Effect of Changing Hydraulic Parameters on a Windlass wih Variable Displacement Motor
Here’s how changing the flow rate and displacement of the hydraulic oil affects the operation of a windlass driven by a variable displacement motor:
(a) Changing Flow Rate of Hydraulic Oil:
The flow rate of hydraulic oil directly affects the speed of the windlass. It’s analogous to the relationship between the amount of gasoline flowing into a car engine and the engine’s RPM.
- Increased Flow Rate: Increasing the flow rate of hydraulic oil delivered to the variable displacement motor results in a faster rotation of the windlass drum. This allows for quicker retrieval or deployment of the anchor.
- Decreased Flow Rate: Decreasing the flow rate of hydraulic oil leads to a slower rotation of the windlass drum. This might be useful for precise control during delicate mooring operations or when handling heavy loads.
Important Note: While increasing flow rate increases speed, it can also lead to higher pressure demands on the hydraulic system. The system needs to be designed to handle the increased pressure without exceeding its limitations.
(b) Changing Displacement of the Motor:
The displacement of the variable displacement motor refers to the volume of hydraulic fluid it can move per revolution. It’s a characteristic of the motor itself and can be adjusted within a specific operating range.
- Increased Displacement: If the motor’s displacement is increased, it will require a lower flow rate to achieve the same rotational speed as before. This can be beneficial for situations where the available hydraulic power is limited. However, it might also reduce the maximum achievable speed of the windlass.
- Decreased Displacement: Decreasing the motor’s displacement will necessitate a higher flow rate to maintain the same rotational speed. This can be useful for applications requiring high speed but can put a higher demand on the hydraulic pump’s capacity.
Choosing the Right Combination:
The optimal combination of flow rate and displacement ultimately depends on the specific requirements of the windlass operation. Factors such as desired hoisting/retrieval speed, weight of the anchor and chain, and available hydraulic power will influence the choice.
In most practical scenarios, the flow rate is adjusted through a control valve to suit the desired windlass speed, while the motor displacement is chosen based on the overall system design and available hydraulic power limitations.