A brushless motor comprising: a stator including three-phase windings (14u, 14v, 14w); a rotor including a permanent magnet, the rotor being configured to rotate in a state facing the stator; Hall sensors (15u, 15v, 15w) configured to detect a rotation positon of the rotor; an inverter including a plurality of switching elements, the inverter being configured to conduct an alternating current to the three-phase windings (14u, 14v, 14w) by turning on or off the plurality of switching elements; and a controller configured to control on or off states of the plurality of switching elements by switching an energization pattern, which represents changes in energization states of phases of the three-phase windings (14u, 14v, 14w) according to rotation of the rotor, to a freeless energization pattern or a rectangular wave energization pattern, wherein the controller is configured to switch the energization pattern to the freeless energization pattern when an accumulated load value is less than a first predetermined threshold value and switch the energization pattern to the rectangular wave energization pattern when the accumulated load value is equal to or greater than the first predetermined threshold value, wherein the accumulated load value is calculated by accumulating a load value related to a rotational speed of the rotor, wherein the rectangular wave energization pattern includes an energization pattern that is a combination of a first state that is a state in which at least one of the switching elements is continuously on, a second state that is a state in which at least another one of the switching elements is continuously off, and a third state that is a state in which at least still another one of the switching elements is PWM controlled, and the brushless motor characterized in that the freeless energization pattern includes an energization pattern that is a combination of a seventh state that is a state in which at least one of the switching elements is continuously on, an eighth state that is a state in which at least another one of the switching elements is PWM controlled by a PWM signal of an instruction duty ratio that is input from the outside, and a ninth state that is a state in which at least still another one of the switching elements is PWM controlled by a PWM signal of a duty ratio that is one half of the instruction duty ratio. a stator including three-phase windings (14u, 14v, 14w); a rotor including a permanent magnet, the rotor being configured to rotate in a state facing the stator; Hall sensors (15u, 15v, 15w) configured to detect a rotation positon of the rotor; an inverter including a plurality of switching elements, the inverter being configured to conduct an alternating current to the three-phase windings (14u, 14v, 14w) by turning on or off the plurality of switching elements; and a controller configured to control on or off states of the plurality of switching elements by switching an energization pattern, which represents changes in energization states of phases of the three-phase windings (14u, 14v, 14w) according to rotation of the rotor, to a freeless energization pattern or a rectangular wave energization pattern, wherein the controller is configured to switch the energization pattern to the freeless energization pattern when an accumulated load value is less than a first predetermined threshold value and switch the energization pattern to the rectangular wave energization pattern when the accumulated load value is equal to or greater than the first predetermined threshold value, wherein the accumulated load value is calculated by accumulating a load value related to a rotational speed of the rotor, wherein the rectangular wave energization pattern includes an energization pattern that is a combination of a first state that is a state in which at least one of the switching elements is continuously on, a second state that is a state in which at least another one of the switching elements is continuously off, and a third state that is a state in which at least still another one of the switching elements is PWM controlled, and the brushless motor characterized in that the freeless energization pattern includes an energization pattern that is a combination of a seventh state that is a state in which at least one of the switching elements is continuously on, an eighth state that is a state in which at least another one of the switching elements is PWM controlled by a PWM signal of an instruction duty ratio that is input from the outside, and a ninth state that is a state in which at least still another one of the switching elements is PWM controlled by a PWM signal of a duty ratio that is one half of the instruction duty ratio.