Trimmable Pod Drive Thrust Vector Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current pod drive systems in marine vessels face inefficiencies in pitch control, leading to reduced thrust efficiency and increased drag, particularly when attempting to trim the vessel, which affects the dynamic planing state and overall performance at high speeds.
Innovation Solution
A trimmable pod drive assembly that allows the pod drive unit to rotate about a trim axis perpendicular to the steering axis, enabling controlled trim adjustments through actuators, which modify the thrust vector's angle relative to the vessel bottom, thereby optimizing planing position and reducing drag.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If trim tabs or interceptor devices are deployed downward at the surface of the water to control pitch, then pitch control is achieved, but parasitic drag force increases reducing thrust efficiency and vessel speed
Solution Approach 1:
The pod drive unit is made dynamically adjustable in its trim angle through actuation mechanisms that allow rotation about a trim axis. This enables the thrust vector to be dynamically adjusted to optimize pitch control without requiring separate trim tabs that create drag, directly resolving the contradiction between pitch control capability and thrust efficiency
Solution Approach 2:
The pod drive unit serves multiple functions: it provides propulsion through the propeller, steering control through rotation about the steering axis, and pitch control through rotation about the trim axis. By integrating pitch control into the pod drive unit itself, the system eliminates the need for separate trim tabs or interceptors, thereby maintaining thrust efficiency while achieving pitch control
2Stability of the object's composition
If the pod drive unit is constrained to steer on the dihedral angle of the vessel bottom, then the steering axis is fixed perpendicular to the vessel bottom, but this introduces a proportional vertical component of thrust and increased drag when the vessel bottom is not horizontal
Solution Approach 1:
The pod drive unit is made dynamically adjustable in its trim angle through actuation mechanisms that allow rotation about a trim axis. This enables the thrust vector to be dynamically adjusted to optimize pitch control without requiring separate trim tabs that create drag, directly resolving the contradiction between pitch control capability and thrust efficiency
Solution Approach 2:
The trim angle of the pod drive unit is changed as a variable parameter rather than being fixed. By allowing the trim angle to be adjusted based on operating conditions and vessel bottom orientation, the system can compensate for non-horizontal mounting surfaces and minimize vertical thrust components and drag, resolving the contradiction between fixed steering axis stability and energy loss
Data Source
AI summary
Disclosed herein is a trimmable pod drive assembly that includes a pod drive unit having a transmission assembly secured to a steering unit, a gear case assembly coupled to and rotatable by the steering unit about a steering axis, and a propeller rotatable about a propeller driveshaft axis extending through the gear case assembly so as to generate thrust along a thrust vector. The trimmable pod drive assembly further includes a trim assembly secured to the pod drive unit in a manner allowing for rotation of the pod drive unit about a trim axis that is substantially perpendicular to the steering axis, wherein actuation of at least one component of the trim assembly causes movement of the pod drive unit and the thrust vector about the trim axis.