Exam Question

Rotary vane steering gears are a highly efficient and compact type of hydraulic steering gear employed to transmit the necessary torque directly to the rudder stock for steering a vessel. They are favoured for their robust construction, high torque output, and direct drive mechanism, eliminating the need for complex linkages between the power unit and the rudder stock.
### Construction and Key Components
A typical rotary vane steering gear consists of the following critical components, which collectively facilitate the transmission of torque:
* **Casing (Stator)**: This is a robust, cylindrical housing, typically manufactured from high-grade cast steel, which is securely bolted to the ship's steering gear flat. The casing is stationary and forms the outer boundary of the steering gear. It contains internal chambers and precisely machined ports for the ingress and egress of hydraulic fluid. Integral to, or securely bolted within, the inner circumference of the casing are the fixed vanes.