Compliant mechanism
Encyclopedia
In mechanical engineering
, compliant mechanisms are flexible mechanisms that transfer an input force or displacement
to another point through elastic body deformation. These are usually monolithic (single-piece) or jointless structures with certain advantages over the rigid-body, or jointed, mechanisms.
Since the compliant mechanisms are single-piece structures, there is no need of assembly. With no joints, "rubbing" between two parts or friction as seen at the joints of rigid body mechanisms is absent. Compliant mechanisms are elastic
. They do not have the backlash
common in rigid-body, jointed mechanisms. They are cheaper to make than the jointed variety.
Compliant mechanisms are usually designed using two techniques, the first being a pseudo-rigid-body model and the second, the topology optimization. Other techniques are being conceived to design these mechanisms. Compliant mechanisms manufactured in a plane the have motion emerging from that plane are known as lamina emergent mechanisms (LEMs)
The flexible drive or resilient drive, often used to couple
an electric motor
to a machine (for example. a pump
), is one example. The drive consists of a rubber "spider" sandwiched between two metal dogs
. One dog is fixed to the motor shaft
and the other to the pump shaft. The flexibility of the rubber part compensates for any slight misalignment between the motor and the pump. See rag joint
and giubo
.
Compliant mechanisms are found in micro-electromechanical systems. For example, amplifying compliant mechanisms are used in micro-accelerometers and electro-thermal micro-actuators.
On Dec 17, 2007, the first International Symposium on Compliant Mechanisms was held at the Indian Institute of Science
, Bangalore
.
The Second International Symposium on Compliant Mechanisms (http://compliantmechanisms.3me.tudelft.nl/mw/index.php/CoMe2011CoMe2011) was held on May 19-20th 2011 at Delft
, The Netherlands.
Mechanical engineering
Mechanical engineering is a discipline of engineering that applies the principles of physics and materials science for analysis, design, manufacturing, and maintenance of mechanical systems. It is the branch of engineering that involves the production and usage of heat and mechanical power for the...
, compliant mechanisms are flexible mechanisms that transfer an input force or displacement
Displacement (vector)
A displacement is the shortest distance from the initial to the final position of a point P. Thus, it is the length of an imaginary straight path, typically distinct from the path actually travelled by P...
to another point through elastic body deformation. These are usually monolithic (single-piece) or jointless structures with certain advantages over the rigid-body, or jointed, mechanisms.
Since the compliant mechanisms are single-piece structures, there is no need of assembly. With no joints, "rubbing" between two parts or friction as seen at the joints of rigid body mechanisms is absent. Compliant mechanisms are elastic
Elasticity (physics)
In physics, elasticity is the physical property of a material that returns to its original shape after the stress that made it deform or distort is removed. The relative amount of deformation is called the strain....
. They do not have the backlash
Backlash (engineering)
In mechanical engineering, backlash, sometimes called lash or play, is clearance between mating components, sometimes described as the amount of lost motion due to clearance or slackness when movement is reversed and contact is re-established...
common in rigid-body, jointed mechanisms. They are cheaper to make than the jointed variety.
Compliant mechanisms are usually designed using two techniques, the first being a pseudo-rigid-body model and the second, the topology optimization. Other techniques are being conceived to design these mechanisms. Compliant mechanisms manufactured in a plane the have motion emerging from that plane are known as lamina emergent mechanisms (LEMs)
Lamina emergent mechanisms (LEMs)
Lamina Emergent Mechanisms also known as LEMs are a subset of compliant mechanisms fabricated from planar materials and have motion emerging from the fabrication plane. LEMs use compliance, or the deflection of flexible members to achieve motion....
