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US4748359A Expired / Lapsed US ⏱️ 0.0 years remaining

Permanent magnet rotor with sinusoidal flux pattern

Assignee: Hitachi Ltd
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Filing: 1986-06-05
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Granted: 1988-05-31
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Expires: 2006-06-05
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Abstract

Abstract A permanent magnet rotor wherein a rotary shaft has an orthogonal cross a sectional shape orthogonal in a longitudinal direction of the rotary shaft, a plurality of circular-arc portions which are around the axis of rotation of the rotary shaft, and rectilinear portions which connect the adjacent circular-arc portions with straight lines having no curved portion. Respective permanent magnets, equal in number to the circular-arc portions, are fixed extending over the circular-arc portions and the rectilinear portions. The surface of each permanent magnet remote from the rotary shaft has a cross sectional contour orthogonal to the longitudinal direction of the rotary shaft, forming a circular arc which protrudes outward.

Inventors

  • 👤 Masataka Yahara
  • 👤 Goro Urayama
  • 👤 Yoshiomi Joujima
  • 👤 Hiroshi Sugai

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-28 20:32
CPC Classifications
H; H02; H02K; H02K1/00; H02K1/06; H02K1/22; H02K1/27; H02K1/2706; H02K1/272; H02K1/274; H02K1/2753; H02K1/278

