US-12618434-B2 - Strut bearing device and vehicle strut suspension

US12618434B2US 12618434 B2US12618434 B2US 12618434B2US-12618434-B2

Abstract

A first lower-case wall surface faces an axial gap. A second lower-case wall surface extends toward a radially outer side from an upper end of the first lower-case wall surface. A third lower-case wall surface extends upward from an end of the second lower-case wall surface in the radially outer side. A first upper-case wall surface faces an upper portion of the first lower-case wall surface. A second upper-case wall surface extends toward a radially inner side from an upper end of the first upper-case wall surface. A third upper-case wall surface extends upward from an end of the second upper-case wall surface in the radially inner side and faces the third lower-case wall surface.

Inventors

Yasuhiro NARAZAKI
Shogo IKEGUCHI
Shogo Fukada
Kohei Shibata
Hiroshi Yano

Assignees

NAKANISHI METAL WORKS CO., LTD.

Dates

Publication Date: 20260505
Application Date: 20241007
Priority Date: 20231010

Claims (6)

1 . A strut bearing device, comprising: a strut bearing; and an upper spring seat that is a spring support component supporting an upper end of a coil spring, wherein the strut bearing includes an upper case, a lower case, an upper raceway ring held by the upper case, a lower raceway ring held by the lower case, rolling elements that roll between the upper raceway ring and the lower raceway ring, and a seal positioned in a radially outer side of the rolling elements, the upper spring seat is in contact with the lower case, an axial gap is present between the upper case and the upper spring seat, the upper case has a first upper-case wall surface, a second upper-case wall surface, and a third upper-case wall surface, each of the first upper-case wall surface and the third upper-case wall surface is an inner peripheral surface of the upper case, the second upper-case wall surface is an annular surface of the upper case, the lower case has a first lower-case wall surface, a second lower-case wall surface, and a third lower-case wall surface, each of the first lower-case wall surface and the third lower-case wall surface is an outer peripheral surface of the lower case, the second lower-case wall surface is an annular surface of the lower case, the first lower-case wall surface faces the axial gap, the second lower-case wall surface extends radially outward from an upper end of the first lower-case wall surface, the third lower-case wall surface extends upward from a radially outer end of the second lower-case wall surface, the first upper-case wall surface faces an upper portion of the first lower-case wall surface, the second upper-case wall surface extends radially inward from an upper end of the first upper-case wall surface, and the third upper-case wall surface extends upward from a radially inner end of the second upper-case wall surface, and faces the third lower-case wall surface.
2 . The strut bearing device according to claim 1 , wherein at least one of an angle formed by the first lower-case wall surface and the second lower-case wall surface and an angle formed by the first upper-case wall surface and the second upper-case wall surface is an acute angle.
3 . A vehicle strut suspension comprising the strut bearing device according to claim 1 .
4 . A strut bearing device comprising: an upper case; a lower case; an upper raceway ring held by the upper case; a lower raceway ring held by the lower case; rolling elements that roll between the upper raceway ring and the lower raceway ring; and a seal positioned in a radially outer side of the rolling element, wherein the lower case is made of a synthetic resin containing a core metal, has a cylindrical portion and an annular portion extending radially outward from an upper portion of the cylindrical portion, and functions as a spring support component that supports an upper end of a coil spring; an axial gap is present between the upper case and the lower case, the upper case has a first upper-case wall surface, a second upper-case wall surface, and a third upper-case wall surface, each of the first upper-case wall surface and the third upper-case wall surface is an inner peripheral surface of the upper case, the second upper-case wall surface is an annular surface of the upper case, the lower case has a first lower-case wall surface, a second lower-case wall surface, and a third lower-case wall surface, each of the first lower-case wall surface and the third lower-case wall surface is an outer peripheral surface of the lower case, the second lower-case wall surface is an annular surface of the lower case, the first lower-case wall surface faces the axial gap, the second lower-case wall surface extends radially outward from an upper end of the first lower-case wall surface, the third lower-case wall surface extends upward from a radially outer end of the second lower-case wall surface, the first upper-case wall surface faces an upper portion of the first lower-case wall surface, the second upper-case wall surface extends radially inward from an upper end of the first upper-case wall surface, and the third upper-case wall surface extends upward from a radially inner end of the second upper-case wall surface and faces the third lower-case wall surface.
5 . The strut bearing device according to claim 4 , wherein at least one of an angle formed by the first lower-case wall surface and the second lower-case wall surface and an angle formed by the first upper-case wall surface and the second upper-case wall surface is an acute angle.
6 . A vehicle strut suspension comprising the strut bearing device according to claim 4 .

