Planetary PTO Gear Assembly for Selectable 540/1000 RPM Output
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Power take-off (PTO) shafts in agricultural tractors and machines are limited to specific rotational speeds, requiring multiple standards and equipment designs, which can be inefficient and inflexible.
Innovation Solution
A planetary gear assembly with a reversible PTO shaft that can operate at two different rotational speeds by using a 6-tooth and 21-tooth spline arrangement, allowing the same input speed to drive implements at either 540 rpm or 1000 rpm through a common longitudinal axis with a central passage and bearing assemblies.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a single PTO shaft is designed for one specific rotational speed and spline arrangement, then it can reliably drive implements at that speed, but it cannot drive implements requiring different speeds or spline arrangements
Solution Approach 1:
The PTO shaft is designed with universal adaptability to perform multiple functions by engaging with different gear elements. The shaft can selectively engage with either the planet carrier or the output sun gear through a common longitudinal axis, allowing a single shaft design to serve multiple speed requirements (540 rpm and 1000 rpm) without requiring separate shafts for each function.
Solution Approach 2:
The system transitions from a static single-speed configuration to a dynamic multi-speed system. The PTO shaft can dynamically switch between different rotational speeds by selectively engaging different gear elements (planet carrier or output sun gear) within the planetary gear assembly, enabling the same shaft to adapt its operating characteristics based on implement requirements.
2Adaptability or versatility
If multiple PTO shafts with different spline arrangements are used to meet different speed requirements, then each shaft can be optimized for its specific function, but the number of power sources and equipment designs must be increased
Solution Approach 1:
A single PTO shaft design achieves universal compatibility with multiple implement types by engaging with the planetary gear assembly that provides different output speeds. The shaft maintains a consistent 21-tooth spline arrangement while the gear assembly provides the versatility to deliver either 540 rpm or 1000 rpm, eliminating the need for separate shafts with different spline configurations.
Solution Approach 2:
The invention merges the functions of multiple dedicated PTO shafts into a single universal shaft system. By combining the shaft with a planetary gear assembly that can selectively engage different gear elements, the system consolidates what would have required separate shafts and power sources into one integrated solution, reducing the quantity of components while maintaining full functional range.
3Productivity
If a planetary gear assembly with reversible PTO shaft is used to provide two different rotational speeds, then a single power source can drive implements at both 540 rpm and 1000 rpm, but the gear assembly structure becomes more complex
Solution Approach 1:
The planetary gear assembly is segmented into distinct functional components: a first planetary gearset for speed reduction to 540 rpm, a second planetary gearset for speed increase to 1000 rpm, and a common planet carrier. This segmentation allows each gearset to be optimized for its specific function while sharing common elements, managing the complexity through modular functional division.
Solution Approach 2:
The planetary gear assembly employs a nested structure where the second planetary gearset is positioned within the same space as the first planetary gearset, both sharing a common planet carrier and central axis. This nesting arrangement allows two complete gearsets to occupy a compact volume, reducing the overall size and complexity of the assembly while providing dual-speed functionality.
Data Source
AI summary
A planetary gear assembly including an input sun gear; a first plurality of planetary gears driven by the input sun gear; a planet carrier coupled with the first plurality of planetary gears; and an output sun gear wherein rotation of the input sun gear drivingly rotates the planet carrier at a first rotational speed and the output sun gear at a different second rotational speed. An output shaft fixed to the planet carrier and the output sun gear are simultaneously rotated about a common longitudinal axis at the different speeds by rotation of the input sun gear. The output sun gear is accessible through a longitudinal passage in the output shaft. A PTO shaft is drivingly couplable with the output sun gear by inserting a first end of the PTO shaft into longitudinally extending passage or with the planet carrier by inserting the second end of the PTO shaft.