GB2050532A

GB2050532A - A Linear Recirculating Roller Bearing Assembly

Info

Publication number: GB2050532A
Application number: GB8004974A
Authority: GB
Original assignee: Dabringhaus G H
Current assignee: Dabringhaus G H
Priority date: 1979-03-09
Filing date: 1980-02-14
Publication date: 1981-01-07
Also published as: IT1126845B; FR2453798A1; IT7951192A0; JPS55119604A

Abstract

A linear recirculating roller bearing assembly 10 including a body defining an elongated block 12 having a load surface 16 and a spaced parallel return surface 18 interconnected by end surfaces 20 and a pair of flanges 14 integral therewith and extending along the sides of the block to define support portions 24 extending outwardly of each end of the block. A plurality of rollers 26 having cylindrical bearing surfaces and stub shafts 30 extending from the ends of the bearing surfaces are disposed in side-by-side relationship with one another and distributed along a continuous path about the block for rolling movement along the path. The rollers are interconnected by links 28 associated with the stub shafts. A sprocket 32 is rotatably supported in the support portions in each of the flanges adjacent each end of the block and includes pockets for engaging the bearing surfaces of the rollers for aligning the rollers perpendicularly to the direction of movement of the rollers along the path. <IMAGE>

Description

SPECIFICATION A Linear Recirculating Roller Bearing Assembly Technical Field The present invention relates to a linear recirculating roller bearing assembly which includes a plurality of rollers disposed in sideby-side relationship with one another for rolling movement along a load surface and recirculation along a return surface to the load surface.

Background Art Such linear recirculating roller bearing assemblies have previously been proposed and are of various different configurations, such as described in U.S. Patents Nos. 3,003,828, 3,341 ,262, 3,920,289, 3,964,802 and 4,102,553. One of the problems with such roller bearing assemblies is that the rollers can become cocked or skewed relative to their direction of rolling movement whereby the workpiece supported for rolling movement by them has the tendency or is urged to move at an angle relative to the desired path of movement and if the rollers remain in this condition scuffing or sliding movement between the rollers and the supported workpiece can occur. In other words, if the rollers are disposed at an angle other than 900 or perpendicular to the path of movement, undesirable loads result.

It is an object of the present invention to alleviate these disadvantages of prior proposals.

Statement of Invention According to the present invention there is provided a linear recirculating roller bearing assembly comprising: a body defining an elongated block having a load surface and a return surface, the surfaces being spaced apart with ends extending therebetween, a plurality of rollers disposed in side-by-side relationship with one another and distributed along a continuous path about the surfaces and the ends of the block for rolling movement along the path, retaining means for retaining the rollers in the path, and alignment means disposed at least at one stationary position along the path to engage the rollers and align them perpendicularly to their direction of movement along the path.

Preferably the alignment means includes a sprocket disposed adjacent one or more of the ends of the block, the rollers being entrained about the or each said sprocket so as to be aligned while moving between the surfaces, and the or at least one end of the block having a sprocket associated therewith may have a face extending substantially transversely to the load surface with a bevelled corner extending between the load surface and the or each said end face to permit unloading of the rollers prior to engaging the sprocket.Support portions may extend outwardly beyond the or each said end having a sprocket associated therewith to rotatably support trunnions of the or each sprocket, and where the body includes a side flange along each of the opposed sides of the block, with the flanges projecting from the load and return surfaces to define channels for the rollers, the support portions are conveniently defined by the flanges.

Preferably the flanges are formed integrally with the block.

Figures in the Drawings One embodiment of an assembly in accordance with the present invention will now be described by way of example only, with reference to the accompanying drawings, in which: Figure 1 is a plan view partially broken away and in cross-section of the embodiment; Figure 2 is a side elevational view taken substantially along line 2-2 of Figure 1; Figure 3 is a cross-sectional view taken substantially along line 3-3 of Figure 2; Figure 4 is a cross-sectional view taken substantially along line 4-4 of Figure 1; and Figure 5 is a fragmentary enlarged crosssectional view taken substantially along line 5-5 of Figure 3.

Detailed Description of the Drawings A linear recirculating roller bearing assembly constructed in accordance with the present invention is generally shown at 10.

The assembly 10 includes an integral body defining an elongated block 12 and side flanges 14. The block 12 includes an upper load surface 1 6 and a bottom return surface 1 8. The load surface 16 and the return surface 1 8 are parallel and spaced apart with ends 20 extending transversely to and between the surfaces 1 6 and 1 8. The ends 20 have faces which extend transversely to the load surface 1 6 and a bevelled corner 22 extends between the load surface 1 6 and each end face 20, the purpose of which will be explained more fully hereinafter.

The flanges 14 are integral with the block 12 and extend along opposite sides of the block 1 2.

The flanges 1 4 extend upwardly or away from the respective load and return surfaces 1 6 and 1 8. In other words, the flanges 14 extend from the respective surfaces 1 6 and 1 8 to form channels.

The flanges 14 also include support portions 24 extending outwardly beyond the ends 20 of the block 12.

