CN203457021U

CN203457021U - A brushless DC motor

Info

Publication number: CN203457021U
Application number: CN201320590264.8U
Authority: CN
Inventors: 余勋杰
Original assignee: Individual
Current assignee: Individual
Priority date: 2013-09-24
Filing date: 2013-09-24
Publication date: 2014-02-26
Anticipated expiration: 2023-09-24

Abstract

The utility model relates to a brushless DC motor comprising a motor housing, a rotor, and a stator. A magnet ring coaxial with the rotor is disposed on the outer side of the motor housing. The pole number of the magnet ring corresponds to that of the rotor. A plurality of position sensors are disposed on a side of the magnet ring and correspond to the position of half of the magnet ring. Each position sensor corresponds to a pole of the magnet ring. The output end of each position sensor is connected with a primary amplifying circuit. The output end of the primary amplifying circuit is connected with a secondary amplifying circuit. The output end of the secondary amplifying circuit is connected with a three-phase inverter bridge circuit which drives the magnetic field transformation of the motor stator. The primary amplifying circuit and the secondary amplifying circuit are also connected with a voltage regulator and a current regulator. The brushless DC motor is suitable for electric tools such as electric drill guns, electric polishing machines, electric angular polishing machines, and electric portable cutting machines, and has advantages of steady operation, large output torque, low noise, and low power consumption. The brushless DC motor is the future development direction of electric manual tools.

Description

A kind of brshless DC motor

Technical field

The utility model relates to a kind of brushless dc machine technology, specifically a kind of brshless DC motor.

Background technology

The controlling organization of existing direct current machine is adopted two closed loop controlling structures as shown in Figure 3, and the speed that can realize in certain limit regulates, and during work, it needs speed feedback and current feedback information, so conventionally speed probe and current sensor need to be set, the operation principle of this system: first Un* of speed preset and speed feedback Un compare, obtain speed difference, through speed adjusting device, regulate, after output compares as the set-point Ui* of electric current loop and current feedback value Ui, electric current difference is carried out necessary amplification and correction through current regulator again, signal after adjusting is transformed into the corresponding pulse duration through PWM at pwm circuit, then comprehensive rotor-position signal produces each required phase pwm control signal, this pwm control signal is delivered to drive circuit, drive three-phase inversion bridge circuit, make corresponding device for power switching work, by suitable PWM duty ratio, remove drive motor winding, in addition this structure utilizes rotor signal feedback that current sensor signal is sampled, and forms a resultant current signal Ui who represents motor torque, and makes the phase place of phase back electromotive force and phase current remain consistent, this pair of closed loop controlling structure is due to needs PWM product high-frequency pulse signal, and coordinate Comprehensive Signal Processing, high-frequency pulse signal easily produces interference signal, the chip of Comprehensive Signal Processing needs initialize program, once in use occur that program confusion and deadlock user cannot repair at once, can only by special instrument, come initialization to recover, the controlling organization of current this motor is because volume is larger in addition, cannot be applied on electric manual tool, in these fields, adopt at present maximum still have brushless motor or series excited machines, this motor exist power consumption and noise high, useful life is short, the problems such as reliability is low, for this reason at electric manual tool field (as: power-driven pistol drill, electric polishing machine, electric hand angular grinder, driven portable cutting machines etc.) more Structure of need is simple, be difficult for breaking down, the motor of good reliability.

Utility model content

A kind of brshless DC motor, a magnet ring is set on motor shaft, the position transducer of corresponding magnet ring half-turn position is set in a side of magnet ring, conventionally the feedback signal of position transducer is carried out to secondary amplification, signal driver three-phase inversion bridge circuit after secondary amplifies, make corresponding device for power switching work, export corresponding emf phase and phase current and carry out the work of drive motor winding, the utility model adopts the control mode that directly feedback is amplified, intermediate link that need not be unnecessary, control circuit is simple in structure, controlling organization small volume, can be assembled on electronic hand-operated tools by brshless DC motor, coordinate voltage regulator and current regulator to come governing speed and overcurrent protection, guarantee reliably operation stably of motor.

For achieving the above object by the following technical solutions:

A kind of brshless DC motor, comprise electric machine casing, rotor and stator, it is characterized in that: in the outer setting of electric machine casing, have the magnet ring with rotor coaxial, magnet ring number of poles is corresponding with the number of poles of rotor, in described magnet ring one side, be also provided with several position transducers of corresponding half-turn magnet ring position, utmost point of the corresponding magnet ring of each position transducer, the output of position transducer connects an amplifying circuit, an amplification circuit output end connecting secondary amplifying circuit, secondary amplification circuit output end connects three-phase inversion bridge circuit, the conversion of three phase inverter bridge drives motor stator magnetic field, No. one time amplifying circuit is also connected with current regulator with voltage regulator with secondary amplifying circuit.

