Pitch Actuator Rod Seal Assembly With Split Retainers
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Solution Overview
Problem
Conventional pitch actuators in wind turbines face issues with high maintenance costs and downtime due to the frequent replacement of damaged seals and glands, which are tedious and require skilled labor, exacerbated by fluctuating hydraulic pressures and frictional forces.
Innovation Solution
A seal assembly for pitch actuators in wind turbines featuring a removable design with split retainers and retainers, allowing easy access and replacement of seals without disassembling the actuator, using a kit containing spare components and tools for quick maintenance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional seals and glands are used in pitch actuators, then the actuator can operate under high hydraulic pressures, but the seals and glands are damaged due to fluctuating pressures and frictional forces, requiring frequent replacement
Solution Approach 1:
The seal assembly is divided into modular components including multiple seals (first seal, second seal, wiper seal) that can be independently replaced. Each seal is supported by separate retainers (first split retainer, second split retainer, third split retainer) allowing selective replacement of individual seals without replacing the entire assembly, thereby reducing maintenance time and downtime.
Solution Approach 2:
The seal assembly is pre-assembled as a complete unit with all seals and retainers configured before installation. This pre-assembly ensures proper positioning and pre-loading of seals, allowing the entire assembly to be installed as one unit while enabling individual seal replacement later without disassembling the complete assembly, thus reducing maintenance time.
2Ease of repair
If seals and glands are damaged, then they must be replaced, but the replacement process is tedious and requires highly skilled labor
Solution Approach 1:
The seal assembly is segmented into modular components with each seal independently supported by its own retainer. This segmentation allows technicians to replace individual seals without disassembling the entire assembly or requiring complex procedures, making repair easier while the modular structure manages complexity through standardization.
Solution Approach 2:
Instead of making the seals fixed and permanent, the design makes them easily removable and replaceable through split retainers that can be quickly released. This inversion of the traditional permanent seal approach allows unskilled or semi-skilled labor to perform replacements that would traditionally require highly skilled technicians.
3Reliability
If a single seal is used, then the structure is simple, but the seal cannot withstand full hydraulic pressure and frictional forces continuously
Solution Approach 1:
The sealing function is divided among multiple specialized seals: a first seal for primary sealing, a second seal for backup sealing, and a wiper seal for contaminant removal. Each seal handles specific aspects of the sealing requirement, allowing the system to withstand full hydraulic pressure and frictional forces while managing complexity through functional specialization.
Solution Approach 2:
Different seals are positioned at different locations along the actuator rod with different properties and functions. The first seal and second seal provide primary sealing at different stages, while the wiper seal provides a different function at the rod exit. This local differentiation allows each seal to be optimized for its specific location and function, improving overall reliability under pressure.
Data Source
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AI summary
Present disclosure discloses a seal assembly for an actuator rod of a pitch actuator. The assembly includes at least one first ring annularly interposed between an actuator rod and a cylinder cover, and removably supported by a first split retainer half pair in an annular recess defined in the cylinder cover. A first seal is annularly interposed between the actuator rod and the cylinder cover. A second seal annularly is interposed between the actuator rod and the cylinder cover is supported by a retainer. The seal assembly also includes a wiper seal which is annularly interposed and supported by a third split retainer half pair between the actuator rod and the cylinder cover. Each of the first, second and third split retainer half pairs, and the retainer is removably connectable to the cover.