Motor-Driven Kitchen Appliance Clutch With Two-Stage Damping
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Solution Overview
Problem
Existing food processors face challenges in the design of their clutches, which can lead to misalignment of shaft axes, increased wear, and reduced service life due to inadequate damping and friction issues during varying load conditions.
Innovation Solution
A two-stage damping device is implemented in the clutch area, with a softer, more elastic first stage and a stiffer second stage, designed to adapt to load conditions, ensuring friction-free joining and separating of coupling partners and minimizing wear by using materials like rubber or thermoplastic elastomers, and structurally engaging only in the circumferential direction.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a single-stage damping device is used in the clutch area, then the structure is simple, but it cannot effectively compensate for shaft misalignment under varying load conditions and leads to increased wear
Solution Approach 1:
The damping device is divided into two distinct stages: a first damping element (softer, more elastic) and a second damping element (stiffer). This segmentation allows each element to handle different load conditions independently, with the softer first element managing low loads and the stiffer second element managing high loads, thereby extending service life without excessive complexity
Solution Approach 2:
Different regions of the damping device are assigned different mechanical properties - the first damping element has softer, more elastic local quality for low-load compensation, while the second damping element has stiffer local quality for high-load support. This local differentiation optimizes performance across varying operating conditions
2Reliability
If a rigid clutch connection is used to ensure precise power transmission, then power transmission efficiency is high, but shaft misalignment causes increased wear and reduced service life
Solution Approach 1:
The two-stage damping device acts as an intermediary between the input and output shafts, providing controlled compliance that compensates for misalignment while maintaining effective power transmission. The damping elements absorb misalignment stresses without compromising the overall clutch connection integrity
3Reliability
If a soft damping element is used to compensate for misalignment, then shaft alignment tolerance is improved, but the element is damaged under high operating loads
Solution Approach 1:
The clutch system transitions dynamically between two damping stages based on load conditions. Under low loads, the softer first damping element is active, providing misalignment compensation. When loads exceed a certain threshold, the system transitions to the stiffer second damping element, which can handle high operating loads without damage
4Reliability
If friction-based coupling is used to join shafts, then power transmission is effective, but wear increases and service life decreases
Solution Approach 1:
The invention replaces traditional friction-based mechanical coupling with a form-fit drive system using non-circular shaft cross-sections (e.g., star-shaped). This substitution eliminates sliding friction and wear, achieving friction-free power transmission while the two-stage damping device handles misalignment compensation
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
The two-stage damping device effectively compensates for shaft axis misalignment, reduces wear, and extends the service life of the clutch components by adapting damping hardness to load conditions, ensuring smooth operation across low and high loads with minimal frictional resistance.
Implementation Method 1
a first damping element (18) which is softer and more elastic than the second damping element (19)
Implementation Method 2
a two-stage damping device (17) with a first damping element (18) which is softer and more elastic than the second damping element (19)
Data Source
Figure 1
Figure 2
Figure 3
AI summary
The appliance (1) has a drive shaft (9) arranged in a mixing bowl (5). The output shaft operates a driven shaft (8) associated with a clutch (7) during insertion of the mixing bowl in a mixing bowl receiver (4). The shafts comprise a damping device in circumferential direction in a clutch region, where the damping device is operated in two stages. A forming element is extended over a portion of periphery of the shafts during operation of the damping device in one stage. The damping device is operated in another stage when exceeding a determined torque level.