AU631171B2 - Continuously variable transmission - Google Patents

Description

FORM COMMONWEALTn O0- u.ALJA S F Ref: 83y59 71 PATENTS ACT 1952 COMPLETE SPECIFICATION (OR!GiNAL) FOFR OFFICE USE: Class Int. Class ti 0 0 1 0 0 o 0 o a 0 oO Application Number: Lodged: Priority: PJ2308 17 January 1989 Accepted: Published: Related Art, Name' and Address of Applicant: 0 000 0000 0 00 00 0 Nallace Bruce McKenzie 24 Elimatta Road Mona Vale New South Wales 2103

AUSTRALIA

Nallace Bruce McKenzie a a ft 04 0 0 Actual Inventor: Address for Service: Complete Specification Sprwt-Tg-&n~^u^^swefy-s Le M a*^rtiinf-T~ew er--M a ke-t S~t- efe-t,, Syd n eyTN e tth-H r aIH-' for the Invention entitled: Continuously Variable Transmission The following statement is a full description of this invention, including the best method of performing it known to me/us I 5815/Z

ABSTRACT

A variable speed transmission including an input shaft to which an input torque is applied. The input torque is divided to provide two torque components by a torque divider. A first and a second gear train receive the torque components, which first and second gear trains being meshingly engaged at several locations so that torque may be transferred therebetween to vary the speed of an output shaft driven by the two gear trains.

o o 0 ;i 0 0 0L- 0 o 0 o a 0 4 8 3LH/375t 1 I-M liesll~e~t~t~t~t~t~t~t~t~t~t~t~t~t~t~~rr This invention relates to a continuously variable transmission.

An engine combined with a continuously variable transmission (CVT) provides the advantage that for any power requirement, and independent of output speed, the engine speed/throttle combination may be controlled so as to provide the minimum fuel consumption.

A number of CVT's have been previously proposed or produced. Some have employed discs, cones, pulleys and the like, multiplying torque by transferring force via friction at the contact point(s) of variable effective diam)ters. Such frictional devices as have been used do not appear to have realised the theoretically available gains in fuel economy.

Current attempts to use the friction principle involve considerable o, sophistication of construction. CVT's using a non-friction principle appear to have been excessively complex. A non-friction device, however, has the potential of high efficiency operation.

0 0 o 00 o o It is an object of this invention to provide a continuously variabie transmission which does not necessarily require a frictional device and which is relatively simple in design.

o According to a first embodiment of this invention there is provided a a o0 continuously variable transmission (CVT) which includes a selectable c::ntinuously variable torque splitter to selectably split input torque into a first torque component and a second torque component, at least one torque processor coupled with the splitter to increase or reduce the first or second torque component and thereby provide a first or second processed i torque and a torque combiner associated with the at least one processor and said splitter wherein said combiner is adapted to combine said first or second torque component with said second or first procassed torque component respectively to provide an output torque having a magnitude which is in a preselected range and is a function of the ratio of the first torque component to the second torque component, DG:0700x In a second embodiment of this invention there is provided a continuously variable transmission (CVT) which includes a selectable continuously variable torque splitter to selectably split input torque into: a first torque component and a second torque component, a first torque processor coupled with the splitter to increase, transmit or reduce the first torque component and thereby provide first and second processed torque components, a second torque processor coupled with the splitter to increase or reduce the second toraue component and thereby provide third and fourth torque components, a first torque combiner associated with the first and second torque splitters to additively combine the first and third processed torque components to provide a first combined torque component a o 0 second torque combiner associated with the first and second torque Sno"o splitters to additively combine the second and fourth processed torque '0"o components to provide a second combined torque component, a th -d torque combiner associated with the first and second combiners to combine the first and second combined torque components to provide an output torque having a magnitude which is in a preseie'ted range and is a function of the ratio of the first torque component to the second torque component.

0 0 o Throughout the specification 'positive' can be taken as referring to o 'clockwise' or 'counterclockwise'. Where 'positive' is taken as 'clockwise' 'negative' is to be taken as refei ring to 'counterclockwise' S and where 'positive' is taken as 'counterclockwise', 'ne tive' is to be taken as referring to 'clo:kwise'.

0 0 According to a preferred emoodiment of this invention there is provided a CVT which includes an input to be provided with a positive input torque coupled with a continuously variable torque splitter to selectably split the input torque into a positive first torque component and a positive second torque component wherein the splitter is coupled with a direct transmission to transmit the first torque component to provide a DG:0700x 3 positive direct torque and a negative direct torque and to transmit the positive and negative direct torques to a torque combiner coupled with the transmission means; and with a torque multiplier to multiply the positive second torque component by a preselected numerical factor to provide a positive multiple torque and a negative multiple torque and to transmit the positive and negative multiple torques to the combiner which is coupled with the multiplier; wherein the combiner additively combines the sum of t-e positive direct torque and the positive multiple torque to provide a first positive resultant torque, additively combines the sum of the negative direct torque and the negative multiple torque to provide a negative resultant torque, changes the negative resultant torque into a 0o-00 second positive resultant torque and additively combines the first and 0o o, second positive resultant torques to provide a single positive output 00 oo torque wherein the output torque has a magnitude in the range between and 0 00 including tne magnitudes of the input torque and the input torque x numerical factor and wherein the magnitude of the output torque witr'n the range is a function of the ratio of the first torque component to the ooo osecond torque component.

