OT-linear bearings

[Chuck Wintle]

I was wondering if anyone is familiar with linear bearings. The reason I am asking is one failed on the testing machine i run at work. These bearings are fed oil under pressure and are there to support a table which moves back and forth. anyway the bearing surface showed some spalling. there are 3 in a line and the other 2 are ok.
thanks,
chuck

[Jerry Bruette]

Hi Chuck

I work with different kinds and types of linear bearings every day at work. It's part of my job to maintain and replace them when needed.

Some of the linears are made by Thomson and some by THK, and other companies. We do see spalling or grooves cut into the rails, usually from balls that aren't recirculating.

How heavy of a load and how many cycles per minute do the linears handle?

For being made the way they are they are amazingly tough.

Jerry

[Chuck Wintle]

Hi Chuck

I work with different kinds and types of linear bearings every day at work. It's part of my job to maintain and replace them when needed.

Some of the linears are made by Thomson and some by THK, and other companies. We do see spalling or grooves cut into the rails, usually from balls that aren't recirculating.

How heavy of a load and how many cycles per minute do the linears handle?

For being made the way they are they are amazingly tough.

Jerry
jerry,

This type work under high pressure, 2500 PSI, and there are no ball bearings in them. The travel is +/- 1 inch and the cycles/second can be as high as 2000. The load on the table is abput 1100 lbs spread over 3 bearings. The bearing at the end of the table is the one that gave up.

[Jerry Bruette]

Yikes, way different than the linears I deal with. How does the machine keep 2500 p.s.i. in a bearing that moves on a shaft in a linear motion?

Could it be that there was a leak and the hydraulic fluid eroded a spot on the shaft and it had the appearance of spalling?

Jerry