The position signalling of the utility model during by machine operation feeds back to the amplifying circuit of secondary in time, the amplifying circuit of secondary directly drives three-phase inversion bridge circuit after feedback signal is amplified to conversion, and carry out drive motors by three-phase inversion bridge circuit, keep motor smooth working, position transducer in the utility model, the amplifying circuit of secondary and three-phase inversion bridge circuit three are equivalent to have the effect of brushless motor commutator, the corresponding magnet ring half-turn of position transducer position, utmost point of the corresponding magnet ring of each position transducer, the position that the magnet ring number of poles of employing half cycle can be extrapolated the every utmost point of rotor, signal in the middle of not having compares and generation high-frequency signal, also without preset control program, form Real-time Collection and amplify in real time the real directly driving closed loop of entering to drive, relatively existing controlling organization, structure of the present utility model is simpler, signal is processed more direct, coordinate voltage regulator and current regulator to come governing speed and overcurrent protection, guarantee reliably operation stably of controlling organization, because the simple controlling organization volume of circuit can greatly reduce, thereby brshless DC motor can be applied to electronic hand-operated tools, promote the reliability of hand-operated tools, manual work with respect to existing employing brush motor, the utlity model has working stability, noise is low, the feature of power consumptive province.

Accompanying drawing explanation

Fig. 1 is control structure schematic diagram of the present utility model;

Fig. 2 is the structural representation of the utility model motor;

Fig. 3 is the schematic diagram of existing control structure.

Embodiment

As shown in Figure 1-2, a kind of brshless DC motor, comprise electric machine casing 1, rotor 3 and stator 2, in the outer setting of electric machine casing 1, there is the magnet ring 4 with rotor coaxial, magnet ring 4 numbers of poles are identical with the number of poles of rotor 3, in described magnet ring 4 one sides, be also provided with several position transducers 5 of corresponding half-turn magnet ring position, 4 one utmost points of the corresponding magnet ring of each position transducer 5, the output of position transducer 5 connects an amplifying circuit, an amplification circuit output end connecting secondary amplifying circuit, secondary amplification circuit output end connects three-phase inversion bridge circuit, the conversion of three phase inverter bridge drives motor stator magnetic field, No. one time amplifying circuit is also connected with current regulator with voltage regulator with secondary amplifying circuit.

The course of work of the present utility model is such: when rotor often turns an angle, the magnetic field that position transducer is corresponding can change, position transducer sends position signalling to amplifying circuit one time, feedback position signal is transformed into the pulse signal that drives three-phase inversion bridge circuit after amplifying circuit and secondary amplifying circuit secondary amplify, three-phase inversion bridge circuit again drive motors keeps steadily operation reliably of motor, voltage regulator is controlled the speed of motor by regulation voltage, current regulator can adjusting control mechanism operating current, when the operating current of controlling organization surpasses current regulator set point, current regulator meeting automatic shutoff circuit, again conducting at once in the time of in electric current drops to range of set value, play the effect of overcurrent protection.

The utility model is simple in structure, signal feedback is direct, comparison in the middle of not having, the higher-order of oscillation and program are preset, in adverse circumstances, also can move reliably by held stationary, there is better reliability, the most important thing is the small volume of motor control mechanism, the brshless DC motor of this controlling organization can be installed on electric manual tool, be highly suitable for power-driven pistol drill, electric polishing machine, electric hand angular grinder, the upper use of the electric tools such as driven portable cutting machine, adopt hand-operated tools more stable work after this brshless DC motor, output torque is large, noise is low, power consumptive province, it is the developing direction of following electric manual tool.

Claims

1. a brshless DC motor, comprise electric machine casing, rotor and stator, it is characterized in that: in the outer setting of electric machine casing, have the magnet ring with rotor coaxial, magnet ring number of poles is corresponding with the number of poles of rotor, in described magnet ring one side, be also provided with several position transducers of corresponding half-turn magnet ring position, utmost point of the corresponding magnet ring of each position transducer, the output of position transducer connects an amplifying circuit, an amplification circuit output end connecting secondary amplifying circuit, secondary amplification circuit output end connects three-phase inversion bridge circuit, the conversion of three phase inverter bridge drives motor stator magnetic field, No. one time amplifying circuit is also connected with current regulator with voltage regulator with secondary amplifying circuit.