Contact type power feeding apparatus
There is provided a contact type power feeding apparatus in which, even if a brush Br disposed in a space between the axis body and the cylinder body that are disposed concentric with each other wears out as a result of sliding, contact can be surely secured between the brush and the axis body as well as the cylinder body, thereby efficiently causing electric current to flow between the two. A brush Br has first brush pieces each having an inner wall surface to make surface-contact with an outer peripheral surface of the axis body; and second brush pieces each having an outer wall surface to make a surface-contact with an inner peripheral surface of the cylinder body. The brush is constituted by alternately arranging, in the circumferential direction, the first brush pieces and the second brush pieces in a state of keeping them in surface-contact with each other. The side wall surfaces of the first brush pieces and the second brush pieces are respectively formed into a tapered shape which is inclined relative to the radial direction. Coil springs are disposed between the second brush pieces that are adjacent to each other, in order to give a biasing force in a direction to move the second brush pieces away from each other.
1. A contact type power feeding apparatus comprising:
a conductive axis body;
a conductive cylinder body concentrically disposed in the circumference of the axis body;
a brush disposed in a space between the axis body and the cylinder body so as to electrically conduct the axis body and the cylinder body while the axis body and the cylinder body rotate relative to each other;
wherein the brush is constituted by: first brush pieces having inner wall surfaces in surface-contact with an outer peripheral surface of the axis body; and second brush pieces having an outer wall surface in surface-contact with an inner peripheral surface of the cylinder body such that the first brush pieces and the second brush pieces are disposed alternately in the circumferential direction in a state of being kept in surface-contact with one another;
wherein the side wall surfaces of the first brush pieces and of the second brush pieces are formed into a tapered shape inclined relative to one another in the radial direction; and
biasing means disposed between at least the adjoining first brush pieces or the adjoining second brush pieces so as to give a biasing force to, and in a direction to move away from each other, the first brush pieces or the second brush pieces.
2. The contact type power feeding apparatus according to claim 1 in which the axis body is cylindrical,
wherein a space is provided between the outer wall surfaces of the first brush pieces and the inner wall surface of the cylinder body, and a space is provided between the inner wall surface of the second brush pieces and the outer wall surface of the axis body, respectively, and
wherein a passage to allow for flow of a fluid is defined between the outer wall surfaces of the first brush pieces and those side wall surfaces of the second brush pieces which extend radially outward beyond the outer wall surfaces of the first brush pieces, and between the inner wall surfaces of the second brush pieces and those side wall surfaces of the first brush pieces which extend radially inward beyond the inner wall surfaces of the first brush pieces.
3. The contact type power feeding apparatus according to claim 2 , wherein the first brush pieces have the outer wall surfaces that curve in an arcuate shape coaxial with the inner wall surfaces, and wherein the second brush pieces have the inner wall surfaces that curve in an arcuate shape coaxial with the outer wall surfaces.
4. The contact type power feeding apparatus according to claim 1 , wherein the biasing means is a coil spring disposed in a compressed manner in a space between the side wall surfaces of the first brush pieces or between the side wall surfaces of the second bush pieces, and wherein a plurality of coil springs are disposed at a predetermined distance from one another in the axial direction.
5. The contact type power feeding apparatus according to claim 2 , wherein the biasing means is a coil spring disposed in a compressed manner in a space between the side wall surfaces of the first brush pieces or between the side wall surfaces of the second bush pieces, and wherein a plurality of coil springs are disposed at a predetermined distance from one another in the axial direction.
6. The contact type power feeding apparatus according to claim 3 , wherein the biasing means is a coil spring disposed in a compressed manner in a space between the side wall surfaces of the first brush pieces or between the side wall surfaces of the second bush pieces, and wherein a plurality of coil springs are disposed at a predetermined distance from one another in the axial direction.