The assembly 10 also includes a plurality of rollers 26 disposed in side-by-side relationship with one another, i.e. parallel to one another. The rollers are distributed along a continuous path about the load and return surfaces 16 and 18 and the ends 20 of the block 12 for rolling movement along the continuous path.

There is also included retaining means comprising links 28 for interconnecting the rollers 26 and retaining the rollers 26 in the continuous path. The rollers 26 include cylindrical bearing surfaces extending between opposite ends with stub shafts 30 extending from each end of the cylindrical bearing surfaces. The links 28 interconnect the stub shafts 30 of the adjacent rollers 26.

The assembly also includes alignment means disposed at least at one stationary position along the continuous path of movement to engage the rollers 26 for aligning the rollers 26 perpendicularly to the movement of the rollers 26 along the continuous path. More specifically, the alignment means includes sprockets 32 disposed adjacent the ends 20 of the block 12. The rollers 26 are entrained about the sprockets 32 so as to be aligned perpendicularly to the path of movement as the rollers move between the load and return surfaces 1 6 and 1 8. The sprockets 32 have trunnions 34 rotatably supported in the support portions 24 of the flanges 14. The sprockets include pockets which engage the cylindrical bearing surfaces of the rollers 26. The pockets in the sprocket extend between the support portions 24 of the flanges 14.In other words, the pockets of the sprockets 32 engage the entire length of the cylindrical bearing surfaces of the rollers 26.

There is also included bearing means defined by bushings 36 disposed in openings through the support portions 24 of the flanges 14 for rotatably supporting the trunnions 34 of the sprockets 32.

The openings in the support portions 24 in which the bushings 36 are disposed are large enough in diameter to allow the sprockets 32 to pass therethrough during assembly. The bushings 36 may be retained in the openings in any wellknown technique as, for xample, being held in place by a set screw which is not shown.

The flanges 14 include holes 38 through which bolts may be inserted for attaching the assembly to a support structure whereby the bottom of the flanges 14 as viewed in Figures 2 to 6 of the drawings would be secured on a support surface and a moving supported member may be disposed upon the rollers 26 as they move along the load surface 1 6. As the rollers 26 move along the continuous path they will, of course, support a load as they move along the load surface 16. The bevelled portions 22 allow the rollers to become unloaded just prior to being engaged by the sprockets 32. The pockets in the sprockets 32 are highly machined to an accurate dimension and configuration so that the sprockets precisely align the rollers 26 so that the rollers are perpendicular to their path of movement As will be appreciated, if the rollers 26 are at all skewed to the direction of movement, scuffing can occur as the load supported on the rollers 26 would be urged to move in a direction at an angle to the path of movement of the rollers 26. The sprockets, therefore, precisely align the rollers to avoid wear and undesired forces in the assembly.

Claims

1. A linear recirculating roller bearing assembly comprising: a body defining an elongated block having a load surface and a return surface, the surfaces being spaced apart with ends extending therebetween, a plurality of rollers disposed in side-by-side relationship with one another and distributed along a continuous path about the surfaces and the ends of the block for rolling movement along the path, retaining means for retaining the rollers in the path, and alignment means disposed at least at one stationary position along the path to engage the rollers and align them perpendicularly to their direction of movement along the path.

2. An assembly as claimed in claim 1 wherein the alignment means includes a sprocket disposed adjacent one or more of the ends of the block, the rollers being entrained about the or each said sprocket so as to be aligned while moving between the surfaces.

3. An assembly as claimed in claim 2 wherein said rollers include cylindrical bearing surfaces extending between the ends thereof and the or each sprocket includes pockets for engaging said bearing surfaces.

4. An assembly as claimed in claim 3 wherein the pockets have machined-finished surfaces.

5. An assembly as claimed in claim 3 or claim 4 wherein the pockets engage the full length of the cylindrical bearing surface of each roller.

6. An assembly as claimed in any one of claims 2 to 5 wherein the or at least one end of the block having a sprocket associated therewith has a face extending substantially transversely to the load surface and wherein a bevelled corner extends between the load surface and the or each said end face.

7. An assembly as claimed in any one of claims 2 to 6 wherein support portions extend outwardly beyond the or each said end having a sprocket associated therewith, and the sprocket or sprockets have trunnions rotatably supported in the support portions.

8. An assembly as claimed in claim 7 including bearing means disposed in openings through the support portions for rotatably supporting the trunnions.

9. An assembly as claimed in claim 8 wherein the openings in the support portions are large enough to allow the associated sprocket to pass therethrough during assembly.

10. An assembly as claimed in any one of the preceding claims wherein the body includes a side flange extending along each of the opposed sides of the block, the flanges projecting from the load and return surfaces to define channels for the rollers.

11. An assembly as claimed in claim 10 when dependent from any one of claims 7 to 9 wherein the flanges extend outwardly beyond the or each said end having a sprocket associated therewith to define said support portions.

12. An assembly as claimed in claim 10 or claim 11 wherein the flanges and the block are integrally formed.

13. An assembly as claimed in any one of the preceding claims wherein the rollers include stub shafts extending from each end thereof and the retaining means includes a plurality of links interconnecting the stub shafts of adjacent rollers.

14. A linear recirculating roller bearing assembly substantially as herein described with reference to the accompanying drawings.