IP Library Granted Patent US 12,401,256
Granted Patent B2
US 12,401,256 · App. 17/858,166 · Granted Aug 26, 2025

Repair method of stator iron core

Inventors: Seijiro Muramatsu (Tokyo, JP); Hiroki Aso (Tokyo, JP); Kota Hosaka (Tokyo, JP)
Assignee: Mitsubishi Generator Co., Ltd.
H02K15/50
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Quick Facts
Patent No.
US 12,401,256
App. No.
17/858,166
Granted
Aug 26, 2025
Kind
B2
Abstract

A repair method of a stator iron core which has a slot for accommodating a stator coil, and is formed by laminating silicon steel sheets. The method is implemented by moving a part of the silicon steel sheets which form the stator iron core while holding the stator coil in the slot to form a gap between the laminated silicon steel sheets of the stator iron core in the existence of a damaged part, and adding an insulation to the damaged part of the silicon steel sheet from the gap formed between the laminated silicon steel sheets to repair the damaged part of the silicon steel sheet.

Claims (12)

1. A repair method of a stator iron core which has a slot for accommodating a stator coil, the stator iron core being formed by laminating silicon steel sheets and the stator iron core having a damaged part that cannot be directly scraped for repair from a surface of the stator iron core, the method comprising the steps of:

moving a part of the silicon steel sheets which form the stator iron core while holding the stator coil in the slot to form a gap, in the location of the damaged part, between the laminated silicon steel sheets of the stator iron core; and

adding an insulation to the damaged part of the silicon steel sheet from the gap formed between the laminated silicon steel sheets to repair the damaged part of the silicon steel sheet.

2. The repair method of the stator iron core according to claim 1 , wherein the insulator is added by applying an insulating plate or an insulating coating.

3. The repair method of the stator iron core according to claim 2 , wherein an L-like insulating plate is applied as the insulating plate, or an L-like brush is used for applying the insulating coating.

4. The repair method of the stator iron core according to claim 1 ,

wherein the part of the silicon steel sheets is moved; and

before forming the gap between the laminated silicon steel sheets, an iron core compression rod as a rod-like member and an iron core compression tab as a fixing member to be fixed to the iron core compression rod are placed to axially fix the silicon steel sheets which are made partially immovable.

5. The repair method of the stator iron core according to claim 4 , wherein the iron core compression tab is fitted with an intermediate duct adjacent to the damaged part of the stator iron core.

6. The repair method of the stator iron core according to claim 5 , wherein a rear stopper is placed between a stator main plate located on an outer circumferential side of the stator iron core and the intermediate duct adjacent to the stator main plate for axially fixing the silicon steel sheets which are made partially immovable.

7. The repair method of the stator iron core according to claim 1 , wherein a coil end part as an axial end of the stator coil is preliminarily hung by a chain block, and the coil end part is preliminarily pushed up by a hydraulic jack.

8. The repair method of the stator iron core according to claim 1 , wherein a rear stopper is placed between a stator main plate located on an outer circumferential side of the stator iron core and an intermediate duct adjacent to the stator main plate to axially fix the silicon steel sheets which are made partially immovable.

Assignments (2)
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Jun 12, 2024
From: MITSUBISHI HEAVY INDUSTRIES, LTD.
To: MITSUBISHI GENERATOR CO., LTD.
Reel/Frame 067701/0151 →
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Jul 6, 2022
From: MURAMATSU, SEIJIRO; ASO, HIROKI; HOSAKA, KOTA
To: MITSUBISHI HEAVY INDUSTRIES, LTD.
Reel/Frame 060407/0618 →