Generator for converting mechanical vibrational energy into electrical energy

1. An electromechanical generator for converting mechanical vibrational energy into electrical energy, the electromechanical generator comprising:

a substantially annular high-permeability core, the core including at least one magnet therein to define a magnetic circuit;

at least one rotatable bearing mounting the core to at least one bearing support, the at least one bearing permitting the core to pivot about a pivot axis when the electromechanical device is vibrated, a gap provided in the core;

a body of high-permeability material located in the gap, the body being independent of, and spaced from, the substantially annular high-permeability core and spaced from respective end faces of the core by a respective spacing whereby pivoting movement of the substantially annular high-permeability core about the pivot axis and relative to the body causes relative movement between the end faces of the core and the body; and

a coil surrounding a length of the core, from which coil an output electrical power is obtainable when the electromechanical device is vibrated;

whereby the core containing the at least one magnet creates magnetic flux that flows from one of the end faces to the other of the end faces via the respective spacings and through the body such as to provide a restoring force on the core.

2. An electromechanical generator according to claim 1 wherein the core is mounted to the support by two of the rotatable bearings which are mutually spaced along the pivot axis.

3. An electromechanical generator according to claim 1 wherein the coil is coaxial with the pivot axis.

4. An electromechanical generator according to claim 3 wherein the coil is rotationally fixed.

5. An electromechanical generator according to claim 1 wherein two magnets are provided in the core, one on each side of the coil.

6. An electromechanical generator according to claim 1 wherein the body of high-permeability material is mounted on a support that is adapted selectively to be movable towards and away from the pivot axis such as to vary a degree of coincidence between the body and the end faces of the core and thereby to vary the restoring force.

7. An electromechanical generator according to claim 1 wherein the annular core is substantially rectangular in shape, having a pivoted end on which the coil is mounted, an opposite free end including the gap, and two opposed sides extending therebetween, each side including a respective magnet.

8. An electromechanical generator according to claim 1 wherein a body of low-permeability material is attached to the core at a position remote from the pivot axis.

9. An electromechanical generator according to claim 1 further comprising a base on which the at least one bearing support and the body of high-permeability material are carried.

10. An electromechanical generator according to claim 1 , comprising a base from which the at least one bearing support extends, wherein the body is mounted on a support extending from the base.

11. An electromechanical generator according to claim 10 , wherein the support upon which the body is mounted is adapted selectively to be moveable towards and away from the pivot axis such as to vary a degree of coincidence between the body and the end faces of the core and thereby to vary the restoring force.