Progressive Gearing

• US 20080257085A1
• Filed: 01/23/2006
• Published: 10/23/2008
• Est. Priority Date: 01/25/2005
• Status: Active Grant

• Current Assignee: Werner M. Bless
• Original Assignee: Werner M. Bless
• Inventors: Rott, Erwin, Bless, Werner M.
• Granted Patent: US 8,196,487 B2
• Time in Patent Office: Days
• US Class Current: 74/421R
• CPC Class Codes: B62D 3/12 of rack-and-pinion type
• CPC Class Codes: F16H 19/04 comprising a rack
• CPC Class Codes: F16H 2035/003 Gearings comprising pulleys or toothed members of non-circular shape, e.g. elliptical gears
• CPC Class Codes: F16H 35/02 for conveying rotary motion with cyclically varying velocity ratio
• CPC Class Codes: Y10T 74/1967 Rack and pinion
• CPC Class Codes: Y10T 74/19679 Spur
• CPC Class Codes: Y10T 74/19884 Irregular teeth and bodies

Abstract

A progressive gear assembly comprises at least one spur gear (1, 2) and a toothed structure (3, 4, 5, 7, 8) with which the spur gear (1, 2) meshes. The spur gear (1, 2) has teeth (11) arranged along a curve (10), the curve (10) comprising a radius of curvature (r) which monotonically rises over an angular range of more than 90° of the curve (10). Preferably the curve is a spiral, particularly a logarithmic spiral. This gear assembly is configured compact and simple, features smooth running and achieves a late end point.

Claims

1. A progressive gear assembly that is a vehicle steering gear, the gear assembly comprising at least one spur gear and a toothed structure with which the spur gear meshes, the spur gear comprising teeth arranged along a curve wherein the curve comprises a radius of curvature which monotonically increases over an angular range of more than 90°

of the curve.

2. The gear assembly as set forth in claim 1 wherein the radius of curvature is a minimum in a center position of the spur gear.

3. The gear assembly as set forth in claim 1 wherein the curve of the spur gear is a spiral.

4. The gear assembly as set forth in claim 1 wherein the at least one spur gear is rotatable about an axis of rotation and the at least one curve comprises a center point which coincides with the axis of rotation of the spur gear.

5. The gear assembly as set forth in claim 3 wherein the curve is a logarithmic spiral at least portionwise, preferably over at least an angular range of 90°

.

6. The gear assembly as set forth in claim 1 wherein the teeth are arranged over an angular range of more than 180°

and less than 360°

, particularly roughly 270°

, on the curve and a remaining circumferential portion of the spur gear is configured toothless.

7. The gear assembly as set forth in claim 1 wherein the spur gear comprises a first and a second group of teeth the first and the second group of teeth each being arranged along a first and a second curve respectively, the first and the second curve each extending over an angular range of the spur gear of 180°

, the two curves being mirror symmetrical.

8. The gear assembly as set forth in claim 1 wherein the gear assembly comprises in addition at least one spur gear, the teeth of which are arranged on a circle.

9. The gear assembly as set forth in claim 1 wherein the toothed structure is at least one gear rack.

10. The gear assembly as set forth in claim 9 wherein the at least one gear rack is configured ramped.

11. The gear assembly as set forth in claim 10 wherein the at least on gear rack comprises a middle tooth at its apex.

12. The gear assembly as set forth in claim 9 wherein at least two gear racks are arranged at least in part one after another and staggered parallel to each other, at least two spur gears being provided, one spur gear of which meshes with one gear rack each.

13. The gear assembly as set forth in claim 12 wherein the at least two gear racks arranged at least in part one after another comprise opposing ramps, each having an apex in a portion adjoining each other.

14. The gear assembly as set forth in claim 9 wherein the at least one gear rack comprises at least one broad and at least one narrow portion wherein, depending on a position of the spur gear this spur gear meshes with the narrow portion or at least one other spur gear meshes with the broad portion.

15. The gear assembly as set forth in claim 9 wherein the at least one gear rack comprises teeth arranged linear.

16. The gear assembly as set forth in claim 9 wherein the at least one gear rack comprises teeth arranged along a curved line.

17. The gear assembly as set forth in claim 1 wherein the toothed structure is a spur gear rotatable about an axis of rotation, the spur gear comprising teeth arranged along a curve with a radius of curvature monotonically increasing over an angular range of more than 90°

of the spur gear.

18. The gear assembly as set forth in claim 17 wherein the spur gear as set forth in claim 1 and the spur gear as set forth in claim 17 have the same number of teeth and the same shape of curve.

20. The gear assembly as set forth in claim 1 wherein in a center position of the steering gear the curve comprises a minimum radius of curvature in a portion in which the spur gear contacts the toothed structure.

21. The gear assembly as set forth in claim 20 wherein the radius of curvature of the curve, starting with a minimum radius of curvature monotonically rises over an angular range of at least 90°

, particularly at least 180°

.

22. The gear assembly as set forth in claim 1 wherein in a center position of the steering gear the distance between an axis of rotation of the spur gear and a contact range of the spur gear with the toothed structure is a minimum.

19. (canceled)