CN201127001Y - brushless motor - Google Patents

Abstract

The brushless motor provided by the utility model has: a stator core, and a stator coil is wound; a rotor, which is arranged opposite to the stator core and is made of a rare earth resin magnet material that is magnetized for driving at multiple places on the inner periphery. A cup-shaped rotor yoke with a ring magnet mounted on its inner circumference and a shaft fixed at the center of the rotor yoke; a bearing that rotatably supports the shaft; and a case that holds the bearing on its inner circumference and The stator core is held on its outer peripheral side; and the circuit board is fixed on the housing and carries a drive and control circuit for driving in rotation and controlling the rotor. In the circuit component mounting surface of the circuit board, the area affected by the magnetic force leaked from the end surface of the magnet is arranged so that the lead wires and pads of the circuit component do not interfere with each other, or the area affected by the magnetic force is covered with an insulating material. Leads and pads of circuit components.

Description

brushless motor

technical field

The utility model relates to a brushless motor used as a main motor for simultaneously driving various mechanisms such as copiers and laser printers, in particular to a stator core with wound stator coils, a rotor equipped with ring magnets, and a holster for detecting the position of the rotor. It is a brushless motor that integrates the drive and control circuits for driving and controlling the rotation of the rotor with the motor.

Background technique

In recent years, document products such as copiers and laser printers have been geared toward higher image clarity, higher-speed printing, and colorization. For this reason, in order to simultaneously achieve the above-mentioned objects, these products tend to have a so-called tandem system in which photosensitive drums are provided for each color. Although it is undeniable to increase the size of the machine in order to make the conventional one-drum structure into a two-drum or four-drum structure, in order to suppress the increase in size, the main motor that drives various mechanisms is required to be thinner and smaller. compact, space-saving and high-output.

In addition, as such a main motor, a brushless motor in which a motor unit including a stator with a stator core suitable for high output, and a drive and control circuit for rotationally driving and controlling the motor are integrally used is generally used. Therefore, reduction in thickness, reduction in diameter, space saving, and increase in output are required for the entire motor including the circuit portion.

For this reason, it is desired that the external dimensions of the stator portion and the circuit portion of the motor be infinitely close to the square size of the circumscribed rotor portion, and the height dimension is also preferably infinitely close to the height dimension of the rotor portion.

In order to solve this problem, conventionally, a brushless motor in which driving and control circuits are integrated has been proposed, for example, as disclosed in Japanese Patent Application Laid-Open No. 2006-25537. In this conventional brushless motor, among the components of the drive and control circuits, in addition to the connector for power supply from the outside of the motor, the capacitor connected between the positive and negative lines of the power supply, and the detection of the voltage supplied to the stator coil In addition to the current detection resistor for the amount of current, other integrated circuits for control and driving, electronic parts corresponding to surface mounting, and Hall elements are all surface-mounted by soldering on the end face of the magnet that becomes the open end of the rotor. The opposite side is the surface of the circuit board on the opposite side.

Fig. 3A shows the structure of a conventional brushless motor, and Fig. 3B shows a view along the line A-A' of the conventional brushless motor.

In FIG. 3A, a brushless motor 30 has: a stator core 32 wound with a stator coil 31; a rotor 36 composed of a cup-shaped rotor yoke 33 and a shaft 35 fixed to the center of the rotor yoke 33; The bearing 37 that supports the shaft 35 firmly; the case 38 that holds the bearing 37 on its inner peripheral side and the stator core 32 on its outer peripheral side; and the circuit board 42 fixed on the case 38 .

In addition, a flange portion 39 serving as an attachment portion to a device on which the electric motor is mounted is formed on the housing 38 . The rotor yoke 33 has ring-shaped magnets 34 that are magnetized for driving at a plurality of places facing the stator core 32 on the inner peripheral side thereof. Further, a drive and control circuit for rotationally driving and controlling the rotor 36 is mounted on the circuit board 42 .

