An adjustable gravity-balancing mechanism using planar extension and compression springs
Journal
Mechanism and Machine Theory
Journal Volume
92
Start Page
314
End Page
329
ISSN
0094114X
Date Issued
2015
Author(s)
Yang, Zongwei
Abstract
Passively compensating a payload weight requires a mechanism that can generate a nonlinear torque curve. Existing gravity-balancing mechanisms (GBMs) rely on linear or torsional springs with various principles to generate the required torque profile. This paper presents the design of a novel GBM whose balancing capability can be adjusted. The idea is to employ two linear springs, one extension spring and one compression spring, to synthesize the required nonlinear torque curve. The springs are concentrated on the base joint to reduce the overall size. An optimization formulation is given to maximize the weight compensation capability. The effects of various parameters on the achievable weight are discussed. Low-volume planar springs are specifically designed to serve as the linear springs so that large stiffness can be generated in a limited space. By preloading the springs, the GBM can easily adjust its torque curve to match different payloads. An illustrative prototype is given with experiment verifications to demonstrate the claimed merits of the proposed GBM.
Subjects
Compliant Mechanisms
Gravity Balancing Mechanisms
Nonlinear Springs
Mechanisms
Torque
Compensation Capability
Compression Springs
Experiment Verification
Extension Springs
Gravity-balancing
Non-linear Springs
Optimization Formulations
Torsional Springs
Compliant Mechanisms
SDGs
Publisher
Elsevier Ltd
Type
journal article