JP3047362U - Brushless motor - Google Patents

Abstract

(57) [Summary] [Problem] Even if a rotor having a field permanent magnet whose pole boundary is skew-magnetized is displaced from an appropriate position in an axial direction of a rotating shaft at the time of assembly, motor characteristics can be improved. To easily adjust the variation of SOLUTION: A stator having an armature coil is fixed to an outer periphery of a cylindrical boss having a flange at one end. At one end of a rotating shaft rotatably penetrating into the boss, a rotor having a permanent magnet for a field facing the stator mounted on the inner periphery of a cup-shaped rotor yoke is fixed. The printed circuit board 11 on which the controller is mounted is fixed to the flange on the opening side of the rotor yoke with fixing screws. A position detector is fixed to the printed circuit board 11 so as to face the field permanent magnet. The screw holes 14 provided for passing the fixing screws through the printed circuit board 11 are formed by arc-shaped long holes centered on the axis 7s of the rotating shaft.

Description

[Detailed description of the invention]

[0001]

[Technical field to which the invention belongs]

 The present invention relates to a brushless motor.

[0002]

[Prior art]

 FIG. 4 shows a configuration of a conventional brushless motor. This brushless motor has a cylindrical boss 2 having a flange 1 at one end. A stator (armature) 3 is fixed to the outer periphery of the boss 2. The stator 3 has a structure in which an armature coil (armature winding) 5 is wound around a stator core (armature core) 4 fixed to the outer periphery of the boss 2. A rotary shaft 7 is rotatably penetrated and supported in the boss 2 via a bearing 6. At one end of the rotating shaft 7, a rotor 8 that rotates to face the stator 3 is fixed. The rotor 8 has a cup-shaped rotor yoke 9 whose center is fixed to the rotating shaft 7 and rotates as the rotating shaft 7 rotates, and a rotor 8 fixed to the inner periphery of the rotor yoke 9 and having a gap around the outer periphery of the stator 3. And a permanent magnet 10 for the field which is opposed to the magnet. On the opening side of the rotor yoke 9, a printed circuit board 11 is arranged in a direction orthogonal to the rotating shaft 7, and is fixed to the flange 1 with fixing screws 12. The printed circuit board 11 has a position detector 13 such as a Hall element for detecting the position of the rotor 8 in the rotation direction, facing the field permanent magnet 10, and a controller (not shown) for driving and controlling the brushless motor. (Not shown). The terminal portion 5a of the armature coil 5 is connected to a predetermined printed wiring on the printed circuit board 11 by soldering.

In such a brushless motor, the position detector 13 and the field permanent magnet 10 of the rotor 8 are arranged in a positional relationship as shown in FIG. In FIG. 5, reference numeral 10a denotes a boundary between the N pole and the S pole of the field permanent magnet 10, which is parallel to the rotating shaft 7.

In the case of a brushless motor having the field permanent magnet 10 magnetized in this way, the position of the rotor 8 (the position of the field permanent magnet 10) viewed from the stator 3 during assembly is rotated. Even if it fluctuates in the axial direction of the shaft 7, the pole boundary 10a is located at a position facing the position detector 13 as shown in FIG. 8 in the rotation direction can be detected.

[0005]

[Problems to be solved by the invention]

 However, as shown in FIG. 6, when the field permanent magnet 10 is magnetized by skewing the boundary 10a between its N and S poles, the stator 3 is viewed from the stator 3 when the brushless motor is assembled. If the position of the rotor 8 (the position of the field permanent magnet 10) is shifted from the appropriate position A in the axial direction of the rotating shaft 7 to the inappropriate position B shifted in the axial direction of the rotating shaft 7, At the position A, the pole boundary 10a located at the position facing the position detector 13 is shifted in the rotational direction at the inappropriate position B, causing a problem that the motor characteristics are changed.

An object of the present invention is to provide a brushless motor capable of easily adjusting a mounting position of a printed circuit board.

