What is Brush Holder?
Brush Holder can be defined as a mechanic device for fixing and supporting the brush. Brush Holder itself is generally made up of graphite or metallic graphite with its excellent current conduction and self-lubrication. And, it acts as ensuring that the brush can stably connect with its rotating component (commutator or slip ring) and be freely moved if wearing.
Deep analysis for operating principle for Brush Holder
The operating principle for Brush Holder is integrated related electromagnetism and mechanic engineering with the following key steps:
First, the bridge for its current transmission
The core role of Brush Holder acts as the point of junction between static circuit and rotating circuit. When the motor is running, its external power is connected with its Brush Holder through related fixing wire, and then the current is transmitted to its rotating commutator or slip ring through its brush for the purpose of transmitting to its winding. Finally, dynamic energy transmission will be realized.
Second, maintain its stable constant pressure
In order to offering stable current transmission, sound contact will be maintained between the brush and rotating surface. There is a spring device in inner brush holder which will force constant thrust to the brush. That preset pressure can ensure tightly contact on its rotating surface, though gradual shorten and shorten brush caused by related friction, avoiding electric spark or inefficient contact.
Third, wear compensation mechanism
With time is passing, the brush will be shorten and shorten caused by its friction with highly rotating component. The design for Brush Holder remains rectilinear motion along with inner cavity. With the force of its spring, the brush is automatically carried forward to plug the gap caused by its wear, prolonging maintenance period for the equipment.
Fourth, spark restraining and reversing
In DC motors, it is important for the position of Brush Holder to realize reversing. Reversing can be defined as the process that the current can be changed its direction in its rotor winding. Brush Holder generally equips adjustable device to realize fine tuning relative position between the brush and its magnetic pole, optimizing direction change opportunity and reducing electric spark as well as improving motor efficiency.
