Gear Transmission Layout With Overlapping Motor and Crankshaft
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Solution Overview
Problem
The existing gear transmission systems, such as those described in Japanese Patent Publication No. 2002-106650, result in a lengthened overall device due to the motor and crankshaft being positioned on opposite sides of the intermediate gear, leading to increased length and potential bending moments in photovoltaic power-generating apparatuses.
Innovation Solution
A gear transmission design where the motor and crankshaft are positioned on the same side relative to the intermediate gear, utilizing a ring gear with internal and external teeth, and an eccentric oscillating-type gear transmission that allows the motor and crankshaft to overlap, reducing the overall length and offset distance, and incorporating a cantilevered shaft support to minimize the radial offset and lubricant usage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If the motor and crankshaft are positioned on opposite sides of the intermediate gear, then torque transmission is achieved, but the overall length of the device is lengthened
Solution Approach 1:
The motor is repositioned from the axial direction (opposite side of intermediate gear) to the radial direction (overlapping with crankshaft when viewed from perpendicular direction). This dimensional change allows torque transmission while reducing overall device length by utilizing radial space instead of axial space.
Solution Approach 2:
The motor is positioned such that it overlaps with the crankshaft in the radial direction, creating a nested spatial arrangement. This nesting allows both components to occupy overlapping radial spaces without interfering with each other's function, thereby compacting the device structure.
2Ease of operation
If the motor is positioned offset from the crankshaft on the outer side in the axial direction, then torque transmission is achieved, but the device length and bending moments increase
Solution Approach 1:
The motor positioning is changed from axial offset to radial overlap. By viewing the device from a direction perpendicular to the axis, the motor and crankshaft overlap radially rather than being offset axially, which reduces device length while maintaining torque transmission capability.
3Ease of operation
If a traditional gear transmission layout is used, then torque transmission is achieved, but lubricant requirements and device complexity increase
Solution Approach 1:
The motor and crankshaft are merged in the radial direction, creating a compact overlapping arrangement. This merging reduces the overall volume requiring lubrication and simplifies the device structure while maintaining effective torque transmission through the gear train.
Data Source
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AI summary
Techniques are taught that minimize the overall length of a device that includes a gear transmission and a motor. The gear transmission comprises a crankshaft that eccentrically rotates one of an internal gear and an external gear, a first gear attached to one end of the crankshaft, a ring gear having internal teeth meshing with the first gear, an intermediate gear meshing with external teeth of the ring gear, and a second gear attached to one end of an output shaft of a motor and meshing with the intermediate gear. The motor and the crankshaft are positioned, relative to the intermediate gear, on the same side in the axial direction of the gear transmission.