Infinitely variable positive gear ratio transmission

A high efficiency transmission having infinitely variable positive gear ratios in forward and reverse directions is disclosed. The preferred embodiment of the transmission comprises a driven housing, an output shaft, a control shaft, a plurality of internal gears and collars constituting an infinitely variable displacement fluid escape system, and a plurality of gears constituting a fixed displacement fluid gear pump.

BACKGROUND OF THE INVENTION 
This invention relates to the field of rotary transmissions and more 
particularly to the field of variable gear ratio transmissions. This 
invention does provide an infinite number of forward gear ratios up to 
unity and a neutral ratio and an infinite number of gear ratios in a 
reverse direction. This transmission is adapted to use with a clutch 
mechanism if necessary. Once a gear ratio and direction are selected with 
the single control mechanism the transmission will maintain that ratio 
regardless of load changes. The unique design of this transmission allows 
achievement of maximum efficiency at higher operational speeds as heat and 
frictional energy losses decrease. This invention is suitable for most 
applications where input and output speed and torque is required to be 
variable. 
Prior to the present invention no device particularly adapted to the 
modulation of speeds between an input force and an output force had the 
combined advantages of; achieving forward and neutral and reverse gear 
ratios utilizing the same rotating components, light weight, ease of 
construction, minimum number of components, increasing efficiency as 
operating speeds escalate and stability of selected gear ratios. Until 
this invention other devices were unable to provide forward, neutral and 
reverse gear ratios without utilizing a clutching system and additional 
components or were confined to low operating speeds due to mechanical 
inefficiencies caused by high frictional forces and subsequent heat 
generation. Prior devices are not easily adaptable to different 
applications such as vehicle transmissions or mechanical equipment drives. 
OBJECTS OF THE INVENTION 
A primary object of this invention is to provide a transmission having an 
infinitely variable gear ratio which includes forward, neutral and reverse 
gear ratios. 
Another primary object of this invention is to provide such a transmission 
whose gear ratios will not vary with load or temperature changes once said 
gear ratios have been set by operator.

