Brushless motor system for power tools

A power tool including a brushless DC (BLDC) motor and a circuit board disposed within a tool housing, the motor comprising:

• a motor housing including a cylindrical body and a rear end that forms a bearing pocket centered on a longitudinal axis of the motor housing and a plurality of openings around the bearing pocket;
• a rotor including a rotor core mounted on a rotor shaft, the rotor core being at least radially supported relative to the motor housing via at least a rear bearing located within the bearing pocket;
• a stator including a stator core, a plurality of stator teeth projecting radially from the stator core, and a plurality of stator windings wound respectively around the plurality of stator teeth;
• and
• a plurality of motor terminals mounted on an axial end of the stator, wherein each of the motor terminals includes a wire receiving member electrically coupled to a respective one of the stator windings, and a tab portion extending from the stator substantially parallel to the longitudinal axis, wherein the tab portions of the plurality of motor terminals extend out of the rear end of the motor housing through the plurality of openings,
• wherein the circuit board is disposed adjacent the motor housing along a plane substantially parallel to the rear end of the motor housing, the circuit board including a plurality of power switches mounted thereon for energizing the stator windings, and wherein a plurality of slots is formed in the circuit board in alignment with and securely receiving the tab portions of the plurality of motor terminals to electrically connect the plurality of motor terminals to the plurality of power switches.

A power tool comprising:

• a tool housing;
• a brushless DC (BLDC) motor disposed within the tool housing, the motor including a stator assembly and a rotor assembly rotatably disposed within the stator assembly, the stator assembly including:
• a generally-cylindrical lamination stack having a stator ring and a plurality of stator teeth extending radially inwardly from the stator ring towards a center bore of the stator assembly, wherein the center bore is arranged to receive the rotor assembly therein;
• an end insulator disposed at an and of the lamination stack, the end insulator having a generally-cylindrical outer ring and a plurality of teeth portions extending radially inwardly from the outer ring towards a center of the end insulator, the outer ring and the plurality of teeth portions corresponding to the stator ring and the plurality of stator teeth respectively;
• a plurality of stator windings wound around the plurality of stator teeth and the corresponding plurality of teeth portion of the end insulator;
• and a plurality of power input terminals extending axially from approximately a periphery of the end insulator;
• and
• a power module for driving the motor disposed proximate the end insulator and disposed in parallel to the end insulator, the power module including a printed circuit board and a plurality of power switches operatively connected to the plurality of stator windings disposed on the printed circuit board, wherein the printed circuit board includes a plurality of peripheral slots to receive distal ends of the power input terminals therein to connect the power switches operatively to the plurality of stator windings.