INFINITELY VARIABLE TRANSMISSION WITH UNIFORM INPUT-TO-OUTPUT RATIO THAT IS NON-DEPENDENT ON FRICTION

CROSS REFERENCE TO RELATED APPLICATIONS

BACKGROUND OF THE INVENTION:

FIELD OF THE INVENTION

This invention pertains to transmissions having variable ratios between input and output velocities. Specifically, it relates to all-gear transmissions whose velocity ratios may be changed continuously over a wide range of values ranging from zero to non-zero values, without depending on friction.

DESCRIPTION OF THE RELATED ART

The patents US 5603240 and US 20100199805 use some of the features used in this design.

The patent US 5603240 does not have a co-axial input to output and therefore cannot be used for applications requiring this configuration. The output travels as the ratio is changed. Therefore, this design cannot be used when stationary output is required. US 20100199805 offers a sinusoidal output and uses several modules just to minimize the "ripple" when a steady and uniform input is provided.

Therefore, the design cannot be used when a steady and uniform output is desired.

The patent US 9970520 offers a steady input to output ratio and co-axial input and output shaft in a comparably smaller envelope than that of its prior art. This is achieved with a use of a set of non-circular gears using as few as three modules. The drawback is that it is hard to mass produce the desired non-circular gears and will add significant manufacturing cost. It is also difficult to accurately design the tooth profile to achieve a uniform input to output ratio.

The present invention uses a custom designed Geneva wheel mechanism to achieve uniform rack velocity during functional region and circular/ non-circular gear for non-functional region. The portion of the region used by the Geneva wheel mechanism is also non-functional region which overlap with the non-functional region achieved by the circular/non-circular gears for smooth transition. It is also possible to use Geneva wheel mechanism for functional and non-functional region. However, it will be economical to use a partial circular gear for the non-functional region. The path of the Geneva slot engaging with the Geneva pin determines the shape of the functional or non-functional region. Using a commonly used Geneva wheel mechanism with straight slot will not achieve uniform rack movement in the functional region and these slots has to have a specific shape to achieve uniform rack movement in the functional region. In general, a Geneva wheel mechanism has straight slot and is commonly used in applications needing indexing.

BRIEF SUMMARY OF THE INVENTION:

The main objective of this invention is to provide a UNIFORM and STEADY output, when the input is uniform and steady, with the ability to transmit high torque without depending on friction or friction factor. Many of the continuously variable transmissions that are in the market today are friction dependent and therefor lack the ability to transmit high torque. Those continuously variable transmissions, which are non-friction dependent do not have a uniform and steady output when the input is uniform and steady. The design that offers all is too complex and hard to mass produce. And This design aids reduction in the overall size and can be economically mass produced. This design can be easily integrated into any system. This design is very versatile and can be used ranging from light duty to heavy duty applications. This design allows replacement of existing regular transmission, requiring very little modification. This design offers stationary and co-axial input and output.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS:

All the gears partial or full in the following figures can be replaced with a sprocket and chain system.

Fig 1- IVT general assembly perspective view - Exploded. Fig 2- Angular velocity module using Geneva pin and wheel mechanism along with partial circular /noncircular gears

Fig 3a - Crank pin displacement mechanism using link mechanism with sliding collar placed coaxially inside the input shaft and crank pin shaft

Fig 3b - Crank pin displacement mechanism using link mechanism with sliding collar placed coaxially inside the input shaft and input disk

Fig 4A-4B - Scotch yoke module and rectifier module. Rectifier module showing rack and pinion, with pinions placed on a common output shaft on a one-way bearing along with dummy rack, and common output shaft. Showing force acting on the rack is co-planer with longitudinal axis of the pinion.

4A - Perspective view

4B - Perspective view exploded

Fig 5 - Input shaft and input disk assembly perspective view

Fig 6A - 6D Input disk, crank pin shaft and link pivot pin assembly

6A - Top view

6B- Front view 6C- Side view 1 6D- Perspective view

Fig 7A - 7C Different configurations for slotted rack holder

Fig 8A - 8C - Geneva pin wheel

8A- Front view 8B- Side view 1 8C- Perspective view

Fig 9 Input disk

Fig 10A - 10B - Geneva slot wheel double sided with slot and wall 10A - Perspective view showing details of the bottom 10B - Perspective view showing details of the top 10C - Perspective view showing different configuration Fig 11 - 12 Additional optional configurations for Geneva slot wheel Fig 13 - Scotch yoke input frame Fig 14 - Scotch yoke frame Fig 15 - Scotch yoke rectifier frame Fig 16 - Ratio modifier frame Fig 17 - Ratio plate

