Brushless DC motor power tool with combined PCB design

摘要

A power tool with a combined printed circuit board (PCB) that reduces internal wiring of the power tool and provides a large amount of air flow to internal components. In some instances, the combined PCB has a surfboard shape and includes a motor control unit and power switching elements (Field Effect Transistors or FETs). The combined surfboard PCB is located above the trigger, but below the motor and drive mechanism. In other instances, the combined PCB has a doughnut shape and is located coaxially with a motor shaft. The combined PCB may be positioned between a doughnut-shaped control PCB and the motor.

主权项

1. A power tool comprising:
a housing; a brushless direct current (DC) motor within the housing and having a rotor and a stator, wherein the rotor is coupled to a motor shaft to produce a rotational output; a heat sink secured to an end of the brushless DC motor; a combined printed circuit board (PCB) having a Hall sensor, power switching elements, and a through-hole, wherein the combined PCB is
coupled to the heat sink, andwherein the motor shaft extends through the through-hole; and a control PCB having a motor control unit that receives motor positional information from the Hall sensor and controls the power switching elements to drive the brushless DC motor, wherein the control PCB is secured to the heat sink and has a second through-hole through which the motor shaft extends.