Furthermore, as shown in FIG. 3B , the drive and control circuits include: a power supply connector 48 from the outside of the motor; a capacitor 49 connected between the positive and negative lines of the power supply; detecting the amount of current supplied to the stator coil 31 current detection resistor 50; drive and control integrated circuit 45; power MOS array 46U, 46V, 46W; chip-type electronic component 51 corresponding to surface mount; and Hall element 47U, 47V, 47W. These drive and control integrated circuits 45, power MOS arrays 46U, 46V, and 46W, chip-type electronic parts 51, and Hall elements 47U, 47V, and 47W are all surface-mounted on the open end side of the rotor 36 by soldering. On one surface 42b of the circuit board 42 opposite to the surface 42a facing the magnet end surface 34a.

With such a configuration, conventional brushless motors can provide a drive and control circuit-integrated motor suitable for size reduction, space saving, and high output.

However, in the conventional structure described above, in order to increase the output of the motor or improve the efficiency, when a magnet made of a rare-earth resin magnet material having a large magnetic energy is used as the magnet of the rotor, the rotor is opened from the open end side of the rotor. The magnetic flux leaked from the end face of the magnet increases. Therefore, for example, a magnetic metal foreign object generated by the screw part for attaching the motor to the machine is attracted by the leaked magnetic force, so that the surface is mounted on the opposite side of the surface facing the magnet end surface on the open end side of the rotor. The driving and control circuits on the surface of the circuit board may adhere to the lead wires of these circuit components or the pads of the wiring pattern, etc., causing a short circuit.

Utility model content

This utility model is proposed to solve these problems, and its purpose is to provide a drive and control circuit and a motor that achieve thinner, smaller diameter, space-saving, and higher output while achieving high reliability. Integrated brushless motor.

The utility model is a brushless motor, comprising: a stator core, a stator coil is wound; a rotor, which is arranged opposite to the stator core and is composed of a rare earth resin magnet material that is magnetized for driving at multiple places on the inner circumference A cup-shaped rotor yoke with a ring-shaped magnet installed on its inner peripheral side and a shaft fixed to the center of the rotor yoke; a bearing that rotatably supports the shaft; and a housing that holds the bearing on its inner peripheral side and The stator core is held on its outer peripheral side; and the circuit board is fixed to the housing and mounted with a drive and control circuit for rotationally driving and controlling the rotor, characterized by having the following structure.

That is, this brushless motor is formed on the casing with a mounting portion to the machine on which the motor is mounted, and the drive and control circuits have: a connector for power supply from outside the motor; Capacitors; current detection resistors that detect the amount of current supplied to the stator coil; integrated circuits for driving and control, electronic components corresponding to surface mounting, and Hall elements, on both the front and back sides of the circuit board, will be connected to the rotor When the surface opposite to the magnet end face on the open end side of the open end is regarded as one surface, and the opposite surface is regarded as the other surface, all integrated circuits for driving and control, electronic components corresponding to surface mounting, and Hall elements are all Surface-mounted on the other surface by soldering, in the circuit component mounting surface of the circuit board, the area affected by the magnetic flux generated from the magnet end surface on the open end side of the rotor and the drive and control circuits Drive and control circuits are mounted in such a way that the lead wires of circuit components and the pads of the wiring pattern do not interfere. According to this structure, even if the magnetic metal foreign matter generated by the screw part for attaching the motor to the machine is attracted by the magnetic force leaked from the end face of the magnet, it will be received by the open end side of the rotor on the circuit component mounting surface of the circuit board. The area affected by the magnetic flux generated on the end surface of the magnet is not provided with lead wires of circuit parts for driving and control circuits and pads of wiring patterns, so foreign objects made of magnetic metal will not adhere to the lead wires or pads, and short circuits will not occur.

