Title:
POWER TOOL
Document Type and Number:
Japanese Patent JP2021053736
Kind Code:
A
Abstract:
To provide a direct drive type power tool using a brushless motor.SOLUTION: A direct drive type power tool includes a tip tool mounted on a rotary shaft. The power tool uses a rotor using permanent magnets 13, a stator around which a coil is wound, and a brushless motor having a rotary shaft 15 for holding the rotor. As the permanent magnets 13, cylindrical pole anisotropic magnets (131 to 133) are arranged side by side in a rotation axis direction. The pole anisotropic magnets 13 are magnetized to a magnetic field which has the magnetic direction directing to the radial direction inside from an outer peripheral surface to an inner peripheral surface, and further the magnetic field is one which has a magnetic field direction U-turning and returning to the outer peripheral surface again before reaching the inner peripheral surface. 2n poles (8 poles in this case) are provided in a circumferential direction on outer peripheries of the pole anisotropic magnets 13 and are fixed to the rotary shaft 15 so that magnetization reference positions 131a to 133a of a plurality of magnetic fields coincide with each other.SELECTED DRAWING: Figure 16
Inventors:
TANIMOTO HIDEYUKI
Application Number:
JP2019178725A
Publication Date:
April 08, 2021
Filing Date:
September 30, 2019
Export Citation:
Assignee:
KOKI HOLDINGS CO LTD
International Classes:
B25F5/00; B24B23/02; H02K1/27; H02K21/16
Domestic Patent References:
| JPS60183547U | 1985-12-05 |
Foreign References:
| US20110081846A1 | 2011-04-07 | |||
| WO2019106934A1 | 2019-06-06 |
Attorney, Agent or Firm:
Aoritsu patent business corporation