Claims Analysis

Total Claims: 12
Claim 1
Independent Claim 162 words
A permanent magnet rotor including a rotary shaft means having an orthogonal cross-sectional shape in a longitudinal direction thereof comprising a plurality of circular-arc portions centered around an axis of rotation of said rotary shaft means, rectilinear portions for connecting adjacent circular-arc portions with straight lines having no curved portion, permanent magnets equal in number to said circular-arc portions fixed so as to extend over said circular-arc portions and said rectilinear portions in close contact therewith or at uniform intervals therefrom, an outer surface of each of said permanent magnets remote from said rotary shaft means having a cylindrical shape in a longitudinal direction of the rotary shaft means an inner surface of said permanent magnets adjacent to said rotary shaft means having a rectilinear portion and two circular-arc portions extending from a rectilinear portion, and wherein each of said permanent magnets is fixed to two of said circular-arc portions and one of said rectilinear portions located between the two circular-arc portions.
Claim 2
Dependent Claim 162 words
A permanent magnet rotor including a rotary shaft means having an orthogonal cross-sectional shape in a longitudinal direction thereof comprising a plurality of circular-arc portions centered around an axis of rotation of said rotary shaft means, rectilinear portions for connecting adjacent circular-arc portions with straight lines having no curved portion, permanent magnets equal in number to said circular-arc portions fixed so as to extend over said circular-arc portions and said rectilinear portions in close contact therewith or at uniform intervals therefrom, an outer surface of each of said permanent magnets remote from said rotary shaft means having a cylindrical shape in a longitudinal direction of the rotary shaft means an inner surface of said permanent magnets adjacent to said rotary shaft means having a rectilinear portion and two circular-arc portions extending from a rectilinear portion, and wherein each of said permanent magnets is fixed to two of said circular-arc portions and one of said rectilinear portions located between the two circular-arc portions.
Claim 3
Dependent Claim 164 words
A permanent magnet rotor including a rotary shaft means having an orthogonal cross-sectional shape in a longitudinal direction thereof comprising a plurality of circular-arc portions centered around an axis of rotation of said rotary shaft means, rectilinear portions for connecting adjacent circular-arc portions with straight lines having no curved portion, permanent magnets equal in number to said circular-arc portions fixed so as to extend over said circular-arc portions and said rectilinear portions in close contact therewith or at uniform intervals therefrom, in outer surface of each of said permanent magnets remote from said rotary shaft means having a cylindrical shape in a longitudinal direction of said rotary shaft means, and an inner surface of said permanent magnets adjacent to said rotary shaft means having a circular arc portion and two rectilinear portions extending from the circular-arc portions, and wherein each of said permanent magnets is fixed to two of said rectilinear portions and one of said circular-arc portions located between the two rectilinear portions.
Claim 4
Dependent Claim 164 words
A permanent magnet rotor including a rotary shaft means having an orthogonal cross-sectional shape in a longitudinal direction thereof comprising a plurality of circular-arc portions centered around an axis of rotation of said rotary shaft means, rectilinear portions for connecting adjacent circular-arc portions with straight lines having no curved portion, permanent magnets equal in number to said circular-arc portions fixed so as to extend over said circular-arc portions and said rectilinear portions in close contact therewith or at uniform intervals therefrom, in outer surface of each of said permanent magnets remote from said rotary shaft means having a cylindrical shape in a longitudinal direction of said rotary shaft means, and an inner surface of said permanent magnets adjacent to said rotary shaft means having a circular arc portion and two rectilinear portions extending from the circular-arc portions, and wherein each of said permanent magnets is fixed to two of said rectilinear portions and one of said circular-arc portions located between the two rectilinear portions.
Claim 5
Dependent Claim 152 words
A permanent magnet rotor comprising mounting surfaces of permanent magnets shaped so as to have a plurality of small diameter circular-arc portions centered around an axis of rotation of a rotary shaft, gentle curve portions located between adjacent small-diameter circular-arc portions and being gentler in curvature than said small-diameter circular-arc portions, respective permanent magnets equal in number to said small-diameter circular-arc portions being fixed so as to extend over said small-diameter circular-arc portions and said gentle portions in close contact therewith or at uniform intervals, an inner surface of said permanent magnets adjacent to said rotary shaft means having a gentle curve portion and two small-diameter circular-arc portions extending from the gentle curve portion, and an outer surface of each of said permanent magnets remote from said rotary shaft having a sectional shape orthogonal to the axis of rotation of said rotary shaft in the form of an outwardly projecting circular arc.
Claim 6
Dependent Claim 152 words
A permanent magnet rotor comprising mounting surfaces of permanent magnets shaped so as to have a plurality of small diameter circular-arc portions centered around an axis of rotation of a rotary shaft, gentle curve portions located between adjacent small-diameter circular-arc portions and being gentler in curvature than said small-diameter circular-arc portions, respective permanent magnets equal in number to said small-diameter circular-arc portions being fixed so as to extend over said small-diameter circular-arc portions and said gentle portions in close contact therewith or at uniform intervals, an inner surface of said permanent magnets adjacent to said rotary shaft means having a gentle curve portion and two small-diameter circular-arc portions extending from the gentle curve portion, and an outer surface of each of said permanent magnets remote from said rotary shaft having a sectional shape orthogonal to the axis of rotation of said rotary shaft in the form of an outwardly projecting circular arc.