In addition, this brushless motor has a mounting part on the casing to the machine on which the motor is mounted, and the drive and control circuits have: a connector for power supply from outside the motor; Capacitors; current detection resistors that detect the amount of current supplied to the stator coil; integrated circuits for driving and control, electronic components corresponding to surface mounting, and Hall elements, on both the front and back sides of the circuit board, will be connected to the rotor When the surface opposite to the magnet end face on the open end side of the open end is regarded as one surface, and the opposite surface is regarded as the other surface, all integrated circuits for driving and control, electronic components corresponding to surface mounting, and Hall elements are all Surface-mounted on the other surface by soldering, on the circuit component mounting surface of the circuit board, mounted on the area affected by the magnetic flux generated from the magnet end surface on the open end side of the above-mentioned rotor For driving and control The leads of the circuit parts of the circuit and the pads of the wiring pattern are covered with an insulating material. According to this structure, even if the magnetic metal foreign matter produced by the screw part for attaching the motor to the machine is attracted by the magnetic flux leaking from the end surface of the magnet and adheres to the position between the lead wires or the pad where the pattern is arranged, it is still held by the insulating material. Covering prevents short circuits, and since the lead wires and pads of the circuit components of the drive and control circuits can be arranged in the area affected by the magnetic flux generated from the end surface of the magnet, the freedom of design of the circuit board will not be damaged. degree, which can reduce the overall size of the substrate.

In addition, in this brushless motor, screen printing is performed in advance on the portion of the circuit board covered with an insulating material. According to such a configuration, since the insulating material can be applied on the basis of the previously screen-printed portion of the circuit board, workability is improved.

In this way, according to the present invention, it is possible to provide a brushless motor in which a driving and control circuit and a motor are integrally assembled together while achieving high reliability, thinning, small diameter, space saving, and high output. .

Description of drawings

FIG. 1A is a cross-sectional view of the structure of the brushless motor according to Embodiment 1 of the present invention.

Fig. 1B is a view taken along the line A-A' of the brushless motor of the first embodiment.

Fig. 1C is a view along the line A-A' of the brushless motor according to the first embodiment in which the arrangement of circuit components is changed.

Fig. 2A is a structural cross-sectional view of a brushless motor according to Embodiment 2 of the present invention.

Fig. 2B is an A-A' line view of the brushless motor of the second embodiment.

Fig. 3A is a sectional view of a conventional brushless motor.

Fig. 3B is an A-A' view of the conventional brushless motor.

Detailed ways

Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

Example 1 will be described.

Fig. 1A, B, C represent the brushless motor of the utility model embodiment 1.

In FIG. 1A, a stator coil 1 is wound on each salient pole of a stator core. The rotor 6 is formed of a cup-shaped rotor yoke 3 made of a magnetic material, and a ring-shaped magnet formed of a rare earth resin magnet material such as a neodymium-iron-boron magnet mounted on the inner peripheral side of the rotor yoke 3. 4; and the shaft 5 fixed at the central part. The bearing 7 rotatably supports the shaft 5 of the rotor 6 . The housing 8 has a cylindrical portion 9 and a flange portion 10 , and the bearing 7 is held on the inner peripheral side of the cylindrical portion 9 of the housing 8 . The stator core 2 is fixed on the outer peripheral side of the cylindrical portion 9 of the housing 8 . The inner peripheral surface of the magnet 4 is magnetized for driving at multiple places in the radial direction. That is, on the inner periphery of the ring magnet 4, a plurality of driving magnetic poles are formed in the circumferential direction.

In addition, in the present embodiment, the flange portion 10 of the case 8 serves as an attachment surface to a device on which the electric motor is mounted, and has an attachment screw hole 11 formed therein. In addition, a circuit board 12 is fixed to the flange portion 10 of the housing 8 on the opposite side to the mounting surface of the device on which the motor is mounted. A drive and control circuit for rotationally driving and controlling the rotor 6 is mounted on the circuit board 12 . In addition, such a drive and control circuit includes: a connector 18; a capacitor 19; a current detection resistor 20; a drive and control integrated circuit 15; electronic components compatible with surface mounting;

