Decoupler Spring Plate Rotational Stops
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Solution Overview
Problem
Existing decouplers for belt drives in internal combustion engines and generators experience undesired relative rotation of spring plates, leading to axial bursting and erratic acoustics due to frictional torque and ramp geometry, which causes the helical torsion spring to press the spring plates apart and results in undesirable run-up.
Innovation Solution
The implementation of mutual rotational stops between the helical torsion spring ends and spring plates, allowing the spring plates to rotate as a unit with the helical torsion spring in both torque directions, preventing relative rotation and ramping up by ensuring the spring plates and torsion spring rotate together, thus preventing axial bursting and erratic acoustics.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If the spring plates rise axially in a ramp-like manner to transmit drive torque, then the drive torque transmission is improved, but the helical torsion spring can press the spring plates apart axially causing axial bursting
Solution Approach 1:
Rotational stops are provided on the spring plates and/or helical torsion spring ends to prevent the undesired relative rotation and ramping up of the spring ends before it can cause axial bursting. This preliminary constraint counteracts the potential harmful effect of the ramp geometry.
Solution Approach 2:
The rotational stops are pre-configured in the structure to engage and prevent relative rotation between spring plates and torsion spring ends. This preliminary structural arrangement ensures that the spring ends cannot ramp up the ramps during operation.
2Power
If the spring plates have ramp geometry for torque transmission, then the torque transmission capability is improved, but erratic acoustics occur due to repeated ramping up and snapping back
Solution Approach 1:
Rotational stops are implemented to prevent the relative rotation that causes the spring ends to ramp up and snap back, thereby eliminating the source of erratic acoustics while preserving the ramp geometry for torque transmission.
3Adaptability or versatility
If the one-way clutch is open during overrunning, then the generator shaft can overtake the belt pulley, but frictional torque causes relative rotation of spring plates leading to undesired ramping up
Solution Approach 1:
Rotational stops are provided to prevent the frictional torque from causing relative rotation and undesired ramping up of the spring ends during overrunning, while still allowing the generator shaft to overtake the belt pulley through the open one-way clutch.
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 effectively prevents the helical torsion spring from ramping up undesirably, ensuring smooth operation and reducing noise by ensuring the spring plates and torsion spring rotate as a unit, even during overrunning modes, thereby maintaining structural integrity and acoustic stability.
Implementation Method 1
the elasticity of the helical torsion spring smoothing out the torsional irregularities
Implementation Method 2
the helical torsion spring can be loaded not only in the direction in which it transmits the drive torque with radial expansion of the winding body. Rather, the helical torsion spring can also be loaded to a sufficiently high degree in the opposite moment direction, in which it radially contracts
Implementation Method 3
the frictional torque between the inner surface of the belt pulley and the sling band lying against it can lead to a relative rotation of the two spring plates
Data Source
Figure 1~3
Figure 4~8
Figure 9~11
AI summary
Disclosed is a decoupler (1, 1') for transferring a drive torque from a rotary drive (3) to a rotary output (5), comprising: - a drive part (7) arranged on the rotary-drive side, - an output part (9) arranged on the rotary output side, - a series connection lying between the drive part and the output part, said connection consisting of a helical torsion spring (11) and a one-way clutch (10), which permits overrunning of the output part with respect to the drive part in the rotational drive direction, - a first spring collar (14), arranged on the drive-part side, for the first end (12) of the helical torsion spring, - and a second spring collar (15), arranged on the output part side, for the second end (13) of the helical torsion spring. The spring collars increase axially in inclination, in the manner of ramps and the helical torsion-spring ends lying thereon expand the helical torsion spring radially whilst transferring the drive torque. The helical torsion-spring ends and the spring collars are to be provided with reciprocal rotary stops (19, 20), which together prevent, in the rotational drive direction, relative torsion of the second spring collar in relation to the second helical torsion-spring end and of the first helical torsion-spring end in relation to the first spring collar.