Fig 18 - Partial driving/driven gear for non-functional region Fig 19 - Link Fig 20 - crank pin

Fig 21 A - 21 D Link Mechanism on crank pin shaft with non-circular input shaft and collar with matching orifice, using offset crank pin mounted on crank pin collar with non-circular orifice sliding on crank pin shaft with matching cross-section 21 A- Top view 21 B- Front view 21 C- Side view 21 D-Perspective view

Fig 22A - 22D Link Mechanism on crank pin shaft with non-circular input shaft and collar with matching orifice, using input disk 22A- Top view 22B- Front view 22C- Side view 22D-Perspective view

Fig 23 - Rack velocity profile

Fig 24 -

Fig 25 - 30 - Options for connecting input, output and wheel using planetary gear

Fig 31 - Possible path of crank pin on Geneva wheel mechanism and showing partial gears for non-functional region

Fig 32 - 34 - Alternate configurations for ratio changing mechanism assembly using different shapes for input shaft, crank pin and collar

Fig 35 - 36 - Input shaft with notch for crank pin shaft, link and pivot pin for collar and link Fig 35 - Front view Fig 36 - Side view Fig 37 - Dummy crank pin assembly

Fig 38 - Mechanism to compensate for vibration due to rotational imbalance

Fig 39 - Slotted hollow input shaft

39A-Top view 39B-Front view 39C-Side view 39D-Perspective view

Fig 40 - Collar with thrust bearings

40A-Top view 4013-Front view 40C-Side view 40D-Perspective view

Fig 41 - 2 racks shown 180 degrees apart

40A-Top view 40B-Front view 40C-Side view 40D-Perspective view

Fig 42 - 2 dummy racks shown 180 degrees apart

40A-Top view 40B-Front view 40C-Side view 40D-Perspective view

Fig 43A - 43B - Alternative angular velocity module using stationary sun gear 43A - Perspective view 43B - Section through driven gear

Fig 44A - 44B - Alternative angular velocity module using stationary ring gear 44A - Perspective view 44B - Section through driven gear Fig 45 - 48 - achieving Reverse/Park/Neutral using bevel gears:

Fig 49 - Rack velocity profile and overlap of functional regions of consecutive modules in X-Y plane

Fig 50 - Rack velocity profile and overlap of functional regions of consecutive modules using polar coordinates DETAILED DESCRIPTION OF THE INVENTION:

SUMMARY OF THE INVENTION

To briefly describe this invention is an Infinitely Variable Transmission (IVT). Unlike existing CVT designs, this particular design does NOT depend on friction to transmit power.

Most of the CVTs that exist today depend on friction to transmit power and therefore cannot be used where there is a need to transmit high power at low speed. Due to this advantage, it is possible to use this invention where high torque transmission is required. Co-axial input and output can be achieved with this layout.

LIST OF COMPONENTS:

All the gears in the following component list can be replaced with a sprocket and chain system. The noncircular gear system can be replaced with a sprocket and chain system where at least one of the sprockets is non-circular.

1) Scotch yoke Input frame

2) Ratio modifier frame

3) Scotch yoke rectifier frame

4) Output frame

5) Ratio plate

6) Geneva slot wheel mechanism a) Pin wheel b) Slot wheel

7A-7B) Non-functional region partial driving and driven gear a) driving partial gear b) driven partial gear

8) Input shaft

9) Crank-Pin

10) Input disk

11) Slotted Rack holder ) Rack ) Dummy Rack ) Pinion ) Pinion shaft ) Collar ) Link ) Dummy link ) Input shaft bearing ) Input-Disk bearing ) Thrust-Bearing ) One-way bearing/ Computer-Controlled-Clutch / Ratchet-mechanism) Crank pin shaft ) Dummy Crank-Pin ) Non-functional region driving gear ) Non-functional region driven gear ) Crank pin to link pivot pin ) Collar to link pivot pin ) Power shaft ) Planetary-Gear ) Miter/Bevel-Gear-Differential-input shaft ) Miter/Bevel-Gear-Differential-output shaft ) Miter/Bevel-Gear ) Rack velocity profile ) Clutch-Park/Neutral/Reverse clutch/dog clutch ) Stationary sun gear ) Shaft-Cam ) Cam gear ) Driving circular or non-circular gear ) Driven circular or non-circular gear 41) Cam-Input-Shaft

