US 12,228,205 B2
Worm reducer
Hiroyuki Sugawara, Gunma (JP)
Assigned to NSK STEERING & CONTROL, INC., Tokyo (JP)
Appl. No. 18/574,626
Filed by NSK STEERING & CONTROL, INC., Tokyo (JP)
PCT Filed Jun. 8, 2022, PCT No. PCT/JP2022/023203
§ 371(c)(1), (2) Date Dec. 27, 2023,
PCT Pub. No. WO2023/276598, PCT Pub. Date Jan. 5, 2023.
Claims priority of application No. 2021-106314 (JP), filed on Jun. 28, 2021.
Prior Publication US 2024/0175489 A1, May 30, 2024
Int. Cl. F16H 57/12 (2006.01); B62D 5/04 (2006.01); F16H 1/16 (2006.01); F16H 57/02 (2012.01); F16H 57/021 (2012.01); F16H 57/039 (2012.01)
CPC F16H 57/12 (2013.01) [F16H 1/16 (2013.01); F16H 57/021 (2013.01); F16H 57/039 (2013.01); B62D 5/0403 (2013.01); F16H 2057/02082 (2013.01); F16H 2057/0213 (2013.01); F16H 2057/127 (2013.01)] 10 Claims
OG exemplary drawing
 
1. A worm reducer comprising:
a housing having a wheel accommodation portion, and a worm accommodation portion disposed in a twisted position with respect to the wheel accommodation portion and having an axially intermediate portion open to the wheel accommodation portion;
a worm wheel having wheel teeth on an outer circumferential surface thereof and rotatably supported inside the wheel accommodation portion;
a worm having worm teeth that mesh with the wheel teeth on an outer circumferential surface thereof, and rotatably supported inside the worm accommodation portion;
a holder configured in an annular shape, through which a tip end portion of the worm is inserted radially inward, and which is internally fitted and fixed to the worm accommodation portion;
a support bearing which is a rolling bearing having an inner ring and an outer ring, and which is disposed between an outer circumferential surface of the tip end portion of the worm and an inner circumferential surface of the holder while a clearance in a radial direction is interposed between an inner circumferential surface of the inner ring and the outer circumferential surface of the tip end portion of the worm, or between an outer circumferential surface of the outer ring and the inner circumferential surface of the holder;
a pad disposed around the tip end portion of the worm at a location adjacent to the support bearing in the axial direction, and used to press the tip end portion of the worm in a direction toward the worm wheel; and
an elastic member assembled to the holder and elastically urging the tip end portion of the worm toward the worm wheel via the pad, wherein:
the holder has a holder engagement portion in at least one of the positions sandwiching the pad from both sides in a third direction orthogonal to both a first direction that is an urging direction of the elastic member and a second direction that is the axial direction of the worm accommodation portion;
the pad has a pad engagement portion that comes into contact with the holder engagement portion in at least one of both side portions in the third direction; and
displacement of the pad in the third direction with respect to the holder is regulated based on contact between the holder engagement portion and the pad engagement portion.