Pulley Decoupler Sheet Metal Spring Plates Torque Smoothing
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Solution Overview
Problem
Existing pulley decouplers for auxiliary unit belt drives are complex and costly due to the use of separate, cost-intensive molded parts and additional components for spring plates and ramp-shaped support surfaces.
Innovation Solution
A simplified structural configuration using sheet metal parts for both spring plates, with the helical torsion spring ends directly contacting these parts, and a radially arranged sling band that expands radially to transmit drive torque, replacing the need for separate molded parts and additional components.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If separate molded parts and additional components are used for spring plates and ramp-shaped support surfaces, then reliable torque transmission is achieved, but manufacturing cost and device complexity increase
Solution Approach 1:
The spring plate and ramp-shaped support surface are merged into a single integrally formed sheet metal part. The support surface is directly formed on the spring plate through sheet metal forming processes, eliminating the need for separate molded parts and additional components while maintaining the functional requirements for torque transmission and spring support
2Reliability
If separate molded parts and additional components are used for spring plates and ramp-shaped support surfaces, then reliable torque transmission is achieved, but manufacturing cost increases
Solution Approach 1:
The spring plate and ramp-shaped support surface are merged into a single integrally formed sheet metal part. The support surface is directly formed on the spring plate through sheet metal forming processes, eliminating the need for separate molded parts and additional components while maintaining the functional requirements for torque transmission and spring support
3Ease of manufacture
If a radially arranged loop band expands radially under torque transmission, then cost-effective sheet metal parts are used, but frictional torque during overtaking increases
Solution Approach 1:
A radially arranged loop band made of flexible material is used instead of rigid components. The loop band expands radially under torque transmission to engage the pulley and spring plate, and contracts during overtaking to minimize frictional torque while maintaining cost-effective manufacturing through sheet metal or flexible composite construction
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
This configuration reduces costs while maintaining effective torque transmission and decoupling functionality, allowing the generator shaft to overtake the pulley with reduced frictional torque, thus effectively smoothing torsional irregularities from the crankshaft.
Implementation Method 1
the helical torsion spring expands radially under transmission of the drive torque and its ends contact an axially ramped spring support surface of a first spring plate and a second spring plate
Implementation Method 2
the loop band ends expand radially under the transmission of the drive torque, whereby the first loop band end running in the drive torque flow towards the pulley is tensioned against an inner shell which is rotationally fixed in the pulley
Data Source
Figure 1~2
Figure 3
Figure 4~5
AI summary
What is proposed is a pulley decoupler (1) for the transfer of drive torque from the belt of an auxiliary unit belt drive to the shaft of one of the auxiliary units; having: – a pulley (2) – a hub (4) to be attached to the shaft – and a series connection arranged between the pulley and the hub in the flow of drive torque and consisting of a one-way clutch (10) and a helical torsion spring (11), which extends in the direction of the axis of rotation (12) of the pulley decoupler and widens radially under transfer of the drive torque, wherein the ends of the helical spring make contact with a spring support surface (30, 39), rising in an axially ramp-shaped manner, of a first spring plate (18) and of a second spring plate (24). In that context, one of the spring plates should be a shaped sheet metal part with the spring support surface formed thereon.