Automatic Gearbox Pressure Supply via Planetary Stage Bore
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Solution Overview
Problem
In automatic transmissions with a planetary stage, supplying pressure medium to the piston-cylinder arrangement from the side opposite the planetary gearset is technically challenging due to spatial constraints within the transmission housing.
Innovation Solution
The pressure medium is routed through the planetary stage, specifically via a bore in the transmission shaft and planet carrier, which connects to the piston-cylinder arrangement's pressure chamber, allowing axial and radial oblique bore configurations for efficient oil supply and lubrication, with sealing elements to prevent leakage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If the planetary stage is disposed in the transmission housing such that the pressure medium cannot be supplied to the pressure chamber from the side facing away from the planetary gearset, then the spatial arrangement is simplified, but the supply of pressure medium becomes difficult
Solution Approach 1:
Instead of supplying pressure medium from the conventional side (away from planetary gearset), the patent supplies pressure medium from the opposite side by conducting it through the planetary stage components (transmission shaft and planet carrier) to reach the pressure chamber, thus resolving the spatial constraint
Solution Approach 2:
The transmission shaft and planet carrier act as intermediary components that conduct the pressure medium from the transmission housing through the planetary stage to the pressure chamber, enabling pressure supply despite the restricted spatial arrangement
2Length of moving object
If the bore for pressure medium supply is directed radially and axially obliquely via the axial bearing, then the distance to the force introduction surface can be kept large, but the bore configuration becomes more complex
Solution Approach 1:
The bore is configured with both radial and axial components (oblique direction), transitioning from a simple radial or axial bore to a three-dimensionally oriented bore that simultaneously achieves adequate distance and connects to the pressure chamber
3Ease of manufacture
If the pressure medium is conducted through the planetary stage, then the pressure medium supply is enabled from the axial end, but additional bores and sealing requirements are introduced
Solution Approach 1:
The transmission shaft and planet carrier serve multiple functions: they transmit torque, support planetary gears, and simultaneously conduct pressure medium to the pressure chamber, reducing the need for separate dedicated pressure supply components
Data Source
AI summary
The present invention relates to an automatic transmission (1) comprising at least one planetary stage (2) and at least one gear shifting element (3), wherein this gear shifting element (3) is disposed axially directly adjacent to the planetary stage (2), wherein a piston-cylinder arrangement (4) is provided for actuating the gear shifting element (3), wherein the planetary stage (2) comprises an internal gear (5), a sun gear (6) and a planet carrier (7), on which planet gears (8) are rotatably mounted, wherein the planet carrier (7) is connected non-rotatably to a transmission shaft (9), and wherein the pressure medium can be fed to the pressure chamber (10) of the cylinder (11) of the piston-cylinder arrangement (4) through a bore (12, 13) in the transmission shaft (9) and in the planet carrier (7).