US 12,328,045 B2
Electric work machine
Kei Kouda, Anjo (JP)
Assigned to MAKITA CORPORATION, Anjo (JP)
Filed by MAKITA CORPORATION, Anjo (JP)
Filed on Aug. 18, 2022, as Appl. No. 17/890,434.
Claims priority of application No. 2021-137332 (JP), filed on Aug. 25, 2021; and application No. 2021-147103 (JP), filed on Sep. 9, 2021.
Prior Publication US 2023/0066000 A1, Mar. 2, 2023
Int. Cl. H02K 21/12 (2006.01); H02K 1/27 (2022.01); H02K 1/278 (2022.01); H02K 3/34 (2006.01); H02K 7/14 (2006.01); H02K 11/215 (2016.01)
CPC H02K 21/12 (2013.01) [H02K 1/278 (2013.01); H02K 3/34 (2013.01); H02K 7/145 (2013.01); H02K 11/215 (2016.01)] 19 Claims
OG exemplary drawing
 
1. An electric work machine comprising:
a brushless motor comprising a rotor and a stator disposed around the rotor; and
an output part configured to be directly or indirectly driven by the rotor;
wherein:
the rotor comprises a rotor core and eight permanent magnets fixed to the rotor core;
the stator comprises a stator core, one or more insulators fixed to the stator core, and six coils respectively wound on six teeth of the stator core via the insulator(s);
the brushless motor has an induced voltage constant k that satisfies the condition below:
0.9≤k≤7.2,
the induced voltage constant k is calculated from the equation E/ω;
E is an induced voltage of the brushless motor in volts; and
ω is a rotational speed of the rotor of the brushless motor in kilorevolutions per minute (krpm).