Axial gap electrical machine

• US 8,525,378 B2
• Filed: 10/13/2010
• Issued: 09/03/2013
• Est. Priority Date: 05/24/2001
• Status: Expired due to Fees

• Current Assignee: Arjuna Indraeswaran Rajasingham
• Original Assignee: Arjuna Indraeswaran Rajasingham
• Inventors: Rajasingham, Arjuna Indraeswaran
• Primary Examiner(s): LE, DANG D
• Application Number:
  US12/925,069
• Publication Number:
  US 20120286628A1
• Time in Patent Office: 1,056 Days
• Field of Search: 310/71, 310/260, 310/270, 310201-208
• US Class Current: 310/71
• CPC Class Codes: B60L 2220/50 Structural details of electrical machines
• CPC Class Codes: H02K 1/06 characterised by the shape, form or construction
• CPC Class Codes: H02K 21/24 with magnets axially facing the armatures, e.g. hub-type cycle dynamos
• CPC Class Codes: H02K 2201/03 Machines characterised by aspects of the air-gap between rotor and stator
• CPC Class Codes: H02K 3/12 arranged in slots
• CPC Class Codes: H02K 9/227 Heat sinks
• CPC Class Codes: Y02T 10/64 Electric machine technologies in electromobility

Abstract

An axial gap electrical machine employs unique architecture to (1) overcome critical limits in the air gap at high speeds, while maintaining high torque performance at low speeds, while synergistically providing a geometry that withstands meets critical force concentration within these machines, (2) provides arrangements for cooling said machines using either a Pelletier effect or air fins, (3) “windings” that are produced as ribbon or stampings or laminates, that may be in some cases be arranged to optimize conductor and magnetic core density within the machine. Arrangements are also proposed for mounting the machines as wheels of a vehicle, to provide ease of removing and installing said motor.

Claims

1. An electrical machine with a coil in a magnetic field wherein one or both of:

the motion of the coil in the magnetic field generates an electrical potential across the coil ends; and

a current resulting from an electrical potential across the ends of the coil result in motion of the coil, wherein said coil has at least two turns and said turns each comprise a first part with a first and second end and composed of a first material, and a second part with a first and a second end composed of a second material, and wherein junction one is where the second end of the first part is connected to the first end of the second part in each turn, and junction two is where the second end of the second part of the first turn is attached to the first end of the first part of the second turn, and wherein when a secondary current is driven through the at least two turns from the first end of the first part of the first turn to the second end of the second part of the second turn, a temperature change is generated between junction one and junction two, thereby providing means to transfer heat from junction one where heat is generated in the machine to junction two for cooling of the electrical machine.

2. An electrical machine as in claim 1, wherein said electrical machine has an axis and a periphery and means to provide the magnetic field lies in a substantially axial direction relative to the coil across an axial air-gap.

3. An electrical machine as in claim 2, wherein the coil is attached to a central axle of the electrical machine and the junction two of the coil is arranged to be near the axle, and wherein the axle is enabled to have a coolant fluid passing through it to absorb heat thereby providing means to cool the electrical machine.

4. An electrical machine as in claim 3, wherein the coil is attached to a central axle of the electrical machine and the junction one of the coil is arranged to be at the outer periphery of the coil, such that heat generated in the electrical machine and diverted to the periphery of the machine may be absorbed by the junction one, thereby cooling the machine.

5. An axial gap electrical machine as in claim 4, wherein the magnetic field is generated by a magnet structure with a plurality of magnets attached to a pivotal axis, wherein the magnets are enable to have radial gaps inclined such that during motion of the magnet structure, relative to the coil across an air-gap, air is scooped up by the radial gaps and deposited on the other side of the magnet structure thereby cooling the magnet structure and generating a pressure differential, and wherein a return path for the air is provided around the periphery of the coil away from its central support axle thereby enabling the junction one to absorb the heat from the circulating air and transferring it to junction two thereby cooling the machine.

6. An electrical machine as in claim 2, wherein the coil is attached to a central axle of the electrical machine and the junction two of the coil is arranged to be on the periphery of the coil away from the axle, and wherein the periphery of the coil is enabled to have a cooling means to dissipate heat generated by the electrical machine.

7. An electrical machine as in claim 6, wherein the coil is attached to a central axle of the electrical machine and the junction one of the coil is arranged to be adjacent to the axle of the coil, such that heat generated in the electrical machine and diverted to the vicinity of the axle of the machine may be absorbed by the junction one, thereby cooling the machine.

8. An axial gap electrical machine as in claim 7, wherein the magnetic field is generated by a magnet structure with a plurality of magnets attached to a pivotal axis, wherein the magnets are enable to have radial gaps inclines such that during motion of the magnet structure, relative to the coil across an air-gap, air is scooped up by the radial gaps and deposited on the other side of the magnet structure thereby cooling the magnet structure and generating a pressure differential, and wherein a return path for the air is provided though vents in the vicinity of the central support axle thereby enabling the junction one to absorb the heat from the circulating air and transferring it to junction two thereby cooling the machine.

9. An electrical machine as in claim 2, wherein the junction one is arranged to lie in the vicinity of the axis of the machine thereby enabling the machine to dissipate heat from the vicinity of the axis of the machine to the location of the junction two.

10. An electrical machine as in claim 9, wherein the junction two is located in the vicinity of the periphery of the machine and heat exchange to transfer heat away from the junction two is achieved by convection from forced fluid motion in the vicinity of the periphery of the machine.

11. An electrical machine as in claim 2, wherein the junction one is arranged to lie in the vicinity of the periphery of the machine thereby enabling the machine to dissipate heat from the vicinity of the periphery of the machine to the location of the junction two.

12. An electrical machine as in claim 11, wherein the junction two is located in the vicinity of the axis of the machine and heat exchange to transfer heat away from the junction two is achieved by convection from forced fluid motion in the vicinity of the axis of the machine.

13. A method for cooling an electrical machine by:

constructing each turn of the coil with a first part of material one and a second part with material two and attaching them end to end to form a turn;

constructing the coil by attaching the turns end to end with dissimilar materials attached to each other;

passing a secondary current through the coil to create a temperature difference between the junction one and junction two;

utilizing the junction one to transfer heat out of the machine to the vicinity of junction two;

creating means in the vicinity of junction two to dissipate heat from the junction two to the environment of the electrical machine.