Driveline and transmission

Types of transmission

There are various types of transmission systems available globally, and the fluid requirements for each type of transmission will be different:

• Manual Transmission (MT): typically consists of a dry, unlubricated clutch and a set of gears which are manually changed by the driver.

• Automatic Transmission (AT): is the most used transmission in the US. This uses a planetary gear system to alter the gear ratio. There is fluid coupling via a torque converter which permanently connects the engine and transmission, and so having to constantly disengage and reengage a clutch is avoided.

• Continuously Variable Transmission (CVT): is a type of AT but possesses a pulley-system instead of gears. Power flows from the engine through a belt and pulleys to the driveshaft. This creates a huge number of gear ratios and there is no loss of drive during gear switches.

• Dual Clutch Transmission (DCT): DCT transmission has no manual clutch and gears can be rapidly shifted up and down. Imagine the DCT to be a system housing two manual transmissions — one for even numbered gears and the other for odd numbered ones — each with their own clutch. Gears can be pre-selected and primed for change when ready, meaning that transitions are fast and smooth. Dry and wet clutch versions are available.

•  Others: include semiautomatic, electric, hydraulic and toroidal transmissions.

In a world where improved fuel economy and reduced emissions is being legislated for, OEMs are looking for ways to not only improve driver experience but to also gain fuel economy benefits through more efficient transmissions. In recent years, a great deal of progression has taken place in the development of new and improved transmission systems.

Why choose Energy Technologies?

We have been a supplier of esters into transmission fluids for many years. As with engine oils, these are often used as additive solubilizers and seal swell agents but can also help in optimising low temperature flow properties. 

Control and durability of friction in wet clutch systems is a key parameter and we can show through our clutch test rig that our esters and friction modifiers can be beneficial in this regard. Additionally, wear protection of transmission components is also a high priority and we offer some opportunities to provide ester technology which may aid formulators in developing formulations which, for example, prevent wear and micro-pitting, using high viscosity complex esters.

Applications

Explore our ester-based Xenitron™ dielectric fluids for formulating insulating lubricants for gearboxes. Unlike traditional automatic transmission fluids, our esters have been specifically engineered for the requirements of electric and hybrid vehicles.