High-Speed Brush Drive Coupling With Dynamic Axial Clamping
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Solution Overview
Problem
High-speed rotating brushes in hard floor cleaning devices experience undesirable vibrations and creep due to imbalances caused by axial play and increased clasping force, which is not effectively addressed by existing drive coupling mechanisms.
Innovation Solution
A drive coupling assembly with a coupling head and coupling member featuring 120-degree rotational symmetry and mirror-symmetric helicoidal drive surfaces, which generates axial and radial forces independently of friction, eliminating axial play and preventing long-term creep by exerting a clasping force only during rotation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If an axial spring mechanism is used to increase clasping force on the brush, then vibrations are suppressed, but creep risk increases during the device's life span
Solution Approach 1:
The drive coupling uses a dynamic wedge-shaped interface that generates axial clasping force only during rotation. The wedge surfaces are inclined relative to the rotation axis, so that rotational motion automatically produces an axial component of force through friction and normal contact forces. This eliminates the need for a static pre-loaded spring mechanism, suppressing vibrations during operation without creating continuous compressive stress that would cause creep over time.
Solution Approach 2:
The invention changes the operational state of the clasping force from static (always present via spring) to dynamic (generated during rotation). The axial force parameter is coupled to the rotational motion parameter through the wedge geometry, so the clasping force appears only when needed for high-speed rotation, avoiding the creep issue associated with continuous spring compression.
2Stability of the object's composition
If an axial spring mechanism is used to eliminate axial play, then brush position is fixed, but imbalances cause high vibrations at high rotational speeds
Solution Approach 1:
The wedge-shaped drive interface dynamically generates axial stabilizing force during rotation, allowing the brush to maintain stable axial position at high speeds without the imbalances that result from over-constraining with spring mechanisms. The system transitions from static pre-loading to dynamic force generation matched to operational conditions.
3Adaptability or versatility
If mirror-symmetric drive surfaces are used, then axial force is independent of rotation direction, but coupling member complexity increases
Solution Approach 1:
The coupling member uses asymmetric wedge surfaces relative to the rotation axis, with each surface inclined at a specific angle to generate the axial force component. The mirror symmetry across three planes (120 degrees apart) creates functional equivalence for both rotation directions while maintaining a relatively simple single-piece structure. The asymmetry is minimal and localized to the drive surfaces, not the overall coupling geometry.
Solution Approach 2:
The three mirror-symmetric wedge surfaces serve multiple functions: they transmit torque from the drive shaft to the brush, generate axial clasping force through their inclination, and provide self-centering through their geometric arrangement. This multi-functionality is achieved within a simple coupling member structure that requires no additional components.
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 drive coupling assembly provides stable operation at high rotational speeds by eliminating axial play and preventing imbalances, reducing vibrations and creep, while allowing for interchangeable coupling members and minimizing wear.
Implementation Method 1
The drive surfaces of the coupling head and the first and second drive surfaces of the coupling member are configured such that rotatably driving the former in contact with the latter results in the exertion of both a torque and an axially directed force on the coupling member
Data Source
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AI summary
Drive coupling assembly (50) for a high-speed rotating brush, comprising: -a coupling head (100) having a coupling head rotation axis (L ch ) and including three drive surfaces (106) which are arranged to be rotationally symmetrical through 120°with respect to said coupling head rotation axis; and -a coupling member (200), having a coupling member rotation axis (L cm ) and including three first drive surfaces (210a) which are arranged to be rotationally symmetrical through 120°with respect to said coupling member rotation axis, wherein said coupling head (100) and said coupling member (200) are detachably couplable, such that, in a coupled condition, their rotational axes (L ch , L cm ) are aligned and the coupling head is rotatable to drive each of its drive surfaces (106) in contact with a respective first drive surface (210a) of the coupling member, to thereby exert both a torque and an axially directed force on the coupling member.