# US 2014/0190762 A1 · Power assist apparatus > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2014/0190762 A1 - Document ID: US20140190762A1 - Status: Published application - Kind: A1 - Application number: 14/239,646 - Filed: 2012-09-28 - Published: 2014-07-10 - Earliest claimed: 2011-09-28 - Assignees: Nsk Ltd. - Applicants: Nsk Ltd. - Inventors: Haruhiko Kiyota; Takeshi Murakami - Web page: https://patentgrep.com/patent/US20140190762A1 ## CPC - B62D 5/0403: {characterised by constructional features, e.g. common housing for motor and gear box} - B62D 5/0409: {Electric motor acting on the steering column} - B62D 6/10: characterised by means for sensing {or determining} torque - G01L 3/101: {involving magnetic or electromagnetic means} - G01L 5/221: {to steering wheels, e.g. for power assisted steering} - B62D: MOTOR VEHICLES; TRAILERS (steering, or guiding on a desired track, of agricultural machines or implements A01B69/00; wheels, castors, axles, increasing wheel adhesion B60B; vehicle tyres, tyre inflation or tyre changing B60C; connections between vehicles of a train or the like B60D; vehicles for use on rail and road, amphibious or convertible vehicles B60F; suspension arrangements B60G; heating, cooling, ventilating or other air treating devices B60H; windows, windscreens, non-fixed roofs, doors or similar devices, protective coverings for vehicles not in use B60J; propulsion plant arrangements, auxiliary drives, transmissions, controls, instrumentation or dashboards B60K; electric equipment or propulsion of electrically-propelled vehicles B60L; power supply for electrically-propelled vehicles B60M; passenger accommodation not otherwise provided for B60N; adaptations for load transportation or to carry special loads or objects B60P; arrangement of signalling or lighting devices, the mounting or supporting thereof or circuits therefor, for vehicles in general B60Q; vehicles, vehicle fittings or vehicle parts not otherwise provided for B60R; servicing, cleaning, repairing, supporting, lifting, or manoeuvring, not otherwise provided for, B60S; brake arrangements, brake control systems or parts thereof B60T; air-cushion vehicles B60V; motor-cycles, accessories therefor B62J, B62K; testing of vehicles G01M) - G01L: MEASURING FORCE, STRESS, TORQUE, WORK, MECHANICAL POWER, MECHANICAL EFFICIENCY, OR FLUID PRESSURE (weighing G01G) ## Abstract A power assist apparatus includes an electric motor, a speed reducer, an annular torque sensor, a housing in which the speed reducer and the torque sensor are arranged, and an annular center aligning bracket. The housing includes a first housing element and a second housing element, and one of the first housing element and the second housing element is made of a synthetic resin. The center aligning bracket is fixed to the one of the first housing element and the second housing element by insert molding such that the center aligning bracket is concentric to the one of the first housing element and the second housing element. The first housing element and the second housing element are joined such that the first housing element and the second housing element are engaged with each other in an axial direction of the torque sensor via the center aligning bracket. ## Claims ### Claim 1 A power assist apparatus comprising: an electric motor; a speed reducer configured to increase a torque generated by the electric motor; an annular torque sensor configured to detect a torque input from a steering wheel to a steering shaft attached to the steering wheel; a housing in which the speed reducer and the torque sensor are arranged; and an annular center aligning bracket, wherein the housing comprises a first housing element and a second housing element, wherein one of the first housing element and the second housing element is made of a synthetic resin, wherein the center aligning bracket is fixed to said one of the first housing element and the second housing element by insert molding such that the center aligning bracket is concentric to said one of the first housing element and the second housing element, and wherein the first housing element and the second housing element are joined such that the first housing element and the second housing element are engaged with each other in an axial direction of the torque sensor via the center aligning bracket. ### Claim 2 (depends on 1) The power assist apparatus according to claim 1, wherein the speed reducer comprises a worm shaft connected to a drive shaft of the electric motor, a worm provided on the worm shaft, and a worm wheel meshed with the worm, wherein the power assist apparatus further comprises: an output shaft arranged along the axial direction inside the housing and onto which the worm wheel is fitted in a fixed manner; an output shaft rolling bearing supporting the output shaft in a rotatable manner; and an annular output shaft bearing holder into which an outer ring of the output shaft rolling bearing is fitted in a fixed manner, and wherein the output shaft bearing holder is made of a metal, and is fixed to said one of the first housing element and the second housing element such that the bearing holder is concentric to the center aligning bracket. ### Claim 3 (depends on 2) The power assist apparatus according to claim 2, wherein the center aligning bracket and the output shaft bearing holder are formed as one piece. ### Claim 4 (depends on 2) The power assist apparatus according to claim 2, wherein the torque sensor is positioned with respect to the axial direction by the output shaft bearing holder, and is fixed to said one of the first housing element and the second housing element. ### Claim 5 (depends on 1) The power assist apparatus according to claim 1, wherein the speed reducer comprises a worm shaft connected to a drive shaft of the electric motor, a worm provided on an intermediate portion of the worm shaft, and a worm wheel meshed with the worm, wherein the power assist apparatus further comprises: a pair of worm shaft rolling bearings supporting respective end portions of the worm shaft in a rotatable manner; and a pair of annular worm shaft bearing holders into which outer rings of the pair of worm shaft rolling bearings are fitted in a fixed manner respectively, and the pair of worm shaft bearing holders is made of a metal, and is fixed to said one of the first housing element and the second housing element such that the worm shaft bearing holders are concentric to one another.