Controlled Tensioner for Accessory Drive Belt
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Traditional accessory drive tensioners face challenges in maintaining optimal belt tension across varying operating conditions, particularly during starting and transients, leading to potential slipping and excessive friction, and are often oversized for most conditions.
Innovation Solution
A controlled tensioner system featuring a rotary motor, planetary gear, and thrust element that selectively contacts a pivoting support to adjust belt tension, allowing for two tension levels – a higher level during starting and a lower level during operation – using a spring and irreversible gear to maintain tension without continuous power.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a traditional tensioner is sized to guarantee correct tensioning during starting, then belt tension is sufficient during starting, but belt tension is excessive during other operating conditions
Solution Approach 1:
The tensioner uses a dynamic control system with a rotary motor and thrust element that can adjust the belt tension in real-time based on operating conditions. The thrust element selectively contacts the pivoting support to increase tension during starting, while allowing reduced tension during normal operation, thus resolving the contradiction between reliable tensioning and energy loss.
Solution Approach 2:
The system changes the belt tension parameter dynamically - maintaining high tension during starting conditions and reducing it during normal operation. This is achieved through the controlled action of the thrust element on the pivoting support, which modifies the tensioner's output force based on operational requirements.
2Reliability
If a traditional tensioner is sized to guarantee correct tensioning during starting, then belt tension is sufficient during starting, but belt tension is excessive during other operating conditions
Solution Approach 1:
The tensioner uses a dynamic control system with a rotary motor and thrust element that can adjust the belt tension in real-time based on operating conditions. The thrust element selectively contacts the pivoting support to increase tension during starting, while allowing reduced tension during normal operation, thus resolving the contradiction between reliable tensioning and energy loss.
Solution Approach 2:
The system changes the belt tension parameter dynamically - maintaining high tension during starting conditions and reducing it during normal operation. This is achieved through the controlled action of the thrust element on the pivoting support, which modifies the tensioner's output force based on operational requirements.
3Adaptability or versatility
If a controlled tensioner system with rotary motor and thrust element is used, then belt tension can be optimized for different operating conditions, but device complexity increases
Solution Approach 1:
The tensioner is segmented into distinct functional components: a rotary motor for power generation, a pivoting support for mechanical advantage, and a thrust element for selective contact. This segmentation allows each component to perform its specific function efficiently while maintaining overall system adaptability.
Solution Approach 2:
The system uses a spring-loaded pivoting support that automatically provides baseline tension, while the rotary motor and thrust element only engage when additional tension is needed. This self-service mechanism reduces the need for continuous active control and simplifies the overall system architecture.
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 solution ensures prompt and safe engine starts during idle-stop conditions, minimizes belt slipping and noise, and reduces overall friction and consumption by optimizing tension levels according to operating conditions, while maintaining belt tension within necessary limits.
Implementation Method 1
a spring (7) acting on the support (4) to apply a torque and tension a belt
Implementation Method 2
a rotary motor (8) housed in the cavity (3) with the spring (7)
Implementation Method 3
a gear (9) to control a thrust element (10) selectively contacting the support (4)
Data Source
Figure 1~2
Figure 3~4
Figure 5
AI summary
A tensioner for a start-stop accessory drive comprises a movable support, a pulley carried by the support to contact a belt of the drive, a spring to load the support so as to tension the belt, and an actuator controlled and movable to push said pulley against the belt in one direction by means of a load in parallel and additional with respect to that of the spring and an irreversible device which enables the action of the actuator and prevents a displacement of said support in response to the loads of the belt.