Comminuting machine drive system
A comminuting machine includes a frame, a comminuting rotor coupled to the frame, and a rotary drive coupled to the rotor. The rotary drive including a controller, a multi-phase motor connected to the controller, a set of contactors disposed between the controller and the multi-phase motor for selectively providing driving motive force to the multi-phase motor, and at least one rheostat disposed between the controller and the multi-phase motor, in parallel with the first set of contactors, for selectively providing a stopping resistance to the multi-phase motor to effect frictionless braking of the comminuting rotor, wherein the controller is configured to operate the set of contactors and the at least one rheostat to single phase lines of the multi-phase motor for providing the stopping resistance.
1. A comminuting machine comprising:
a frame;
a comminuting rotor coupled to the frame; and
a rotary drive coupled to the rotor, the rotary drive including
a controller,
a multi-phase motor connected to the controller,
a set of contactors disposed between the controller and the multi-phase motor for selectively providing driving motive force to the multi-phase motor, and
at least one rheostat disposed between the controller and the multi-phase motor, in parallel with the set of contactors, for selectively providing a stopping resistance to the multi-phase motor to effect frictionless braking of the comminuting rotor,
wherein the controller is configured to operate the set of contactors and the at least one rheostat to single phase lines of the multi-phase motor for providing the stopping resistance.
2. The comminuting machine of claim 1 , wherein the controller is configured to operate the set of contactors to single phase lines of the multi-phase motor to disengage the driving motive force to the multi-phase motor.
3. The comminuting machine of claim 1 , wherein the controller is configured to operate the at least one rheostat to single phase lines of the multi-phase motor to provide the stopping resistance to the multi-phase motor.
4. The comminuting machine of claim 1 , wherein the controller is configured such that the set of contactors is closed and contactors of the rheostat are open during operation of the comminuting rotor, where the controller is configured to control the contactors of the rheostat.
5. The comminuting machine of claim 4 , wherein the set of contactors includes a contactor for each phase of the multi-phase motor and the controller is configured to control each contactor to open one phase of the multi-phase motor and then open the remaining phases of the multi-phase motor.
6. The comminuting machine of claim 4 , wherein the at least one rheostat includes a contactor for each phase of the multi-phase motor and the controller is configured to control each contactor to close two phases of the multi-phase motor and then close a remaining phase of the multi-phase motor.
7. The comminuting machine of claim 1 , wherein the at least one rheostat is disposed on a stator circuit of the multi-phase motor.
8. A comminuting machine comprising:
a frame;
a comminuting rotor coupled to the frame; and
a rotary drive coupled to the rotor, the rotary drive including
a multi-phase motor,
a controller connected to the multi-phase motor,
a first set of contactors disposed in the connection between the multi-phase motor and the controller such that each phase of the multi-phase motor includes a respective contactor,
a second set of contactors disposed in the connection between the multi-phase motor and the controller in parallel with the first set of contactors such that each phase of the multi-phase motor includes a respective contactor, where the first set of contactors and the second set of contactors are selectably engageable, and
a load disposed on each phase of the multi-phase motor in-line with a respective one of the second set of contactors,
wherein the controller is configured to open each contactor in the first set of contactors in a first predetermined sequence and close each contactor in the second set of contactors in second predetermined sequence to provide frictionless braking of the multi-phase motor.
9. The comminuting machine of claim 8 , wherein
the multi-phase motor is a three phase motor,
the first predetermined sequence is open a contactor of the contactors on one phase and then substantially simultaneously open contactors of the first set of contactors on remaining phases, and
the second predetermined sequence is substantially simultaneously close contactors of the second set of contactors on two phases and then close a contactor of the second set of contactors on a remaining phase.
10. The comminuting machine of claim 8 , wherein the controller is configured to open the first set of contactors prior to closing the second set of contactors to provide the frictionless braking of the multi-phase motor.
11. The comminuting machine of claim 8 , wherein the load is at least one rheostat.
12. The comminuting machine of claim 11 , wherein the at least one rheostat is disposed on a stator circuit of the multi-phase motor.
13. A method for providing frictionless braking of a comminuting rotor of a comminuting machine where the comminuting rotor is driven by a multi-phase motor, the method comprising:
controlling, with a controller of the comminuting machine, a set of contactors disposed between the controller and the multi-phase motor where the set of contactors selectively provide driving motive force to the multi-phase motor,
controlling, with the controller, at least one rheostat disposed between the controller and the multi-phase motor, in parallel with the set of contactors, for selectively providing a stopping resistance to the multi-phase motor to effect frictionless braking of the comminuting rotor, and
operating, with the controller, the set of contactors to single phase lines of the multi-phase motor for providing the stopping resistance to effect the frictionless braking of the comminuting rotor.
14. The method of claim 13 , wherein the set of contactors are operated by the controller to single phase lines of the multi-phase motor to disengage the driving motive force to the multi-phase motor.
15. The method of claim 13 , wherein the at least one rheostat is operated by the controller to single phase lines of the multi-phase motor to provide the stopping resistance to the multi-phase motor.
16. The method of claim 13 , wherein the set of contactors is closed and contactors of the rheostat are open during comminuting operation of the comminuting rotor.
17. The method of claim 16 , wherein the set of contactors includes a contactor for each phase of the multi-phase motor and the method further includes controlling each contactor to open one phase of the multi-phase motor and then open the remaining phases of the multi-phase motor.
18. The method of claim 16 , wherein the at least one rheostat includes a contactor for each phase of the multi-phase motor and the method further includes controlling each contactor of the rheostat to close two phases of the multi-phase motor and then close a remaining phase of the multi-phase motor.