Here, in the magnet 4, the end surface on the open end side of the rotor 6 is the magnet end surface 4a, and of the two front and back surfaces of the circuit board 12, the surface facing the magnet end surface 4a is the one side. When the surface is one surface 12a, and the surface on the opposite side is used as the other surface, that is, one surface 12b, a Hall element 17U, which is a circuit component of a drive and control circuit, is surface-mounted on the one surface 12b by soldering. , 17V, 17W, and chip-type electronic parts 21, etc. The power part of the drive and control circuit is divided into a drive and control integrated circuit 15, a first power MOS array 16U for turning on/off the energization to the U-phase stator coil, and a first power MOS array 16U for connecting energization to the V-phase stator coil. The second power MOS array 16V for on/off, and the third power MOS array 16W for turning on/off the energization to the W-phase stator coil are constituted by a plurality of cards. In this way, in this embodiment, the integrated circuits 15 for driving and control, the chip-type electronic components 21, and the power MOS arrays 46U, 46V, 46W, etc., that is, the electronic components corresponding to surface mounting, and the Hall elements 17U, 17V, 17W all pass through It is surface-mounted on one side 12b of the circuit board 12 by soldering.

In addition, only a connector 18 for power supply from the outside of the motor, a capacitor 19 connected between the positive and negative lines of the power supply, and a current detector for detecting the amount of current supplied to the stator coil 1 are arranged on one side 12a of the circuit board 12 . Parts with lead wires or terminals such as the sense resistor 20 . Lead wires or terminals of these components protrude toward the surface 12 b which is the opposite side of the circuit board 12 , and are mounted. In this way, all the solder lands for mounting lead parts and terminal parts are arranged on the surface 12b opposite to the surface 12a facing the magnet end surface 4a on the open end side of the rotor 6 .

In addition, as described above, a magnetic metal screw is screwed into the screw hole 11 which is a hole formed in the flange portion 10 of the case 8, so that the motor can be attached to the machine on which the motor is mounted.

In this case, it is difficult to avoid generation of magnetic metal foreign matter from the screw portion. The output of the motor can be increased or the efficiency can be improved by using a rare-earth resin magnet material with high magnetic energy, but the magnetic flux leaking from the magnet end surface 4a side of the open end of the rotor 6 increases. Therefore, the magnetic metal foreign matter is attracted by the leaked magnetic force and easily adheres to the circuit board 12 surface 12b opposite to the surface 12a facing the magnet end surface 4a on the open end side of the rotor 6 .

In the present embodiment, as shown in FIG. 1B and C, in the one surface 12a of the above-mentioned circuit board 12 and the one surface 12b on the opposite side, in the area affected by the magnetic flux leaked from the magnet 4a side (denoted by symbol P As shown), there are no driving and control integrated circuits 15, power MOS arrays 16U, 16V, 16W, lead wires L of Hall elements 17U, 17V, 17W, and pads R of circuit patterns. Therefore, according to the present embodiment, it is possible to prevent a short circuit caused by adhering magnetic metal foreign matter to the lead L or the pad R of the circuit components of the drive and control circuit.

The region affected by the magnetic flux leaking from the magnet end surface 4a side indicated by the symbol P in FIGS.

FIG. 1B shows that all the lead wires L of the drive and control integrated circuits 15, power MOS arrays 16U, 16V, and 16W, and Hall elements 17U, 17V, and 17W, and the pads R of the circuit pattern are arranged on the leakage from the side of the magnet end face 4a. An example of the radially inner side of the region P affected by the magnetic flux. According to this embodiment, there is an effect that the external size of the circuit board 12 can be minimized.

In addition, in the case where there is a margin in the external dimensions of the circuit board 12, the integrated circuit 15 for driving and controlling, the power MOS array 16U, 16V, 16W and the lead wires of the Hall elements 17U, 17V, 17W, etc. L and the pads R of the circuit pattern are arranged dispersedly inward and outward in the radial direction of the region P affected by the magnetic flux leaked from the magnet end surface 4a side.

In addition, FIG. 1C shows that the drive and control integrated circuits 15 housed in the dual-in-line card are arranged in such a way that the lead wires straddle the radially outer and inner sides of the region P affected by the magnetic flux leaked from the magnet end face 4a side. example of. The power MOS arrays 16U, 16V, and 16W accommodated in the dual-in-line card can also be configured in the same manner. The arrangement freedom of the circuit components of this structure is greater than that of the embodiment shown in FIG. 1B , and there is an effect that the outer dimensions of the circuit board 12 can also be made smaller.