DESCRIPTION OF THE PREFERRED EMBODIMENT 
Referring to the drawings wherein like numerals designate like parts 
throughout the several views, the illustrated transmission designated (11) 
is shown in FIG. 4 as a simplified schematic, FIG. 1 shows the main 
portion of the transmission housing, FIG. 2 shows the secondary portion of 
the transmission housing which also displays the gear motor and output 
shaft components and FIG. 3 shows the component parts of the variable 
fluid displacement mechanism. 
With reference now to the transmission (11) that includes a housing (12) 
which is of split construction and fixedly combined and includes inner 
chamber bores enclosing in a fluid tight manner the rotor assembly 
(23,25,26, and 28) and the stator assembly (13,17,18 and 22) of the 
variable fluid displacement mechanism. At opposing longitudinal end of 
housing (12) from said variable fluid displacement mechanism are chamber 
bores to incorporate a gear pump (15,16,19 and 24). The maximum fluid 
displacement capacity of gears 15 and 24 is less than the maximum fluid 
displacement of gears 13 and 25. The smaller fluid displacement of gears 
15 and 24 is derived by making said gears either smaller in diameter or 
shorter from front to back than gears 13 and 25. The complete housing (12) 
as shown in FIG. 4 is supported in a rotational manner about the 
longitudinal axis of control shaft (18) and output shaft (19). Referring 
to FIGS. 2 and 4 said gear pump (15,16,19 and 24) is fitted within bore 
chambers in a fluid tight manner. Gear (24) is fixedly attached to output 
shaft (19) which rotates within and extends from housing (12). Gear (15) 
intermeshes with gear (24) and rotates about trunion (16). Fluid driven by 
said gears (15 and 24)is circulated through and along passageways (14 and 
21) and ports (27 and 29) within housing (12) as it is directed to said 
rotor assembly (23,25,26 and 28) and said stator assembly (13, 17, 18 and 
22). Referring to FIG. 3 said rotor assembly (23,25,26 and 28) is 
comprised of stub shaft (28) around which is fixedly mounted collar (23), 
rotationally mounted gear (25) and fixedly mounted collar (26). Said 
collar (23) is cylindrically shaped and of the same external dimension as 
said gear (25) and said collar (26). Said collar (26) incorporates a 
semi-circular cut in its outer dimension and parallel to its longitudinal 
axis. Said cut is of same surface arc as the outer surface of collar (17) 
of said stator assembly (13, 17, 18 and 22). Said rotor assembly (23,25,26 
and 28) is enclosed within bore chamber in said housing (12) in a fluid 
tight manner such that only a portion of said assembly's longitudinal 
surface is exposed to and drivingly engages in a parallel manner said 
stator assembly (13, 17, 18 and 22). Said stator assembly (13,17,18 and 
22) has control shaft (18) on which is fixedly attached said collar (17), 
fixedly attached gear (13) and rotationally mounted collar (22) which has 
a semi-circular cut in its outer surface along longitudinal axis and 
engaging said collar (23). Control shaft (18) moves only longitudinally 
along its axis with regard to housing (12) and as regulated in a 
particular manner not critical to this invention. 
OPERATION OF THE PREFERRED EMBODIMENT 
In order to obtain useful output from the transmission (11) a rotary power 
source is connected to the transmission housing (12) and a load is 
attached to output shaft (19). As the rotational force is applied to the 
transmission housing (12) the load will tend to keep the output shaft (19) 
immobile. This will pressurize the working fluid on one side of the gear 
pump (15,16, and 24) attached to the output shaft (19). In FIG. 4 the 
pressurized fluid is shown as a heavily shaded area and the unpressurized 
fluid is a lighter shade. The pressurized fluid is directed to the rotor 
and stator assemblies through passageway (14) in the transmission housing 
(12). The passageway (14) opens into the confluence of the variable fluid 
displacement gears (13,25) at port (29). The high pressure fluid creates 
resistance within the transmission (11) when the fluid displacement of the 
stator (13) and rotor (25) gears is less than the fluid displacement 
capacity of gear pump (15,24) on output shaft (19). The resistance will 
cause the output shaft (19) to follow the transmission housing (12) at a 
rate predetermined by the amount of fluid released through the variable 
fluid displacement unit (23,25,26,28,13, 17, 18 and 22). As the 
pressurized fluid is directed into said displacement unit it is carried 
around the outside of gears (13 and 25) to the point where said gears 
intermesh on the opposite side at port (27). The fluid is then 
recirculated through passageway (21) back to the low pressure side of said 
gear pump (15, 16,24 and 19) where the entire cycle repeats. Changes in 
output shaft (19) speed are accomplished through the stator assembly 
(13,17,18 and 22). The control shaft (18)is free to move longitudinally 
along its axis in a fluid tight manner in and out of the transmission 
housing (12). The two collars (17 and 22) and gear (13) also move 
longitudinally with the control shaft (18). The longitudinal movement 
serves to increase or decrease the amount of engagement between the rotor 
and stator gears (25 and 13). The amount of engagement determines the 
volume of working fluid displaced. The control shaft (18) is not allowed 
to rotate with transmission housing (12). Collar (17) and gear (13) are 
non-rotatably fixed to control shaft (18). As the rotor unit (23,25,26 and 
28) is carried by the transmission housing (12) around the stator unit 
(13,17,18 and 22) the rotor gear (25) turns on stub shaft (28) allowing 
gears (13 and 25) to release the pressurized working fluid. Collars (23 
and 26) are non-rotatably fixed to stub shaft (28). No parts of said rotor 
assembly move longitudinally along the axis of stub shaft (28). Referring 
to FIG. 4, collar (22) on control shaft (18) and collar (26) on stub shaft 
(28) have a semicircular cut in them parallel to the axis to allow for 
fluid tight clearance of gears (13 and 25) and collars (17 and 23) as 
control shaft (18)is moved laterally in and out of transmission housing 
(12). Fluid pressure must be maintained through close machined tolerances 
between moving parts. The shape, size and location of the collars act to 
prevent the loss of fluid from the gears as the collars pass over the gear 
teeth surfaces. At the same time the collars seal the sides of the gears. 
In full neutral position with the output shaft (19) not turning the 
displacement gears (13 and 25) are engaged to the position necessary to 
displace the same volume of fluid as the output shaft gear motor (15,16 
and 24). In full speed position with the output shaft (19) rotating at the 
same rate as housing (12) the displacement gears (13 and 25) are 
completely disengaged from each other. Reverse in the transmission (11) is 
achieved by increasing the fluid displacement by fully engaging them of 
gears (13 and 25) to exceed the displacement of gears (15 and 24). The 
variable displacement gears (13 and 25) will then act as a conventional 
gear pump and drive the output shaft (19) backward at a rate exceeding the 
forward rotation of housing (12) . The constituent parts of transmission 
(11) are shown at a minimum for ease of understanding. In actual practice 
it would be reasonable to construct this transmission (11) with a 
plurality of rotor assemblies (23,25,26 and 28) working about a common 
stator assembly ((13, 17, 18 and 22) to spread fluid loads. Additional 
gears (15) and trunions (16) would also be used about the output shaft 
gear (24). Maximum hydraulic drag would occur in the neutral and low speed 
operation as the working fluid is circulated at its most rapid rate. The 
transmission (11) would gain efficiency as the output shaft (19) speed 
increases.