0000 0"o Preferably a CVT of the invention is adapted to be combined with an o automobile engine having appropriate properties for such an application. A CVT according to the invention can be combined with other engines requiring torque conversion. The torque splitter can be coupled with a selector to select the ratio of the first 'orque component to the second torque component as a function of a selected variable(s). For an automobile engine the selector can be a governor, a microprocessor controlled step motor or other appropriate selector means.

The invention can be put into practice in the form of a CVT which is solely of mechanical arrangement using simple technology, which can provide slip free continuously variable torque conversion within practically useful DG:0700x 4 -1114wlimits and it is anticipated of comparable manufacturing cost to that of orthodox manual or automatic transmissions. Further the invention can provide a CVT which does not necessarily require a separate clutch can provide a range of fixed ratios, and which is of comparable ho sepower capacity to a similarly sized orthodox transmission.

Preferred embodiments of the invention are now described, with reference to the following drawings in which:- Figure 1 is a block diagram of the first embodiment of the invention; Figure 2 is a block diagram of tne second embodiment of the invention; Figure 3A is a block diagram of a preferred continuously variable .ooo transmission according to the invention; Figure 3B is a block diagram of an alternative preferred continuously variable transmissioi according to the invention; o oo Figure 4 is a schematic blocked off diagram of a still further .o alternative continuously variable transmission to that described with reference to Figures 1 to 38.

Referring to Figure 1 continuously variable transmission 100 (CVT 100) includes a selectable continuously variable torque splitter 101 to S selectably split input torque T100 into torque components T101 and T102.

So, Torque processor 102 is coupled with splitter 101 to increase or. reduce T102 to provide processed torque 103 to provide output torque T104. Toroue oo T104 has a magnitude which is in a preselected range and is a function of the ratio T101:T102.

Referring to Figure 2 continuously variable transmission 200 (CVT 200) includes a selectable continuously variable splitter 201 to selectably split input torque T200 in torque components T201 and T202. Torque processor 202 is coupled with splitter 201 ,o increase, transmit or reduce torque T201 to provide processed torque components T203 and T204. Torque processor 203 is coupled with splitter 201 to increase or reduce tori4ue DG:0700x 5 ~-~un~rr;nu*an~PirPa~~ T202 to provide processed torque components T205 and T206.

Torque combiner 204 is associated with processors 202 and 203 to additively combine torques T203 and T205 to provide combined torque T207.

Torque combiner 205 is also associated with processors 202 and 203 to additively combine torques T204 and T206 to provide combined torque T208.

Torque combiner 206 is associated with combiners 204 and 205 to combine torques T207 and T208 to provice output torque T209. The magnitude of torque T209 is in a preselected range and is a function of the ratio T201:T202.

Referring to Figure 3A continuously variable transmission 10 (CVT includes input 11 which is provided with counterclockwise input torque T1.

Input 11 is coupled with a selectable continuously variable torque splitter 0 0 S 12 which selectably splits torque T1 into counterclockwise torque 0 0 0 o o> components T2 and T3. Splitter 12 can be coupled with a selector to select °the ratio of T2 and T3 as a function of a desired parameter(s).

Splitter 12 is coupled with direct transmission 13 which receives and divides torque T2 into a counterclockwise torque component T4 and a clockwise torque component T5 and then transmits T4 and T5 to torque 000 0" combiner 0.0 4* Splitter 12 is also coupled with torque multiplier 14 which receives 0 1 torque T3, and, by appropriate separation, multiplication and reduction S processes, as required, involving a selected numerical factor, provides S counterclockwise multiple torque T6 and clockwise multiple torque T7.

Torques T6 and T7 are then transmitted to combiner Splitter 12 is preferably selectably adjustable to split torque TI into torques T2, T3 wherein the ratio T2:T3 is within the range T1:0 to 0:T1.

Combiner 15 receives additively combined T5 and T7, and reverses the combined torque to provide counterclockwise resultant torque T9. Torques DG:0700x 6

C'

F I 7.

9*04 o 9 a o aa 0 9 P Q a 044 4 9 aa a a 4 a, a 944 4 a aa a a 49 9 9 94 aaaa 9494 r- r rrrrr^rr are connected via a shaft 118. 'he gears 117 in turn drive an idler gear 119 which is rotatively supported by means of a shaft 120. The ,haft 120 is fixed to a rotatable arm 121. The arm 121 is rotatable about a central shaft 122 which also rotatively supports the shaft 118. The arm 121 also rotatively supports a further shaft 123 to which gear 124 is attached. The gear 124 meshingly engages with the gear 119 and transmits rotary power to the gear 125. The gear 125 drives a gear 126 fixed to the shaft 122.

Accordingly, a first portion of the torque delivered by the input drive 102 is delivered to the shaft 122.

