PIECE D'ECARTEMENT POUR ARBRE DE TRANSMISSION

SPACER FOR TRANSMISSION SHAFT

Abrégé anglais

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Title
Spacer for Transmission Shaft
Abstract of the Invention
An improved spacer for a transmission gear shaft
facilitates axial locations of pairs of gears or
bearings along the shaft. In a preferred form the
spacer comprises an open coil member which defines a
helicoidal body portion resiliently disposed between
a pair of bearings. In addition to axially locating
the bearings relative to one another, the helicoidal
body portion facilitates the flow of splash and spray
oil along the shaft between the bearings. In the
same preferred form, the spacer is made of a non-heat
treated high carbon spring steel.

Revendications

THE EMBODIMENTS OF THE INVENTION IN WHICH AN EXCLUSIVE
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. A spacer disposed for circumferentially encasing a
non-rotatable transmission gear shaft, said spacer
comprising a helicoidal body portion defining an open coil,
said body portion having ends resiliently disposed between a
pair of bearings rotatably supported on said shaft, said
bearings supporting a gear rotatable about said
non-rotatable shaft, said body portion being radially
encased by said gear, said body portion causing a unidirec-
tional axial flow of splash and spray oil along said shaft
between said rotating bearings thereby defining an axial
flow pumping means, said ends of said coil being squared and
defining radially uniform resilient support surfaces for
contact with opposing ends of said bearings, said shaft
having an outside diameter slightly less than the inside
diameter of the spacer, whereby as said bearings rotate
about said non-rotatable shaft, said spacer rotates about
said shaft with said bearings.
2. The spacer of Claim 1 wherein said ends are
squared for establishing a radially uniform support surface
for contact with each of said bearings.
3. The spacer of Claim 1 wherein said shaft is a non-
rotatable reverse idler shaft, and wherein the shaft
contains a rotatable gear supported on said non-rotatable
shaft radially outwardly of said spacer, whereby said splash
and spray oil is urged through the bearings disposed either
side of said spacer by said helicoidal body portion of said
spacer.
4. The spacer of Claim 3 wherein said gear shaft has
an outside diameter less than the inside diameter of the
spacer.
5. The spacer of Claim 3 wherein said helicoidal body
portion is a non-heat treated, high carbon spring steel.

6. The spacer of Claim 5 wherein said squared ends
are disposed for making resilient contact with needle
bearings.

Description

$
Title
Spacer for Transmission Shaft
Back~round of the Invention
This invention relates ~o spacer members
positioned on transmission gear shafts for axially
locating gears and bearings. The majority of
standard or manually shifted transmissions are
internally lubricated by "splash and spray" oil,
whereby rotatiny members within the transmission
housing extend into an oil sump at the bottom of the
transmission housing and disperse oil over the
internals of the transmission. Numerous efforts have
been made to achieve satisfactory oil dispersions
within the transmission housing; one of the more
noteworthy being the use of troughs which receive oil
thrown randomly for redirecting same to specific
locations within the housing. One particular
location of critical importance, for example, is the
transmission pocket bearing. Another of such
locations is the reverse idler shaft which is
typically non-rotatable, but carries a reverse idler
gear rotatable thereabout on needle bearings
interposed between gear and shaft members.
~rypically, two such sets of needle bearings are
utilized to support the rotation of the reverse idler
gear. A spacer member is positioned between the sets
of needle bearings to first axially locate the
bearings, and then to insure proper rotational
position of the bearings during operation. Typical
spacers are generally tubular in design, and operate
only to hold the bearings apart, providing no
facilitation of lubrication of the bearingsO

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Summary of he Invention
The transmission gear shaft spacer disclosed
herein provides a system whereby a flow of splash and
spray oil along the shaft between the bearings is
facilitated. In a preferred form, the spacer has
squared ends which engage a pair of bearings
supporting a rotatable reverse idler gear on a
non-rotatable shaft. The spacer defines a helicoidal
body of an open coil configuration, the squared ends
providing radially uniform support surfaces
resiliently disposed between the bearingsO In a
preferred form the helicoidal body is of a non-heat
treated high carbon steel.
A second embodiment of a transmission gear shaft
spacer defines a helicoidal body of a closed coil
configuration disposed tightly between a pair of
gears radially fixed to a gear shaftO The spacer
provides axial positioning of the gears with respect
to one another. The ends of the spacer are also
squared in the second preferred form.
Brief Description of the Drawings
Figure l is a cross sectional view of a
transmission which employs two alternate preferred
embodiments of the spacer of the present invention.
Figure 2 is an isolated side view, partly in
section and in a free standing mode, of one of the
preferred émbodiments shown in Figure l.
Figure 3 is a side view, also in a free standing
mode, of the other preferred embodiment shown in
Figure l.
Detail _ Description of Preferred Embodimen~s
Referring initially to Figure l, a sectional view
of a transmission lO includes two separate alternate
emobidments of s~acers made in accordance with this
invention at 20 and 30, respectively. The
transmission lO embodies a relatively standard
configuration of manually shifted gears, the gears

