# US 2026/0066751 A1 · Method for manufacturing rotor for hollow shaft motor

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- Number: US 2026/0066751 A1
- Document ID: US20260066751A1
- Status: Published application
- Kind: A1
- Application number: 19/299,333
- Filed: 2025-08-14
- Published: 2026-03-05
- Earliest claimed: 2024-08-27
- Assignees: Kwangho Choi
- Inventors: KWANGHO CHOI; BEOMLAE KIM
- Web page: https://patentgrep.com/patent/US20260066751A1

## CPC

- H02K 15/035: on the rotor
- H02K 1/28: Means for mounting or fastening rotating magnetic parts on to, or to, the rotor structures
- H02K 1/30: using intermediate parts, e.g. spiders
- H02K 15/027: Punching the cores
- H02K 15/0273: Laminating the cores
- H02K 15/03: having permanent magnets
- H02K 15/12: Impregnating, moulding insulation, heating or drying of windings, stators, rotors or machines
- H02K 2201/09: Magnetic cores comprising laminations characterised by being fastened by caulking
- H02K: DYNAMO-ELECTRIC MACHINES (dynamo-electric relays H01H53/00; conversion of DC or AC input power into surge output power {H03K3/53})

## Abstract

A method for manufacturing a rotor of a hollow shaft motor according to the present invention includes: a step of manufacturing a rotor core; and a step of placing the rotor core in a die-casting mold to mold a hollow shaft housing, wherein the step of manufacturing the rotor core includes: a plurality of piercing processes for molding a shape of a laminar member in an electrical steel plate; a blanking process for separating the laminar member from the electrical steel plate; a stacking process for stacking a plurality of laminar members to manufacture a rotor core; an ejecting process for ejecting the stacked rotor core to the outside; and a magnet inserting process for inserting a magnet into the rotor core.

## Claims

### Claim 1

A method for manufacturing a rotor for a hollow shaft motor, comprising:
a step of manufacturing a rotor core; and
a step of placing the rotor core in a die-casting mold to mold a hollow shaft housing.

### Claim 2 (depends on 1)

The method of claim 1, wherein the step of manufacturing the rotor core comprises:
a plurality of piercing processes for molding a shape of a laminar member in an electrical steel plate;
a blanking process for separating the laminar member from the electrical steel plate;
a stacking process for stacking a plurality of laminar members to manufacture a rotor core;
an ejecting process for ejecting the stacked rotor core to the outside; and
a magnet inserting process for inserting a magnet into the rotor core.

### Claim 3 (depends on 2)

The method of claim 2, further comprising:
a cover molding process for molding a lower cover member and an upper cover member after the magnet inserting process.

### Claim 4 (depends on 3)

The method of claim 3, wherein the electrical steel plate is an SB electrical steel plate.

### Claim 5 (depends on 1)

The method of claim 1, wherein the adhesive coating layer formed on the SB electrical steel plate is thermally hardened in the step of molding the hollow shaft housing in the die-casting mold.

### Claim 6 (depends on 1)

The method of claim 1, wherein the hollow shaft housing comprises:
an upper core cover part formed on an upper surface of the rotor core;
an upper support part formed in a cylindrical shape on an upper part of the upper core cover part; and
an upper bearing support part formed on an upper part of the upper support part.

### Claim 7 (depends on 6)

The method of claim 6, wherein a plurality of upper fixing points are formed at regular intervals on the upper core cover part to expose both ends of the magnet inserted into the rotor core.

### Claim 8 (depends on 1)

The method of claim 1, wherein the hollow shaft housing comprises:
a lower core cover part formed on a lower part surface of the rotor core;
a lower support part formed on a lower part of the lower core cover part and having a shape with a diameter decreasing towards the lower part;
a lower bearing support part 126 formed in a cylindrical shape on a lower part of the lower support part; and
a ball screw coupling part formed on a lower end of the lower bearing support part.

### Claim 9 (depends on 8)

The method of claim 8, wherein a plurality of lower fixing points are formed at regular intervals on the lower core cover part to expose both ends of the magnet of the rotor core.

### Claim 10 (depends on 8)

The method of claim 8, wherein a plurality of core fixing holes are formed at regular intervals on the lower core cover part.

### Claim 11 (depends on 1)

The method of claim 1, wherein a magnet support part and a magnet end support part 128A are formed around the magnet of the rotor core, and
a core inner support part is formed on an inner circumferential surface of the rotor core.

### Claim 12 (depends on 11)

The method of claim 11, wherein an inner surface groove is formed on an inner circumferential surface of the rotor core.