device according to claim 1 , wherein the axial seal lip is configured such that when the axial lip is in a natural state, a distal end outer diameter of the axial lip is smaller than an inner diameter of the cylindrical portion of the seal metal core, and when the axial lip is kept in elastic contact with the side surface of the circular protrusion, the distal end outer diameter of the axial lip is smaller than an outer diameter of the circular protrusion.

4. The fulcrum bearing device according to claim 1 , wherein each of the seal members is made of a synthetic rubber comprising any one of nitrile rubber, hydrogenated nitrile rubber, ACM rubber, silicon rubber and fluororubber.

5. A fulcrum bearing device for a pulley arm,
wherein a sleeve is inserted in a shaft hole formed in a boss portion of the pulley arm,
wherein washers are attached to two respective end portions of the sleeve so as to be opposed to two respective end surfaces of the boss portion in an axial direction,
wherein the sleeve is fixed in position by means of a bolt which is inserted through the sleeve, screwed into a member to which the pulley arm is attached, and tightened, whereby the pulley arm is pivotally supported,
wherein the shaft hole of the boss portion is formed, at two respective end portions of the shaft hole, with seal receiving recesses having diameters larger than a diameter of the shaft hole,
wherein seal members are incorporated in the respective seal receiving recesses, so as to prevent a foreign object from going into the boss portion from outside,
wherein each of the seal members is made of an elastic material, and comprises a cylindrical portion press-fitted on an inner diameter surface of the seal receiving recess, an inwardly extending annular portion integrally connected with an outer side end of the cylindrical portion, and a tapered radial lip extending obliquely inwardly from an inner periphery of the annular portion inside of the cylindrical portion, and having a distal end portion kept in elastic contact with an outer diameter surface of the sleeve,
wherein the annular portion of each of the seal members has an outer side surface provided, on an inner peripheral portion of the outer side surface, with an axial lip extending obliquely outwardly and having a distal end portion kept in elastic contact with an inner side surface of a corresponding one of the washers,
wherein each of the washers is formed with an annular recessed step in the inner side surface of the washer at an outer peripheral portion thereof opposed to a corresponding one of the end surfaces of the boss portion, the annular recessed step defining, inside the annular recessed step, a circular protrusion fitted in a corresponding one of the seal receiving recesses,
wherein the annular recessed step has a side surface opposed to the respective end surface of the boss portion with a gap defined between the respective side surface and the respective end surface of the boss portion, and configured to restrict an axial movement of the pulley arm, and
wherein the axial lip is kept in elastic contact with a side surface of the respective circular protrusion, and
wherein each of the seal receiving recesses has an open end formed with a tapered surface at an inner peripheral portion of the open end such that a gap is defined between the tapered surface and an outer peripheral edge of a corresponding one of the circular protrusions.

Assignees

• Tanaka Tadahisa
• Sato Seiji
• Takano Takehiro
• Ntn Toyo Bearing Co Ltd

Inventors

• Tanaka Tadahisa
• Sato Seiji
• Takano Takehiro

Classifications

• F16H2007/0893

  Circular path · CPC title

• F16C2361/63

  Gears with belts and pulleys · CPC title

• F16C33/74 Primary

  of sliding-contact bearings · CPC title

• F16H7/1281

  where the axis of the pulley moves along a substantially circular path · CPC title

• F16H7/12

  of an idle pulley · CPC title