Electromagnetic brake

An electromagnetic brake comprising an exciting coil with a water-proofing means, disposed in an armature or a serrated inductor, a liquid cooling cavity embracing the exciting coil, and a support ring to which the exciting coil is attached. The supporting ring and the water-proofing means are made of nonconducting materials.

FIELD OF THE INVENTION 
The invention relates to electromagnetic brakes with massive armatures, in 
which the operating force is obtained from eddy currents. The invention is 
applicable for use in testing various motors, transport machines, reducing 
gears and hydraulic clutches. 
DESCRIPTION OF THE PRIOR ART 
Known in the art are electromagnetic induction-type brakes with massive 
armatures, in which the exciting coil is fixed to a conducting body (cf. a 
brochure issued by the Schenck Company and presented at the "Electro-77" 
Fair). Such brakes are disadvantageous since eddy currents tend to pass 
through the supporting ring and water-proofing means of the exciting coil, 
which are made of conducting materials. This gives increased transient 
times during the changing of the braking torque. 
Known in the art is an electromagnetic brake comprising an exciting coil 
with a water-proofing means, disposed in an armature or a serrated 
inductor, a liquid cooling cavity embracing the exciting coil, and a 
support ring to which the exciting coil is attached. 
The exciting coil is disposed in a water-proofing brass casing and is 
attached to a brass support ring (cf. R. A. Ioganson, "Induction Brakes", 
Energya Publishers, p. 64, 1966). 
In the described device, the eddy currents occurring in the brass support 
ring and the water-proofing brass casing tend to retard the rate of rise 
of the magnetic flux with the result that the time within which the brake 
settles is increased. The latter condition is not desirable for braking 
systems in which the simulation of rapid load variation is required. 
SUMMARY OF THE INVENTION 
An object of the invention is to provide for an increased rate of rise of 
the magnetic flux. 
There is disclosed an electromagnetic brake comprising an exciting coil 
with a water-proofing means, disposed in an armature or a serrated 
inductor, a liquid cooling cavity embracing the exciting coil, and a 
support ring to which the exciting coil is attached, which electromagnetic 
brake comprises, according to the invention, the support ring and the 
water-proofing means made of nonconducting materials. 
The electromagnetic brake of the invention provides for an increased rate 
of rise of the magnetic flux with the result that the time required for 
expensive field tests of transport machines is reduced.

DESCRIPTION OF THE INVENTION 
The invention will now be described, by way of example, with reference to 
the accompanying drawing which shows a longitudinal section of an active 
portion of the electromagnetic brake, according to the invention. 
The electromagnetic brake of the invention comprises an exciting coil 1 
disposed in an armature 2 or a serrated inductor 3, a liquid cooling 
cavity 4 embracing the exciting coil 1, a nonconducting water-proofing 
means 5 for the exciting coil, and a nonconducting support ring 6 to which 
the exciting coil 1 is attached. 
The electromagnetic brake of the invention operates as follows. 
When the current through the exciting coil 1 changes, no current is 
produced in the water-proofing means 5 and the support ring 6. As a 
result, the water-proofing means 5 and the support ring 6 respond in no 
way to the variation of the magnetic flux, with the result that the 
transient becomes faster. 
Since the water-proofing means 5 and the support ring 6 are made of 
nonconducting materials, the rate of rise of the magnetic flux is 
increased and the time required for expensive field tests of transport 
machines is reduced due to the fact that an adequate simulation of natural 
conditions can be achieved with a test bench. 
In addition, this provides for an increased productivity of bench tests, 
decreased labor requirements and decreased time necessary for bench tests, 
with the result that the service life of the items being tested is 
increased. 
A reduced test time results in fuel saving.