Magnetic particle brake
A magnetic powder brake is a magnetic brake with ferromagnetic powder in the shear gap of the coupling surfaces, which can transmit torque through a magnetic field.
Magnetic particle brakes and magnetic particle clutches , which work according to the same principle, are used in mechanical engineering in web tension regulators and for the implementation of gentle starts and stops as well as in load tests. Features are the compact design, the low control power requirement and the uniform torque curve.
Working principle
A magnetic particle brake consists of a stator with a built-in coil and an opposite one, with z. B. a shaft connected rotor . In the air gap between the two non-touching components, there is a ferromagnetic powder that forms chain-like structures in the magnetic field when current flows through the coil. The torque is transmitted and friction is generated via these structures, which now touch both components (non-positive connection). The braking effect is roughly proportional to the current flowing through the coil.
In contrast to eddy current brakes, the torque is independent of the (differential) speed
However, it is characterized by a hysteresis behavior and a moment that is not zero when there is no field or no current. With the same coil current, the torque decreases with aging.
With the magnetic particle clutch, the stator is also rotatably mounted and can therefore transmit a torque to a second shaft.
application
Magnetic powder brakes enable uniform continuous operation even at very low speeds and are often used as web tension regulators, for example in printing machines, food packaging or laminating and plastic film machines. In addition, the magnetic powder brake is used to simulate loads, for example in engine test stands, friction testers or fitness equipment .
history
The magnetic particle brake was developed by Alex Hammecke in the 1950s for Elektro-Mechanik GmbH, Olpe , and a patent was applied for on July 21, 1955 .
Individual evidence
- ↑ What is meant is the tensile stress in paper, fabric or film webs during their manufacture or processing
- ↑ a b Magnetic particle clutches, brakes and control devices. Company brochure of Kendrion GmbH, p. 24, accessed on March 21, 2018.
- ↑ Eberhard Kallenbach, Rüdiger Eick, Peer Quendt, Tom Ströhla, Karsten Feindt, Matthias Kallenbach, Oliver Radler: Electromagnets. Basics, calculation, design and application . 4th edition. Vieweg + Teubner , Wiesbaden 2012, ISBN 978-3-8348-0968-1 , p. 318 .
- ↑ Magnetic particle brakes and magnetic particle clutches. In: IBD Wickeltechnik (website of the manufacturer / supplier). Retrieved January 11, 2016 .
- ↑ Magnetic particle clutches and brakes. Company publication of LIEDTKE Antriebstechnik GmbH & Co. KG, accessed on March 21, 2018.
- ↑ Magnetic particle brake and magnetic particle clutch. Corporate typeface from IBD Wickeltechnik
- ↑ Example of an exercise bike with magnetic particle brake. (No longer available online.) Archived from the original on March 4, 2016 ; accessed on January 11, 2016 .
- ↑ Magnetic particle brake - technology and advantages. In: Maschinenbau Aktuell . February 26, 2015, accessed January 11, 2016 .
- ↑ Patent DE1067645B : Magnetic particle brake. Registered on July 21, 1955 , published on October 22, 1959 , applicant: Elektro-Mechanik GmbH, inventor: Alex Hammecke.