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positioned on a mainshaft 8, a countershaft 14 and a
non-rotatable reverse idler shaft 12. Each of the
two spacers circumferentially encases a portion of a
transmission gear shaft. The spacer 20 is of an open
coil configuration, and circumferentially encases the
reverse idler shat 12, while the closed coil spacer
30 encases the countershaft 14.
The open coil spacer 20 is axially interposed on
the reverse idler shaft 12 between a parallel ~et of
bearings 16 and 18. In the preferred embodiment, the
bearings are needle bearings, although the spacer of
the invention described herein is suitable for use
with other types or styles of bearings as well. The
bearings 16 and 18 support a reverse idler gear 22,
for rotation thereo about the reverse idler shaft 12
on the bearings 16 and 18.
Referring now particularly to Figure 2, the open
coil spacer 20 defines a helicoidally shaped body
portion 24, and has first and second squared ends 26
and 28, respectively. The squared ends 26 and 28
provide for radially uniform resilient support
surfaces for contact with opposing inner ends 36 and
38 of respective bearings 16 and 18. In the
preferred embodiment, the shaft will have an outside
diameter slightly less than the inside diameter of
the spacer. To the extent that the spacer is
situated between the bearings 16 and 18, it will tend
to rotate about the idler shaft 12 by virtue of
friction drag forces imposed on the spacer ends 26
and 28 during rotation of the bearing inner ends 36
and 38 about the shaft 12. ThuS the needle bearings
16 and 18 will frictionally cause the spacer 20 to
`rotate about the stationary reverse idler shaft 120
The resultant rotational movement of the helicoidal
body portion 24 of the spacer 20 will produce an
axial oil movement along the shaft 12 to facilitate

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lubrication of the needle bearings 16 and 18, which
are not exposed directly to the splash and spray oil
environment wi~hin the transmission 10.
It should be noted that the open coil spacer 20
may be disposed between the bearings 16 and 18 under
a slight load thus under a pre-loaded condition. It
is suggested that the latter would insure continuous
rotational movement of the spacer with the bearings
about the non-rotatin~ shaft 12. On the other hand,
the spacer will move with the bearings without such
pre-load, and even if there is slight axial floating
of the spacer between the bearings by virtue of
viscous drag forces imposed on the spacer due to
surface tension of the oil.
An alternate preferred emboidment of the spacer
of the present invention is shown at 30 in Figure 3.
The spacer 30, however, is positioned (see Figure 1)
between a pair of gears 32 and 34 located on the
countershaft 14. The gears 32 and 34 are keyed
radially to the shaft 14, and the spacer insures the
axial position of the gears with respect to one
another on the shaft~ Similarly to the ends 26 and
28 of the spacer 20, the ends 26' and 28' of the
spacer 30 are squared for establishing a radially
uniform support surface for contact with each of the
gears. In this case, however, the contact is not
resilient as there is no need for preloading of the
sides of the gears 32 and 34.
It will be appreciated by those skilled in the
art that the countershaft 14 is a rotatable shaft,
and as a result will rotate the spacer member 30.
The member 30 i5 fully exposed to the splash and
spray oil environment within the transmission body.
Those skilled in the art will appreciate the fact
that the helicoidal body portion 24' of the spacer 30
will tend to cause oil slung away from the spacer to

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have a slight axial, as opposed to fully radial,
component. As a result, the closed coil spacer 30
may be employed to enhance the oil dispersion within
the transmission body by distributing the oil in a
more desirable spray pattern~ Again, in a preferred
form, the spacer 30 is made of non-heat treated high
carbon spring steel.
Although only two preferred embodiments of the
spacer of the present invention have been described
and shown herein, there are many variations of the
invention which will fall within the scope o the
following apended claims.