The flexible drive or resilient drive, often used to couple
Coupling
A coupling is a device used to connect two shafts together at their ends for the purpose of transmitting power. Couplings do not normally allow disconnection of shafts during operation, however there are torque limiting couplings which can slip or disconnect when some torque limit is exceeded.The...
an electric motor
Electric motor
An electric motor converts electrical energy into mechanical energy.Most electric motors operate through the interaction of magnetic fields and current-carrying conductors to generate force...
to a machine (for example. a pump
Pump
A pump is a device used to move fluids, such as liquids, gases or slurries.A pump displaces a volume by physical or mechanical action. Pumps fall into three major groups: direct lift, displacement, and gravity pumps...
), is one example. The drive consists of a rubber "spider" sandwiched between two metal dogs
Dog (engineering)
In engineering a dog is a tool that prevents movement or imparts movement by offering physical obstruction or engagement of some kind. It may hold another object in place by blocking it, clamping it, or otherwise obstructing its movement...
. One dog is fixed to the motor shaft
Driveshaft
A drive shaft, driveshaft, driving shaft, propeller shaft, or Cardan shaft is a mechanical component for transmitting torque and rotation, usually used to connect other components of a drive train that cannot be connected directly because of distance or the need to allow for relative movement...
and the other to the pump shaft. The flexibility of the rubber part compensates for any slight misalignment between the motor and the pump. See rag joint
Rag joint
A rag joint refers to certain flexible joints found on automobiles. They are typically found on steering shafts that connect the steering wheel to the steering gear input shaft, usually at the steering gear end. They provide a small amount of flex for a steering shaft within a few degrees of the...
and giubo
Giubo
A giubo , also known as a flex disc,http://www.pelicanparts.com/bmw/techarticles/E36-Guibo/E36-Guibo.htm and sometimes misspelled as guibo, is a flexible coupling used to transmit rotational torque between the drive shaft and the companion flange on mechanical devices, such as an automobile engine...
.
Compliant mechanisms are found in micro-electromechanical systems. For example, amplifying compliant mechanisms are used in micro-accelerometers and electro-thermal micro-actuators.
On Dec 17, 2007, the first International Symposium on Compliant Mechanisms was held at the Indian Institute of Science
Indian Institute of Science
Indian Institute of Science is a research institution of higher learning located in Bangalore, India. It was established in 1909.-History:After a chance meeting between Jamsetji N...
, Bangalore
Bangalore
Bengaluru , formerly called Bengaluru is the capital of the Indian state of Karnataka. Bangalore is nicknamed the Garden City and was once called a pensioner's paradise. Located on the Deccan Plateau in the south-eastern part of Karnataka, Bangalore is India's third most populous city and...
.
The Second International Symposium on Compliant Mechanisms (http://compliantmechanisms.3me.tudelft.nl/mw/index.php/CoMe2011CoMe2011) was held on May 19-20th 2011 at Delft
Delft
Delft is a city and municipality in the province of South Holland , the Netherlands. It is located between Rotterdam and The Hague....
, The Netherlands.
Research Labs and Researchers
- University of Michigan Compliant Mechanism Design Lab
- Prof. Larry HowellLarry HowellDr. Larry L. Howellreceived a B.S. degree in mechanical engineering from Brigham Young University and M.S. and Ph.D. degrees from Purdue University. His Ph.D. advisor was Ashok Midha, who is regarded as the "Father of Compliant Mechanisms." Howell is currently a professor at Brigham Young...
at Brigham Young University Compliant Mechanisms research - The Multidisciplinary and Multiscale Device and Design Laboratory (M2D2) at the Indian Institute of Science, Bangalore
- Prof. Sridhar Kota's Home Page
- Prof. Martin Culpepper at MIT Precision Compliant Systems Laboratory
- Prof. Shorya Awtar at University of Michigan
- Prof. Just L. Herder at Delft University of Technology
- Prof. G. K. Ananthasuresh at IISc, Bangalore
- Prof. Stephen L. Canfield at Tennessee Tech University
- Prof. Charles Kim at Bucknell University
- Prof. Anupam Saxena at IIT Kanpur, India
- Prof. Mary Frecker at The Pennsylvania State University, University Park