Extendable Wheel Mount for Dual Grind Spindle Cost Reduction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The high cost of double spindle air bearing systems in grinding machines limits their widespread use in dual grind applications, necessitating a design that reduces costs while maintaining throughput and precision.
Innovation Solution
A coupler/spline shaft assembly is used to relocate the fine and coarse wheel actuation and support within a wheel mount assembly, allowing for vertical movement and torque transmission through a spline interface with preloaded springs and face gears, enabling the coarse wheel to be actuated using pressurized fluid, thus eliminating the need for an inner concentric shaft and reducing overall system costs.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If a double spindle air bearing system is used to achieve dual grind applications, then productivity is improved, but device complexity and cost increase significantly
Solution Approach 1:
The patent combines the coarse and fine grinding wheel actuation mechanisms into a single integrated wheel mount assembly. The coupler/spline shaft assembly merges the rotational drive from the spindle with the vertical actuation of the coarse wheel, eliminating the need for a separate inner concentric shaft system. This consolidation reduces device complexity while maintaining dual grind capability.
Solution Approach 2:
The wheel mount assembly serves multiple functions: it supports both the coarse and fine grinding wheels, provides the actuation mechanism for wheel engagement/disengagement, and transmits torque to both wheels. The coupler/spline shaft assembly universally handles both rotational transmission and vertical positioning, replacing multiple specialized components with a multi-functional unit.
2Productivity
If the coarse wheel actuation mechanism is integrated into the spindle assembly, then productivity is improved, but manufacturing cost increases dramatically
Solution Approach 1:
The patent segments the grinding system into distinct functional modules: the spindle assembly that provides rotational drive, the wheel mount assembly that holds both wheels, and the coupler/spline shaft assembly that connects them. This segmentation allows each component to be manufactured and assembled separately, reducing overall manufacturing cost compared to an integrated spindle design.
Solution Approach 2:
The coupler/spline shaft assembly acts as an intermediary component between the spindle and the wheel mount. It mediates the transmission of rotational motion from the spindle to the wheels while allowing independent vertical actuation of the coarse wheel. This intermediary mechanism simplifies the overall design and reduces manufacturing complexity.
3Manufacturing precision
If the coarse wheel is retracted in the wheel mount assembly, then manufacturing precision is maintained for high-speed grinding, but the actuation mechanism becomes more complex
Solution Approach 1:
The coarse wheel is nested within the wheel mount assembly, allowing it to be retracted inside the mount when not in use. The coupler/spline shaft assembly is nested within the wheel mount structure, with the spline shaft providing both rotational connection and vertical movement guidance. This nesting arrangement maintains precision by keeping the coarse wheel in a stable, balanced position when retracted.
Solution Approach 2:
The wheel mount assembly is designed to be dynamic, allowing the coarse wheel to move vertically between retracted and extended positions. The coupler/spline shaft assembly enables this dynamic positioning while maintaining a rigid, balanced connection when the coarse wheel is retracted, ensuring precision is maintained during high-speed operation.
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 design provides a cost-effective, repeatable, and stiff connection for grinding wheels, enabling high-speed grinding with reduced system expenses and improved balance, while maintaining precision and throughput in dual grind applications.
Implementation Method 1
Springs between the middle coupler and the bottom coupler preload the middle coupler in the retract position, the middle coupler pushing against the top coupler engaging the two mating face gears
Implementation Method 2
Pressurized fluid enters the center of the wheel mount through the hollow spindle shaft. Since the center portion of the wheel mount is sealed with a rolling diaphragm, pressure builds up creating a force which pushes down the diaphragm guide
Implementation Method 3
Indentations on the inside diameter of the middle coupler and the outside diameter of the spline shaft create a spline interface, which prevents the middle coupler from rotating relative to the spline shaft but allows for vertical movement
Implementation Method 4
The couplers face gears are made with the same diameter, same number of teeth, and have equal tooth geometry. Due to the number of contact points during the interface of the two face gears, the contact stresses are minimized enabling torque to be transmitted
Data Source
AI summary
A grinding machine wherein coarse and fine grind wheels are mounted to a single rotating spindle. A multiple grind wheel mount is attached to the lower portion of the rotating spindle, the coarse and fine wheels being supported by the wheel mount, the wheel mount containing the mechanism for moving the inner coarse wheel down relative to the stationary outer fine wheel.