Transmission PTO Clutch Torque Control via Integrated Piston

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Solution Overview

Problem

Conventional PTO systems face issues with clutch engagement and disengagement, leading to potential damage from sudden torque application, insufficient engagement, and energy wastage due to the lack of integrated transmission control, resulting in inefficient power transfer and potential clutch failure.

Innovation Solution

A PTO drive assembly with a clutch assembly that includes a piston assembly with a housing and a piston movably disposed in a cavity, allowing for selective engagement and disengagement to control torque transfer between the shaft and the PTO gear, featuring a thrust bearing and tangs for rotational coupling, enabling precise torque management.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If the clutch assembly is integrated within the transmission system, then control precision and energy efficiency are improved, but device complexity increases

Engineering Contradiction:
Improvecontrol precisionVSAvoiddevice complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The clutch assembly is integrated within the transmission system, combining the clutch housing with transmission components. The clutch assembly includes a piston assembly with a housing and piston movably disposed in a cavity, allowing selective engagement and disengagement to control torque transfer between the shaft and PTO gear. This integration enables centralized control of torque transfer while utilizing the transmission system's existing structural framework.

Inventive Principle:
Principle #5Merging (Combining)

2Measurement precision

If the piston is rotationally coupled to the PTO gear, then rotational coupling precision is improved, but manufacturing complexity increases

Engineering Contradiction:
Improverotational coupling precisionVSAvoidmanufacturing complexity
Core Design Contradiction:
Measurement precisionVSEase of manufacture

Solution Approach 1:

A rotational coupling mechanism serves as an intermediary between the piston and PTO gear. The piston is rotationally coupled to the PTO gear through this intermediate mechanism, which enables precise rotational coupling while simplifying the manufacturing process by separating the rotational coupling function from the piston's primary linear movement function.

Inventive Principle:
Principle #24Intermediary (Mediator)

Data Source

PatentEP3419850B1Transmission internal PTO clutch and method of control
Publication Date: 2021.09.01 ALLISON TRANSMISSION INC
  • EP3419850B1 patent drawingFigure 1
  • EP3419850B1 patent drawingFigure 2
  • EP3419850B1 patent drawingFigure 3

AI summary

A power take-off (PTO) drive assembly for a transmission includes a shaft defining a shaft axis, a PTO gear defined radially about the shaft axis, and a clutch assembly positioned between the shaft and the PTO gear and having an engaged position and a disengaged position. When the clutch assembly is in the engaged position, torque is transferred from the shaft to the PTO gear. When the clutch assembly is in the disengaged position, torque is not transferred from the shaft to the PTO gear.