Brushless motor for a power tool

Abstract

An electric brushless DC (BLDC) motor includes a motor housing having a substantially cylindrical body including an open end and a peripheral slot formed through a circumferential surface of the cylindrical body extending from the open end; a stator having stator windings; and a rotor including a rotor shaft and rotor magnets. A series of motor terminals are provided substantially adjacent one another and extending substantially parallel to an axial direction of the rotor shaft along on an outer circumferential surface of the stator. The motor terminals are at least partially received within the peripheral slot of the motor housing so as to be accessible outside the motor housing.

1 . A power tool having a housing and an electric brushless DC (BLDC) motor housed inside the housing, the motor comprising:
 a motor housing having a substantially cylindrical body including an open end on one end and a back plate on another end, the cylindrical body of the motor housing defining a peripheral slot formed through a circumferential surface of the cylindrical body extending from the open end;   a stator having a plurality of stator windings;   a rotor in rotatable interaction with the stator, the rotor comprising a rotor shaft and a plurality of rotor magnets, wherein a bearing mounted on the rotor shaft is supported by a bearing pocket formed in the back plate of the motor housing; and   a plurality of motor terminals provided substantially adjacent one another and extending substantially parallel to an axial direction of the rotor shaft along on an outer circumferential surface of the stator, the plurality of motor terminals being at least partially received within the peripheral slot of the motor housing so as to be accessible outside the motor housing.   
     
     
         2 . The power tool of  claim 1 , further comprising a fan mounted on the rotor shaft to rotate therewith and generate an airflow through the motor, wherein the motor housing comprises a plurality of air vents formed in the back plate to allow passage of the airflow generated by the fan. 
     
     
         3 . The power tool of  claim 2 , wherein the fan is disposed outside the motor housing adjacent the back plate. 
     
     
         4 . The power tool of  claim 1 , wherein the plurality of motor terminals is oriented radially outward relative to the outer circumferential surface of the stator. 
     
     
         5 . The power tool of  claim 1 , further comprising:
 a sense magnet mounted on the rotor shaft; and   a positional sensor board having a plurality of positional sensors in magnetic interaction with the sense magnet and a terminal block mounted thereon.   
     
     
         6 . The power tool of  claim 5 , wherein the motor housing further comprises a peripheral slot arranged to receive the terminal block of the positional sense magnet board therein. 
     
     
         7 . The power tool of  claim 6 , wherein the plurality of positional sensors comprises a plurality of Hall sensors mounted on a first surface of the positional sensor board facing the sense magnet, a second surface of the positional sensor board being in contact with the end cap. 
     
     
         8 . The power tool of  claim 1 , further comprising an end cap mounted on the open end of the motor housing and configured to support a second bearing mounted on the rotor shaft. 
     
     
         9 . The power tool of  claim 8 , wherein the end cap includes a peripheral slot that cooperatively with the peripheral slot of the motor housing receives the plurality of terminals therein. 
     
     
         10 . The power tool of  claim 1 , wherein at least one wire coupled to the plurality of stator windings passes through the peripheral opening of the motor housing and is coupled to the plurality of stator terminals. 
     
     
         11 . An electric brushless DC (BLDC) motor comprising:
 a motor housing having a substantially cylindrical body including an open end on one end and a back plate on another end, the cylindrical body of the motor housing defining a peripheral slot formed through a circumferential surface of the cylindrical body extending from the open end;   a stator having a plurality of stator windings;   a rotor in rotatable interaction with the stator, the rotor comprising a rotor shaft and a plurality of rotor magnets, wherein a bearing mounted on the rotor shaft is supported by a bearing pocket formed in the back plate of the motor housing; and   a plurality of motor terminals provided substantially adjacent one another and extending substantially parallel to an axial direction of the rotor shaft along on an outer circumferential surface of the stator, the plurality of motor terminals being at least partially received within the peripheral slot of the motor housing so as to be accessible outside the motor housing.   
     
     
         12 . The BLDC motor of  claim 11 , further comprising a fan mounted on the rotor shaft to rotate therewith and generate an airflow through the motor, wherein the motor housing comprises a plurality of air vents formed in the back plate to allow passage of the airflow generated by the fan. 
     
     
         13 . The BLDC motor of  claim 12 , wherein the fan is disposed outside the motor housing adjacent the back plate. 
     
     
         14 . The BLDC motor of  claim 11 , wherein the plurality of motor terminals is oriented radially outward relative to the outer circumferential surface of the stator. 
     
     
         15 . The BLDC motor of  claim 11 , further comprising:
 a sense magnet mounted on the rotor shaft; and   a positional sensor board having a plurality of positional sensors in magnetic interaction with the sense magnet and a terminal block mounted thereon.   
     
     
         16 . The BLDC motor of  claim 15 , wherein the motor housing further comprises a peripheral slot arranged to receive the terminal block of the positional sense magnet board therein. 
     
     
         17 . The BLDC motor of  claim 16 , wherein the plurality of positional sensors comprises a plurality of Hall sensors mounted on a first surface of the positional sensor board facing the sense magnet, a second surface of the positional sensor board being in contact with the end cap. 
     
     
         18 . The BLDC motor of  claim 11 , further comprising an end cap mounted on the open end of the motor housing and configured to support a second bearing mounted on the rotor shaft. 
     
     
         19 . The BLDC motor of  claim 18 , wherein the end cap includes a peripheral slot that cooperatively with the peripheral slot of the motor housing receives the plurality of terminals therein. 
     
     
         20 . The BLDC motor of  claim 11 , wherein at least one wire coupled to the plurality of stator windings passes through the peripheral opening of the motor housing and is coupled to the plurality of stator terminals.