Power tool
A power tool is provided comprising: a motor, an output shaft driven by the motor along a longitudinal axis, a fan rotationally coupled to the motor to generate an airflow, and a housing comprising two calm shells mated together to support the motor and forming a back wall behind the motor along the longitudinal axis. The rear wall includes a plurality of air intakes. An end cap is attached to the housing adjacent the rear wall with an air gap therebetween. The airflow generated by the fan enters through the air gap in a substantially radial direction, then passes through the plurality of air intakes to enter the housing in thermal contact with the motor.
1. A power tool comprising:
a motor;
an output shaft driven by the motor along a longitudinal axis;
a fan rotationally coupled to the motor to generate an airflow;
a housing comprising two housing halves mated together to support the motor and forming a rear wall behind the motor along the longitudinal axis, wherein the rear wall includes a plurality of air intakes;
an end cap attached to the housing adjacent the rear wall with an air gap therebetween, wherein at least a portion of the end cap does not overlap an outer circumferential surface of the housing so as to form a circumferential opening around the air gap, wherein the airflow generated by the fan suctions ambient air from an outside environment directly through the circumferential opening into the air gap in a substantially transverse direction relative to the longitudinal axis, and the airflow then passes through the plurality of air intakes to enter the housing in thermal contact with the motor.
2. The power tool of claim 1 , wherein the end cap is oriented substantially along a plane that is perpendicular to the longitudinal axis.
3. The power tool of claim 1 , wherein the fan is disposed between the motor and the rear wall of the housing.
4. The power tool of claim 1 , wherein the plurality of air intakes is oriented radially around the longitudinal axis.
5. The power tool of claim 4 , wherein the fan is located adjacent the rear wall of the housing and includes a plurality of fan blades facing the rear wall, wherein a distance between the plurality of air intakes and the longitudinal axis is less than a distance between than the plurality of fan blades and the longitudinal axis, to allow the fan to repel the airflow entering through the plurality of air intakes radially outwardly.
6. The power tool of claim 1 , wherein the end cap comprises two side caps extending axially to overlap opposite side portions of the housing.
7. The power tool of claim 1 , wherein the motor comprises:
a stator including a stator core and a plurality of stator windings connected in phases;
a rotor rotatably disposed within the stator to magnetically interact with the plurality of stator windings; and
at least one heat sink in contact with the stator core and supported by the housing.
8. The power tool of claim 7 , wherein the heat sink comprises a plurality of fins forming a plurality of air channels therebetween extending longitudinally along an outer surface thereof, wherein the plurality of air channels is in fluid communication with the airflow.
9. The power tool of claim 8 , wherein the end cap comprises two side caps extending axially to overlap opposite side portions of the heat sink to direct the airflow into the plurality of air channels.
10. The power tool of claim 1 , wherein the end cap does not include any air intakes in its rear surface to allow entry of airflow.
11. A power tool comprising:
a tool housing including a motor housing defining a longitudinal axis and having a rear wall formed at a rear end thereof, a handle portion extending from the motor housing in a direction traversal to the longitudinal axis, and a battery receptacle formed at an end of the handle portion opposite the motor housing;
a motor disposed within the motor housing;
an output assembly mounted forward of the motor housing and driven by the motor along the longitudinal axis;
a fan rotationally coupled to the motor to generate an airflow;
an end cap attached to the motor housing adjacent the rear wall with an air gap therebetween, wherein at least a portion of the end cap includes a diameter that is at most substantially equal to a diameter of the tool housing so as to form a circumferential opening around the air gap, wherein the airflow generated by the fan enters through the circumferential opening into the air gap in a substantially radial direction, then passes through the plurality of air intakes to enter the housing in thermal contact with the motor.
12. The power tool of claim 11 , wherein the end cap is oriented substantially along a plane that is perpendicular to the longitudinal axis.
13. The power tool of claim 11 , wherein the fan is disposed between the motor and the rear wall of the housing.
14. The power tool of claim 11 , wherein the plurality of air intakes is oriented radially around the longitudinal axis.
15. The power tool of claim 14 , wherein the fan is located adjacent the rear wall of the housing and includes a plurality of fan blades facing the rear wall, wherein a distance between the plurality of air intakes and the longitudinal axis is less than a distance between than the plurality of fan blades and the longitudinal axis, to allow the fan to repel the airflow entering through the plurality of air intakes radially outwardly.
16. The power tool of claim 11 , wherein the end cap comprises two side caps extending axially to overlap opposite side portions of the housing.
17. The power tool of claim 11 , wherein the motor comprises:
a stator including a stator core and a plurality of stator windings connected in phases;
a rotor rotatably disposed within the stator to magnetically interact with the plurality of stator windings; and
at least one heat sink in contact with the stator core and supported by the housing.
18. The power tool of claim 17 , wherein the heat sink comprises a plurality of fins forming a plurality of air channels therebetween extending longitudinally along an outer surface thereof, wherein the plurality of air channels is in fluid communication with the airflow.
19. The power tool of claim 18 , wherein the end cap comprises two side caps extending axially to overlap opposite side portions of the heat sink to direct the airflow into the plurality of air channels.
20. The power tool of claim 11 , wherein the end cap does not include any air intakes in its rear surface to allow entry of airflow.