US 12,113,424 B2
Drive motor with an insulating housing
Volker Barth, Aichwald (DE); and Florian Goos, Stutensee (DE)
Assigned to FESTOOL GMBH, Wendlingen (DE)
Appl. No. 17/607,197
Filed by Festool GmbH, Wendlingen (DE)
PCT Filed Apr. 30, 2020, PCT No. PCT/EP2020/062055
§ 371(c)(1), (2) Date Oct. 28, 2021,
PCT Pub. No. WO2020/221869, PCT Pub. Date Nov. 5, 2020.
Claims priority of application No. 102019111334.2 (DE), filed on May 2, 2019.
Prior Publication US 2022/0224192 A1, Jul. 14, 2022
Int. Cl. H02K 5/22 (2006.01); H02K 3/52 (2006.01); H02K 15/02 (2006.01)
CPC H02K 5/225 (2013.01) [H02K 3/522 (2013.01); H02K 15/028 (2013.01)] 25 Claims
OG exemplary drawing
 
1. A drive motor for a suction device or a machine tool in the form of a handheld machine tool or a semi-stationary machine tool, the drive motor having a stator with an excitation coil assembly and a rotor with a motor shaft, which is rotatably mounted by means of a bearing assembly, on the stator or with respect to the stator, around a rotational axis, and which passes through a shaft through-opening of a laminated core that is held on the motor shaft and is electrically insulated from the motor shaft, wherein an insulation sleeve is arranged between the motor shaft and the laminated core, said sleeve plugged into the shaft passage and having a socket with an insertion opening, through which the motor shaft is plugged into the plug socket along an insertion axis,
wherein at least one buttress projection protrudes from the laminated core into the shaft through-opening and which penetrates and/or engages in the insulation sleeve, and
wherein the socket has a first inner cross section which is associated with a longitudinal end region of the laminated core facing the insertion opening, and has a second inner cross section, which is associated with a longitudinal end region of the laminated core facing away from the insertion opening, and in a state of the motor shaft in which the shaft is fully plugged in the socket, a portion of the motor shaft with a first outer cross section presses against the socket in the region of the first inner cross section and a portion of the motor shaft with a second outer cross section presses against the socket in the region of the second inner cross section, the first inner cross section of the socket being larger than the second inner cross section and/or the first outer cross section of the motor shaft being smaller than the second outer cross section, and
wherein the second inner cross section of the socket is enlarged or widened by the second outer cross section of the motor shaft inserted into it.