42) Planet gear

43) Stationary sun gear

44) Stationary ring gear

45) Carrier shaft

The working of this CVT can be described by the following simple sequential of operations. a) A Crank pin 9 (Fig. 3B), revolves around the longitudinal axis of an Input disk 10

(Fig. 9) or a Input shaft 4 (Fig. 39) at an offset distance as shown in Fig. 3A, and this offset distance can be altered. The offset distance ranges from zero to a non-zero value. The concept described in this operation exists in several other patent application US 20100199805, US 9970520 etc. b) This offset Crank pin 9 is caged in

1) the Input disk 10 or alternatively slides on a Crank pin shaft 23, and

2) a slot of a Slotted rack holder 11 (Fig. 7A-7C).

The input shaft is slotted to allow the crankpin and link to pass thru it allowing the longitudinal axis of the input shaft or the input disk to be co-axial with the longitudinal axis of the crank pin. The Slotted rack holder 11 is restricted such that it can move only in the direction that is normal to its slot. A Rack 12is fastened to the Slotted rack holder 11 , such that the Rack 12 is parallel to the Slotted rack holder's 44 direction of movement. In the alternative construction, the Crank pin shaft 23 is orthogonal to the Input shaft 4. The revolution of the Crank pin 9 about the longitudinal axis 1021 of Input disk 10 is translated to pure linear back and forth movement or reciprocating movement of the Rack 12. This mechanism is commonly known as "Scotch-Yoke- Mechanism" in the industry. The distance of this linear back and forth movement (stroke) is directly proportional to the radial distance of the Crank pin 9 from the longitudinal axis 1021 of the Input disk 10. Since the work done is constant, which is a product of force applied multiplied by the distance traveled (F*stroke), for a smaller stroke, the force applied is greater and for a longer stroke, the force applied is smaller. c) The Rack 12 is linked to a Pinion 14 (Fig. 4A) converting this linear movement of the Rack 12 to rocking oscillation of the Pinion 14. d) This rocking oscillation is converted to a unidirectional rotation, using a One-way bearing/ Computer- Controlled-Clutch / Ratchet-mechanism 22.

One main purpose of this invention is to achieve a CONSTANT AND UNIFORM output angular velocity when the input angular velocity is constant and uniform. However, using the steps described above, this is NOT achieved, as the output is sinusoidal.

By modifying the rate of change of angular displacement of the Input disk 10, a uniform steady output can be achieved. Patent US9970520 uses a pair of non-circular gears to achieve this. This invention achieves it by using modified Geneva mechanism customized for this.

By using a set of Geneva pin wheel 6a (Fig. 8A-8C) and Geneva slot wheel 6b (Fig. 10A - 10C) the instantaneous rate of change of angular displacement at the Input disk 10can be altered. The components are grouped into modules/mechanisms for easier understanding:

Detailed description of Assembly, Sub-assembly of components/ Modules and their functions: a) Angular-Velocity-Modifier-Module (Fig. 2) The main purpose of this module is to change the uniform power input to a reciprocal of sinusoidal output. This is to reverse the effect of the sinusoidal output in a scotch yoke mechanism. This module comprises of:

