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US 6,628,037 B2Granted
Power generator, electronic device using the same, method of setting plate thickness in a magnetic circuit in electronically controlled timepiece and power generator
AssigneeSeiko Epson Corporation
InventorKinya Matsuzawa
Life of this patent
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Abstract
In a power generator (20) including a rotor (21), a stator (magnetic core) (22) and a coil (23), a formula (1) including hysteresis loss coefficient kh, eddy-current loss coefficient ke, resistivity ρ (Ω·m), frequency f (Hz) and maximum amplitude magnetic flux density Bm (T) is applied in setting plate thickness of the stator (22). Since the plate thickness (d) (m) of the stator (22) is set to the minimum iron loss plate thickness (d) obtained by the formula (1), the iron loss of the magnetic circuit of the power generator can be reduced, thereby improving efficiency of the power generator.
Claims28
A power generator, comprising:
- a rotor having a permanent magnet;
- a stator and a magnetic core of soft magnetic material constituting a magnetic circuit;
- and
- a coil wound around the magnetic core,
- wherein the plate thickness d (m) of the soft magnetic material constituting at least one of the stator and the magnetic core is set at a value represented by the following formula of d = k h k e ρ · f - 0.375 B m - 0.175 ( 1 )
- where kh represents hysteresis loss coefficient, ke represents eddy-current loss coefficient, ρ (Ω·m) represents resistivity, f (Hz) represents frequency and Bm (T) represents maximum amplitude magnetic flux density of the soft magnetic material.
3 more elements
A power generator, comprising:
- a rotor having a permanent magnet;
- a stator and a magnetic core of soft magnetic material constituting a magnetic circuit;
- and
- a coil wound around the magnetic core,
- wherein the plate thickness d (m) of the soft magnetic material constituting at least one of the stator and the magnetic core is set within a plate thickness range determined so that iron loss W does not exceed a reference value W2, the reference value W2 being obtained by a thickness d obtained in accordance with the following formula of d = k h k e ρ · f - 0.375 B m - 0.175 ( 1 )
- where kh represents hysteresis loss coefficient, ke represents eddy-current loss coefficient, ρ (Ω·m) represents resistivity, f (Hz) represents frequency and Bm (T) represents maximum amplitude magnetic flux density of the soft magnetic material, which is assigned to the following formula of W ≅ k h d - 1 B m 1.65 + k e 1 ρ df 0.75 B m 2 ( 6 )
- to calculate a minimum value W1 of the iron loss W (J/m3), the reference value W2 being set greater than the minimum value W1.
4 more elements
An electronic device, comprising:
- a power generator comprising:
- a rotor having a permanent magnet;
- a stator and a magnetic core of soft magnetic material constituting a magnetic circuit;
- and
- a coil wound around the magnetic core,
- wherein the plate thickness d (in) of the soft magnetic material constituting at least one of the stator and the magnetic core is set at a value represented by the following formula of d = k h k e ρ · f - 0.375 B m - 0.175 ( 1 )
- where kh represents hysteresis loss coefficient, ke represents eddy-current loss coefficient, ρ (Ω·m) represents resistivity, f (Hz) represents frequency and Bm (T) represents maximum amplitude magnetic flux density of the soft magnetic material;
- and
- a processor actuated by the electric energy generated by the power generator.
6 more elements
An electronically controlled timepiece, comprising:
- a power generator comprising:
- a rotor having a permanent magnet;
- a stator and a magnetic core of soft magnetic material constituting a magnetic circuit;
- and
- a coil wound around the magnetic core,
- wherein the plate thickness d (m) of the soft magnetic material constituting at least one of the stator and the magnetic core is set at a value represented by the following formula of d = k h k e ρ · f - 0.375 B m - 0.175 ( 1 )
3 more elements
A method of setting plate thickness in a magnetic circuit in a power generator, the power generator including a rotor having a permanent magnet, a stator and a magnetic core made of a soft magnetic material constituting the magnetic circuit and a coil wound around the magnetic core,
- wherein the plate thickness d of at least one of the stator and the magnetic core is set at a value represented by the following formula of d = k h k e ρ · f - 0.375 B m - 0.175 ( 1 )
- where kh represents hysteresis loss coefficient, ke represents eddy-current loss coefficient, ρ (Ω·m) represents resistivity, f (Hz) represents frequency and Bm (T) represents maximum amplitude magnetic flux density of the soft magnetic material.