Claim 7
Dependent Claim 133 words
A permanent magnet rotor comprising a rotary shaft means having a cross-sectional shape orthogonal to a longitudinal direction thereof including a plurality of outwardly projecting circular-arc portions and rectilinear portions for connecting the adjacent circular-arc portions with straight lines having no curved portion, respective permanent magnets equal in number to said circular-arc portions being fixed so as to extend over said circular-arc portions and said rectilinear portions in close contact therewith or at uniform intervals therefrom, and an outer surface of each of said permanent magnets remote from said rotary shaft means having a cylindrical shape in a longitudinal direction of said rotary shaft means, and wherein an inner surface of said permanent magnets adjacent to said rotary shaft means having a rectilinear portion and two circular-arc portions extending from the rectilinear portion.
Claim 8
Dependent Claim 133 words
A permanent magnet rotor comprising a rotary shaft means having a cross-sectional shape orthogonal to a longitudinal direction thereof including a plurality of outwardly projecting circular-arc portions and rectilinear portions for connecting the adjacent circular-arc portions with straight lines having no curved portion, respective permanent magnets equal in number to said circular-arc portions being fixed so as to extend over said circular-arc portions and said rectilinear portions in close contact therewith or at uniform intervals therefrom, and an outer surface of each of said permanent magnets remote from said rotary shaft means having a cylindrical shape in a longitudinal direction of said rotary shaft means, and wherein an inner surface of said permanent magnets adjacent to said rotary shaft means having a rectilinear portion and two circular-arc portions extending from the rectilinear portion.
Claim 9
Dependent Claim 140 words
A permanent magnet rotor comprising a rotary shaft means having an orthogonal cross-sectional shape in a longitudinal direction thereof including a plurality of circular-arc portions centered around an axis of rotation of said rotary shaft means and rectilinear portions for connecting the adjacent circular-arc portions with straight lines having no curved portion, respective permanent magnets equal in number to said circular-arc portions are fixed so as to extend over said circular-arc portions and said rectilinear portions in close contact therewith or at uniform intervals therefrom, and an outer surface of each of said permanent magnets remote from said rotary shaft means having a sectional shape orthogonal to the longitudinal direction of said rotary shaft means forming a circular arc, a center of which deviates toward said permanent magnet with respect to the axis of rotation of said rotary shaft means.
Claim 10
Dependent Claim 140 words
A permanent magnet rotor comprising a rotary shaft means having an orthogonal cross-sectional shape in a longitudinal direction thereof including a plurality of circular-arc portions centered around an axis of rotation of said rotary shaft means and rectilinear portions for connecting the adjacent circular-arc portions with straight lines having no curved portion, respective permanent magnets equal in number to said circular-arc portions are fixed so as to extend over said circular-arc portions and said rectilinear portions in close contact therewith or at uniform intervals therefrom, and an outer surface of each of said permanent magnets remote from said rotary shaft means having a sectional shape orthogonal to the longitudinal direction of said rotary shaft means forming a circular arc, a center of which deviates toward said permanent magnet with respect to the axis of rotation of said rotary shaft means.
Claim 11
Dependent Claim 145 words
A permanent magnet rotor comprising a boss snugly fitted on a rotary shaft so as to prevent a turning thereof and having a sectional contour orthogonal to a longitudinal direction of said rotary shaft including a plurality of outwardly projecting circular-arc portions and rectilinear portions for connecting adjacent circular-arc portions with straight lines having no curved portion, permanent magnets equal in number to said circular-arc portions being respectively fixed so as to extend over said circular-arc portions and said rectilinear portions in close contact therewith or at uniform intervals therefrom, and an outer surface of each of said permanent magnets having a sectional shape orthogonal to the longitudinal direction of said rotary shaft forming an outwardly projecting circular arc, an inner surface of said permanent magnets adjacent to said rotary shaft means having a rectilinear portion and two circular-arc portions extending from the rectilinear portion.
Claim 12
Dependent Claim 145 words
A permanent magnet rotor comprising a boss snugly fitted on a rotary shaft so as to prevent a turning thereof and having a sectional contour orthogonal to a longitudinal direction of said rotary shaft including a plurality of outwardly projecting circular-arc portions and rectilinear portions for connecting adjacent circular-arc portions with straight lines having no curved portion, permanent magnets equal in number to said circular-arc portions being respectively fixed so as to extend over said circular-arc portions and said rectilinear portions in close contact therewith or at uniform intervals therefrom, and an outer surface of each of said permanent magnets having a sectional shape orthogonal to the longitudinal direction of said rotary shaft forming an outwardly projecting circular arc, an inner surface of said permanent magnets adjacent to said rotary shaft means having a rectilinear portion and two circular-arc portions extending from the rectilinear portion.

References Cited (Backward Citations)

DE1942855A1 Cited
JPS5553164A Cited
US4625135A Cited
US4617726A Cited
US4591749A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1991-05-31 1991-11-30 1992-05-31 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1995-05-31 1995-11-30 1996-05-31 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1999-05-31 1999-11-30 2000-05-31 $7700.00 Window Closed / Lapsed

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