Inertial Hysteresis Couplings

This thesis presents the Inertial Hysteresis Coupling (IHC), a new family of variable-slip mechanical couplings/clutches aimed at achieving order-of-magnitude (∼10x) improvements in torque density (torque capacity / coupling diameter) over existing magnetic and fluid options. IHCs leverage combined...

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Main Author: Wheeler, Charles Michael
Other Authors: Culpepper, Martin L.
Format: Thesis
Published: Massachusetts Institute of Technology 2024
Online Access:https://hdl.handle.net/1721.1/154373
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author Wheeler, Charles Michael
author2 Culpepper, Martin L.
author_facet Culpepper, Martin L.
Wheeler, Charles Michael
author_sort Wheeler, Charles Michael
collection MIT
description This thesis presents the Inertial Hysteresis Coupling (IHC), a new family of variable-slip mechanical couplings/clutches aimed at achieving order-of-magnitude (∼10x) improvements in torque density (torque capacity / coupling diameter) over existing magnetic and fluid options. IHCs leverage combined normal, frictional, and inertial forces acting on sliding mechanical elements to realize this torque density improvement. The new design (a) allows for continuous modulation of these high-torque loads while (b) naturally achieving lockup at maximum engagement and (c) remaining well-suited to forced-convection cooling in high-heat-dissipation scenarios. Additionally, the base IHC design can be modified to achieve “one-way clutching” behavior while still retaining the ability to speed-synchronize (transmit load under partial slip) and achieve lockup. These characteristics make IHCs particularly well-suited to automotive and mobile robotics applications – for example, active control of vehicle differential slip – where high torque density and slip control are both of critical importance. As the first investigation into IHCs, this research establishes multiple important foundations for analysis, simulation, and design. Starting from first principles, a ground-up model for IHC behavior is derived that encapsulates IHC geometry, relevant coordinate systems/transformations, kinematics, equilibrium equations, thermal loads, etc. Implemented in MATLAB, this model facilitates the selection of IHC parameters via performance projections, sensitivity studies, and a variety of different visualizations and animations. These tools enabled the design and fabrication of a physical IHC prototype, “ihcBENCH.” Through testing of this prototype, the key desired behaviors were successfully demonstrated: linear torque modulation via control of the “clutch angle” βo (max slip torque before lockup = 13.2 Nm, max/min slip torque ratio = 3.8, R² = 0.986); IHC lockup at high clutch engagement angles (βo ⪆ 37°); and the one-way clutching behaviors previously described.
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spelling mit-1721.1/1543732024-05-02T03:17:11Z Inertial Hysteresis Couplings Wheeler, Charles Michael Culpepper, Martin L. Massachusetts Institute of Technology. Department of Mechanical Engineering This thesis presents the Inertial Hysteresis Coupling (IHC), a new family of variable-slip mechanical couplings/clutches aimed at achieving order-of-magnitude (∼10x) improvements in torque density (torque capacity / coupling diameter) over existing magnetic and fluid options. IHCs leverage combined normal, frictional, and inertial forces acting on sliding mechanical elements to realize this torque density improvement. The new design (a) allows for continuous modulation of these high-torque loads while (b) naturally achieving lockup at maximum engagement and (c) remaining well-suited to forced-convection cooling in high-heat-dissipation scenarios. Additionally, the base IHC design can be modified to achieve “one-way clutching” behavior while still retaining the ability to speed-synchronize (transmit load under partial slip) and achieve lockup. These characteristics make IHCs particularly well-suited to automotive and mobile robotics applications – for example, active control of vehicle differential slip – where high torque density and slip control are both of critical importance. As the first investigation into IHCs, this research establishes multiple important foundations for analysis, simulation, and design. Starting from first principles, a ground-up model for IHC behavior is derived that encapsulates IHC geometry, relevant coordinate systems/transformations, kinematics, equilibrium equations, thermal loads, etc. Implemented in MATLAB, this model facilitates the selection of IHC parameters via performance projections, sensitivity studies, and a variety of different visualizations and animations. These tools enabled the design and fabrication of a physical IHC prototype, “ihcBENCH.” Through testing of this prototype, the key desired behaviors were successfully demonstrated: linear torque modulation via control of the “clutch angle” βo (max slip torque before lockup = 13.2 Nm, max/min slip torque ratio = 3.8, R² = 0.986); IHC lockup at high clutch engagement angles (βo ⪆ 37°); and the one-way clutching behaviors previously described. Ph.D. 2024-05-01T14:31:41Z 2024-05-01T14:31:41Z 2023-06 2023-07-19T18:42:25.878Z Thesis https://hdl.handle.net/1721.1/154373 In Copyright - Educational Use Permitted Copyright retained by author(s) https://rightsstatements.org/page/InC-EDU/1.0/ application/pdf Massachusetts Institute of Technology
spellingShingle Wheeler, Charles Michael
Inertial Hysteresis Couplings
title Inertial Hysteresis Couplings
title_full Inertial Hysteresis Couplings
title_fullStr Inertial Hysteresis Couplings
title_full_unstemmed Inertial Hysteresis Couplings
title_short Inertial Hysteresis Couplings
title_sort inertial hysteresis couplings
url https://hdl.handle.net/1721.1/154373
work_keys_str_mv AT wheelercharlesmichael inertialhysteresiscouplings