Floating Bushing Sealing in Planetary Gears With Relative Movement
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Solution Overview
Problem
In compact and high-performance planetary gearboxes, especially those with multiple stages, there is limited space for lubricant and coolant distribution, and existing systems like the double pitch tube system are not suitable due to their dependence on the inner diameter of the sun gear, leading to leakage issues during radial and axial movements.
Innovation Solution
A planetary gear with a transmission device featuring an annular groove on one gear part and holes distributed over the circumference, a floating bushing with sealing grooves and rings to minimize leakage, allowing for efficient lubricant/coolant transfer between rotating and stationary systems with relative mobility, suitable for hybrid drives and wind turbines.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a double pitch tube system is used for supply medium distribution, then the system can provide lubricant and coolant, but it is not suitable for planetary gears with multiple stages due to dependence on sun gear inner diameter and causes leakage during radial and axial movements
Solution Approach 1:
The supply medium distribution is segmented into multiple independent channels (first supply channel, second supply channel, third supply channel) that can operate independently. Each channel serves specific gear stages, allowing the system to adapt to multi-stage configurations without requiring a completely different design approach.
Solution Approach 2:
The bushing is designed to be axially displaceable relative to the sun gear, allowing dynamic adjustment of the supply channels' positions. This dynamic capability enables the system to maintain proper alignment and sealing during radial and axial movements, preventing leakage while adapting to different operational conditions.
2Productivity
If compact design is implemented to increase power density, then installation space is reduced, but there is limited space available for supply medium distribution between stationary and rotating components
Solution Approach 1:
The supply medium distribution system is merged with the existing gear components. The first supply channel is formed in the sun gear, the second supply channel in the planet carrier, and the third supply channel in the ring gear. This integration eliminates the need for separate distribution mechanisms, reducing overall device complexity while maintaining compact dimensions.
Solution Approach 2:
The gear components (sun gear, planet carrier, ring gear) serve dual functions: they transmit mechanical power and simultaneously serve as conduits for supply medium distribution. This multi-functionality reduces the number of dedicated distribution components needed, enabling compact design without sacrificing distribution capability.
3Ease of manufacture
If sealing rings are made stationary relative to one gear part, then sealing is simplified, but wear increases due to relative rotational movement between sealing rings and the other gear part
Solution Approach 1:
The bushing acts as an intermediary component between the sun gear and the sealing rings. By making the bushing axially displaceable, it absorbs the relative motion between the stationary sealing rings and the rotating sun gear, preventing direct contact and wear between the sealing rings and the gear part while maintaining effective sealing.
Solution Approach 2:
The axially displaceable bushing automatically adjusts its position to maintain proper sealing contact during operation. The bushing's displacement capability allows it to self-adjust to radial and axial movements, maintaining sealing effectiveness without requiring the sealing rings themselves to be movable or complex in design.
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 enables low-leakage lubricant/coolant transfer with high radial and axial relative movements, reducing wear and maintenance needs, while being compact and suitable for high-performance applications, allowing for direct coupling with electric machines and efficient power transmission in wind turbines.
Implementation Method 1
a sealing ring (7) which seals a supply medium (50) in the area of a transition between the first gear part (11) and the second gear part (12) with two surfaces
Implementation Method 2
a floating bushing (8) which is arranged on the first gear part (11) in such a way that it rests opposite the first gear part (11), with at least one sealing groove (6) being arranged on the floating bushing (8) on each side of the annular groove (3)
Data Source
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AI summary
The invention relates to a planetary transmission (1) with a transmission device (2) for the transmission of a supply medium, wherein a first transmission part (11) and a second transmission part (12) have a rotational relative movement with respect to one another, wherein the transmission device (2) has an annular groove (3) on the surface (4) of the first transmission part (11) or on the surface (5) of the second transmission part (12), wherein the transmission device (2) has bores (9) distributed over the circumference, wherein the first transmission part (11) has a separate bushing (8) which points towards the second transmission part, wherein in each case one sealing groove with a sealing ring (7) is provided axially on both sides of the annular groove (3), wherein the bushing (8) is arranged in a stationary manner fixedly on the remaining first transmission part (11) for conjoint rotation, wherein the bushing (8) is designed so as to float in the axial direction with sufficient play in order to tilt out of a coaxial relative position with respect to the first transmission part (11) and/or with respect to the second transmission part (12) to the extent of a relative movability of the respective sealing ring (7) within the associated sealing groove (6).