1) Driving Geneva pin wheel,

2) Driven Geneva slot wheel and

3) Power shaft

The Driving Geneva pin wheel 6a is mounted on the Input shaft 4. The shape of the Geneva slot wheel 6b is designed to achieve the end result which is the reciprocal of sinusoidal output. Multiple pins and multiple slots are used and with an overlap of more than one pin achieving a portion of the same results simultaneously. More than one set of driving Geneva pin wheel and driven Geneva slot wheel can be used in a single module. The slot or the walls of the slot are terminated where a pin’s path forms loop. Also, multiple modules can share a common Geneva pin wheel or a common Geneva slot wheel. In the slot wheel the paths of the slots are cut from a slot wheel or the walls of the path can be raised from a slot wheel or a combination of both. This is to clear the interference of the pin where the pin and slot or slot walls do not produce desired result. Pins of the Geneva pin wheel can be made with different heights so that they do not interfere with the wall of slots of other Geneva pins. A portion of the rotation of the Geneva pin wheel and Geneva slot wheel be achieved using one or more partial circular gears and/or one or more partial non-circular gear in parallel. The partial gears generate the non-functional region of the rack velocity while the Geneva wheel system generates functional portion of the rack velocity. The Geneva wheel slots also have an overlap of the region generated by the partial gear. This is to achieve a 1 :X ratio of rotation between Geneve pin wheel and Geneva slot wheel. Here X is an integer or a reciprocal of an integer. Optionally, a one-way bearing can be placed between the circular or non-circular gear linking the Geneva slot wheel to the partial driven gear. Depending on the scenario either the Geneva pin wheel or the Geneva slot wheel can be made driving or driven. b) Scotch-Yoke-Module (Fig. 4A, 4B): The main purpose of this module is to convert circular motion to a reciprocating motion. The output is sinusoidal for a steady, uniform input. This output is converted to a steady, uniform output using Angular-Velocity-Modifier-Module.

This Scotch-Yoke-Module comprises of:

1) Input disk 10,

2) Slotted Rack holder 11 , and

3) Crank pin 9

The Input disk 10has a radial slot. The Slotted rack holder 11 has a slot namely "Crank-Pin-Slot" 1013. It also has an extension on either side of the slot at the middle of the slot. This extension is normal to the Crank-Pin-Slot 1013. The Slotted rack holder 44, is placed on the other side of the Input disk 10 sandwiching the Input disk 10between the Slotted rack holder H and a Ratio-Changing-Mechanism, which is described in subsequent paragraphs. The Crank pin 9 passes through the slots of Ratio-Changing-Mechanism, Input disk 10, and Slotted rack holder 11 c) Rectifier-Module: The main purpose of this module is a mechanical equivalent to a diode in an electrical circuit. It allows power transfer to one specific direction.

1) Rack 12,

2) Pinion 14,

3) Shaft-Pinion 48 and

4) One-way bearing/ Computer-Controlled-Clutch / Ratchet-mechanism 22

The Rack 12is attached to the Slotted rack holder 11 normal to the Crank-Pin-Slot 1013 and paired with the Pinion 14. The Pinion 14 is mounted on a Shaft-Pinion 48. The Computer- Controlled-Clutch /One-Way-Bearing / Ratchet-Mechanism 50 is mounted on the Shaft- Pinion 48. The Output-Gear / Output-Sprocket 51 is mounted on the OD of the One-Way- Bearing 50.

Multiple pinions from multiple modules can be mounted on a common shaft-pinion 48. The one-way bearing can be placed between the pinion and the pinion shaft. In this scenario the shaft-pinion 48 will function as the CVT output. The shaft-pinion can be made hollow so that the CVT input shaft can pass thru the shaft-pinion 48 making the input and output of the CVT co-axial. d) Gear-Changing-Mechanisms Link Mechanism:

The Input shaft 66 has a non-circular hole in the middle. This is paired with a Sliding-Collar with a matching exterior contour, which is co-axially placed allowing relative axial movement while restricting rotational angular displacement with respect to each other. Two thrust-Bearings 40 are co-axially placed in contact with one on either end of the Sliding-Collar 67 as shown in Fig. 22D and the Sliding-Collar-Auxiliary- Shaft 67 has a pivot 1028 on the other end. One end of a Link 68 is attached to the pivot 1028 and the other end of the Link 68 is either attached to the Crank pin 9, as shown in (Fig. 3A) or to the Crank pin shaft 23, as shown in (Fig. 3A) as appropriate. An axial displacement of the Sliding-Collar-Auxiliary-Shaft 67 will cause a radial displacement of the Crank pin 9 thru the Link 68. This axial translation is achieved with a Lever-Ratio- Changing-Spiral-Flute-Mechanism 41 that pushes the Thrust-Bearing 40 attached to the Sliding-Collar- Auxiliary-Shaft 67. Optionally this can be sprung back with a Compression-Spring 39 placed between Input disk 10and the Sliding-Collar-Auxiliary-Input-Shaft 67. Also, when this link mechanism is used the Driven- Geneva-slot wheel 6b can also function as the Input disk 10when a radial slot is added to the Driven-Geneva- slot wheel 6b, thereby eliminating the need for a separate Input disk 10.

