Single-stage gear reduction output mechanism with a locking fork providing anti-back drive capability for automotive seat adjuster drives

Patent metadata

Field	Value
Publication number	US-9902295-B2
Application number	US-201615245719-A
Country	US
Kind code	B2
Filing date	Aug 24, 2016
Priority date	Aug 25, 2015
Publication date	Feb 27, 2018
Grant date	Feb 27, 2018

Abstract

A single-stage gear reduction output mechanism for an automotive seat assembly including a gear housing bracket, gear housing, axle shaft, eccentric, and first and second gears. The axle shaft extends through the eccentric with a slip fit, the first gear rotates with the axle shaft, and the second gear is carried on a first bearing surface of the eccentric and meshingly engages the first gear in a planetary arrangement. A locking plate including first, second, and third slot cutouts is disposed within the gear housing. A support pin extends from the gear housing through the first slot cutout and a second bearing surface of the eccentric extends through the second slot cutout to support the locking plate and limit its movement along a lateral axis. The second gear includes a first pin that extends through the third slot cutout to prevent the first gear from back-driving the second gear.

First claim

What is claimed is:

1. A single-stage gear reduction output mechanism for an automotive seat adjuster drive, said single-stage gear reduction output mechanism comprising:
a gear housing bracket;
a gear housing extending from said gear housing bracket to define a cavity therein;
an axle shaft disposed within said cavity of said gear housing and extending along an axis of rotation;
said axle shaft being supported within said cavity of said gear housing such that said axle shaft is free to rotate about said axis of rotation;
an eccentric carried on said axle shaft and including a first bore that is concentric with said axle shaft, a first bearing surface that is eccentric relative to said axle shaft, and a second bearing surface that is concentric with said axle shaft;
said axle shaft extending through said first bore in said eccentric with a slip fit such that said eccentric is free to rotate relative to said axle shaft;
a first gear carried on said axle shaft that is rotatably coupled with said axle shaft such that said first gear rotates with said axle shaft about said axis of rotation;
a second gear carried on said first bearing surface of said eccentric and disposed in meshing engagement with said first gear;
said second gear including a second bore and a centerline axis that extends co-axially through said second bore;
said first bearing surface of said eccentric extending through said second bore in said second gear with a slip fit such that said eccentric is free to rotate relative to said second gear;
said first gear and said second gear having a planetary arrangement where said centerline axis of said second gear is parallel to and spaced from said axis of rotation of said axle shaft;
a locking plate disposed within said cavity of said gear housing and including a first slot cutout, a second slot cutout, and a third slot cutout;
a support pin rigidly fixed in place relative to said axle shaft that is parallel to and spaced from said axis of rotation of said axle shaft and that extends through said first slot cutout in said locking plate;
said second bearing surface of said eccentric extending through said second slot cutout in said locking plate where said second bearing surface of said eccentric and said support pin cooperate to support said locking plate within said cavity of said gear housing and limit movement of said locking plate relative to said gear housing to movement along a lateral axis that is transverse to said axis of rotation of said axle shaft; and
said second gear including a first pin that is spaced from and parallel to said centerline axis of said second gear where said first pin extends through said third slot cutout in said locking plate and prevents said first gear from driving rotation of said second gear.

2. The single-stage gear reduction output mechanism of claim 1 , wherein said locking plate is longitudinally offset relative to said first and second gears.

3. The single-stage gear reduction output mechanism of claim 2 , wherein said first and second bearing surfaces of said eccentric are cylindrical and are arranged next to one another on said eccentric relative to and along said axis of rotation, said first bearing surface having a first radius, and said second bearing surface having a second radius that is smaller than said first radius to form a slot in said eccentric that is longitudinally aligned with said second bearing surface.

4. The single-stage gear reduction output mechanism of claim 3 , wherein at least part of said locking plate is slidingly received in said slot in said eccentric.

5. The single-stage gear reduction output mechanism of claim 1 , wherein said locking plate includes a fourth slot cutout and said second gear includes a second pin that is spaced from and parallel to said centerline axis of said second gear and said first pin where said second pin extends through said fourth slot cutout in said locking plate and cooperates with said first pin to prevent said first gear from driving rotation of said second gear.

6. The single-stage gear reduction output mechanism of claim 5 , wherein said first and second slot cutouts in said locking plate are spaced apart and extend along said lateral axis of said locking plate and wherein said third and fourth slot cutouts are disposed on opposite sides of said lateral axis and are transverse to said lateral axis.

7. The single-stage gear reduction output mechanism of claim 5 , wherein said first slot cutout of said locking plate has a rectangular shape that is closed on four sides and said second, third, and fourth slot cutouts of said locking plate each has a U-like shape that is open on one side.

8. The single-stage gear reduction output mechanism of claim 1 , wherein said first gear includes a number of internal teeth and said second gear includes a number of external teeth that are meshingly engaged with said internal teeth of said first gear and wherein said first pin of said second gear and said locking plate constrain said second gear to a planetary, wobbling movement around said axis of rotation of said shaft and within said internal teeth of said first gear when said eccentric is rotatably driven.

9. The single-stage gear reduction output mechanism of claim 8 , wherein said first and second gear have a gear ratio that is a positive number equaling said number of internal teeth of said first gear divided by the difference between said number of internal teeth of said first gear and said number of external teeth of said second gear.

10. The single-stage gear reduction output mechanism of claim 1 , wherein said first gear includes a number of external teeth and said second gear includes a number of internal teeth that are meshingly engaged with said external teeth of said first gear and wherein said first pin of said second gear and said locking plate constrain said second gear to a planetary, wobbling movement around said axis of rotation of said shaft and about said external teeth of said first gear when said eccentric is rotatably driven.

11. The single-stage gear reduction output mechanism of claim 10 , wherein said first and second gear have a gear ratio that is a negative number equaling said number of external teeth of said first gear divided by the difference between said number of internal teeth of said second gear and said number of external teeth of said first gear.

12. The single-stage gear reduction output mechanism of claim 1 , wherein said support pin and said first pin are cylindrical in shape.

13. The single-stage gear reduction output mechanism of claim 12 , wherein said support pin and said first pin each includes a roller sleeve that is free to rotate.

14. The single-stage gear reduction output mechanism of claim 1 , wherein said support pin extends between a first support pin end that is supported by said gear housing and a second support pin end that is supported by said gear housing bracket.

15. The single-stage gear reduction output mechanism of claim 1 , wherein said gear housing bracket includes a bearing sleeve, said first gear includes an external bearing surface that contacts and extends through said bearing sleeve, and said axle shaft is support by said housing at one end and said first gear and said bearing sleeve at another end.

16. An automotive seat adjuster drive comprising:
a gear housing bracket;
a gear housing extending from said gear housing bracket to define a cavity therein;
an axle shaft disposed within said cavity of said gear housing and extending along an axis of rotation;
said axle shaft being supported within said cavity of said gear housing s

Assignees

• Fisher & Co Inc

Inventors

• Napau Mircea
• Napau Doina
• Napau Ileana Dacia
• Lenane Dean
• Essian Matthew
• Napau Ioan

Classifications

• B60N2/1835

  pivoting about an axis located in the front · CPC title

• B60N2/1867 Primary

  Cycloidal or planetary mechanism · CPC title

• B60N2/1871 Primary

  Worm and worm gear articulations · CPC title

• B60N2/1864

  Gear wheel driven mechanism · CPC title

• B60N2/0232

  Operations & Transport · mapped topic