Another object of the present invention is to provide a motor having a skew-magnetized permanent magnet for a field even if the rotor is displaced from an appropriate position in an axial direction of a rotating shaft during assembly. An object of the present invention is to provide a brushless motor that can easily adjust the variation in motor characteristics.

[0008]

[Means for Solving the Problems]

 The present invention relates to a cylindrical boss having a flange at one end, a stator having an armature coil and fixed to the outer periphery of the boss, and a rotating shaft rotatably penetrated through the boss via a bearing. A rotor in which a permanent magnet for field fixed to one end of the rotating shaft and facing the stator is attached to the inner periphery of the cup-shaped rotor yoke, and a flange is provided on the opening side of the rotor yoke in a direction orthogonal to the rotating shaft. A brushless motor equipped with a printed circuit board mounted with a controller for driving and controlling the brushless motor, which is fixed with fixing screws, and a position detector fixed to the printed circuit board so as to face the field permanent magnet. It is to improve the motor. In particular, it is preferable to apply the present invention to a brushless motor having a skew-magnetized field permanent magnet.

In the present invention, the screw hole provided for passing the fixing screw through the printed circuit board is formed by an arc-shaped elongated hole centered on the axis of the rotating shaft.

With such a structure, the adjustment of the mounting position of the printed circuit board can be easily performed. In particular, when a rotor with a skew-magnetized field permanent magnet is assembled out of position in the axial direction of the rotating shaft during assembly, the printed circuit board is removed while observing the armature current. If the printed circuit board is fixed to the flange with a fixing screw at the position where the armature current waveform becomes an appropriate waveform by turning the axis of rotation of the rotation axis as the center of rotation using a long hole, it is easy to adjust the variation in motor characteristics. It can be carried out.

In this case, if the terminal portion of the armature coil is connected to the printed board with a slack, the printed board can be rotated without any trouble.

[0012]

[Embodiment of the invention]

 1 to 3 show an example of an embodiment of a brushless motor according to the present invention. Parts corresponding to those in FIGS. 4 to 6 are denoted by the same reference numerals.

In this brushless motor, a screw through hole 14 provided for passing the fixing screw 12 through the printed circuit board 11 is formed by an elongated hole having an arc shape centered on the axis 7 s of the rotating shaft 7. ing. The printed circuit board 11 is fixed to the flange 1 by screwing the fixing board 12 into the screw hole 14 and screwing it to the flange 1. The terminal portion 5a of the armature coil 5 is soldered to the land portion of the printed wiring on the printed circuit board 11 with some slack. Reference numeral 15 denotes a hole provided in the printed board 11 for fitting the printed board 11 to the outer periphery of the boss 2.

A controller mounted on the printed circuit board 11 for driving and controlling the brushless motor supplies an exciting current to each of the armature coils 5A, 5B, 5C of the stator 3 in a configuration as shown in FIG. An excitation switching circuit 16 is provided. The excitation switching circuit 16 is formed by a bridge circuit of switching transistors Tr1 to Tr6, which are switching elements. The armature coil 5A and the armature coil 5B are connected in series and the connection point between the switching transistors Tr1 and Tr2 and Tr3, Tr3. The armature coil 5B and the armature coil 5C are connected in series and connected between the connection point of the switching transistors Tr3 and Tr4 and the connection point of Tr5 and Tr6. This bridge circuit is grounded via a current detector 17 composed of a resistor.

In the brushless motor having such a structure, as shown in FIG. 6, the rotor 8 having the field permanent magnet 10 skew-polarized by skewing the pole boundary 10 a is rotated by the rotating shaft 7 during assembly. When the printed circuit board 11 is displaced from the appropriate position in the axial direction of the printed circuit board 11 while the fixing screw 12 is loosened, the printed circuit board 11 is extended while observing the armature current using the current detector 17 shown in FIG. The printed circuit board 11 is fixed to the flange 1 with the fixing screw 12 at a position where the armature current waveform becomes an appropriate waveform by turning the rotary shaft 7 around the axis 7 s using the screw through hole 14 formed of a hole. . By doing so, it is possible to easily adjust the variation in the motor characteristics. At this time, since the terminal portion 5a of the armature coil 5 is connected to the printed board 11 with a slack, the printed board 11 can be rotated without any trouble.

