Piston-mounted power generator, especially for telemetry systems
First Claim
1. A piston-mounted power generator comprising a permanent magnet unit, having a coil and magnet with a pair of axially spaced pole extensions, mounted to a skirt of a reciprocating piston, and shallow grooves formed in a facing wall of a cylinder within which the piston is mounted for reciprocation and which have an axial spacing corresponding to that of said pole extensions of the magnet;
- wherein said pole extensions have a radial clearance relative to the facing wall of the cylinder to enable a magnet circuit to be created through the cylinder wall from one pole extension to the other when each of the grooves is disposed between the pole extensions; and
wherein each of the grooves has a depth sufficient to break said magnet circuit when each groove radially overlies one of the pole extensions.
2 Assignments
0 Petitions
Accused Products
Abstract
A piston-mounted power generator has a piston-mounted magnet unit (1) formed of a coil (2) with a permanent magnet core (3) that is fitted with pole extensions (5, 6). The unit (1) is mounted to the piston skirt (8) with the pole extensions having a small clearance from the inner wall (10) of the piston cylinder formed by cylinder wall liner (12). Shallow grooves (14) are machined into the cylinder wall (10). The grooves (14) have a crescent-shaped longitudinal cross section, that extends circumferentially in the cylinder wall (10) for a distance that is only slightly longer than the width of the pole extensions. The width of each groove (14) is equal to the spacing between the pole extensions (5, 6) and the axial spacing between the adjacent pairs of grooves (14) is equal to the thickness of the pole extensions (5, 6). Electrical power is generated in the coil 2 by the rapid change in flux in the magnetic circuit linked through it as the effective gap between the poles and wall changes as the poles (5, 6) pass each of the grooves (14) and is maximized when the spacing of the poles and grooves results in the magnetic circuit being made and broken simultaneously at both poles. Transducers and telemetry modules (TTM) can be mounted within the interior of the piston and electrically connect to the coil to be powered thereby. To increase the power generated, the grooves (14'"'"') can be backfilled with a nonmagnetic material (15) by flame-spraying or the like. For special pistons, annular grooves can be used instead ones having the preferred crescent shape.
37 Citations
19 Claims
-
1. A piston-mounted power generator comprising a permanent magnet unit, having a coil and magnet with a pair of axially spaced pole extensions, mounted to a skirt of a reciprocating piston, and shallow grooves formed in a facing wall of a cylinder within which the piston is mounted for reciprocation and which have an axial spacing corresponding to that of said pole extensions of the magnet;
- wherein said pole extensions have a radial clearance relative to the facing wall of the cylinder to enable a magnet circuit to be created through the cylinder wall from one pole extension to the other when each of the grooves is disposed between the pole extensions; and
wherein each of the grooves has a depth sufficient to break said magnet circuit when each groove radially overlies one of the pole extensions. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19)
- wherein said pole extensions have a radial clearance relative to the facing wall of the cylinder to enable a magnet circuit to be created through the cylinder wall from one pole extension to the other when each of the grooves is disposed between the pole extensions; and
Specification