US3886256A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Stator core for rotary electric machines and method of manufacturing the same
Assignee: Hitachi Ltd
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Filing: 1973-11-30
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Granted: 1975-05-27
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Expires: 1993-11-30
Abstract
Abstract A stator core for rotary electric machines, which is formed by helically and closely winding a steel strip formed by stamping with equally spaced inner slots defining a plurality of equally spaced tooth portions. The steel strip is also formed with notches each on each side of the stem portion of each tooth portion for the purpose of minimizing the plastic deformation stresses induced at the time of winding it.
Inventors
- 👤 Yasushi Ohuchi
- 👤 Toshiyuki Ebine
- 👤 Takefumi Ohwada
- 👤 Ryozo Tomozaki
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 07:45
CPC Classifications
H; H02; H02K; H02K1/00; H02K1/06; H02K1/12; H02K1/16
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
119 words
A stator core for rotary electric machines, said stator core being in the form of a helically and closely wound steel strip, the inner side of said wound steel strip having equally spaced slots defining a plurality of equally spaced tooth portions, each of said tooth portions having a recess on the opposite edges of the stem portion thereof, each recess extending from the tail portion of its associated tooth to a location intermediate the stem portion of said associated tooth, each recess having a notch extending from said tail portion of its associated tooth to a location intermediate the associated recess, said notches serving to minimize plastic deformation stresses induced at the time of winding said steel strip.
Claim 2
Dependent Claim
119 words
A stator core for rotary electric machines, said stator core being in the form of a helically and closely wound steel strip, the inner side of said wound steel strip having equally spaced slots defining a plurality of equally spaced tooth portions, each of said tooth portions having a recess on the opposite edges of the stem portion thereof, each recess extending from the tail portion of its associated tooth to a location intermediate the stem portion of said associated tooth, each recess having a notch extending from said tail portion of its associated tooth to a location intermediate the associated recess, said notches serving to minimize plastic deformation stresses induced at the time of winding said steel strip.
Claim 3
Dependent Claim
30 words
The stator core for rotary electric machines according to claim 1, wherein said steel strip is also formed with circular recesses individually in the head of the respective tooth portions.
Claim 4
Dependent Claim
50 words
The stator core for rotary electric machines according to claim 1, wherein the opposite end portions of said steel strip closely wound into the helical form substantially lie in the same straight line drawn across the center of a recess at the back of a tooth portion of said core.
Claim 5
Dependent Claim
137 words
A stator core for rotary electric machines, said stator core provided with a plurality of equally spaced slots defining a plurality of equally spaced and inwardly extending teeth, each of said teeth including a stem portion and a head portion at the free end of said stem portion, said stator core being in the form of a helically and closely wound steel strip having two free ends and formed on one side thereof with said equally spaced slots defining said plurality of equally spaced teeth, each of said free ends of said steel strip forming an acute angle with the longitudinal axis of said strip, the vertices of the acute angles lying along a line parallel to the central axis of said stator core, said ends in superposition seen in plan view forming an inwardly flaring angle.
Claim 6
Dependent Claim
137 words
A stator core for rotary electric machines, said stator core provided with a plurality of equally spaced slots defining a plurality of equally spaced and inwardly extending teeth, each of said teeth including a stem portion and a head portion at the free end of said stem portion, said stator core being in the form of a helically and closely wound steel strip having two free ends and formed on one side thereof with said equally spaced slots defining said plurality of equally spaced teeth, each of said free ends of said steel strip forming an acute angle with the longitudinal axis of said strip, the vertices of the acute angles lying along a line parallel to the central axis of said stator core, said ends in superposition seen in plan view forming an inwardly flaring angle.
Claim 7
Dependent Claim
20 words
The stator core as defined in claim 4 wherein said inwardly flaring angle subtends at least one of said teeth.
Claim 8
Dependent Claim
60 words
The stator core as defined in claim 4 wherein the inner edge portion of said head portion of each tooth at said free end of said stem portion is in the form of an arcuate recess portion with flat portions on opposite sides of said arcuate recess portion, each said arcuate recess portion lying along the circumference of a circle.
Claim 9
Dependent Claim
35 words
The stator core as defined in claim 4 wherein said slots include notches formed on opposite sides of the stem portion of each tooth to minimize plastic deformation of said teeth of said stator core.
Claim 10
Dependent Claim
78 words
THe stator core as defined in claim 4 wherein each of said teeth has a recess on the opposite edges of the stem portion thereof, each recess extending from the tail portion of its associated tooth to a location intermediate the stem portion of said associated tooth, each recess having a notch extending from said tail portion of its associated tooth to a location intermediate the associated recess, said notches serving to minimize plastic deformation of said teeth.
References Cited (Backward Citations)
US3320451A
Cited
US3270231A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-05-26 | 1978-11-25 | 1979-05-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-05-26 | 1982-11-25 | 1983-05-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-05-26 | 1986-11-25 | 1987-05-27 | $7700.00 | Window Closed / Lapsed |