In the brushless motor of the present invention, the threaded hole 14 is made to be a long hole even in the case of the rotor 8 having the skew-magnetized field permanent magnet 10 as shown in FIG. This makes it possible to adjust the mounting position, which is preferable.

[0017]

[Effect of the invention]

 In the present invention, the screw holes provided to pass the fixing screws through the printed circuit board are elongated holes that form an arc around the axis of the rotating shaft, making it easy to adjust the mounting position of the printed circuit board. Can be done. In particular, when a rotor with a skew-magnetized permanent magnet for a field is assembled out of the proper position in the direction of the axis of the rotating shaft during assembly, the printed circuit board is turned using the long holes. This makes it possible to easily adjust the variation in motor characteristics.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view showing an example of an embodiment of a brushless motor according to the present invention.

FIG. 2 is a plan view showing an example of a printed circuit board used in the brushless motor.

FIG. 3 is a circuit diagram showing an example of an exciting current switching circuit used in the brushless motor.

FIG. 4 is a longitudinal sectional view of a conventional brushless motor.

FIG. 5 is an explanatory diagram showing a relationship between a rotor having a skew-magnetized field permanent magnet and a stator having a position detector.

FIG. 6 is an explanatory diagram showing a relationship between a rotor having a skew-magnetized field permanent magnet and a stator having a position detector.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Flange 2 Boss 3 Stator (armature) 4 Stator core (armature core) 5, 5A, 5B, 5C Armature coil (armature winding) 5a Terminal part 6 Bearing 7 Rotation axis 8 Rotor 9 Rotor yoke 10 Field field Permanent magnet 10a Pole boundary 11 Printed circuit board 12 Fixing screw 13 Position detector 14 Screw hole 15 Hole 16 Excitation switching circuit 17 Current detector

Claims (3)

[Utility model registration claims] A cylindrical boss having a flange at one end;
A stator having an armature coil and fixed to the outer periphery of the boss, a rotating shaft rotatably penetrated through the boss through a bearing, and fixed to one end of the rotating shaft and fixed to the stator; A rotor having opposed field permanent magnets attached to the inner periphery of a cup-shaped rotor yoke, and a brushless motor fixed to the flange in a direction orthogonal to the rotation axis on the opening side of the rotor yoke, A brushless motor including a printed circuit board on which a controller for driving and controlling is mounted, and a position detector fixed to the printed circuit board so as to face the field permanent magnet; A screw hole provided for passing a screw is formed by a long hole having an arc shape centered on the axis of the rotating shaft. Brushless motor. 2. A cylindrical boss having a flange at one end;
A stator having an armature coil and fixed to the outer periphery of the boss, a rotating shaft rotatably penetrated through the boss through a bearing, and fixed to one end of the rotating shaft and fixed to the stator; A rotor having opposed field permanent magnets attached to the inner periphery of a cup-shaped rotor yoke, and a brushless motor fixed to the flange in a direction orthogonal to the rotation axis on the opening side of the rotor yoke, A printed circuit board on which a controller for driving and controlling is mounted; and a position detector fixed to the printed circuit board so as to face the field permanent magnet. In a brushless motor having magnetism, a screw through hole provided for passing the fixing screw through the printed circuit board has a circle centered on the axis of the rotating shaft. A brushless motor characterized by being formed by arc-shaped long holes. 3. The brushless motor according to claim 1, wherein a terminal portion of the armature coil is connected to the printed circuit board with a slack.