As described above, in the brushless motor mechanism of this embodiment, on the circuit component mounting surface 12b of the circuit board 12, the lead wires L of the circuit components of the drive and control circuits and the pads R of the wiring pattern are arranged on the slave rotor. 6. The outside of the area P affected by the magnetic flux generated from the magnet end surface 4a on the open end side, that is, the area P affected by the magnetic flux generated from the magnet end surface 4a on the open end side of the rotor 6 and the drive and control circuits. The drive and control circuits are mounted in such a way that the leads L of the circuit components and the pads R of the wiring pattern do not interfere.

According to this structure, since it is possible to prevent the circuit short-circuit due to the adhesion of foreign matter made of magnetic metal to the lead wire L or the pad R of the circuit part, it is possible to increase the output of the motor or realize the Increased efficiency. In addition, since there is no need for additional mounting parts, the constituent parts of the motor can be reduced, so the height of the motor can be further reduced, so it can provide a suitable and excellent small diameter, space saving and high output that also reduces assembly man-hours. Functions and effects of brushless motors with integrated drive and control circuits.

Embodiment 2 will be described below.

2A and B show a brushless motor according to Embodiment 2 of the present invention.

In FIGS. 2A and 2B , the same components as those in the first embodiment are assigned the same reference numerals, and description thereof will be omitted. The difference from Embodiment 1 is that, in the surface 12a of the circuit board 12 facing the magnet end surface 4a on the open end side of the rotor 6 and the surface 12b on the opposite side, the leakage from the magnet end surface 4a side In the region affected by the magnetic flux (the region between the imaginary circles C1 and C2 in FIG. 2B ), the drive and control integrated circuits 15, the power MOS arrays 16U, 16V, 16W, and the Hall elements 17U, 17V, 17W, etc. are arranged. The lead L and the pad R of the circuit pattern; and the point where the insulating material 22 covers the above-mentioned lead L and the pad R of the circuit pattern.

The area between the imaginary circles C1 and C2 in FIG. 2B is the same area as the area indicated by symbol P in FIGS. 1B and C .

And, according to the structure of the present embodiment, the lead wire L and the pad R of the circuit components of the drive and control circuit arranged in the area affected by the magnetic flux leaked from the magnet end face 4a side are covered with the insulating material 22, so Even if foreign matter made of magnetic metal adheres to the position of the lead L or the pad R, since it is covered with the insulating material 22, there is an effect of preventing the occurrence of a short circuit. In addition, since the lead L and pad R of the circuit components of the drive and control circuit can be arranged in the area affected by the magnetic flux leaked from the magnet end face 4a side, it also has advantages compared with the structure of the first embodiment. The design freedom of the circuit board 12 is not affected, and the external dimension of the circuit board 12 can be reduced.

As the insulating material 22, by using the paint used for the moisture-proof treatment of general circuit boards, it can also be used as a moisture-proof treatment.

In addition, if the insulating paint to which fluorescent dye is added is used, the confirmation of paint work becomes easy.

In addition, the insulating material 22 can be coated on the basis of the screen printing since the screen printing is performed in advance on the surface 12b of the circuit board 12 covered with the insulating material 22 . As a result, the workability is significantly improved, and the coating operation of the insulating material 22 can be performed intensively at desired locations, so that the amount of coating of the insulating material 22 can be kept to a minimum necessary, thereby suppressing an increase in cost.

In addition, in the present embodiment 2, only the insulating material 22 for the lead wire L and the pad R of the circuit parts of the drive and control circuit arranged in the area affected by the magnetic flux leaked from the magnet end face 4a side Covering, but because the operation of coating the insulating material 22 is completed at one time, even if the entire area affected by the magnetic flux leaking from the magnet end face 4a side is covered, the same effect can be obtained. In addition, in the case where only one lead wire of circuit components such as an integrated circuit accommodated in a dual in-line card is arranged in the area affected by the magnetic flux leaked from the side of the magnet end face 4a, in consideration of workability, It is also possible to cover the entire integrated circuit with an insulating material 22 .

