摘要:
A power tool that includes a housing assembly, a motor received in the housing assembly, a trigger, an output spindle, a transmission and a bearing. The transmission is received in the housing assembly and transmits rotary power between the motor and the output spindle. The transmission has an output planetary stage with an output planet carrier. The transmission also has a member that is axially movable between a first position, which causes the transmission to operate in a first speed ratio, and a second position in which the transmission operates in a second speed ratio that is different than the first speed ratio. The bearing is disposed radially between and engages both the housing assembly and the output planet carrier. The output spindle is at least partially received into the output planet carrier such that the bearing indirectly supports the output spindle.
摘要:
A power tool includes a housing, a motor contained in the housing, an output shaft extending proximate a front of the housing, an end effector coupled to the output shaft and configured to hold an accessory; and a transmission disposed in the housing between the motor and the output shaft. The transmission includes a variable ratio gear set configured to transmit power from the motor to the output shaft at a substantially variable speed ratio. The transmission may further include a constant ratio gear set configured to transmit power from the motor at a substantially constant speed ratio. The transmission may be automatically or manually shiftable between a first mode where it transmits power through the constant speed ratio gear set and a second mode where it transmits power through the variable speed ratio gear set.
摘要:
A power tool includes a housing, a motor contained in the housing, an output shaft extending proximate a front of the housing, an end effector coupled to the output shaft and configured to hold an accessory; and a transmission disposed in the housing between the motor and the output shaft. The transmission includes a variable ratio gear set configured to transmit power from the motor to the output shaft at a substantially variable speed ratio. The transmission may further include a constant ratio gear set configured to transmit power from the motor at a substantially constant speed ratio. The transmission may be automatically or manually shiftable between a first mode where it transmits power through the constant speed ratio gear set and a second mode where it transmits power through the variable speed ratio gear set.
摘要:
A permanent magnet electric motor has a stator and a rotor. The stator has a stator housing with at least a North pole and a South pole, each pole including permanent magnets affixed to an inner surface of the stator housing, where at least two of the magnets within a pole have dissimilar characteristics, e.g., different widths or different grades of demagnetization resistance.
摘要:
An electric motor has a rotor and a stator. The rotor or the stator has arced permanent magnets that have essentially the same inner radius (IR) and outer radius (OR). In an aspect, the stator has a stator housing having a plurality of poles. Each pole includes a plurality of flat magnets affixed to an inner surface of the stator housing. In an aspect, flats on the outside of the stator housing key the stator assembly in a power tool housing. In an aspect, flat magnets are pre-magnetized, pre-assembled with alternating magnetic polarities, inserted into a stator housing, and remagnetized to a final, desired magnetic polarity configuration. In an aspect, pre-magnetized magnets and unmagnetized magnets are pre-assembled with unmagnetized magnets between magnetized magnets, the pre-assembled magnets inserted into a stator housing, and the unmagnetized magnets magnetized to a final, desired magnetic polarity configuration. In an aspect, pre-magnetized magnets are inserted between anchors inwardly extending from an inner surface of a stator housing with the anchors retaining each magnet placed in the stator housing between anchors from being angularly displaced by subsequently inserted magnets. In an aspect, pre-magnetized magnets are inserted in recesses in an inner surface of a stator housing with the recesses retaining each magnet placed in the stator housing between anchors from being angularly displaced by subsequently inserted magnets. In an aspect, each pole has at least three magnets, at least one of the magnets being thinner than the other magnets. In an aspect, the outer most magnets are made of magnetic material that is more resistant to demagnetization than at least one of the other magnets. In an aspect, the magnets of each pole are unevenly spaced over the pole In an aspect, a power tool includes such an electric motor.
摘要:
A power tool with a motor, a housing, a transmission, an output spindle, a front bearing and a rear bearing. The motor has an output shaft. The transmission is disposed in the housing and receives a rotary input from the output shaft. The transmission includes an input planetary stage, which has an input planet carrier, and an output planetary stage. The output spindle is driven by the transmission and has a first end, which extends at least partly through the input planetary stage, and a second end opposite the first end. The front bearing is disposed between the output spindle and the housing to support the second end of the output spindle for rotation about the spindle axis. The rear bearing indirectly supports the first end of the output spindle in the housing for rotation about the spindle axis.
摘要:
A power tool includes an output shaft configured to rotate about a longitudinal axis, a motor drivably connected to the output shaft to impart rotary motions thereto, and a rotational motion sensor spatially separated from the output shaft and operable to determine the user-imparted rotational motion of the power tool with respect to the longitudinal axis. A controller is electrically connected to the rotational motion sensor and the motor. The controller determines angular velocity of the power tool about the axis, rotational displacement of the power tool about the axis, and/or a direction of the rotational displacement using input from the rotational motion sensor. The controller then controls the motor according to the angular velocity, the rotational displacement, and/or the direction of the rotational displacement.
摘要:
A permanent magnet electric motor has a stator and a rotor. The stator has a stator housing with at least a North pole and a South pole. Each pole includes at least two permanent magnets arranged on an inner surface of the stator housing near the pole tips and an overmold of magnetic material molded around the permanent magnets and over the inner surface of the stator between the permanent magnets. Alternatively, an overmold of magnetic material may be provided over an inner surface of the stator, where the thickness of the overmold layer is greater near tips of each pole than in the middle portion of each pole.
摘要:
A power tool with a housing, a motor, a transmission, a spindle and an impact mechanism. The motor has an output shaft that drives the transmission. The transmission has a plurality of planet gears, a planet carrier journally supporting the planet gears for rotation about an axis, and a ring gear that is in meshing engagement with the planet gears. The impact mechanism has a plurality of anvil lugs, an impactor and an impactor spring. The anvil lugs are coupled to the ring gear and are not engaged by the planet gears. The impactor is mounted to pivot about the spindle and has a plurality of hammer lugs. The impactor spring biases the impactor toward the ring gear to cause the hammer lugs to engage the anvil lugs. A power tool having an impact mechanism with an external adjusting member that can be moved to vary a trip torque of the impact mechanism is also provided.
摘要:
A power tool with a motor, a housing, a transmission, an output spindle, a front bearing and a rear bearing. The motor has an output shaft. The transmission is disposed in the housing and receives a rotary input from the output shaft. The transmission includes an input planetary stage, which has an input planet carrier, and an output planetary stage. The output spindle is driven by the transmission and has a first end, which extends at least partly through the input planetary stage, and a second end opposite the first end. The front bearing is disposed between the output spindle and the housing to support the second end of the output spindle for rotation about the spindle axis. The rear bearing indirectly supports the first end of the output spindle in the housing for rotation about the spindle axis.