EP0189172A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Steering system for automotive vehicle or the like
Assignee: Nissan Motor Co Ltd
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Filing: 1986-01-21
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Granted: —
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Expires: 2006-01-21
Abstract
Abstract In order to simplify the construction of a power steering system and simultaneously allow for unassisted steering in the event that the motor (9) or the like of the system malfunctions, the differential gear (4) which established the drive connection between the auxiliary motor (9), the steering input shaft (2) and the steering output shaft (3) is such that when the element of the differential gear (4) which is connected to a variable speed motor (9) is not driven by the motor (9), an essentially 1:1 drive is established between the steering input and output shafts (2,3) while at thise time the motor driven element is braked only by the friction and other natural resistances which occur in the system. Further, the differential gear (4) is such as to have a relatively low responsiveness to the rotational speed of the motor (9) and thus eliminates the need for a reduction gear between the motor (9) and the differential gear (4).
Inventors
- 👤 Megumu Higuchi
- 👤 Tokiyoshi Yanai
- 👤 Masafumi Nakayama
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-28 00:53
CPC Classifications
B; B62; B62D; B62D5/00; B62D5/008; B62D6/00; B62D6/002
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
194 words
A steering system for an automotive vehicle comprising: a steering input shaft (2), said input shaft (2) having a steering wheel (1) connected thereto for inducing rotation thereof; and an output shaft (3), said output shaft (3) being operatively connected with a steerable wheel (13) of the vehicle; characterized b y a variable speed motor (9); a differential gear (4) interconnecting said input shaft (2) said output shaft (3) and said variable speed motor (9), said differential gear (4) including: an element which is operatively connected with said motor (9) to be driven by the same; and means operatively connected with said element for: (i) causing one of (a) essentially the same force to be transmitted between said input and output shafts (2,3) and (b) the input shaft (2) and output shaft (3) to rotate at essentially the same rotational speed when said element is not driven by said motor (9) and for: (ii) causing one of (a) a different force to be transmitted between said input and output shafts (2,3) and (b) said input and output shafts (2,3) to rotate at different rotational speeds when said element is driven by said motor (9).
Claim 2
Dependent Claim
194 words
A steering system for an automotive vehicle comprising: a steering input shaft (2), said input shaft (2) having a steering wheel (1) connected thereto for inducing rotation thereof; and an output shaft (3), said output shaft (3) being operatively connected with a steerable wheel (13) of the vehicle; characterized b y a variable speed motor (9); a differential gear (4) interconnecting said input shaft (2) said output shaft (3) and said variable speed motor (9), said differential gear (4) including: an element which is operatively connected with said motor (9) to be driven by the same; and means operatively connected with said element for: (i) causing one of (a) essentially the same force to be transmitted between said input and output shafts (2,3) and (b) the input shaft (2) and output shaft (3) to rotate at essentially the same rotational speed when said element is not driven by said motor (9) and for: (ii) causing one of (a) a different force to be transmitted between said input and output shafts (2,3) and (b) said input and output shafts (2,3) to rotate at different rotational speeds when said element is driven by said motor (9).
Claim 3
Dependent Claim
85 words
A steering system as claimed in claim 1, characterized in that when said element is not driven by said motor (9) said operatively connecting means operates so that the ratio of one of (a) the force transmitted between said input and output shafts (2,3) and (b) the rotational speeds of said input and output shaft (2,3) lies in the range of 0.9 to 1.1 and simultaneously the rotational speed ratio between said input and output shafts (2,3) and the said element is greater than 2.0.
Claim 4
Dependent Claim
66 words
A steering system as claimed in claim 1, characterized in that said operatively connecting means takes the form of a planetary gear train having: first and second sun gears (A,D); a carrier (S) on which first and second sets of pinion gears (B,C) are supported, said first and second sets of pinion gears (B,C) meshing with said first and second sun gears (A,D) respectively (Fig. 4).
Claim 5
Dependent Claim
59 words
A steering system as claimed in claim 3, characterized in that the number (Z A ,Z D ) of teeth on said first and second sun gears ( A , D ) are the same and the number (Z B' Z C ) of teeth on said first and second sets of pinion gears (B,C) are different (Fig. 4).
Claim 6
Dependent Claim
55 words
A steering system as claimed in claim 3, characterized in that the number (Z A ,Z D ) of teeth on said first and second sun gears (A,D) is different and the number (Z B ,Z C ) of teeth on said first and second sets of pinion gears (B,C) is the same (Fig. 4).
Claim 7
Dependent Claim
33 words
A steering system as claimed in claim 3, further characterized by a ring gear (C), said ring gear (C) being arranged to mesh with said first set of pinion gears (B) (Fig. 5).
Claim 8
Dependent Claim
43 words
A steering system as claimed in claim 6, characterized in that the number of teeth on said first and second sun gears are the same and the number of teeth on said first and second sets of pinion gears are different (Fig. 5).
Claim 9
Dependent Claim
43 words
A steering system as claimed in claim 6, characterized in that the number of teeth on said first and second sun gears is different and the number of teeth on said first and second sets of pinion gears is the same (Fig. 5).
Claim 10
Dependent Claim
22 words
A steering system as claimed in claim 3, characterized in that said element takes the form of said carrier (S) (Fig. 4).
Claim 11
Dependent Claim
23 words
A steering gear as claimed in claim 6, characterized in that said element takes the form of said ring gear (C) (Fig. 5).
Claim 12
Dependent Claim
60 words
A steering system as claimed in claim 1, characterized in that said operatively connecting means takes the form of a harmonic drive which includes: first and second rigid circular splines (A,C); a flexible spline (B) in drive connection with said first and second rigid circular splines (A,C); and a wave generator (D) in drrve connection with said flexible spline (B).
Claim 13
Dependent Claim
21 words
A steering system as claimed in claim 11, characterized in that said element takes the form of said wave generator (D).
Claim 14
Dependent Claim
21 words
A steering system as claimed in claim 11, characterized in that said element takes the form of said first circular spline.
Claim 15
Dependent Claim
80 words
A steering system as claimed in claim 11, further characterized by : a steering input gear (G) which is operatively connected with one of said first and second rigid circular splines, said steering input gear (G) being disposed in drive connection with steering input shaft (2), and a steering output gear (I), said steering output gear (I) being disposed in drive connection with said steering output shaft (3), said steering output gear (I) being operatively connected to said wave generator.
References Cited (Backward Citations)
No citation records indexed.
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