Rotator technology

There are two types of valve rotator. Both operate by means of the increase in valve spring loads from valve closed to valve open.

Rotators can be manufactured in sizes ranging from 25mm to 150mm diameter. Each one is tailor-made for a specific application.

Helical has the design expertise and flexibility to complete the development cycle rapidly from design to prototype stage, and then to on-time delivery of serial production.

Garter spring type

The increase in valve spring load deflects a washer spring (similar to a Belleville washer), which compresses an internal garter spring located in a circumferential groove in the rotator body which is attached to the engine valve. This deflection of the garter spring coils causes the body and valve to rotate in small increments each time the valve operates. Garter spring rotators are used for applications with relatively low valve spring loads.

View an animated video of features and functions.

Ball and spring type

This type of rotator operates by using a series of balls and springs, located in ramps formed in the rotator body which is attached to the engine valve. A disc spring (similar to a Belleville washer) is compressed by the action of the valve spring. The deflection of the disc spring forces the balls down the ramps, causing the body and valve to rotate. As the valve spring load is reduced, the balls are forced back up the ramps by the springs locating the balls. The process is repeated each time the valve operates. Ball and spring rotators are used for applications with relatively high valve spring loads.

View an animated video of features and functions.

Testing

All Helical rotators are tested to meet customers’ overspeed, overload and temperature specifications. We have test rigs for engines up to 460 mm cylinder diameter.

Quality standard

BS EN ISO 9001:2000