CVT vs Universal Transmission

A CVT uses friction against
 the side of the rock.

To put it simply, the CVT performs 

work through dynamic friction which is like placing a lever against the side of a rock and using dynamic friction to lift the rock as in the illustration to the right. The advantage for the CVT is the fulcrum is able to constantly vary its position without interrupting the work in order to reset its position like a standard or automatic transmission must do. Because the CVT is forcing the lever against the side of the rock it cannot perform high torque work.

The Universal Transmission places 
the lever under the rock.
The Universal Transmission can perform high torque work because it places the lever under the rock (as illustrated to the right) like a standard transmission does. Because of its unique MoonGear™ - to-chain relationship and simple controller, the fulcrum is able to be moved in infinite increments without interrupting the work to reset the fulcrum.

The Universal Transmission is similar in design to a conventional belt driven CVT, although the Universal Transmission “belt” is actually a chain and has teeth on its inner surface as shown below. These teeth are engaged by one or more MoonGears™ which are connected directly to a driving or driven member. By a controlled means, the MoonGears™ are designed for radial (orbital) movement so that they may synchronously follow and engage the belt in its inward and outward movement. 

The MoonGears™ provide a positive displacement of torque from the input to the output of the mechanism. Both transmissions use sheaves. However, the sheave face on the CVT is used to transfer the torque  requiring powerful hydraulics as the sheaves clamp the belt. In the Universal Transmission the sheaves are used primarily to form circles and do not transfer torque by clamping the belt or chain. The Universal Transmission sheave clamping force or axial pressure to maintain a circle with the belt or chain is 1/3 of that needed in a typical friction CVT. This saves money and increases efficiency.

Finding the Solution

While they have much in common, creating the Universal Transmission did not come simply by making a few alterations to the standard CVT. In fact a radical departure was needed. 

Through intensive study and examination of principles, VMT engineers determined that they had to establish some strict design criteria or standards for discovery:

1. Metal-to-metal gear teeth engagement had to be constant – always remaining engaged –
 never disconnecting like a clutch transmission – in order to achieve constant engagement.
2. When changing ratios, multiple gear teeth will remain engaged yet could not be dragged 
 out of engaged tooth slots when the ratios are spreading.
3. Involutometry had to be addressed properly.
4. Using Dynamic Friction as a solution to changing any ratios (as standard CVTs do) was 
 totally unacceptable because Dynamic Friction always causes heat and therefore wear and 
 is incapable of handling high torque. 

VMT engineers knew that unless these four criteria were properly addressed and solutions found, the goal of a radically new transmission could not be achieved. They knew a revolutionary transmission must keep the positive characteristics of the clutch transmissions, most notably the ability to handle significant power and torque for great performance. They knew they had to keep the most notable attribute of the CVT, namely its efficiencies for better fuel economies. They knew they had to keep these positive characteristics while eliminating the inherent weaknesses of both.

It is important to remember that this has long been desired but never been accomplished. After several theoretical engineer proof models were first built, metal proof models were then built to see if the principles listed above could be incorporated into working metal models.

P-1 Proof Model

The initial metal proof model (P-1) was created to demonstrate that we could correct for the partial tooth integer. In this example the sheave circumference was set at 49.5 teeth. This required a correction for every MoonGear so that it could engage the chain correctly or synchronously. This model proved successful and that our theory and calculations were correct. That moved us on to our next model. 

The metal proof model (P-2 shown below) was then built to demonstrate that we could index correctly with varying orbital radii while under load. This was designed to match the requirements of a small wind turbine. It is shown with all of the independent laboratory controls for data collection. During the testing and development of the P-2 we were able to simplify and create the elegant solutions of the current design. 

The epiphany that led to the real invention in this breakthrough was realizing that the increase in the radius was directly linked to the indexing or correction of the integers of the MoonGears™. That led to the discovery that one part - one single, simple part - could control in a direct linear fashion five distinct actions in a coordinated or fully orchestrated manner. It sounds like it could be complicated, but the beauty is it all works so simply together, eliminating many parts. Truly an efficient, elegant solution. 

The P-2 with 
Chief Engineer Will Decker