Wind Turbine Lubrication Pump Gearbox for Cold-Start Torque
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Wind turbine lubrication systems require larger motors during cold start-ups due to the higher viscosity of lubricants, leading to increased torque requirements and reduced motor efficiency during normal operations, as the motor needs to be oversized to handle cold start-up conditions.
Innovation Solution
A gearbox arrangement is introduced between the motor and the pump, allowing the motor to operate at its rated speed by reversing the direction of rotation, which reduces the motor torque required during cold start-ups and enables the use of a smaller, more efficient motor by varying the pump speed through an epicyclic gear set.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If a large motor is used to drive the pump during cold start-up, then the pump can overcome higher lubricant viscosity, but the motor runs outside its optimum load area during normal operation reducing efficiency
Solution Approach 1:
The patent applies a variable speed drive system that dynamically adjusts the motor speed based on operating conditions. During cold start-up, the motor operates at reduced speed to match the higher lubricant viscosity requirements, while during normal operation, the speed is optimized for efficiency. This dynamic speed adjustment allows the same motor to operate efficiently across different loading conditions without being oversized.
Solution Approach 2:
The patent changes the operational parameters of the motor by implementing variable speed control. By adjusting the motor speed parameter according to the lubricant temperature and viscosity conditions, the system optimizes the motor's operating point. During cold conditions, lower speeds are used, while during warm conditions, the motor operates at its optimal efficiency point, eliminating the need for oversized motors.
2Force
If the motor speed is reduced during cold start-up, then the torque requirement is reduced, but the power induced into the oil via the pump is also reduced
Solution Approach 1:
The patent introduces a gearbox as an intermediary mechanism between the motor and the pump. The gearbox provides mechanical advantage through its gear ratio, allowing the motor to operate at lower speeds during cold start-up while still delivering sufficient torque to the pump. During normal operation, the gearbox transmits power efficiently, ensuring that the pump receives adequate power to induce oil flow and heat the lubricant effectively.
Data Source
AI summary
A pump system for supplying lubricant to components of a wind turbine comprises: a pump for pumping lubricant through a fluid circuit of the wind turbine; a drive means for driving the pump; and, a gearbox arrangement arranged to couple the drive means to the pump. The gearbox arrangement comprises a rotatable input shaft configured to be driven by the drive means and a rotatable output shaft configured to drive the pump. The input shaft is rotatable in a first direction of rotation and a second direction of rotation when driven by the drive means. The output shaft is rotatable in the first direction of rotation, and the speed of rotation of the output shaft is determined by an operational mode of the gearbox arrangement. In a first mode of operation, when the input shaft rotates in the first direction of rotation at a first speed of rotation, the gearbox arrangement is configured to drive the output shaft to rotate also in the first direction of rotation at the first speed of rotation. In a second mode of operation, when the input shaft rotates in the second direction of rotation at the first speed of rotation, the gearbox arrangement is configured to drive the output shaft to rotate in the first direction of rotation at a second speed of rotation.