Clutch Bearing Lubrication With Grease Shields and Release Gaps
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Solution Overview
Problem
Fluid actuated clutches face issues with lubricant retention and heat dissipation due to high temperatures and centrifugal forces, leading to premature wear and failure, and excessive lubrication can cause chemical breakdown and heat retention.
Innovation Solution
A lubrication arrangement that eliminates resilient contact seals and uses annular grease shields to retain lubricant and facilitate heat dissipation, preventing damage from high temperatures and pressures, and allowing excess lubricant to escape through fixed gaps.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If resilient contact seals are used to retain lubricant in clutch bearings, then lubricant retention is improved, but the seals fail due to high temperatures and pressures
Solution Approach 1:
The patent removes resilient contact seals from the lubricant retention system and replaces them with a grease shield arrangement. The grease shield is a non-resilient, temperature-resistant component that retains lubricant through mechanical barrier rather than elastic sealing, eliminating the temperature sensitivity of resilient materials.
Solution Approach 2:
The grease shield is designed as a simple, replaceable component that can be easily manufactured and installed. Rather than relying on expensive, temperature-vulnerable resilient seals, the system uses a straightforward metallic or composite shield that withstands high temperatures without degradation.
2Quantity of substance
If excess lubricant is packed into sealed areas, then lubricant availability is improved, but heat dissipation is prevented causing chemical breakdown
Solution Approach 1:
The grease shield includes an overflow gap that dynamically adjusts lubricant retention based on temperature and operational conditions. When temperature rises and lubricant expands, or when centrifugal forces increase, the excess lubricant automatically escapes through the gap, preventing overheating while maintaining adequate lubrication during normal operation.
Solution Approach 2:
The overflow gap acts as a passive feedback mechanism that responds to temperature and pressure conditions within the sealed area. When lubricant quantity exceeds the safe threshold or temperature rises, the system automatically releases excess lubricant, creating a self-regulating lubrication system that prevents thermal runaway.
3Reliability
If resilient contact seals are used for sealing, then sealing effectiveness is improved, but the seals suffer damage from high temperature and pressure operating conditions
Solution Approach 1:
The patent eliminates resilient contact seals entirely from the bearing sealing system. Instead, it employs a grease shield with an overflow gap that provides sealing through geometric configuration rather than elastic deformation, removing the component vulnerable to temperature and pressure damage.
Solution Approach 2:
The grease shield can be constructed from composite materials or treated surfaces that combine wear resistance, temperature resistance, and appropriate friction characteristics. This composite approach provides sealing effectiveness without relying on the mechanical properties of resilient materials that degrade under operating conditions.
4Reliability
If lubricant is retained in sealed areas, then lubrication is maintained, but heat dissipation is hindered causing lubricant breakdown
Solution Approach 1:
The overflow gap creates a dynamic lubrication system that adjusts lubricant retention based on thermal and operational conditions. During normal operation, the gap maintains lubricant presence for effective lubrication. When heat accumulation occurs, the gap allows lubricant escape, enabling heat dissipation and preventing thermal degradation.
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
The solution effectively retains lubricant and prevents overheating, reducing wear and failure risks while maintaining lubrication effectiveness under high operating conditions.
Implementation Method 1
centrifugal forces produced by rotation of clutch components at high speeds may result in seal leakage and loss of lubricant
Implementation Method 2
Excess lubricant can sometimes prevent the escape of heat from the sealed area. This can also result in chemical breakdown of the lubricant
Data Source
AI summary
A fluid actuated clutch (40) includes a disc pack (120) that includes friction discs (122) and separator discs (124) mounted on a hub (50). A cylinder (68) which includes a movable piston (72) is in connection with the hub. The introduction and release of fluid to a variable volume chamber (76) selectively applies force to the disc pack to engage the clutch and releases the force to disengage the clutch. The clutch includes internal bearings (90, 82). Grease or other lubricant material is injected into a radially extending lubricant passage (96). The lubricant is held in the area of the bearings and other moving parts by rigid annular grease shields (93, 79). Annular grease release gaps (61, 107) prevent over packing with lubricant while maintaining lubrication and facilitating cooling.