Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
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CROSS REFERENCE TO REL~TED APPLICATIONS
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I This application is related to the subject matter of my
¦ Canadian Patent 1,108,998, ~~~~
j which discloses a micro-processor system for controlling the
, wheels of a multi-wheel vehicle which have individually
controlled traction motors and indiviaually controlled steering
actuators.
BACKGROUND OF THE INVENTION
Generally speaking, this invention relates to self-pro- !
pelled vehicles used primarily to transport long loads across
roadless terrain. More specifically, it relates to rubber-
tired vehicles that have wheel suspension mechanisms which pro-
vide balanced weight distribution on its wheels and individually
controlled motors for respectively applying traction power and
steering torque to each such wheel, as wel'l as an individually
controlled brake for each wheel.
As described in my Canadian Patent no. 1,10~,~43,
the mounting of each wheel of the quad
wheel assembly wasaccomplished by an axle'housing which is med-
ially pivoted to the end of the walking beam. A motor driven
linear actuator is then mounted between one end of the axle
housing and a medial portion of the walking beam and provides
steering movements of the'axle housing about its pivot mounting
axis. Thus, a triangular relationship is defined between the
`'25 walking beam, axle housing and the steering actuator. A
driving motor is mounted at another medial position on the
¦ axle housing and, by virtue of conventional gearin~ c~ntained
within the confines of the hollow axle housing, imparts traction
torque to the particular wheel.
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SU~MARY OF THE INVE:NTION
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This invention constitutes an improved arrangement of the
¦mounting, driving, and steering mechansim for the individual wheels
~of a multi-wheeled, off-road vehicle. In contrast to the structure
l~disclosed in my aforementioned Canadian ~atent no. 1,102,843,
¦ this invention does not employ a triangular relationship ¦
,between the axle housing, the walking beam, and the steering actual
¦tor. Such arrangement, while very effective to produce the requir~c
Isteering movement about a relatively large radius, i.e. on the ord~r
¦of two to four feet, was subject to the disadvantage that rocks,
istumps, or tree branches could become entrapped with~n the triangle
defined by such members.
¦ In accordance with the construction of this invention, an axlq
Ihousing is provided which provides a hub-type mounting for a wheelj
1 on one end thereof, for rotational movements about a normally hori~
zontal axis, and the other end is designed to be plvotally mounted
in a housing mounted on the end of the walking beam for movements
about a normally vertical axis. Both the traction motor and the
Isteering motor are mounted on a top cover for such housing thus
¦providing an environmentally protected location for such rel,atively
1~9~ fragile elements. The torque required to impart traction
¦power to the individual wheel as well as the torque required to
¦effect steering movements of the wheel about the vertical axis
idefined by the mounting housing, are both transmitted by separate
gearing mechanisms that are concentric with the axis of the moun-
ting housing. There is, therefore, no opportunity for a tree limb
or boulder to become wedged between elements of the steering mecha _
ism and thus render it ineffective. Additionally, the mounting con-
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I struction of this invention permits the utilization of either
¦ a planetary or harmonic type gear reduction unit to transmit
¦ steering torque from the motor that does not vary as a
¦ function of the angular steering position of the wheel.
I Other advantages and objects of this invention will become
apparent when the following description is read with reference
to the accompanying drawings.
DESCRIPTION OF DRAWINGS
Figure 1 is a perspective view of a portion of a multi-wheel,
off-road vehicle, more specifically, the quad-wheel suspension
mechanism for such vehicle.
Figure 2 is a partial sectional view taken on the plane 2-2
of Figure 1.
DESCRIPTION O~ PREFERRED EMBODIMENT
As described in more detail in my aforementioned Canadian
Patent no. 1,10~,993, ~ ~~ ~ numeral
32 in Figure 1 represents the main longitudinal frame element of
a multi-wheel, off-road vehicle. The frame 32 which serves as
a backbone of the vehicle may be a rectangular tube. A plurality
of rigid cross beams 38 extend outwardly from the frame 32 in
both directions to form load carrying cradles. Upright side
stakes 44 may be provided on the outer ends of the cross beams 38
The sta~es, along one or both sides, may be releasably mounted
to permit sidewise dumping of the load on either side by appro-
priately tilting the bed frame element 32 about the roll axis
of the ~uad-~heel suspension assembly to be here.inafter described
Two substantially identical quad-wheel assemblies 24 are provided
in spaced relationship along the elongated bed frame 32, but only
one is illustrated.
