A forward and reverse switching device and a single-phase series motor

Abstract

The invention discloses a forward and reverse switching device, wherein the carbon brush module can rotate clockwise and counterclockwise with respect to the chassis; The middle part of the reversingrod is rotatably connected to the chassis, the first end of the reversing rod is rotated by the carbon brush module, The second end of the commutation pull-out lever is in contact with and matched with the positive and negative swing lever of the positive and negative swing switching assembly, and the second end of the commutation pull-out lever can drive the positive and negative swing lever to swing, so that the positive and negative swing lever swings downward and backward, and the conductive loop of the motor lead connecting the plug in the positive and negative swing switching assembly ischanged, and the direction of the current is changed to realize commutation. Between that carbon brush module and the forward and reverse assembly, A forward and reverse assembly need not be providedat the air inlet, The invention effectively solves the contact ignition failure caused by the exposure of the contact point changing the current direction, the insufficient rigidity of the contact piece at the contact end, the plastic melting of the positioning base, the poor contact after the dust piles up for a long time, and improves the commutation stability in the bad working environment ofthe electric tool with high dust and strong vibration.

Description

technical field [0001] The invention relates to the technical field of electric tools, and further relates to a forward and reverse switching device. In addition, the invention also relates to a single-phase series motor. Background technique [0002] Motors can be divided into DC motors and AC motors due to different input currents. Motors driven by DC currents are called DC motors. DC motors can be divided into series-excited motors and split-excited motors due to the different connection methods between the magnetic field circuit and the armature circuit. Electric motors, re-excited motors; motors that use alternating current to rotate are called alternating current motors. [0003] The excitation winding of the DC series motor is connected in series with the rotor winding through the brush and the commutator, the excitation current is proportional to the armature current, the magnetic flux of the stator increases with the increase of the excitation current, and the torq...

AI Technical Summary

Problems solved by technology

[0005] The current forward and reverse switching assembly is directly driven by the brush holder. The operator manually twists the brush holder. When the brush holder rotates, it drives the swing of the forward and reverse switching assembly itself, so the forward and reverse switching assembly itself pulls out. The rod must adopt an L-shaped structure, and the forward and reverse switching components can only be installed side by side with the brush holder, so it must be installed at the air inlet of the motor. point; and because the brush holder and the forward and reverse switching assembly itself have a certain thickness, the L-shaped pull rod of the forward and reverse switching assembly itself needs to be set to a relatively large length in order to be in contact with the brush holder, and the brush holder drives The L-shaped lever swings, and the L-shaped lever itself is a plastic part, which will produce a certain degree of bending deformation, and cannot be accurately and quickly positioned when switching between forward and reverse

[0006] For those skilled in the art, how to avoid the impact of air intake impurities on the forward and reverse switch components is a technical problem that needs to be solved at present

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