Description

FIELD The present invention relates to a strut bearing device for use in a vehicle strut suspension. BACKGROUND There is a strut suspension including a coil spring that supports a wheel on a vehicle body and an expandable strut that is fixed to an axle, contains a shock absorber, and serves as a suspension provided with a shock absorber to absorb vertical vibrations. Strut suspensions are widely used primarily for front wheels of a passenger car. As a strut bearing device for use in an upper portion of a strut suspension, there is a strut bearing device (see Patent Literature (PTL) 1, for example) including: an upper case that is made of a synthetic resin and holds an upper raceway ring (e.g., an upper cap 3 in PTL 1); a lower case that is made of a synthetic resin and holds a lower raceway ring (e.g., a lower cap 4 in PTL 1); an inner diameter side seal that is made of an elastomer and is provided in the lower case to be located in a radially inner side of rolling elements (e.g., an inner seal 6 in PTL 1); and an outer diameter side seal that is made of an elastomer and is located in a radially outer side of the rolling elements (e.g., an outer seal 7 in PTL 1). CITATION LIST Patent Literature [PTL 1] U.S. Pat. No. 10,753,389 SUMMARY Technical Problem As described above, the upper and lower cases are made of a synthetic resin. In order to eliminate generation of abnormal noise and increase of torque, which are caused by contact between the upper and lower cases, axial and radial gaps with required sizes are provided between the upper and lower cases. Furthermore, the strut bearing device is used in severe muddy-water environments where the strut bearing device directly receives muddy water on a road surface, which is splashed up by wheels. Furthermore, if a high-pressure washer is used when washing a car, the strut bearing device receives high-pressure water discharged from the high-pressure washer when washing the undercarriage. In the strut bearing device of PTL 1, for example, when high-speed water such as muddy water enters an axial gap between the upper cap 3 and the lower cap 4 from an outer diameter side, the water rises along an outer peripheral surface of the lower cap 4 and reaches the outer seal 7 without sufficiently decelerating, causing the outer seal 7 to become wet, which may result in a decrease in sealing performance. A purpose of the present invention is to provide a strut bearing device that can enhance an effect of decelerating high-speed water, such as muddy water, which has entered an axial gap between an upper case and a lower case, or an axial gap between the upper case and an upper spring seat from a radially outer side, before the water reaches an outer diameter side seal. Solution to Problem A strut bearing device according to a first aspect of the present invention is a strut bearing device that includes: a strut bearing; and an upper spring seat that is a spring support component supporting an upper end of a coil spring. The strut bearing includes an upper case, a lower case, an upper raceway ring held by the upper case, a lower raceway ring held by the lower case, rolling elements that roll between the upper raceway ring and the lower raceway ring, and a seal positioned in a radially outer side of the rolling elements. The upper spring seat is in contact with the lower case. An axial gap is present between the upper case and the upper spring seat. The upper case has a first upper-case wall surface, a second upper-case wall surface, and a third upper-case wall surface. Each of the first upper-case wall surface and the third upper-case wall surface is an inner peripheral surface of the upper case. The second upper-case wall surface is an annular surface of the upper case. The lower case has a first lower-case wall surface, a second lower-case wall surface, and a third lower-case wall surface. Each of the first lower-case wall surface and the third lower-case wall surface is an outer peripheral surface of the lower case. The second lower-case wall surface is an annular surface of the lower case. The first lower-case wall surface faces the axial gap. The second lower-case wall surface extends radially outward from an upper end of the first lower-case wall surface. The third lower-case wall surface extends upward from a radially outer end of the second lower-case wall surface. The first upper-case wall surface faces an upper portion of the first lower-case wall surface. The second upper-case wall surface extends radially inward from an upper end of the first upper-case wall surface. The third upper-case wall surface extends upward from a radially inner end of the second upper-case wall surface, and faces the third lower-case wall surface. A strut bearing device according to a second aspect of the present invention includes an upper case; a lower case; an upper raceway ring held by the upper case; a lower raceway ring held by the lower case; rolling elements that roll between the u