Brushless DC ring motor cooling system

• US 20020003381A1
• Filed: 05/03/2001
• Published: 01/10/2002
• Est. Priority Date: 05/03/2000
• Status: Active Grant

• Current Assignee: Horton Incorporated
• Original Assignee: Horton Incorporated
• Inventors: Nelson, Christopher A., Palmer, Bradford K.
• Granted Patent: US 6,600,249 B2
• Time in Patent Office: Days
• US Class Current: 310/67R
• CPC Class Codes: F01P 11/10 Guiding or ducting cooling-air, to, or from, liquid-to-air heat exchangers
• CPC Class Codes: F01P 2005/046 with electrical pump drive
• CPC Class Codes: F01P 7/048 using electrical drives
• CPC Class Codes: F04D 25/0633 Details of the magnetic circuit
• CPC Class Codes: F04D 25/064 Details of the rotor
• CPC Class Codes: F04D 25/0646 Details of the stator
• CPC Class Codes: F04D 25/08 the working fluid being air, e.g. for ventilation
• CPC Class Codes: F04D 29/582 specially adapted for elastic fluid pumps
• CPC Class Codes: H02K 1/187 to inner stators
• CPC Class Codes: H02K 5/1735 radially supporting the rotary shaft at only one end of the rotor H02K5/1737 takes precedence
• CPC Class Codes: H02K 7/14 Structural association with mechanical loads, e.g. with hand-held machine tools or fans with fan or impeller for cooling the machine H02K9/06

Abstract

A cooling system for a vehicle includes a shroud attachable to a fixed portion of the vehicle. A stator assembly for a brushless DC ring motor is attached to at least one mounting support of the shroud. A cooling fan is piloted on the stator assembly, and includes a ring supporting a plurality of fan blades for sweeping an area inside the shroud. A rotor assembly for the brushless DC ring motor is attached to the ring of the cooling fan. The rotor assembly confronts the stator assembly around an outer diameter of the stator assembly. The cooling system is controlled by an electronic controller to rotate the cooling fan to provide appropriate cooling for the vehicle.

Claims

1. A cooling system for a vehicle, the cooling system comprising:

a shroud attachable to a fixed portion of the vehicle, the shroud including at least one mounting support;

a stator assembly for a brushless DC ring motor attached to the at least one mounting support, the stator assembly having an outer diameter;

a cooling fan piloted on the stator assembly, the cooling fan including a ring supporting a plurality of fan blades for sweeping an area inside the shroud; and

a rotor assembly for the brushless DC ring motor attached to the ring of the cooling fan, the rotor assembly confronting the stator assembly around the outer diameter of the stator assembly.

2. The cooling system of claim 1, wherein the stator assembly for the brushless DC ring motor is configured in a three phase arrangement.

3. The cooling system of claim 1, wherein the stator assembly for the brushless DC ring motor comprises a plurality of laminations exposed around the outer diameter of the stator assembly to confront the rotor assembly.

4. The cooling system of claim 3, wherein the rotor assembly comprises a back-iron ring attached to the ring of the cooling fan and a plurality of permanent magnets attached to the back-iron ring to confront the plurality of laminations of the stator assembly.

5. The cooling system of claim 1, wherein a clearance between the shroud and the plurality of fan blades of the cooling fan is no greater than about one-eighth of an inch.

6. The cooling system of claim 1, wherein the plurality of fan blades are individually removable from the ring of the cooling fan.

7. The cooling system of claim 1, wherein the ring supporting the plurality of fan blades is removable from the cooling fan.

8. The cooling system of claim 1, wherein the fixed portion of the vehicle is a radiator.

9. The cooling system of claim 8, wherein the rotor assembly is drivable to rotate the cooling fan in a first direction for cooling and in a second direction for expelling debris from the radiator.

10. The cooling system of claim 8, wherein the radiator is mounted remotely from an engine of the vehicle.

11. The cooling system of claim 1, further comprising an electronic controller operatively connected to an engine control module (ECM) of the vehicle for controlling operations of the cooling system.

