초록 ▼

A permanent magnet electrical machine comprises a first substantially planar member (9, 10) and a second substantially planar member (3) arranged substantially parallel to the first substantially planar member. The first and second members are rotatable relative to each other about a common axis sub

A permanent magnet electrical machine comprises a first substantially planar member (9, 10) and a second substantially planar member (3) arranged substantially parallel to the first substantially planar member. The first and second members are rotatable relative to each other about a common axis substantially perpendicular to the planes of the first and second members. The first member (9, 10 ) is provided with an annular array of permanent magnets (7, 8) coaxial with the common axis and configured to provide a substantially axial magnetic field passing through the second member. The second member (3) is provided with a first annular array of flat coils (1) coaxial with the common axis and arranged substantially side-by-side in a first layer and with a second annular array of flat coils (2) coaxial with the common axis and arranged substantially side-by-side in a second layer. The coils (2) of the second array are offset in a circumferential direction relative to the coils (1) of the first array.

대표청구항 ▼

The invention claimed is: 1. A synchronous axial field electrical machine comprising a first substantially planar member (9, 10) and a second substantially planar member (3) arranged substantially parallel to the first substantially planar member, the first and second members being rotatable relati

The invention claimed is: 1. A synchronous axial field electrical machine comprising a first substantially planar member (9, 10) and a second substantially planar member (3) arranged substantially parallel to the first substantially planar member, the first and second members being rotatable relative to each other about a common axis substantially perpendicular to the planes of the first and second members wherein the first member (9, 10) is provided with an annular array of magnets (7, 8) coaxial with the common axis and configured to provide a substantially axial magnetic field passing through the second member and the second member is provided with a first annular array of flat coils (1) coaxial with the common axis and arranged substantially side-by-side in a first layer and with a second annular array of flat coils (2) coaxial with the common axis and arranged substantially side-by-side in a second layer, the coils (2) of the second array being offset in a circumferential direction relative to the coils (1) of the first array by an amount corresponding substantially to the pitch of adjacent coils divided by the number of layers. 2. An electrical machine as claimed in claim 1, wherein two layers of coils (1, 2) are provided, the coils (1) of one layer being offset relative to the coils (2) of the other layer by an amount corresponding substantially to half the spacing between adjacent coils. 3. An electrical machine as claimed in claim 1, wherein the magnets (7, 8) and the coils (1, 2) are disposed at substantially the same radial distance from the common axis. 4. An electrical machine as claimed in claim 1, wherein the first planar member comprises first and second coaxial plates (9, 10) which are spaced apart from each other. 5. An electrical machine as claimed in claim 4, wherein the magnets (7, 8) are provided on that face of each one of the first and second plates (9, 10) facing the other thereof. 6. An electrical machine as claimed in claim 1, wherein the first and second arrays of flat coils (1, 2) are provided on opposing sides of a support member (3). 7. A synchronous axial field electrical machine comprising a first substantially planar member (9, 10) and a second substantially planar member (3) arranged substantially parallel to the first substantially planar member, the first and second members being rotatable relative to each other about a common axis substantially perpendicular to the planes of the first and second members wherein the first member (9, 10) is provided with an annular array of magnets (7, 8) coaxial with the common axis and configured to provide a substantially axial magnetic field passing through the second member and the second member is provided with a first annular array of flat coils (1) coaxial with the common axis and arranged substantially side-by-side in a first layer and with a second annular array of flat coils (2) coaxial with the common axis and arranged substantially side-by-side in a second layer, the coils (2) of the second array being offset in a circumferential direction relative to the coils (1) of the first array, and the ratio of angular separation of adjacent coils (1, 2) in each array to the angular separation of adjacent magnets (7, 8) corresponding to the number of electrical phases. 8. An electrical machine as claimed in claim 7, wherein the magnets (7, 8) and the coils (1, 2) are disposed at substantially the same radial distance from the common axis. 9. An electrical machine as claimed in claim 7, wherein the first planar member comprises first and second coaxial plates (9, 10) which are spaced apart from each other. 10. An electrical machine as claimed in claim 9, wherein the magnets (7, 8) are provided on that face of each one of the first and second plates (9, 10) facing the other thereof. 11. An electrical machine as claimed in claim 7, wherein the first and second arrays of flat coils (1, 2) are provided on opposing sides of a support member (3).