Rotatable Disc Exercise Apparatus with Nested Ball Bearing Retention
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional stacked rotatable discs experience dynamic side loads that can dislodge bearings, limiting movement and preventing the use for strengthening exercises beyond momentary torque, due to the lack of rotational resistance between discs.
Innovation Solution
The discs are designed with a first and second annular set of ball bearings, where the central hub portions have annular walls that cooperate to retain the bearings against side loads, and an optional coil spring is integrated to provide resistance, allowing for controlled rotation and increased stability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional stacked rotatable discs are used with bearings sandwiched between sheet metal plates or in an annular plastic frame, then the discs can rotate relative to each other, but the dynamic side loads can dislodge the bearings from their frames, rendering the stacked set either jammed together or limited in movement between the discs
Solution Approach 1:
The bearing retention system is segmented into two separate annular walls: an outer annular wall extending axially beyond the inner annular wall of the same hub portion, and an inner annular wall extending axially beyond the outer annular wall of the other hub portion. This segmentation creates distinct retention zones for the ball bearings, allowing each wall to independently secure bearings against different directional loads, thereby preventing dislodgement while maintaining rotation freedom
Solution Approach 2:
The ball bearings are nested between the two annular walls formed by the hub portions of the first and second discs. The outer annular wall of one hub portion and the inner annular wall of the other hub portion create a nested configuration that traps the ball bearings in place, securing them against dynamic side loads while allowing the discs to rotate freely relative to each other
2Adaptability or versatility
If conventional stacked rotatable discs are designed to allow free rotation between discs, then the discs can rotate relatively to each other, but no rotational resistance is provided between the discs such that they cannot be utilized for strengthening exercises beyond generating a momentary torque
Solution Approach 1:
The apparatus transitions from a static free-rotation design to a dynamic resistance system by incorporating a spring mechanism between the first and second discs. This spring provides variable rotational resistance that adapts to different exercise intensities and user strengths, enabling the discs to be used for strengthening exercises while maintaining the ability to rotate relative to each other
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 solution ensures the ball bearings remain secure, providing rotational resistance and stability, enabling the discs to be used for a wider range of exercises, including strengthening, with adjustable resistance depending on the spring type.
Implementation Method 1
the second disc is rotatably stacked and fastened onto the first disc so as to remain aligned with the first disc as the second disc is rotated via bearings about a central axis
Implementation Method 2
An inner set of ball bearings is mounted in a hub portion of the first disc and an outer set of ball bearings is mounted in a hub portion of the second disc
Data Source
Figure 1~2
Figure 3
Figure 4
AI summary
A rotatable disc exercise apparatus is disclosed that includes a first disc having a first outer planar surface and a first inner surface, a second disc fastened to the first disc and rotatably supported on the first disc by a first annular set of ball bearings and a second annular set of ball bearings. The second disc has a second outer planar surface and a second inner surface facing the first inner surface. A single biasing member sandwiched between the first and second discs resiliently biases the second disc to a neutral rotational position between the discs. The first annular set of bearings is captured between the inner surfaces by an annular outer wall of one of the discs and an inner annular rib of the other one of the discs. The second set of bearings is carried in an annular race between the first and second inner surfaces.