Title:
EXCAVATION DEVICE
Document Type and Number:
Japanese Patent JP2001241283
Kind Code:
A
Abstract:
To miniaturize an excavation device and reduce its weight, and to reduce drilling time and noise.
A direct motor 2 is composed of a cylindrical rotor 17 which a cylindrical rotary shaft 11 penetrates, and a cylindrical stator 18 that is provided at the outer periphery of the rotor 17. As a magnet composing the stator 18, a rare earth magnet where the maximum product of magnetic energy is 100 kJm-3 or more is used. Diameter D of the rotor 17 is set to less than length dimensions L, and, furthermore, is set to 150 mm or less.
Inventors:
MAZAKI SHIGERU
IMAOKA TOSHIO
SATO KUSUO
IMAOKA TOSHIO
SATO KUSUO
Application Number:
JP2000054809A
Publication Date:
September 04, 2001
Filing Date:
February 29, 2000
Export Citation:
Assignee:
MITSUBISHI MATERIALS CORP
NIPPON DAIYAMONDO KK
NIPPON DAIYAMONDO KK
International Classes:
E21B10/02; E21B3/02; H02K7/14; H02K23/04; (IPC1-7): E21B10/02; E21B3/02; H02K7/14; H02K23/04
Attorney, Agent or Firm:
Masatake Shiga (6 people outside)