Abstract: In a centrifuge having a rotor with a rotor body that holds a sample and that is rapidly rotated, an inclined surface that extends upward as it extends radially outward is formed on an upper-side outer peripheral portion of the rotor, in a region that is at a radially outward side and at an upper side of the outer edge of an opening. The inclined surface is a continuous ring-like inclined surface that has the same cross-sectional shape in the circumferential direction and is formed into a straight-line shape or a curved-line shape in cross-section along a rotation central axis. Although winds occur during high-speed rotation of the rotor, the winds are rectified by the inclined surface, and a component force for pressing the rotor body in a downward direction acts thereon.
Abstract: An electrically powered tool (1) includes a motor (10), a battery pack (5) supplying electric power to the motor (10), a battery voltage detection circuit (17) detecting battery voltage, a current detection circuit (15) detecting current flowing through the motor (10), and a microcomputer (20) controlling driving of the motor (10). The microcomputer (20) discriminates a load state of the motor (10) according to whether or not the current flowing through the motor (10) is equal to or greater than a threshold value, and the microcomputer (20) can change the threshold value in accordance with the battery voltage. When the current flowing through the motor (10) remains below the threshold value for a predetermined period of time, the microcomputer (20) stops the supply of electric power to the motor (10).
Abstract: An electric power tool includes a brushless motor, a control unit configured to control power supply to the brushless motor, a rotary tool configured to be rotated by the brushless motor, a rotation speed detecting unit configured to detect a rotation speed of the brushless motor, a main switch configured to transmit, to the control unit, an ON/OFF signal for switching between driving and stopping of the brushless motor, and a mode switching unit configured to transmit, to the control unit, a mode switching signal for switching between multiple modes of rotation control of the brushless motor, the control unit is configured to perform the rotation control of the brushless motor in any one of the multiple modes including at least a high-speed mode and a low-speed mode.
Abstract: A power planer includes a casing, a motor having rotation shaft, a power supply portion for supplying electric power to the motor, a control portion, a cutter block, and a fan. The casing has intake and discharge openings and provides an air passage from the intake opening to the discharge opening. The control portion is connected to the electric motor and to the power supply portion. The cutter block has an axis parallel to the rotation shaft, and is supported to the casing and rotatable about the axis. A blade is provided in the cutter block. The fan is provided in the casing and configured to generate air stream within the casing and flowing along the air passage in a flowing direction. The air passage includes a control portion cooling passage for cooling the latter. The fan is positioned downstream of the control portion in the flowing direction.
Abstract: A centrifuge including a lid section of a sample container, the lid section having a rotating shaft for swinging, and a swing-type rotor, and the centrifuge conducts centrifugation operation in a state where the sample container is seated in a bucket housing section by making the sample container in which the rotating shaft is mounted to a rotating shaft engagement groove of the rotor swing due to the rotation of the rotor. The rotating shaft comprises a plurality of members connected by a connection section and is configured so as to be bendable at the connection section by a centrifugal load accompanying the rotation of the rotor.
Abstract: A portable work tool includes: a housing; a motor; and a restraining surface. The housing has an outer surface including a covered region that is covered with a soft layer and an uncovered region that is exposed to an outside. The covered region and the uncovered region define a boundary therebetween. The motor is accommodated in the housing. The restraining surface is disposed in proximity to the boundary and protrudes from the covered region.
Abstract: In order to provide a battery pack that allows information inside the battery pack to be output via communication with an external device without being provided with a dedicated terminal, the battery pack 20 according to the present invention has: a temperature detection element 33 that monitors the temperature of battery 21; a battery type identification element 34 that identifies the type of battery; a first terminal d for transferring information of the temperature detection element to an external device 1; and a second terminal e for transferring information of the battery type identification element to the external device 1. The battery pack 20 is characterized in having blocking means 35 and 36 for blocking the transfer of the information from the temperature detection element and the battery type identification element to another external device 60.
Abstract: An electric power tool includes: a brushless motor having a plurality of stator windings and configured to rotate in accordance with voltages applied to the plurality of stator windings, an induced voltage being generated in accordance with a rotation of the brushless motor; a rectifier circuit configured to rectify an AC voltage; a smoothing capacitor configured to smooth the AC voltage rectified by the rectifier circuit to a pulsation voltage having a maximum value larger than the induced voltage and a minimum value smaller than the induced voltage; and an inverter circuit configured to perform switching operations to output the pulsation voltage to the plurality of stator windings by rotation.
Abstract: “A self-propelled grass mower and a self-propelled wheeled apparatus that can perform precise guidance control by reliably detecting a guidance signal with a guidewire are provided. The self-propelled grass mower includes wheel motors for driving wheels, a cutting blade motor for driving a cutting blade, a rechargeable battery for supplying electrical power to these motors, and a guidewire sensor for detecting a magnetic field generated by a guidewire formed into a loop. In the self-propelled grass mower that detects whether is inside or outside of a region enclosed by the guidewire and runs autonomously in a grass cutting region, only the supply voltage for the cutting blade motor is reduced when a magnetic field is detected by the guidewire sensor. Driving of the cutting blade motor is restarted after detection of the magnetic field has completed. Thereby, the impact of noise due to the cutting blade motor is eliminated.
Abstract: An electric tool includes a brushless motor having a plurality of phases, the brushless motor. The brushless motor includes a plurality of stator coils connected in parallel with each of the plurality of phases, and a plurality of crossover wires, each of the crossover wires being configured to electrically connect the plurality of stator coils for each of the plurality of phases to each other. The plurality of crossover wires for the plurality of phases are electrically connected to each other.