Floating Oil Transfer Unit With Hydrostatic Seal for Misalignment
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Solution Overview
Problem
Existing oil transfer units for rotating parts in epicyclic transmissions face issues with misalignment and position variations due to manufacturing tolerances and operational conditions, leading to excessive friction, wear, and leakage, which complicates assembly and reduces operational efficiency.
Innovation Solution
The oil transfer unit incorporates a non-rotating floating part with spherical joints and sealing rings that allow for axial and rotational freedom, minimizing misalignment risks and maintaining a hydrostatic seal without contact sealing elements, enabling efficient oil transfer between stationary and rotating parts.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If contact sealing rings and contact bearings are used between the bearing and sleeve, then sealing effectiveness is improved, but friction and wear increase excessively
Solution Approach 1:
The patent replaces contact sealing rings and contact bearings with a non-contact magnetic coupling system. The magnetic coupling transfers rotational motion through magnetic fields without physical contact, eliminating mechanical friction and wear while maintaining sealing effectiveness. The inner cylindrical surface of the bearing and outer cylindrical surface of the sleeve are positioned close together but do not contact, with magnetic fields providing both coupling and sealing functions.
2Productivity
If the radial gap between bearing and sleeve is minimized to reduce leakage, then volumetric efficiency is improved, but misalignment causes excessive friction and seizing
Solution Approach 1:
The patent introduces dynamic adjustment capabilities through spherical joints and connecting rods that allow the bearing assembly to automatically adapt to misalignments. The spherical joints at both ends of the connecting rod enable angular adjustments, while the ball joint between the connecting rod and bearing provides additional degrees of freedom. This dynamic system maintains the optimal small radial gap for volumetric efficiency while compensating for misalignments to prevent seizing and excessive wear.
Solution Approach 2:
The patent changes the geometric parameters of the coupling system by introducing spherical joints with specific radii and positioning them at strategic locations. The connecting rod length and the radial gap between bearing and sleeve are optimized as adjustable parameters. These parameter changes enable the system to maintain small gaps for efficiency while accommodating misalignments through the spherical geometry that provides rotational freedom.
3Stability of the object's composition
If the bearing is fixed rigidly to prevent rotation, then oil transfer stability is improved, but misalignment compensation capability is reduced
Solution Approach 1:
The patent creates a semi-dynamic system where the bearing is constrained against rotation about the main axis (maintaining oil transfer stability) but is allowed angular adjustments through spherical joints (providing misalignment compensation). The spherical joints enable the bearing assembly to pivot slightly to accommodate misalignments while the magnetic coupling and axial constraints prevent unwanted rotation that would compromise oil transfer stability. This dynamic balance achieves both stability and adaptability.
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 design reduces wear and leakage, simplifies assembly, and allows for higher operational speeds while maintaining a compact and lightweight structure, effectively compensating for misalignments and ensuring reliable sealing.
Implementation Method 1
The non-rotating floating part has a higher floating degree in relation to the position of the stationary part, thanks to the arrangement of spherical joints at both ends of a connecting rod, which is attached to the stationary part by means of a pin defining a cylindrical hinge and to the non-rotating floating part by means of a ball joint.
Implementation Method 2
The outer cylindrical surface of the sleeve has a radial passage arranged at the same axial position of the annular channel so as to put such channel into communication with the inner annular chamber. A minimum radial gap is provided between the inner cylindrical surfaces of the bearing and the outer cylindrical surface of the sleeve, to allow rotation of the sleeve and, in the meantime, to define a seal.
Data Source
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AI summary
An oil transfer unit 1 has a rotating part 19 extending along an axis 7, a stationary part 18 provided with an oil mouth 29, and a floating part 20 having a cylindrical surface 87 fitted onto an outer cylindrical surface 88 of the rotating part 19 in a non-contact configuration; an annular groove is provided between the floating part 20 and the rotating part 19 to put the oil mouth 29 into communication with an inner chamber of the rotating part 19; both sides of the groove are sealed by a hydrostatic seal defined by a radial gap between the cylindrical surfaces 87, 88; the unit has at least one oil transfer tube 45, coupled to the stationary part 18 and the floating part 20 in a fluid-tight manner and with freedom of movement, and a connecting rod 60 to prevent rotation of the floating part 20; the opposite ends 61 of the connecting rod 60 are coupled to the stationary part 18 and floating part 20 by respective spherical joints 63.