12. The cooling system of claim 11, wherein the electronic controller comprises:

a control/communications system operatively connected to the ECM of the vehicle;

a DC-to-DC converter operatively connected to a power source; and

a commutation switching segment operatively connected to the DC-to-DC converter and to the control/communications system, the commutation switching segment being connected to provide signals for operating the brushless DC ring motor.

13. The cooling system of claim 12, wherein the control/communications system is operable to receive pulse width modulated (PWM) signals from the ECM of the vehicle to control the brushless DC ring motor.

14. The cooling system of claim 12, wherein the control/communications system is operable to receive digital signals from a serial line of the ECM of the vehicle to control the brushless DC ring motor.

15. The cooling system of claim 12, wherein an output of the DC-to-DC converter is variable for gross adjustment of a speed of the motor and an output of the commutation switching segment is variable for fine adjustment of the speed of the motor.

16. The cooling system of claim 12, wherein the power source is a vehicle battery.

17. The cooling system of claim 16, wherein the DC-to-DC converter is operable to selectively draw power from the vehicle battery in demanding cooling conditions.

18. A cooling system for a vehicle, the cooling system comprising:

a cooling fan assembly attached to a fixed portion of the vehicle, the cooling fan assembly including a cooling fan driven by a brushless DC ring motor;

a control/communications system operatively connected to an engine control module (ECM) of the vehicle;

a DC-to-DC converter operatively connected to a power source; and

a commutation switching segment operatively connected to the DC-to-DC converter and to the control/communications system, the commutation switching segment being connected to provide signals for operating the brushless DC ring motor of the cooling fan assembly.

19. The cooling system of claim 18, wherein the control/communications system is operable to receive pulse width modulated (PWM) signals from the ECM of the vehicle to control the brushless DC ring motor.

20. The cooling system of claim 18, wherein the control/communications system is operable to receive digital signals from a serial line of the ECM of the vehicle to control the brushless DC ring motor.

21. The cooling system of claim 18, wherein an output oft he DC-to-DC converter is variable for gross adjustment of a speed of the motor and an output of the commutation switching segment is variable for fine adjustment of the speed of the motor.

22. The cooling system of claim 18, wherein the power source is a vehicle battery.

23. The cooling system of claim 22, wherein the DC-to-DC converter is operable to selectively draw power from the vehicle battery in demanding cooling conditions.

24. A brushless DC ring motor comprising:

a stator assembly having an outer diameter and a plurality of laminations exposed around the outer diameter; and

a rotor assembly piloted on the stator assembly, the rotor assembly having a back-iron ring and a plurality of permanent magnets on an inner diameter of the back-iron ring confronting the plurality of laminations exposed around the outer diameter of the stator assembly.

25. The brushless DC ring motor of claim 24, wherein the stator assembly is configured in a three phase arrangement.

26. A method of operating a cooling fan in a cooling system for a vehicle, the method comprising:

determining a required speed of the cooling fan; and

providing first and second signals to a motor controller operatively connected to a motor having a rotatable portion connected to the cooling fan, the first signal coarsely controlling a rotational speed of the motor and the second signal finely controlling the rotational speed of the motor so that the cooling fan rotates at the required speed.

27. The method of claim 26, wherein the step of determining the required speed of the cooling fan comprises:

analyzing a pulse width modulated (PWM) signal from the engine control module (ECM) of the vehicle.

28. The method of claim 26, wherein the step of determining the required speed of the cooling fan comprises:

analyzing digital signals from a serial line of the engine control module (ECM) of the vehicle.

29. A method of operating a cooling fan in a cooling system for a vehicle, the method comprising:

analyzing digital signals from a serial line of the engine control module (ECM) of the vehicle to determine a required speed of the cooling fan; and

providing at least one signal to a motor controller operatively connected to a motor having a rotatable portion connected to the cooling fan, the at least one signal being related to a rotational speed of the cooling fan in such a manner that the cooling fan rotates at the required speed.

30. The method of claim 29, wherein the step of providing at least one signal to the motor comprises:

providing first and second signals to the motor controller, the first signal coarsely controlling the rotational speed of the motor and the second signal finely controlling the rotational speed of the motor so that the cooling fan rotates at the required speed.