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The suspellsion system for quad-wheel asscmbly 24 includes a
main pivot block 46 which is pivotally suspended beneath the tubular
bed frame 32 between a pair of depending blocks 32a, thus pro-
Ividing pivotal movement about a longitudinal, horizontal roll
laxis which is parallel to and slightly below the axis of the
tubular bed frame 32. Such pivotal mounting is not shown but is
~entirely conventional. A torque transmission tube 94 extends
¦rearwardly from the main pivot block 46 in the case of the front
¦quad-wheel assembly, and fon7ardly from the main pivot block 46
in the case of the rear quad-wheel assembly, ana each is co-
movable with the respective pivot block about the vehicle roll
¦axis. The adjacent ends of the tubes94 are respectively inter-
connected by a roll control linkage mechanism (not shown) but
which i5 fully described and illustrated in my aforementioned co-
pending application.
The bottom portion of main pivot block 46 is provided with a
pair of laterally projecting, horizontal pivot pins 46a which
xespectively provide pivotal mountings for a pair of walking
beams-~8, which are of identical configuration except that they
are mounted in reversed positions on the piVQt pins 46a. Each
walking beam is of a generally truncated W-shaped configuration
in plan view, including a central truncated inverted V-shaped
portion 48a defining a bearing for pivotal mounting on pin 46a,
and identical angularly disposed, tubular ena elements 48b which
provide mountings for steerable wheel mountings 60, there being a
separate mounting for each wheel of the quad-wheel assemblies~
I The horizontal angle of walking beam elements 48b determines the
¦ maximum steering angle of each wheel relative to the suspension.
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IlReferring p~rticularly to Figure 2, each wheel mounting
assembly 60 includes a main hollow housing 62 which defines an
open top, vertical cylindrical chamber portion 63, and a radially~
! extending axle housing portion 64 in communication therewith.
¦ Immediately above the chamber 63, an inverted bowl shaped
¦ gear reduction housing cover 66 is pivotally mounted on the main 'I
housing 62 by a conventional anti-friction swing bearing unit 68.1
On one side of cover housing 66 an integral collar 65 (Fig. 1) isj
formed to permit the Convenient rigid mounting of the cover housilg
66 to the respective tubular end 48b of the walking beam 48. Thi~s
permits the main hausing 62 to freely pi~ot about the vertical
axis 68a of bearing 68 to provide steering movements for the axle
housing portion 64 of such housing.
On the end of axle housing portion 64 thexe is mounted a
wheel mounting hub member 70, as by bolts 71, and the hub member
70 not only provides for conventional mounting of a large ground
engaging wheel Cnot shown) on its periphery, but also within such
hub mounts a conventional planetary transmission for dri~ing such
wheel at reduced speed from a drive shaft 72 which is axially dis
posed within the hub 70 and the axle housing 64. The steering
radius of each wheel is on the order of two to four feet.
A hydraulic or electric steering motor 80 is suitable mount ed
on the top of the gear reduction housing 66 as by bolts 81 and t~ e
output shaft (not shown) of suCh motor mounts a pinion gear 82
which engages a ring gear 84 concentricall~ mounted on the peri-
phery of a speed reduction unit 86 for rotation about steering
axis 68a.
Speed reduction unit 86 will not be described in detail
inasmuch as it comprises either a compound planetary gear unit o~
the type well known in the art or a harmonic type gear reduction
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unit similar to those manufactured and sold by the Gear Systems
I Division of U. S. M. Corporation of Wakefield, Massachusetts.
¦ Such harmonic drive reduction units are fully described and illu-
strated in a Designers Manual published by the aforesaid Gear
I Systems Division of U. S. M Corporation. In any event, regard-
¦l less of whether a compound planetary gear reduction system or a
I harmonic drive unit is employed, the output sleeve 88 thereof
I is connected to housing 62 and a significant reduction in speed,
¦ on the order of 1000 to 1, is effected between the steering drive . .
motor 80 and the main housing 62, permitting such main housing
1 62 and hence the connected hub housing to be slowly turned about
¦ the axis 68a of the power drive shaft 71.
Traction motors 74 and steering motors 80 are individually
controlled by suitable circuitry, for example, by the control
system described in my said Canadian Patent no. 1,108,998.
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. From the foregoing description, it is apparent that this
invention provides an unusually compact, yet economical con-
struction for effecting the transmission of the relatively large
¦ torque required for producing both the rotational or motive power
¦ torque to be applied to each wheel of a multi-wheel, off-road
¦ vehicle but also applies adequate torque to effect the turning
¦ of such wheels about the same axis as the motive power is trans-
¦ mitted to the wheel from the traction motor
¦ Modifications of this invention will be obvious to those
¦ skilled in the art, and it is intended that the scope of the invel ~_
ion e determined solely by th ppended claims.
