Worm reduction gear assembly

A worm reduction gear assembly has a casing or housing composed of two tube parts and three flanges on ends of the tube parts. The worm wheel is journaled between bearings in one tube and meshes with a worm in the other tube. The bearings are received in centering bushes which are sealed by seals in grooves formed in the respective tube. A supporting connecting can be provided on the casing or housing for a steering wheel preferably along the center of the worm wheel and worm and perpendicular to the axes of the worm and worm wheel shaft.

FIELD OF THE INVENTION 
My present invention relates to worm-reduction gearing, and more 
particularly, to a worm reduction gear assembly which can be used in a 
variety of applications and mounted with high versatility in various 
configurations with motors, driving elements and driven elements. In 
particular, the invention relates to a worm reduction gear assembly which 
can be used in steering applications. 
BACKGROUND OF THE INVENTION 
A worm reduction gear generally comprises a worm shaft carrying a worm and 
lying orthogonal to a worm-wheel shaft on which a worm wheel is keyed to 
mesh with the worm. Both shafts are journaled in a housing which is 
usually specially designed for the particular application to which the 
reduction gearing is to be put. 
Such systems lack versatility, generally make use of expensive housing 
structures and are largely unsatisfactory for other reasons as well. 
OBJECTS OF THE INVENTION 
It is the principal object of the present invention to provide an improved 
worm reduction gear with greater versatility. 
Another object of the invention is to provide a worm reduction gear which 
can be fabricated at low cost and can be readily adapted to a wide variety 
of applications. 
It is also an object of this invention to provide an improved worm 
reduction gear assembly which extends the principles set forth in my 
earlier application. 
SUMMARY OF THE INVENTION 
These objects and others which will become apparent hereinafter are 
achieved in accordance with the invention, by providing a worm reduction 
gear assembly which comprises: 
a housing formed with: 
a first generally cylindrical tube having a first axis and opposite open 
axial ends, 
a second generally cylindrical tube connected laterally to the first tube 
and having a second axis orthogonal to the axis of the first tube and 
offset therefrom in a direction perpendicular to both of the axes, the 
second tube being open axially at least at one of the ends of the second 
tube, and 
respective circular flanges formed on each of the open ends and lying in 
respective planes perpendicular to the axes; 
a worm wheel shaft extending along the first axis and rotatable 
therearound; 
a worm wheel keyed to the worm wheel shaft in the first tube intermediate 
the ends thereof; 
a worm shaft extending along the second axis and rotatable therearound in 
the second tube; 
a worm keyed to the worm shaft in the second tube between the ends thereof 
and meshing with the worm wheel; 
centering bushes received in the first tube flanking the worm wheel; 
respective first bearings interposed between the worm wheel shaft and the 
bushes for journaling the worm wheel shaft in the first tube, the first 
tube being formed with inwardly open grooves opening toward the bushes; 
circular seals in the grooves sealing between the bushes and the first 
tube; 
respective second bearings in the second tube flanking the worm and 
journaling the worm shaft in the second tube; and 
a shaft stub formed on the housing substantially perpendicular to both of 
the axes. 
According to a feature of the invention, the second tube is provided with 
pair of bearings spaced apart by the worm shaft and an end of the second 
tube which is not provided with a flange is capped.

SPECIFIC DESCRIPTION 
FIG. 1 illustrates a worm reduction gear in accordance with the invention 
which comprises a casing 1 consisting of a tube 2 and a tube 3. The tube 2 
is, of course, the first tube of the present invention while the tube 3 is 
the second tube thereof. A flange 4 can be welded onto the second tube 3 
(FIG. 1) or can be integral therewith (FIGS. 1A and 2) and a supporting 
connection 5 is shown to be welded onto the second tube 2 in FIG. 1 and to 
be integral with this tube in FIG. 1A to enable a steering element, such 
as a steering wheel, to be coupled to the housing for rotating it about an 
axis perpendicular to the axes of the tubes which themselves are 
orthogonal to one another. 
In particular in FIG. 1, the connection 5 is shown to extend upwardly into 
a shaft 6 which is keyed at 67 to a worm gear 25' meshing with a worm 
wheel 29 of a further assembly provided with a flange at 4' and driven by 
means shown at 32 so that the entire casing 1 can be rotated about the 
vertical axis. The shaft 6 formed by the connection 5 is here journaled in 
a double-row ball-bearing 44 of a housing 43. A spacer 68 can be provided 
on the shaft 6 as shown in FIG. 1A. Locking nuts 69' secure the worm wheel 
25' in place. 
Within the casing 1 is a shaft 12, hereinafter referred to as the 
worm-wheel shaft, a shaft 30 referred to as the worm shaft and pairs of 
bearings which will be described in greater detail hereinafter. 
Referring now to FIG. 3 which shows the construction of the worm-wheel 
assembly in greater detail, it will be seen that a worm wheel 25 is 
connected (keyed) to the shaft 12 by keys 28 and is flanked by bearings 16 
received in centering bushes 17, the latter being sealed in the tube 2 by 
sealing rings 24 lodged in inwardly open grooves 19 formed in the tube 2. 
An annular bulge 2' is formed in the tube 2 around the worm wheel 25. 
The centering bushes 17 are held in place by C clips 23 (FIG. 3), i.e. 
internal spring rings or Seeger rings. 
The worm wheel 25 (FIGS. 1 and 3) meshes with the worm 29 which can be 
formed unitarily on the worm shaft 30. A drive shaft 31 of an electric 
motor 32, for example, bolted to the flange 4, may be keyed to the shaft 
30 by the key 31a (FIG. 1). 
The tube 2 is formed at each of its axially oppositely open ends with a 
respective flange 10 to which a load unit can be bolted for connection to 
the stub 12a (FIG. 3) of the worm-wheel shaft by a key 12b. It will be 
understood that the load unit can be bolted to either flange 10 and that 
the entire worm-wheel shaft assembly can be reversed in the tube 2 so that 
the stub 12a will project from the opposite axial end and the load will be 
bolted to the opposite flange 10. 
Turning again to FIG. 1 and 2, it can be seen that the shaft 30 is 
journaled in the second tube 3 by at least one bearing 34 although 
preferably two such bearings are provided, the second bearing being 
represented at 33' in FIG. 2. Seals 33 can seal the axial end of the tube 
formed with the flange 4 around the shaft. 
The axial bearing 34 is located between a seat 35 formed by a shoulder in 
FIG. 1 and by a Seeger ring 36 in FIG. 2 and another Seeger ring 36' (FIG. 
1) or the end of the cap 38 or cover which is held in place, in turn, by a 
Seeger ring 41 (FIG. 1) or 41' (FIG. 2). A plug bolt 42 FIGS. 1 and 2) can 
be removed to permit filling of the casing with oil. Around the cover or 
cap 38, a seal 39 is provided in an annular inwardly open groove formed in 
the tube 3. The bolt 42 can also serve to cooperate with a cover remover. 
In FIG. 1, the cover can engage a shoulder or seat 40 formed in the 
housing. 
A pair of bearing nuts 37 may hold the inner race of the bearing 34 in 
place axially on the shaft 30. 
It will be apparent that the worm reduction gearing of FIGS. 1 and 1A, 
provided with a formation 5 to which a mechanism for rotating the casing 
can be connected and the worm reduction gearing of FIGS. 2 and 3 which are 
not provided with this additional formation have extremely high 
versatility.