Composite Thrust Bearing Pad With Thermal Warp Variable Taper
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Solution Overview
Problem
Conventional hydrodynamic thrust bearings require expensive machining operations to create permanent tapers for lubricant entry, limiting their bi-directional rotation capability and increasing the risk of failure due to thermos-elastic instabilities and thermo-viscous distress from heat-induced friction.
Innovation Solution
The use of composite laminate bearing pads that warp thermally to create a variable taper, allowing lubricant entry without pre-formed tapers, utilizing anisotropic thermal expansion to control the pad profile and minimize friction and wear.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If permanent taper contours are machined or pre-formed on bearing pads to facilitate lubricant entry, then lubricant flow is improved, but manufacturing cost increases and bi-directional rotation capability is limited
Solution Approach 1:
The bearing pad uses a composite laminate structure with plies having different coefficients of thermal expansion that dynamically change shape in response to temperature variations during operation. This dynamic shape change creates variable taper contours that adapt to operational conditions, eliminating the need for pre-formed permanent tapers and enabling bi-directional rotation capability.
Solution Approach 2:
The invention utilizes differential thermal expansion of composite laminate plies with different coefficients of thermal expansion. When heated during operation, the plies expand at different rates, causing the bearing pad to warp and form taper contours that facilitate lubricant entry. This thermal-based mechanism replaces expensive machining operations and enables adaptive geometry control.
2Reliability
If permanent taper contours are machined on bearing pads to allow lubricant entry, then lubricant flow is facilitated, but the risk of bearing failure due to thermos-elastic instabilities and thermo-viscous distress increases
Solution Approach 1:
The composite laminate bearing pad dynamically adjusts its shape through differential thermal expansion of its plies, creating variable taper contours that adapt to operational temperature and load conditions. This dynamic adaptation optimizes lubricant film thickness and reduces the risk of thermos-elastic instabilities and thermo-viscous distress compared to fixed permanent tapers.
Solution Approach 2:
The invention changes the physical parameters of the bearing pad geometry in response to temperature changes. As the composite laminate plies heat up during operation, their differential expansion alters the pad's shape and taper contours, dynamically optimizing the lubricant film parameters to prevent failure modes associated with fixed geometry pads.
3Ease of manufacture
If single-direction taper contours are provided on bearing pads to minimize cost, then manufacturing cost is reduced, but rotation capability is limited to a single direction
Solution Approach 1:
The composite laminate bearing pad uses differential thermal expansion of its plies to dynamically create variable taper contours that adapt to the direction and magnitude of applied loads. This dynamic shape change enables the pad to accommodate bi-directional rotation and variable load conditions without requiring complex pre-formed contours, achieving versatility without sacrificing manufacturing simplicity.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This solution eliminates the need for costly machining, enables bi-directional rotation, and reduces the risk of bearing failure by dynamically adjusting the pad profile to maintain an optimal lubricant film thickness.
Implementation Method 1
The at least one ply is configured to expand non-uniformly when heated from a first temperature to a second temperature for causing the composite laminate to warp from an unstressed state to a stressed state
Implementation Method 2
during service, the lubricating oil is inevitably heated by friction which reduces the oil film thickness, thereby increasing surface wear
Data Source
AI summary
A hydrodynamic thrust bearing pad includes a composite laminate including at least one ply including a plurality of fibers oriented in at least one direction, and a bearing surface configured to confront a rotating thrust surface of a rotating shaft for transmitting axial thrust loads from the rotating shaft to the composite laminate. The bearing pad also includes a support surface configured to confront a stationary surface of a stationary housing for transmitting the axial thrust loads from the composite laminate to the stationary housing, and at least one side surface extending between the bearing and support surfaces. The at least one ply is configured to expand non-uniformly when heated from a first temperature to a second temperature for causing the composite laminate to warp from an unstressed state to a stressed state.