For each scotch yoke module two Racks 64 can be placed on the Slotted rack holder 11with a phase shift of 180° engaged with their respective pinions placed co-axially on a common pinion shaft via a one-way bearing/computer-controlled clutch/a ratchet mechanism to allow the pinion shaft to rotate in a specific direction. Many of these scotch yoke modules can be stacked and all the pinions of all the modules can be placed on one common pinion shaft, making the pinion shaft the output of the IVT. Further this common pinion shaft can be made hollow allowing the power shaft which drives the driving Geneva pin wheel, to pass thru. With this arrangement a co-axial input to output can be achieved. This configuration allows to modify the output with a planetary gear system to achieve reverse gear converting the CVT to an IVT. This configuration also allows the force on the rack holder to pass thru the plane of the common pinion shaft axis. In other words, the longitudinal axis of the common pinion and the force of the crankpin acting on the rack holder will be co-planer. This will minimize the moment of the force from the crank pin acting on the rack holder due to the resistance by the pinion and maximize the tangential force on the pinion.

Two Rectifier-Modules 1001 are placed next to the Slotted rack holder 11 as shown in

Fig. 83 such that the Rack 12is placed normal to the Slotted rack holder's 44 Crank-Pin-Slot

1013.

MECHANISM TO COMPENSATE VIBRATION (ROTATIONAL IMBALANCE):

1. Dummy-Crank-Pin 43: The Crank pin 9 is placed off-center when the Input disk 10 revolves. This imbalance will result in vibration. To compensate this, a Dummy-Crank-Pin 43 is placed at same distance 180° apart. This movement is identical to the movement of the Crank pin 9. The dummy crank pin is attached to a dummy link that links to the dummy crank pin 43 that is pivoted to the collar placed to move in the opposite direction of the crank-pin. The input shaft is slotted to allow the link and crank pin and dummy link and dummy crank pin to pass thru

2. Dummy-Rack 55 for counter oscillation: As the Input disk 10 rotates the Slotted Rack holder 11 has an oscillatory motion which will result in vibration. It is cancelled by having an appropriate mass oscillating in the opposite direction. This is achieved by pinion as shown in Fig.4A&4B in contact with the Rack 12, which will spin back and forth. Bringing an appropriate mass in contact with the pinion at 180° apart will compensate for this vibration. A separate wheel can also be used in spite of the pinion or a lever pivoting on the pinion shaft can be used to link the rack and the dummy rack such that they move in opposite direction. A slider connecting the lever and sliding in a slot normal to the rack teeth will guide the lever allowing the rack and dummy rack to only slide in the direction of the longitudinal axis of the rack.

REVERSE GEAR MECHANISM:

When the output from the Pinion shaft 15 is coupled with Miter/Bevel-Gear-Differential-input shaft 31. The Miter/Bevel-Gear-Differential-output shaft 32 will rotate in opposite directions via Miter/Bevel-Gear 33. The Miter/Bevel-Gear-Differential-input shaft 31 of this differential-mechanism is placed co-axial with The Miter/Bevel-Gear-Differential-output shaft 32 with clearance so that it is free to spin independently with respect to the Miter/Bevel-Gear-Differential-input shaft 31. Two Clutch-Park/Neutral/Reverse clutch/dog clutch 35 with a clutch are placed on the Miter/Bevel-Gear 33 allowing them to move axially. These can be made to link with either of the Miter/Bevel-Gear 33, which rotate in opposite direction. When one of the collars is made to link via the Clutch-Park/Neutral/Reverse clutch/dog clutch 35, by means of clutch, with a particular output Clutch-Park/Neutral/Reverse clutch/dog clutch 35 and the Miter/Bevel-Gear-Differential- output shaft 31 will rotate in a particular direction. It will reverse its direction if the link is swapped to the other Miter/Bevel-Gear 33.

NEUTRAL GEAR MECHANISM:

When the collars are not in link via the Clutch-Park/Neutral/Reverse clutch/dog clutch 35 with any of the Miter/Bevel-Gear 33, the collar and the Miter/Bevel-Gear-Differential-output shaft 32 are not restricted and, therefore, they are free to spin in any direction and function as a "neutral" gear.

PARK MECHANISM:

When the collars are in link via the Clutch-Park/Neutral/Reverse clutch/dog clutch 35 with both the Miter/Bevel-Gear 33, the collar is restricted from spinning and the Miter/Bevel-Gear-Differential-output shaft 32 is totally restricted and, therefore, they are restricted to spin in any direction and function as a "parking" gear.

