Rolling-element telescoping shaft assembly

Patent metadata

Field	Value
Publication number	US-9958015-B2
Application number	US-201414498216-A
Country	US
Kind code	B2
Filing date	Sep 26, 2014
Priority date	Sep 27, 2013
Publication date	May 1, 2018
Grant date	May 1, 2018

Abstract

A rolling-element telescoping shaft assembly for connecting a driveshaft and transmitting a torque includes an outer shaft member extending along a longitudinal axis and defines an interior bore and inner surface. An inner shaft member is at least partially disposed within the bore and telescopically moveable relative thereto along the axis and defines an outer surface. Rolling-element outer grooves are arranged in the inner surface, distributed around the axis, and functional (i.e., used for transmitting a torque). Outer recesses are defined between the outer grooves and define a shorter distance between adjacent torque-transmitting outer grooves. Rolling-element inner grooves are defined on the outer surface and distributed around the axis. Rolling elements are rollingly arranged in the outer and inner grooves and rollingly engage the outer and inner shaft members during telescoping movement of the shaft assembly to reduce friction therebetween.

First claim

Having thus described the invention, it is claimed:

1. A rolling-element telescoping shaft assembly for connecting a driveshaft and transmitting a torque, the shaft assembly comprising:
an outer shaft member extending along a longitudinal axis and defining an interior bore and inner surface;
an inner shaft member at least partially disposed within the interior bore of the outer shaft member, telescopically moveable along the longitudinal axis relative to the outer shaft member, and defining an outer surface;
a plurality of formed outer prismatic recesses that are arranged about the inner surface of the outer shaft member;
a plurality of rolling-element outer grooves that are arranged in adjacent sets of at least two about the inner surface of the outer shaft member, the adjacent sets being distributed around the longitudinal axis without a prismatic recess disposed between the rolling-element outer grooves that define each adjacent set, used for the transmittal of the torque, and each of which defines a radius of the outer groove;
the plurality of formed outer prismatic recesses being defined between sets of the plurality of rolling-element outer grooves, the plurality of formed outer prismatic recesses without rolling elements define a distance between adjacent ones of the plurality of rolling-element outer grooves and a shape different than that of the rolling-element outer grooves and each of which defines a radius of the formed outer prismatic recess lesser than that of the outer grooves;
a plurality of rolling-element inner grooves that are arranged in sets of at least two about the outer surface of the inner shaft member that are complementary to the adjacent sets of the plurality of rolling-element outer grooves, the complementary sets being distributed around the longitudinal axis, and each of which defines a radius of the inner groove;
a plurality of formed inner prismatic recesses that define a shape different than that of the outer and inner grooves and are defined between the sets of the plurality of rolling-element inner grooves and are arranged such that corresponding outer and inner recesses are radially spaced from each other and each of which defines a radius of the inner recess lesser than that of the inner and outer grooves; and
a plurality of rolling elements that are rollingly arranged in the outer and inner grooves, the plurality of rolling elements rollingly engage the outer and inner shaft members during telescoping movement of the shaft assembly and guide a cage that is arranged between the outer surface of the inner shaft member and the inner surface of the outer shaft member, the cage defining a plurality of radial-through pockets in which the rolling elements are engaged and kept spaced apart from each other.

2. The shaft assembly of claim 1 , wherein the bore is substantially centered on the longitudinal axis.

3. The shaft assembly of claim 1 , wherein the inner surface of the outer shaft member is at least one of substantially circular-cylindrical and multi-lobed.

4. The shaft assembly of claim 1 , wherein the outer recesses are distributed between the outer grooves and arranged substantially parallel with the longitudinal axis.

5. The shaft assembly of claim 1 , wherein a width of the outer recesses at the bore is lesser than a width of the outer grooves at the bore.

6. The shaft assembly of claim 1 , wherein the inner grooves are distributed around the longitudinal axis and extend substantially parallel therewith.

7. The shaft assembly of claim 1 , wherein a number of the inner grooves corresponds to a number of the outer grooves, each of the inner grooves is arranged substantially opposite to a corresponding one of the outer grooves to form pairs, and at least one of the rolling elements is rollingly arranged in each of the pairs of the opposed outer and inner grooves.

8. The shaft assembly of claim 7 , wherein the pairs are arranged in groups of three adjacent pairs.

9. The shaft assembly of claim 8 , wherein the cage is sleeve-like.

10. The shaft assembly of claim 8 , wherein the rolling elements are engaged and kept spaced from each other in a set of imaginary planes defined in the outer and inner grooves.

11. The shaft assembly of claim 10 , wherein the set of imaginary planes are defined substantially perpendicular to the longitudinal axis.

12. The shaft assembly of claim 1 , wherein the outer and inner grooves are arranged substantially opposite to each other around the longitudinal axis in groups of two or three adjacent pairs of the grooves.

13. The shaft assembly of claim 12 , wherein the number of pairs is a multiple of two or three and greater than or equal to four.

14. A rolling-element telescoping shaft assembly comprising:
an outer shaft member defining an interior bore and inner surface;
an inner shaft member at least partially disposed within the interior bore of the outer shaft member defining an outer surface;
a plurality of rolling-element outer grooves, the plurality of rolling-element outer grooves are arranged in sets of at least two adjacent pairs about the inner surface of the outer shaft member without a prismatic recess disposed between the rolling-element outer grooves that define each adjacent pair, and each of which defines a radius of the outer groove;
a plurality of formed outer prismatic recesses that are defined between respective upper parts of the outer grooves and empty and define a distance between adjacent ones of the torque-transmitting outer grooves and a shape different than that of the outer grooves and each of which defines a radius of the outer recess lesser than that of the outer grooves;
a plurality of rolling-element inner grooves distributed around the longitudinal axis, are defined on the outer surface of the inner shaft member, and each of which defines a radius of the inner groove;
a plurality of formed inner prismatic recesses that define a shape different than that of the outer and inner grooves and are empty and defined between respective lower parts of the inner grooves such that corresponding outer and inner recesses are radially spaced from each other and each of which defines a radius of the inner recess lesser than that of the inner and outer grooves;
a plurality of rolling elements that are rollingly arranged in the outer and inner grooves and rollingly engage the outer and inner shaft members during telescoping movement of the shaft assembly; and
a sleeve-like cage that is arranged within the interior bore of the outer shaft member between the outer surface of the inner shaft member and inner surface of the outer shaft member, the sleeve-like cage defines a plurality of radial-through pockets in which corresponding ones of the rolling elements are engaged and kept spaced from each other in a set of imaginary planes defined in the outer and inner grooves and defined substantially perpendicular to the longitudinal axis.

15. The rolling-element telescoping shaft assembly of claim 14 , wherein a depth of each of the plurality of formed inner prismatic recesses is different than a depth of each of the plurality of formed outer prismatic recesses.

Assignees

• Steering Solutions Ip Holding

Inventors

• Mondragon Eduardo
• Skvarla William P

Classifications

• F16D3/065 Primary

  by means of rolling elements · CPC title