GB1587785A

GB1587785A - Design of core laminations for large electrical rotating machines

Info

Publication number: GB1587785A
Application number: GB1347278A
Authority: GB
Original assignee: WING FAT MA
Current assignee: WING FAT MA
Priority date: 1978-04-06
Filing date: 1978-04-06
Publication date: 1981-04-08

Description

(54) IMPROVEMENTS IN DESIGN OF CORE LAMINATIONS FOR LARGE ELECTRICAL ROTATING MACHINES (71) We, WAI SUN LEUNG of 140, Pokfulam Road, Flat 65, Hong Kong, British (Hong Kong) and WING FAT MA of 45, Sai Wan Ho Street, 2/F., Hong Kong, British (Hong Kong), do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to b'e particularly described in and by the following statement:- The present invention relates to a new design of core laminations suitable for use in stators of large electrical rotating machines.

The laminations are so designed that the path of the magnetic flux is primarily along the length of the laminations. Cold-rolled or other types of grain-oriented steel laminations are used and most of the flux will travel in the easy direction of magnetisation, thus taking full advantage of the directional properties of the grain-oriented steel. Fur thermore the laminations have the teeth stamped out separately instead of as part of a lamination consisting of both the teeth and the yoke. As a result, the utilization of core material for the new design is considerably increased.

A complete layer of the stator core in a large electrical rotating machine is normally made up of a number of lamination segments, the conventional type of which consists of both the teeth and the yoke having the commonly-used configuration as shown in Fig. 1. As the direction of the flux in the teeth is perpendicular to that in the yoke, there is no advantage in using grain-oriented steel for the lamination. The steel, which is stamped out to provide for the slots, constitutes wastage in the core material.

In the new design for the stator core of a large electrical rotating machine, the tooth and the yoke are separate laminations with tapered edges. The tapered edge of the tooth lamination matches that of the yoke lamination when the two laminations are assembled together. The layouts for a pair of alternate layers of lamination segments for the stator core are shown in Fig. 2(a) and Fig. 2(b). As successive layers are reversed, no two joints fall together. Such laminations are assembled in a way similar to that of a transformer core.

WHAT WE CLAIM IS:- 1. Separate tooth and yoke laminations for the stator cores of large electrical rotating machines, such that the tapered edge of the tooth lamination matches with that of the yoke lamination when the two laminations are assembled together.

2. A stator core for large electrical rotating machines comprising a plurality of laminations according to Claim 1 and comprising two reversed layouts of laminations arranged in alternate layers of the core so that no two joints fall together.

3. A stator core for large electrical rotating machines according to Claim 2 wherein grain-oriented steel is used as the lamination material and all the flux, except a small portion at the joints, will travel in the easy direction of magnetisation of the lamination material.

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **. (54) IMPROVEMENTS IN DESIGN OF CORE LAMINATIONS FOR LARGE ELECTRICAL ROTATING MACHINES (71) We, WAI SUN LEUNG of 140, Pokfulam Road, Flat 65, Hong Kong, British (Hong Kong) and WING FAT MA of 45, Sai Wan Ho Street, 2/F., Hong Kong, British (Hong Kong), do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to b'e particularly described in and by the following statement:- The present invention relates to a new design of core laminations suitable for use in stators of large electrical rotating machines. The laminations are so designed that the path of the magnetic flux is primarily along the length of the laminations. Cold-rolled or other types of grain-oriented steel laminations are used and most of the flux will travel in the easy direction of magnetisation, thus taking full advantage of the directional properties of the grain-oriented steel. Fur thermore the laminations have the teeth stamped out separately instead of as part of a lamination consisting of both the teeth and the yoke. As a result, the utilization of core material for the new design is considerably increased. A complete layer of the stator core in a large electrical rotating machine is normally made up of a number of lamination segments, the conventional type of which consists of both the teeth and the yoke having the commonly-used configuration as shown in Fig. 1. As the direction of the flux in the teeth is perpendicular to that in the yoke, there is no advantage in using grain-oriented steel for the lamination. The steel, which is stamped out to provide for the slots, constitutes wastage in the core material. In the new design for the stator core of a large electrical rotating machine, the tooth and the yoke are separate laminations with tapered edges. The tapered edge of the tooth lamination matches that of the yoke lamination when the two laminations are assembled together. The layouts for a pair of alternate layers of lamination segments for the stator core are shown in Fig. 2(a) and Fig. 2(b). As successive layers are reversed, no two joints fall together. Such laminations are assembled in a way similar to that of a transformer core. WHAT WE CLAIM IS:-

1. Separate tooth and yoke laminations for the stator cores of large electrical rotating machines, such that the tapered edge of the tooth lamination matches with that of the yoke lamination when the two laminations are assembled together.