High torque eccentric electric motor
A drive system for a high torque mechanical load includes a power supply, a controller, and a high torque electric motor. The electric motor includes a rotor that is oriented eccentrically relative to a stator. In one form, the electric motor has a crankshaft that transmit the torque to the mechanical load. In other variations, the electric motor includes at least two electric motor lobes with opposite stroke positions to provide a smoother output at higher speeds. During operation, the rotor is magnetically attracted to the energized electromagnet. With the rotor attracted to the electromagnet in the stator, the rotor contacts or comes in close proximity to the stator at a contact area. The close proximity between the rotor and stator at the contact area allows very large magnetic forces to be utilized to produce torque without increasing the size or weight of the electric motor.
1. An electric motor system, comprising:
a first lobe including a first rotor and a first stator;
wherein the first rotor is configured to move in an eccentric manner relative to the first stator;
a second lobe including a second rotor and a second stator;
wherein the second rotor is configured to move in an eccentric manner relative to the second stator;
wherein the second rotor is eccentrically oriented in an opposite position to the first rotor;
a mid-link connecting the first rotor to the second rotor;
wherein the first rotor has a first rotor body;
wherein the first rotor has one or more rotor first guide tabs extending longitudinally from the first rotor body;
wherein the second rotor has a second rotor body;
wherein the second rotor has one or more second rotor guide tabs extending longitudinally from the second rotor body;
wherein the mid-link defines one or more first mid-link guide slots in which the first rotor guide tabs are slidingly received;
wherein the mid-link defines one or more second mid-link guide slots in which the second rotor guide tabs are slidingly received;
wherein the first mid-link guide slots and the second mid-link guide slots are located on opposite sides of the mid-link;
wherein the first mid-link guide slots and the second mid-link guide slots are arranged transverse to one another;
a shield disposed between the first lobe and the second lobe;
wherein the shield is configured to electromagnetically shield the first lobe from the second lobe; and
wherein the mid-link is disposed inside the shield.
2. The electric motor system of claim 1 , wherein the first rotor is disposed inside the first stator and contacts the first stator at a contact area.
3. The electric motor system of claim 2 , wherein the first rotor is spaced apart from the first stator by a gap opposite the contact area.
4. The electric motor system of claim 1 , wherein the first rotor is spaced at most 1 mm from the first stator at a contact area.
5. The electric motor system of claim 4 , wherein the first rotor is spaced apart from the first stator by a gap opposite the contact area that is greater than 1 mm.
6. The electric motor system of claim 1 , wherein the first rotor has a central rotor axis that is offset from a central stator axis of the first stator.
7. The electric motor system of claim 1 , further comprising a crankshaft to which the first rotor is coupled.
8. The electric motor system of claim 7 , further comprising a bearing disposed between the first rotor and the crankshaft.
9. The electric motor system of claim 1 , further comprising at least two crank pins on a crankshaft.
10. The electric motor system of claim 1 , wherein the first rotor is a south rotor having permanent magnets with south poles facing radially outward.
11. The electric motor system of claim 10 , wherein the second rotor is a north rotor having one or more permanent magnets with north poles facing radially outward.
12. The electric motor system of claim 1 , further comprising an indexing mechanism.
13. The electric motor system of claim 12 , wherein the indexing mechanism includes a ring gear and a planet gear eccentrically disposed in the ring gear.
14. The electric motor system of claim 13 , wherein the ring gear includes a ring body and a series of pins extending from the ring body in a longitudinal direction.
15. The electric motor system of claim 1 , further comprising a universal joint configured to output power from the first lobe and the second lobe.
16. The electric motor system of claim 15 , wherein the universal joint includes a planet gear with an opening and an output adapter pin in the opening.
17. The electric motor system of claim 1 , wherein the first stator includes a series of electromagnets circumferentially disposed around the first rotor.
18. The electric motor system of claim 17 , wherein the electromagnets each include a pole pair with at least two coils wound in opposing directions.
19. The electric motor system of claim 18 , wherein the first rotor includes a rotor body made of material configured to be magnetically attracted by the pole pair.
20. The electric motor system of claim 17 , wherein the electromagnets include a first pole pair and a second pole pair.
21. The electric motor system of claim 20 , further comprising:
a controller having a drive circuit; and
wherein the drive circuit is configured to provide opposite currents to the first pole pair and the second pole pair.
22. The electric motor system of claim 1 , wherein:
the first rotor is a south rotor having permanent magnets with south poles facing radially outward; and
the second rotor is a north rotor having permanent magnets with north poles facing radially outward.