Even if the brushless motor integrally assembled with the drive and control circuits of the present invention is made by soldering the drive and control integrated circuits, the electronic parts corresponding to the surface mounts, and the Hall elements, the surface mounts on the surface of the rotor and the rotor. The structure on the surface of the circuit board on the opposite side of the surface facing the magnet end surface on the side of the open end also has a magnetic force that prevents magnetic metal foreign objects generated by the screw part that attaches the motor to the machine from being leaked from the magnet end surface. The effect of attracting and adhering to lead wires or pads to cause a short circuit is effective as a brushless motor used as a main motor for simultaneously driving various mechanisms such as copiers and laser printers.

Claims (3)

1. brushless motor possesses: stator core, and package has stator coil; Rotor, by will be relative with this stator core configuration and implemented in interior all many places drive with the magnetized ringshaped magnet that constitutes by terres rares resin magnet material and the cup-shaped rotor yoke of side Monday within it be installed and be fixed on spool constituting of these rotor yoke iron central authorities; Bearing, rotation support above-mentioned axle freely; Housing keeps within it side and the said stator iron core remained on its of side outer Monday Monday with this bearing; And circuit substrate, be fixed on the above-mentioned housing and carry the driving, the control that are used to rotate the driving and control above-mentioned rotor and use circuit, it is characterized in that:

Be formed with the installation portion to the machine that carries motor on above-mentioned housing, above-mentioned driving, control have with circuit: the connector of supplying with usefulness from the power supply of motor outside; Be connected the capacitor between the positive and negative circuit that power supply supplies with; Detection is to the current sense resistor of the magnitude of current of above-mentioned stator coil supply; And drive, control with integrated circuit and electronic component and the Hall element corresponding with mounted on surface,

In the table of foregoing circuit substrate in two faces, will with opposed of the magnet end face of open end one side of above-mentioned rotor as a face, the face that will become its opposite side is during as another face, driving, control all are surface mounted on above-mentioned another face by solder with integrated circuit and electronic component and the Hall element corresponding with mounted on surface

In the circuit component installed surface of this circuit substrate, above-mentioned driving is installed, controls and use circuit with the configuration mode that the pad of the lead-in wire of the circuit component of circuit and Wiring pattern does not interfere from zone that the magnetic flux that the magnet end face of open end one side of above-mentioned rotor takes place influences and above-mentioned driving, control being subjected to.

2. brushless motor possesses: stator core, and package has stator coil; Rotor is installed the cup-shaped rotor yoke of side Monday within it and is fixed on spool constituting of these rotor yoke iron central authorities by being oppositely arranged with this stator core and having implemented in interior all many places to drive with the magnetized ringshaped magnet that is made of terres rares resin magnet material; Bearing, rotation support above-mentioned axle freely; Housing keeps within it side and the said stator iron core remained on its of side outer Monday Monday with this bearing; And circuit substrate, be fixed on the above-mentioned housing and carry the driving, the control that are used to rotate the driving and control above-mentioned rotor and use circuit, it is characterized in that:

Be formed with the installation portion to the machine that carries motor on above-mentioned housing, above-mentioned driving, control have with circuit: the connector of supplying with usefulness from the power supply of motor outside; Be connected the capacitor between the positive and negative circuit that power supply supplies with; Detection is to the current sense resistor of the magnitude of current of above-mentioned stator coil supply; And drive, control with integrated circuit and electronic component and the Hall element corresponding with mounted on surface,

In the table of foregoing circuit substrate in two faces, will with opposed of the magnet end face of open end one side of above-mentioned rotor as a face, the face that will become its opposite side is during as another face, driving, control all are surface mounted on above-mentioned another face by solder with integrated circuit and electronic component and the Hall element corresponding with mounted on surface

In the circuit component installed surface of this circuit substrate, be installed in the driving, the control that are subjected to from the zone that the magnetic flux that the magnet end face of open end one side of above-mentioned rotor takes place influences and coated by insulating material with the lead-in wire of the circuit component of circuit and the pad of Wiring pattern.

3. brushless motor according to claim 2 is characterized in that, has implemented silk screen printing in advance at the position with the insulating material coating of foregoing circuit substrate.

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