Re: Truck bearings: Solid vs. RB


tyesac@...
 

Richard, Pierre,

Right you are! If anybody thinks that solid bearings are obsolete technology, think again. Anything driven by a crankshaft has solid bearings; from a formula 1 race car to diesel locomotive. Properly lubricated, they're a low resistance bearing that's able to tolerate heavy loads. A key issue for the changeover for the railroads was that roller bearings have less finicky lubrication requirements, typically only the roller cage requires greasing at initial installation. Having large percentages of the freight car fleet that doesn't require constant vigilance for oiling helped tip the scales for the more expensive roller bearings.

Now if we could only get some model RR manufactures to drop the "friction bearing" term.

Tom Casey


Thanks Richard, for that clarification. I've never been comfortable with the "friction bearing" phrase myself and I've always wondered what the correct term should be. In part because a solid bearing is closer to a bushing than a bearing in my world of mechanical creations.
Pierre Oliver

--- In STMFC@..., Richard Hendrickson <rhendrickson@...> wrote:

Several times lately I have noticed members of this group using the
term "friction bearings" to differentiate solid bearings from roller
bearings, despite objections on previous occasions from myself, Tony
Thompson, and others. The correct terminology for solid truck
bearings is "solid." "Plain bearings" is an acceptable alternative.
"Friction bearings" is wrong and misleading. All bearings have
friction, including roller bearings. "Friction bearing" was invented
as an advertising ploy by roller bearing manufacturers to imply,
incorrectly, that roller bearings were frictionless. In fact, though
roller bearings have much less starting resistance than solid
bearings, they have considerable friction which - as with other
bearings - increases as load and speed increase. The term "friction
bearings" was never adopted by railroad mechanical engineers, who
knew better; it does not appear in the dictionary section of any
edition of the Car Builders' Cyclopedia. So please, guys, don't
perpetuate the mistake of calling solid bearings "friction" bearings.

Richard Hendrickson





-----Original Message-----
From: Pierre <pierre.oliver@...>
To: STMFC <STMFC@...>
Sent: Wed, Apr 25, 2012 7:49 pm
Subject: [STMFC] Re: Truck bearings: Solid vs. RB




Thanks Richard, for that clarification. I've never been comfortable with the "friction bearing" phrase myself and I've always wondered what the correct term should be. In part because a solid bearing is closer to a bushing than a bearing in my world of mechanical creations.
Pierre Oliver

--- In STMFC@..., Richard Hendrickson <rhendrickson@...> wrote:

Several times lately I have noticed members of this group using the
term "friction bearings" to differentiate solid bearings from roller
bearings, despite objections on previous occasions from myself, Tony
Thompson, and others. The correct terminology for solid truck
bearings is "solid." "Plain bearings" is an acceptable alternative.
"Friction bearings" is wrong and misleading. All bearings have
friction, including roller bearings. "Friction bearing" was invented
as an advertising ploy by roller bearing manufacturers to imply,
incorrectly, that roller bearings were frictionless. In fact, though
roller bearings have much less starting resistance than solid
bearings, they have considerable friction which - as with other
bearings - increases as load and speed increase. The term "friction
bearings" was never adopted by railroad mechanical engineers, who
knew better; it does not appear in the dictionary section of any
edition of the Car Builders' Cyclopedia. So please, guys, don't
perpetuate the mistake of calling solid bearings "friction" bearings.

Richard Hendrickson











[Non-text portions of this message have been removed]

Join main@RealSTMFC.groups.io to automatically receive all group messages.