CONVERTING CVT TO AN IVT (INFINITELY-VARIABLE-TRANSMISSION):

Having a co-axial input and output allows the CVT to function as an IVT. This can be achieved by adding a Planetary-Gear-System with a Sun-Gear, Ring-Gear and Planets supported by Carriers, and linking with Input shaft 4, the Co-Axial-Output-Element-With-lnternal- Gear/Planetary-Gear 65.

The following are the options to achieve this: a) The Input shaft 4 is directly linked to the Sun-Gear of the planetary-Gear-System with following 2 sub-options a. The Co-Axial-Output-Element-With-lnternal-Gear/Planetary-Gear 65 is directly linked to the Carrier of the Planetary-Gear-System and Ring-Gear of the Planetary-Gear-System functions as the final output or wheel system 1022 b. The Co-Axial-Output-Element-With-lnternal-Gear/Planetary-Gear 65 is linked to the Ring-Gear of the Planetary-Gear-System and the Carrier functions as the final output or wheel system 1022. b) The Co-Axial-Output-Element-With-lnternal-Gear/Planetary-Gear 65 is directly linked to the Sun-Gear of the Planetary-Gear-System with following 2 sub-options. a. The Input shaft 4 is directly linked to the Carrier of the Planetary-Gear-System and the Ring-Gear of the Planetary-Gear-System functions as the final output or wheel system 1022. b. The Input shaft 4 is directly linked to the Ring-Gear of the Planetary-Gear- System and the Carrier functions as the final output or wheel system. c) The Input shaft 4 is directly linked to the Ring-Gear of the planetary-Gear-System with following 2 sub-options a. The Co-Axial-Output-Element-With-lnternal-Gear/Planetary-Gear 65 is directly linked to the Carrier of the Planetary-Gear-System and Sun-Gear of the Planetary- Gear-System functions as the final output or wheel system 1022. b. The Co-Axial-Output-Element-With-lnternal-Gear/Planetary-Gear 65 is linked to the Sun-Gear of the Planetary-Gear-System and the Carrier functions as the final output or wheel system 1022. d) The Co-Axial-Output-Element-With-lnternal-Gear/Planetary-Gear 65 is directly linked to the Ring-Gear of the Planetary-Gear-System with following 2 sub-options. a. The Input shaft 4 is directly linked to the Carrier of the Planetary-Gear-System and the Carrier of the Planetary-Gear-System and the Sun-Gear of the Planetary- Gear-System functions as the final output or wheel system 1022. b. The Input shaft 4 is directly linked to the Sun-Gear of the Planetary-Gear-System and the Carrier functions as the final output or wheel system 1022. e) The Input shaft 4 is directly linked to the Carrier of the planetary-Gear-System with following 2 sub-options a. The Co-Axial-Output-Element-With-lnternal-Gear/Planetary-Gear 65 is directly linked to the Ring-Gear of the Planetary-Gear-System and Sun-Gear of the Planetary-Gear-System functions as the final output or wheel system 1022. b. The Co-Axial-Output-Element-With-lnternal-Gear/Planetary-Gear 65 is linked to the Sun-Gear of the Planetary-Gear-System and the Sun-Gear functions as the final output or wheel system 1022. f) The Co-Axial-Output-Element-With-lnternal-Gear/Planetary-Gear 65 is directly linked to the Carrier of the Planetary-Gear-System with following 2 sub-options. a. The Input shaft 4 is directly linked to the Ring-Gear of the Planetary-Gear- System and the Ring-Gear of the Planetary-Gear-System and the Sun-Gear of the Planetary-Gear-System functions as the final output or wheel system 1022. b. The Input shaft 4 is directly linked to the Sun-Gear of the Planetary-Gear-System and the Ring-Gear functions as the final output or wheel system 1022.

In other words, The Co-Axial-Output-Element-With-lnternal-Gear/Planetary-Gear 65 is connected to one of the three elements, either a Ring-Gear, a Carrier, or a Sun-Gear of a Planetary-Gear-System. The Input shaft 4 is connected to one of the remaining two elements of the Planetary-Gear-System. The third remaining element of the Planetary-System functions as the final output or wheel system 1022. This converts the CVT to an IVT.

