US 12,661,771 B1 · Power tool with electronic spindle positioning

Abstract

A method for operating a power tool includes electronically braking a motor shaft of a brushless electric motor using a controller of the power tool. A spindle unit, positioned on the motor shaft, has a known rotational position relative to at least one pole of a plurality of poles of a rotor of the motor shaft. The method further includes stopping the motor shaft, using the controller, in a predetermined rotational position relative to a stator of the electric motor based on a detected position state of a plurality of position states as detected by a plurality of position sensors of the electric motor. The plurality of position states identify a rotational position of the rotor relative to the stator, and at the predetermined rotational position, a spindle lock of the power tool is configured to engage the spindle unit without additional rotation of the motor shaft.

Claims18

Dependent claims

A method for operating a power tool, comprising:

electronically braking a motor shaft of a brushless electric motor of the power tool, using a controller of the power tool, wherein a spindle unit positioned on the motor shaft has a known rotational position relative to at least one pole of a plurality of poles of a rotor of the motor shaft;
stopping the motor shaft, using the controller, in a predetermined rotational position relative to a stator of the electric motor based on a detected position state of a plurality of position states as detected by a plurality of position sensors of the electric motor,
wherein the plurality of position states identify a rotational position of the rotor relative to the stator,
wherein at the predetermined rotational position a spindle lock of the power tool is configured to engage the spindle unit without additional rotation of the motor shaft, and
wherein when the spindle lock is engaged with the spindle unit, rotation of the motor shaft relative to the stator is prevented.

2 more elements

A power tool, comprising:

a brushless electric motor including (i) a stator, (ii) a motor shaft having a rotor mounted on the motor shaft, and (iii) a plurality of position sensors configured to output a plurality of position states corresponding to a rotational position of the rotor relative to the stator;
a spindle unit mounted on the motor shaft in a known rotational position relative to at least one pole of a plurality of poles of the rotor;
a spindle lock movable to (i) a first position at which the spindle lock engages the spindle unit to prevent rotation of the motor shaft relative to the stator, and (ii) a second position at which the spindle lock is disengaged from the spindle unit and the motor shaft is configured for rotation relative to the stator;
and
a controller configured to control rotation of the motor shaft, the controller configured to:
electronically brake the motor shaft to slow rotation of the motor shaft, and
stop the motor shaft in a predetermined rotational position relative to the stator based on a detected position state,
wherein at the predetermined rotational position the spindle lock is movable from the second position to the first position without additional rotation of the motor shaft.

5 more elements

Dependencies are inferred from the claim text.

Power tool with electronic spindle positioning

Life of this patent

Power tool with electronic spindle positioning

Life of this patent

Abstract

Claims18