A method of setting plate thickness in a magnetic circuit in a power generator, the power generator including a rotor having a permanent magnet, a stator and a magnetic core made of a soft magnetic material constituting the magnetic circuit and a coil wound around the magnetic core,
- wherein the plate thickness d of at least one of the stator and the magnetic core is set within a plate thickness range determined so that iron loss W does not exceed a reference value W2, the reference value W2 being obtained by a thickness d obtained in accordance with the following formula of d = k h k e ρ · f - 0.375 B m - 0.175 ( 1 )
- where kh represents hysteresis loss coefficient, ke represents eddy-current loss coefficient, ρ (Ω·m) represents resistivity, f (Hz) represents frequency and Bm (T) represents maximum amplitude magnetic flux density of the soft magnetic material, which is assigned to the following formula of W ≅ k h d - 1 B m 1.65 + k e 1 ρ df 0.75 B m 2 ( 6 )
- to calculate a minimum value W1 of the iron loss W (J/m3), the reference value W2 being set greater than the minimum value W1.
An electronic device, comprising:
- a power generator comprising:
- a rotor having a permanent magnet;
- a stator and a magnetic core of soft magnetic material constituting a magnetic circuit;
- and
- a coil wound around the magnetic core,
- wherein the plate thickness d (in) of the soft magnetic material constituting at least one of the stator and the magnetic core is set within a plate thickness range determined so that iron loss W does not exceed a reference value W2, the reference value W2 being obtained by a thickness d obtained in accordance with the following formula of d = k h k e ρ · f - 0.375 B m - 0.175 ( 1 )
- where kh represents hysteresis loss coefficient, ke represents eddy-current loss coefficient, ρ (Ω·m) represents resistivity, f (Hz) represents frequency and Bm (T) represents maximum amplitude magnetic flux density of the soft magnetic material, which is assigned to the following formula of W ≅ k h d - 1 B m 1.65 + k e 1 ρ d f 0.75 B m 2 ( 6 )
- to calculate a minimum value W1 of the iron loss W (J/m3), the reference value W2 being set greater than the minimum value W1;
- and
- a processor actuated by the electric energy generated by the power generator.
7 more elements
An electronically controlled timepiece, comprising:
- a power generator comprising:
- a rotor having a permanent magnet;
- a stator and a magnetic core of soft magnetic material constituting a magnetic circuit;
- and
- a coil wound around the magnetic core,
- wherein the plate thickness d (in) of the soft magnetic material constituting at least one of the stator and the magnetic core is set within a plate thickness range determined so that iron loss W does not exceed a reference value W2, the reference value W2 being obtained by a thickness d obtained in accordance with the following formula of d = k h k e ρ · f - 0.375 B m - 0.175 ( 1 )
- where kh represents hysteresis loss coefficient, ke represents eddy-current loss coefficient, ρ (Ω·m) represents resistivity, f (Hz) represents frequency and Bm (T) represents maximum amplitude magnetic flux density of the soft magnetic material, which is assigned to the following formula of W ≅ k h d - 1 B m 1.65 + k e 1 ρ d f 0.75 B m 2 ( 6 )
- to calculate a minimum value W1 of the iron loss W (J/m3), the reference value W2 being set greater than the minimum value W1;
- and
- a processor for driving a time display by the electric energy generated by the power generator.
7 more elements
Dependencies are inferred from the claim text.