Bodies Fixedly Restrained at One End for Parts of a System That Rotate into the Supercritical Speed Range and Method for Producing the Bodies

Simple SummaryContent extracted from patent full text and abstract with AI.

This patent describes a tubular, hollow body (such as a tool shaft) that is fixed at one end and contains one or more internal chambers partially filled with a free-flowing mass (like fine sand). During high-speed rotation, this free-flowing mass moves within the chamber in response to manufacturing or mounting imbalances, effectively counteracting these unbalances and damping vibrations. The result is better stability and reduced risk of damage as the shaft rotates through its critical and supercritical speed ranges. The patent also outlines how to manufacture such a system for use in rotating machinery.

Use CasesContent extracted from patent full text and abstract with AI.

• High-speed machining tools (like spindles, drills, and mills) that require long, slender shafts with minimal vibration for precision manufacturing.
• Rotating shafts in high-speed mixers or stirrers, where vibration control is crucial for safety and efficiency.
• Turbine or propeller drive shafts in marine or aerospace applications, where imbalances at high speeds can cause critical failures.
• Any rotational system with long, cantilevered, hollow shafts subject to unbalance from fabrication or mounting inaccuracies.

BenefitsContent extracted from patent full text and abstract with AI.

• Passive, self-balancing and vibration-damping effect without need for external sensors, electronics, or control systems.
• Allows safe operation through the critical speed range (resonant frequencies), reducing risk of breakage or wear.
• Facilitates higher operating speeds (over critical speeds), improving the efficiency and performance of machines like high-speed cutters or spindles.
• Enhances tool lifetime and reliability by reducing dynamic stresses and vibrations during use.
• Enables the use of longer, more slender shafts in high-speed applications, expanding design possibilities and tool capabilities.
• Potentially lowers manufacturing costs by reducing need for extremely high-precision (and costly) balancing and mounting procedures.

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Inventors & Applicants

Patent Abstract

The invention relates to bodies fixedly restrained at one end while mounted so as to resist movement and tilting for parts of a system (22) that rotate into the supercritical speed range and to a method for producing the bodies, wherein the body (2) represents a hollow body of a tubular form comprising a specified substance, the flexural vibrations of which that occur during rotation are caused by unbalance U resulting from production and mounting inaccuracies and owing to a local difference between the geometrical axis of symmetry (75) of the hollow body (2) and the axis of rotation (76) of the hollow body (2), and which has a closed-off hollow space (7), which is symmetrical with respect to the geometrical axis of symmetry (75) of the hollow body (2) and is also closed towards its end faces (8, 9). In the hollow space (7) of the hollow body (2) that is fixed and mounted at one end and is formed as at least one balancing chamber (70, 71), at least one free-flowing formless substance (4) with a defined mass ms has been introduced into the balancing chamber (71), partially filling the balancing chamber (71), and the mass ms of the free-flowing formless substance (4) introduced is defined in such a way that a vibrational damping with respect to the hollow body can be achieved in the subcritical and critical speed ranges and a damage-free resonance penetration can be achieved in the critical speed range and that the distribution of the substance (4) in the supercritical speed range that is caused by the effect of the unbalance U of the hollow body (2) compensates in a self-stabilizing manner for the effect of the unbalance U while allowing for a specified ratio between the mass ms of the substance (4) and the unbalance U in accordance with the equation (V).