The arm 104, by being fixed to the shaft 109 drives a gear 127, which in turn drives a further gear 128. The gear 128 drives a shaft 129 extending to a "differential" gear assembly 130. The differential gear assemoiv 130 includes a carrier 131 rotatively supporting a pair of 0 o o, o 'o planetary gears 132. The planetary gears 132 divide the drive and torque S between a pair of gears 133 and 134. The gear 133 drives a shaft 135 which eventually drives a gear 136 via a pair of intermediate gears 137 and 138.

The gear 137 is rotatably supported by the base 116. The gear 136 is also i fixed to the shaft 122 and accordingly a furthe portion of the driving o torque is delivered to the shaft 122.

A portion of the torque transmitted from the differential 130 drives the gear 139, which in turn drives the gear 140. The gear 140 via a link j 141 is coupled to the arm 121. The gear 140 also drives a further gear 142 via a shaft 143 also rotatively mounted on the shaft 122. A further arm 144 is also rotatively supported on the shaft 122. The arm 144 rotatively supports a shaft 145 extending between a pair of gears 146 and 147. The gear 146 is meshed with gear 142. Also fixed to the arm 144 is a shaft 148 rotatively supporting an idler gear 149 which transfers torque to a gear 150 also fixed to the shaft 122. Accordingly, a further portion of the driving torque is delivered to the shaft 122.

DG:0700x ~j -~lc-l*rpiaraPilll*r~ The arm 144, via a link 151 rotatively supports a pair of planetary gears 152 of a further differential 153. However, the differential 1;3 has a pair of gears 154 and 155, of which gear 154 is fixed to the shaft 122 so as to receive torque therefrom Accordingly, at the differential 153, all the torque delivered to the shaft 122, as well as the torque delivered to the shaft 143 is combined to be delivered to the shaft 156 attached to the output gear 157.

By altering the position of the input drive member 106, the torque transmitted through the various driving gears is varied so that the torque applied to the output gear 157 is varied to meet operating demands. In this regard it should be appreciated that the total power delivered to the 157 o input drive 102 is equal to the power delivered to the gear 1 3: less frictional losses.

0 8 -9-

Claims (4)

1. A continuously variable transmission (CVT) which incluces a selectable continuously variable torque splitter to selectably split input torque into a first torque component and a second torque component, at least one torque processor coupled with the splitter to increase or reduce *he first or second torque component and thereby provide a first or second processed torque and a torque combiner associated with the at least one processor and said splitter wherein said combiner is adapted to combine said first or second torque component with said second or first processed torque component respectively to provide an output torque having a magnitude which is in a preselected range and is a function of the ratio of the first torque component to the second torque component,

2. A continuously variable transmission (CVT) which includes a 'no selectable continuously variable torque splitter to selectably split input torque into a first torque component and a second torque component, a first o torque processor coupled with the splitter to increase, transmit or reduce 0 the first torque component and thereby provide first and second processed 'o torque components, a second torque processor coupled with the splitter to ooo oooo increase or reduce the second torque component and thereby provide third and fourth torque components, a first torque combiner associated with the first and second torque splitters to additively combine the first and third processed torque components to provide a first combined torque component a oooo second torque combiner associated with the first and second torque c'oo splitters to additively co'l0ine the second and fourth processed torque components to provide a second combined torque component, a third torque combiner associated with the first and second combiners to combine the first and second combined torque components to provide an output torque having a magnitude which is in a preselected range and is a function of the Soo ratio of the first torque component to the second torque component, oakgo.

3. A CVT which includes an input to be provided with a positive input torque coupled with a continuously variable torque splitter to selectably split the input torque into a positive first torque component and a positive second torque component wherein the splitter is coupled with a direct transmission to transmit the first torque component to provide a positive direct torque and a negative direct torque and to transmit the positive and negative direct torques to a torque combiner coupled witf the transmission means; and with a torque nultiplier to multiply The positive second torque component by a preselected numerical facto to provide a p,:'tive multiple torque and a negative multiple torque and to JLH/375t 10 L 0 4 4 4 0004 4 0 o ~0G o 0 000 0 0 00 00 0 00 0 0 00 00 0 00 0 0000 0000 40 0 00 0 04 000 0 0 C. 0

4; Ow 4 00;0 0 00 00 000000 I 041 f 00 00 00 0. o @0 0~ 0, 0 o 00 4 0 @0040 0 000 000 4* 0 0 00 14000000 00 0 -000 (0 o 0*0 400 00 0* 0 ii its own axis, while orbiting about the axis of said shaft; and mounting means for said further primary gear rot j ii ounted for rotation about said shaft and to receive tor o n said second transfer gear, and wherein said further mou eans is drivingly associated with said further differential o apply torque thereto to be combined with the torque appl i said further differential by said primary shaft. ;ariable speed transmission substantially as hereinbefore DATED this SEVENTEENTH day of JANUARY 1990 Wallace Bruce McKenzie 000 ou c Sc Patent Attorneys for the Applicant" Doo J SPRUSON--FERGI4&ONW t .l 0 00 00 0 0 0 0 C 0 npo 000 0 0 0 /3