Re: Solid Bearings vs. Roller Bearings

Todd Horton

Solid bearings have less drag than roller bearings at speed. The initial start up from a dead stop might favor roller bearings but the  mechanical drag of metal against metal in a roller bearing causes more resistance at higher speeds,

Roller bearing are superior when it comes to minimal amounts of lubrication where as a solid bearing will quickly fail under the same conditions.

Internal combustion engines are a prefect example of this. In 70's and 80's a lot of motorcycle engines were built using roller bearings on the crankshafts and connecting rods, As the power in these engines continued to elevate to higher levels these engines went to solid bearings for cranks and rods because of mechanical drag and horsepower loss.

A  somewhat educated guess, but a 1000cc 4 cylinder engine at 10,000 rpms will probably make about 10 hp over a similar engine with roller bearings. 

Two cycle engines, with roller bearing cranks and rods with a slight amount of oil mixed in with the gas will live a long time. They could make more power if they used a closed loop pressurized oiling system but that presents another set of problems not for discussion on a  freight car related message board.

Todd Horton

From: "thecitrusbelt@... [STMFC]"
To: STMFC@...
Sent: Thursday, March 23, 2017 3:37 PM
Subject: [STMFC] Solid Bearings vs. Roller Bearings

I found this statement in Volume 72 of the Proceedings Of The American Railway Engineering Association:
"There is no appreciable difference between solid bearings and roller bearings above 35 mph, but other mechanical considerations heavily favor the use of all roller bearings."
I believe I have seen this same statement elsewhere.
So what other mechanical considerations favor the use of all roller bearings?
Bob Chaparro
Hemet, CA

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