US4778022A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Electric power steering system
Assignee: Aisin Corp
•
Filing: 1987-03-13
•
Granted: 1988-10-18
•
Expires: 2007-03-13
Abstract
Abstract Herein disclosed is an electric power steering system which comprises: a detecting unit for detecting the direction and magnitude of a relative angular displacement betweeen input and output shafts; and an electric motor connected to the output shaft and having its revolutions controlled through a controller in accordance with the output signal of the detecting unit. The detecting unit includes a converting mechanism for converting the relative angular displacement into an axial displacement, and a displacement detecting unit for detecting the magnitude of the displacement in the axial direction. The displacement detecting unit can have its neutral position adjusted independently of other parts.
Inventors
- 👤 Akihide Kamiya
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 15:42
CPC Classifications
B; B62; B62D; B62D6/00; B62D6/08; B62D6/10
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
335 words
An electric power steering system comprising: a housing; an input shaft connected to a steering wheel and including an outer circumference formed with a helical groove therein; an output shaft connected to a steering gear; an electric motor connected to the output shaft; control means for controlling the revolutions of the electric motor in accordance with a relative angular displacement between the input shaft and the output shaft; detecting means detachably mounted on said housing for detecting the magnitude and direction of the relative angular displacement between the input shaft and the output shaft, said detecting means including converting means for converting the relative angular displacement between the input and output shafts into an axial displacement, the converting means including a torsion bar having two ends, one of the ends being fixed to the input shaft and the other of the ends being fixed to the output shaft, a slider having an outer annular groove and a hole in its outer circumference, the slider being rotatably and axially movable relative to the input shaft but irrotatable relative to the output shaft, and a ball fitted in the hole of the slider and engaging the helical groove of the input shaft so that the slider is moved axially along the input shaft when the input shaft rotates relative to the slider, and displacement detecting means for detecting the direction and magnitude of the axial displacement of the slider, the displacement detecting means including a casing mounted on the housing, a lever formed of a leaf spring having two ends, one of the ends being held fixedly in the casing and the other of the ends being provided with a ball receivable in the annular groove of the slider, and a sensor carried on the lever; and adjustment means for adjusting the position of the lever relative to the input shaft, the adjustment means including an adjusting shaft fixedly supporting the one of the ends of the lever, the adjusting shaft being rotatably adjustable in the casing.
Claim 2
Dependent Claim
335 words
An electric power steering system comprising: a housing; an input shaft connected to a steering wheel and including an outer circumference formed with a helical groove therein; an output shaft connected to a steering gear; an electric motor connected to the output shaft; control means for controlling the revolutions of the electric motor in accordance with a relative angular displacement between the input shaft and the output shaft; detecting means detachably mounted on said housing for detecting the magnitude and direction of the relative angular displacement between the input shaft and the output shaft, said detecting means including converting means for converting the relative angular displacement between the input and output shafts into an axial displacement, the converting means including a torsion bar having two ends, one of the ends being fixed to the input shaft and the other of the ends being fixed to the output shaft, a slider having an outer annular groove and a hole in its outer circumference, the slider being rotatably and axially movable relative to the input shaft but irrotatable relative to the output shaft, and a ball fitted in the hole of the slider and engaging the helical groove of the input shaft so that the slider is moved axially along the input shaft when the input shaft rotates relative to the slider, and displacement detecting means for detecting the direction and magnitude of the axial displacement of the slider, the displacement detecting means including a casing mounted on the housing, a lever formed of a leaf spring having two ends, one of the ends being held fixedly in the casing and the other of the ends being provided with a ball receivable in the annular groove of the slider, and a sensor carried on the lever; and adjustment means for adjusting the position of the lever relative to the input shaft, the adjustment means including an adjusting shaft fixedly supporting the one of the ends of the lever, the adjusting shaft being rotatably adjustable in the casing.
Claim 3
Dependent Claim
21 words
An electric power steering system according to claim 1, wherein said sensor is a strain gauge adhered fixedly to said lever.
Claim 4
Dependent Claim
38 words
An electric power steering system according to claim 1, wherein said control means is made operative to control the current to be fed to said electric motor in accordance with the output signal of said displacement detecting means.
References Cited (Backward Citations)
US3683685A
Cited
US3910106A
Cited
JPS58133957A
Cited
JPS58177773A
Cited
JPS58194664A
Cited
US4574903A
Cited
JPS59227560A
Cited
JPS6025853A
Cited
US4621701A
Cited
US4645024A
Cited
US4676331A
Cited
US4724711A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1991-10-18 | 1992-04-18 | 1992-10-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-10-18 | 1996-04-18 | 1996-10-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-10-18 | 2000-04-18 | 2000-10-18 | $7700.00 | Window Closed / Lapsed |