Many years ago, the final drive for the M55, a 50 ton 500 horse power
tracked vehicle, was redesigned and still failed.
The cross drive transmission has splines that drive the pinions that
drive bull gears that are on the same shaft as the sprockets that drive
the tracks.
An old man wants to know if there are now pre twisted spur gear pinions
so, when highly loaded, a gear will be twisted straight.
TIA

--
Be careful what you pray for, it can happen.

"Clark Magnuson" wrote in message
...
Many years ago, the final drive for the M55, a 50 ton 500 horse power
tracked vehicle, was redesigned and still failed.
The cross drive transmission has splines that drive the pinions that
drive bull gears that are on the same shaft as the sprockets that drive
the tracks.
An old man wants to know if there are now pre twisted spur gear pinions
so, when highly loaded, a gear will be twisted straight.
TIA


Chuckle!

You're kidding, right?

Once metal heat treated metal, as gears should be, has reached its yield
point, it's not exactly reliable. I may be mistaken, but I think that's
called broken teeth. Lets see what gear experts have to say.

Harold

"Harold and Susan Vordos" wrote in message
...

"Clark Magnuson" wrote in message
...
Many years ago, the final drive for the M55, a 50 ton 500 horse power
tracked vehicle, was redesigned and still failed.
The cross drive transmission has splines that drive the pinions that
drive bull gears that are on the same shaft as the sprockets that drive
the tracks.
An old man wants to know if there are now pre twisted spur gear pinions
so, when highly loaded, a gear will be twisted straight.
TIA


OK- I think this time it may make more sense-----I should read what I post
before doing so!

Chuckle!

You're kidding, right?

Once heat treated metal, as gears should be, has reached its yield
point, it's not exactly reliable. I may be mistaken, but I think that's
called broken teeth. Lets see what gear experts have to say.

Harold

One problem with this type of system is what I believe is called
recirculating horsepower. Although the engine might be able to provide
500hp to move the vehicle along, the actual tranmission may have to be
able to transmit 2000hp for instance. IIRC this situation arrises due to
the load on the tracks when steering.

Clark Magnuson wrote:

Many years ago, the final drive for the M55, a 50 ton 500 horse power
tracked vehicle, was redesigned and still failed.
The cross drive transmission has splines that drive the pinions that
drive bull gears that are on the same shaft as the sprockets that
drive the tracks.
An old man wants to know if there are now pre twisted spur gear
pinions so, when highly loaded, a gear will be twisted straight.
TIA

Yes quite right, and I failed to mention that the part of the
transmission which sees this problem is that which links the tracks
together. I only mentioned the issue because maybe the original
designers of the m55 didn't know about this or had failed ot take it
into account fully. It is possibly a non obvious problem which effects
the design of this type of vehicle.

Tom wrote:

David Billington wrote:

One problem with this type of system is what I believe is called
recirculating horsepower. Although the engine might be able to provide
500hp to move the vehicle along, the actual tranmission may have to be
able to transmit 2000hp for instance. IIRC this situation arrises due to
the load on the tracks when steering.

Clark Magnuson wrote:

Many years ago, the final drive for the M55, a 50 ton 500 horse power
tracked vehicle, was redesigned and still failed.
The cross drive transmission has splines that drive the pinions that
drive bull gears that are on the same shaft as the sprockets that
drive the tracks.
An old man wants to know if there are now pre twisted spur gear
pinions so, when highly loaded, a gear will be twisted straight.
TIA


I think you are confusing horsepower with torque...

Tom

David Billington wrote:

One problem with this type of system is what I believe is called
recirculating horsepower. Although the engine might be able to provide
500hp to move the vehicle along, the actual tranmission may have to be
able to transmit 2000hp for instance. IIRC this situation arrises due to
the load on the tracks when steering.

Clark Magnuson wrote:

Many years ago, the final drive for the M55, a 50 ton 500 horse power
tracked vehicle, was redesigned and still failed.
The cross drive transmission has splines that drive the pinions that
drive bull gears that are on the same shaft as the sprockets that
drive the tracks.
An old man wants to know if there are now pre twisted spur gear
pinions so, when highly loaded, a gear will be twisted straight.
TIA


I think you are confusing horsepower with torque...

Tom