COMPENSATING FOR DEVIATION IN RACK MOVEMENT WITH CAMS:

It is beneficial to have smooth and gradual transitions in the rack movement profile to improve the life of the transmission. As shown in Fig. 23, the ideal rack velocity profile is as follows:

1. gradual increase in acceleration from rest 1025

2. a region of acceleration 1026

3. gradual reduction in acceleration to a constant velocity 1027

4. a region of constant velocity 1028

5. gradual increase in deceleration to a constant deceleration 1029

6. a region of deceleration 1030

7. gradual reduction in deceleration to zero velocity 1031

8. steps 1 through 7 above repeated in the opposite direction

It may not always be possible to generate perfect Geneva wheel mechanism to meet the above desired Rack 12movement. If the slot curves 1006 of the Geneva slot wheel and the Geneva pin wheel 6a & 6b do not to achieve this desired Rack 12 movement, a planetary system can be used to compensate for any deviations from the desired Rack 12 movement profile. To achieve this, a Stationary Sun Gear 36 with respective to the ratio modifier frame 2 is placed co-axial with a driven circular or non-circular gear 40 which is driven by a driving circular or non-circular gear 39 as appropriate. This can be used in addition to the Geneva wheel system. This is shown in Fig.43A& 43B. This driving circular or non-circular gear is mounted on the power shaft 29. One or more Shaft-Cam 37 is placed on the driven circular or non-circular gear 40 which acts like a carrier of the planetary gear system. A Cam-Gear 38 is rigidly attached on the Shaft-Cam 37. Each of this Cam-Gear 38 is made to engage another Cam-Input-Shaft 41 each, which is rigidly attached on the Input shaft 8. The cams can be designed to give a desired rack velocity profile. The above configuration will also work when the stationary sun is replaced with a stationary ring gear. This is shown in Fig. 44A&44B.

Mathematical Model

The following formula is used in pitch curve generation of the driving non-circular gear and driven non-circular gear, when expressed using Cartesian coordinates (X ₁ ,Y ₁ and (X ₂ , Y ₂ ) respectively, as a function of angle θ are where Φ(θ) is a solution to a piece-wise differential equation which gives rotation ratio of the driving and driven Geneva wheel system as well as the driving and driven non-circular gears. k _i if θ _1i < θ < θ _{2 i,} function of any linear or nonlinear curve connecting points (θ _2i , 0) to (θ _3; , —k _i ) if θ _2i < θ < θ _3i ,

-k _i if θ _{3 i} < θ < θ _4i , function of any linear or nonlinear curve connecting points (θ _4i , 0) to or function of any linear or nonlinear curve connecting points (θ _1i ,k _i ) to (θ ₂ , —k _i ) if θ _1i < θ < θ

-k _i ifθ _2i < θ < θ _3i , function of any linear or nonlinear curve connecting points (θ ₃ -k _i ) to (θ _4i ,k _i ) if θ _{3 i} < θ < θ _4i , where boundary conditions are

Φ(0) = 0;

Where,

CTR is a center-to-center distance of the driving non-circular gear and the driven non-circular gear, θ is an angular displacement of the driving non-circular gear; Φ is an angular displacement of the driven non-circular gear; i refers to an i-th revolution the input disk from 0 to N*n-1 with a 1st rotation being i=0;

N is a number of times the input disk rotates when the driven non-circular gear rotates once; n is a number of times the driven non-circular gear rotates when the driving non-circular gear rotates once; regions where the piece-wise function for the rack velocity is constant are functional regions and regions where the piece-wise function for the rack velocity is not constant are non-functional regions which can be linear or non-linear functions of θ; θ _1i ,θ _2i , θ _{3 i} , θ _4i are specific angular positions of the driving non-circular gear, the values of which are solved for using a solution to the piece-wise differential equation;

Φ ₁ ,Φ ₂ ,Φ ₃ ,Φ ₄ are specific angular positions of the driven non-circular gear corresponding to angular positions θ _1i ,θ _2i , θ _{3 i} , θ _4i of the driving non-circular gear respectively, and are a cutoff between the functional and non-functional regions, values of Φ ₁ ,Φ ₂ ,Φ ₃ ,Φ ₄ which can to be solved for by using arbitrary values for θ _1i ,θ _2i , θ _{3 i} , θ _4i ; and k _i are constants, which are all equal.