JP2021060086A5 - - Google Patents

Description

The hub unit bearing of the present invention includes an outer ring, a hub, a plurality of rolling elements, a seal ring, a cap, and a valve device.
The outer ring has a double-row outer ring track on the inner peripheral surface, is supported and fixed to the suspension device, and does not rotate.
The hub has a double-row inner ring track on the outer peripheral surface, and the wheels are fixed and rotate together with the wheels.
The plurality of rolling elements are rotatably arranged between the outer ring track of the double row and the inner ring track of the double row.
The seal ring closes an axially outer opening of the rolling element installation space existing between the inner peripheral surface of the outer ring and the outer peripheral surface of the hub.
The cap is fitted inside the axially inner end of the outer ring and closes the axially inner opening of the outer ring.
The valve device has a pair of elastic members.
The pair of elastic members have through holes that penetrate in the axial direction at positions that do not match each other, and from the flat plate portion in which the axial side surfaces facing each other are brought into contact with each other and the radial outer end portion of the flat plate portion. It is provided with an inclined plate portion that extends in a direction away from each other toward the outer side in the radial direction and is fitted inwardly on the inner peripheral surface of the hub .

On the other hand, when the pressure in the internal space 38 becomes a negative pressure due to the temperature drop of the hub unit bearing 1, the flat plate portion 36b of the elastic member 34b on the outer side in the axial direction is pushed inward in the axial direction, and the flat plate portion 36b Is elastically deformed so as to be curved, and the flat plate portion 36a of the elastic member 34a on the inner side in the axial direction is pushed toward the inner side in the axial direction. As a result, at least a part of the opening on the inner side in the axial direction of the through hole 35b provided in the flat plate portion 36b of the elastic member 34b on the outer side in the axial direction is the axial outer surface of the flat plate portion 36a in the elastic member 34a on the inner side in the axial direction. At least a part of the opening on the outer side in the axial direction of the through hole 35a provided in the flat plate portion 36a of the elastic member 34a on the inner side in the axial direction is the axis of the flat plate portion 36b of the elastic member 34b on the outer side in the axial direction. Separate from the inner side of the direction. As a result, a ventilation path connecting the internal space 38 and the external space is secured, and air is supplied to the internal space 38 from the external space through this ventilation path, so that the pressure inside the internal space 38 rises and the outside. It becomes the same as the pressure in space.

When the pair of elastic members 34a and 34b are elastically deformed due to the pressure change in the internal space 38, the volume of the annular space existing between the inclined plate portions 37a and 37b decreases, and the pressure in the annular space decreases. Rise. When the air passage connecting the internal space 38 and the external space is secured in a state where the pressure in the annular space is increased, the air vigorously passes through the air passage by the pumping action. As a result, the pressure difference between the internal space 38 and the external space can be quickly eliminated.

Of the pair of elastic members 34c and 34d, the elastic member 34d on the outer side in the axial direction is an engaging protrusion protruding inward in the axial direction to a portion of the flat plate portion 36d located on the inner side in the radial direction of the through hole 35b. It has a portion 46b and has an engaging recess 47b at a portion located on the radial opposite side of the engaging convex portion 46b.

In the valve device 7a of this example, the pair of elastic members 34c and 34d are concavely engaged with the engaging convex portion 46a of the elastic member 34c on the inner side in the axial direction and the engaging concave portion 47b of the elastic member 34d on the outer side in the axial direction. In addition, the side surfaces of the flat plate portions 36c and 36d facing each other in a state where the engaging recess 47a of the elastic member 34c on the inner side in the axial direction and the engaging convex portion 46b of the elastic member 34d on the outer side in the axial direction are concavely engaged. It is composed by abutting each other and combining them.

In the valve device 7a of this example, the engaging convex portion 46a of the elastic member 34c on the inner side in the axial direction and the engaging concave portion 47b of the elastic member 34d on the outer side in the axial direction are concavely engaged with each other, and the elastic member on the inner side in the axial direction is engaged. Since the engaging recess 47a of the 34c and the engaging convex portion 46b of the elastic member 34d on the outer side in the axial direction are engaged with each other unevenly, it is possible to more reliably prevent the pair of elastic members 34c and 34d from rotating relative to each other. Can be done. Therefore, according to this example, it is possible to more effectively prevent foreign matter from easily entering the internal space 38.

In the valve device 7b of this example, the pair of elastic members 34e and 34f have the small diameter portion 53 of the shaft portion 52 of the elastic member 34e on the inner side in the axial direction inside the fitting hole 56 of the elastic member 34f on the outer side in the axial direction. In the fitted state, the flat plate portions 36e and 36f are configured by abutting and combining the side surfaces facing each other. In a state where the pair of elastic members 34e and 34f are combined by abutting the side surfaces of the flat plate portions 36e and 36f facing each other, the flat plate portion 36f on the outer side in the axial direction has the step portion 55 on the shaft portion 52 and the inner side in the axial direction. It is elastically sandwiched between the flat plate portion 36e and the outer surface in the axial direction. Therefore, before mounting the valve device 7b on the inner peripheral surface of the hub 3, the pair of elastic members 34e and 34f can be temporarily assembled so as not to be inadvertently separated. Therefore, the work of attaching the valve device 7b to the inner peripheral surface of the hub 3 can be facilitated, and the work of shifting the phases of the through holes 35a and 35b of the pair of elastic members 34e and 34f in the circumferential direction from each other. The sex can be improved.