Outer rotor brushless motor and planetary gear assembly for power tool
AssigneeBlack & Decker Inc.
InventorsDustin Jefferies, Bhanuprasad V. Gorti, John B. Fogle, John D. Cox
Life of this patent
Estimating the term…
Abstract
A power tool is provided including a housing, a brushless direct-current (BLDC) motor, and a gear assembly. The motor includes a stator having an inner stator, a rotor shaft extending along a center axis and including a first bearing and a second bearing; an outer rotor, a first end cap, and a second end cap. The first end cap includes a radial back plate having a center opening in the radial back plate through which the rotor shaft extends and pins projecting around the rotor shaft and parallel to the rotor shaft. The gear assembly is mounted on the first end cap and includes planetary gears supported by the pins in engagement with the rotor shaft.
Claims16
A power tool comprising:
- a housing;
- a brushless direct-current (BLDC) motor comprising:
- a stator having a stator core, a plurality of teeth extending radially outwardly from the stator core, and a plurality of windings wound around the stator teeth;
- a rotor shaft extending along a center axis and including a first bearing and a second bearing;
- a rotor having a rotor core disposed around the stator, a plurality of permanent magnets secured to the rotor core, an inner annular member mounted on the rotor shaft;
- a first end cap secured to the housing configured to support the first bearing, the first end cap including a radial back plate having a center opening in the radial back plate through which the rotor shaft extends and a plurality of pins projecting around the rotor shaft and parallel to the rotor shaft;
- and
- a second end cap configured to support the second bearing;
- a gear assembly mounted on the first end cap and including a plurality of planetary gears supported by the plurality of pins in engagement with the rotor shaft;
- a ring gear that engages the plurality of planetary gears to transfer a rotational of the rotor shaft to the ring gear and cause the rotation of the ring gear at a reduced speed compared to a rotational speed of the rotor shaft;
- and
- an output member rotationally coupled with the ring gear.
A power tool comprising:
- a housing;
- a tubular cylinder housed within the housing defining a longitudinal axis;
- a piston reciprocatingly disposed within the tubular cylinder;
- a crank mechanism disposed within the housing configured to convert a rotary motion to a reciprocating motion for driving the piston;
- a handle having two ends mounted to the housing;
- a battery receptacle disposed adjacent a first end of the handle;
- a brushless direct-current (BLDC) motor mounted within or on the housing, the motor comprising:
- a stator having a stator core, a plurality of teeth extending radially outwardly from the stator core, and a plurality of windings wound around the stator teeth;
- a rotor shaft extending along a center axis and including a first bearing and a second bearing;
- a rotor having a rotor core disposed around the stator, a plurality of permanent magnets secured to the rotor core, an inner annular member mounted on the rotor shaft;
- a first end cap secured to the housing configured to support the first bearing, the first end cap including a radial back plate having a center opening in the radial back plate through which the rotor shaft extends;
- and
- a second end cap configured to support the second bearing;
- and
- a gear assembly disposed between the first end cap of the motor and the crank mechanism and engaging the rotor shaft to reduce an output speed of the motor,
- wherein the motor and the gear mechanism are mounted on the housing outside a cylindrical envelope defined by the tubular cylinder, and the motor is disposed adjacent a second end of the handle.
Dependencies are inferred from the claim text.