vahekorrad

Vahekorrad is a mechanical engineering term used to describe an intermediate gear or wheel placed between a driver gear and a driven gear in a gear train. The intermediate gear serves to transmit motion, adjust spacing between shafts, and sometimes change the direction of rotation, while often not altering the overall gear ratio in a simple external gear train. If the intermediate gear has a different teeth count than the driver or driven gear, the total ratio from input to output remains determined by the driver and final gear, though the intermediate gear can affect direction and layout.

Common configurations include single-idler setups, where the intermediate gear changes rotation direction and spacing, and compound or multi-gear arrangements when several gears share shafts. Planetary or complex trains may also use intermediate wheels to achieve compact layouts. Design considerations cover bearing supports, shaft alignment, backlash, lubrication, and tooth profile (spur, helical, or others). Materials are selected for wear resistance and stiffness to sustain loads and reduce losses.

Applications span automotive transmissions, machine-tool drives, conveyor systems, and robotics, particularly where space constraints or installation geometry require repositioning of shafts or reversing rotation without changing the primary gear ratio. Limitations include added complexity, increased friction and wear risks, and greater sensitivity to misalignment and tolerance stack-up.

Usage and terminology vary by language and discipline; in some contexts vahekorrad may be used interchangeably with idler gear or intermediate wheel.