JPS61189160A - Small-sized motor - Google Patents

Abstract

PURPOSE:To reduce the size and to increase the efficiency by mounting a controller on a substrate having arms contacted with an engaging hole to be engaged with a projections of a bobbin of a stator winding and a stator core, and interposing it between the support of a bracket and the core. CONSTITUTION:A yoke 3 on which a winding 2 is wound is provided at a stator core 1, a permanent magnet is provided at the core of a rotor to be mounted on a rotational shaft, they are assembled by the first and second brackets to form a small-sized motor. A controller 23 for molding a control circuit and a rotor position detector 24 are mounted on a substrate 25. In this case, engaging holes 26, 27 and arms 28, 29 are provided on the substrate 25, and projections 33, 34 to be engaged with the holes 26, 27 are provided on a bobbin 30 of a stator winding 2. Thus, after the holes 26, 27 of the substrate 25 are engaged with the projections 33, 34 of the bobbin 30 and positioned when a motor is assembled, the substrate 25 is interposed between the core 1 and the second bracket to readily and accurately mount the substrate 25.

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Field of Industrial Application The present invention relates to a skeleton type small electric motor, and in particular, aims to improve the efficiency and downsize of this electric motor by making it brushless.

(b) Conventional technology A small electric motor, commonly known as a skeleton type, has a stator core made of a plurality of laminated rectangular iron plates, which has an aperture for inserting the rotor and a yoke for stator windings. For example, the corner motor described in Japanese Patent Publication No. 57-16575 is small and has a simple structure, and is easy to manufacture, so it is used as an inexpensive motor. It was commonly used.

←] Problems to be Solved by the Invention In such a corner motor, a corner coil is provided in the stator core in addition to the stator winding to form a rotating magnetic field. Generally, a large current flows through this corner coil, which causes a decrease in the efficiency of the motor. Therefore, it has been difficult to increase the efficiency of the motor by using the additional corner coils. In addition, since an AC power supply, generally a commercial power supply, is used as the driving power source for the motor, the rated rotation speed of the motor is mainly determined by the frequency of the commercial power supply, and a complicated control circuit is required separately in order to use various rated rotation speeds. Or, it was necessary to design and manufacture each one individually for each rated rotation speed.

Furthermore, when such a control circuit is provided, the motor becomes large in size.

In view of these problems, the present invention provides a compact electric motor that is highly efficient and compact by converting a skeleton type electric motor into a DC brushless motor.

The present invention provides a stator in which rectangular iron plates are laminated to form a yoke for winding a single stator winding and an opening into which a rotor is inserted, facing each other. An iron core, a rotor whose surface has magnetic poles magnetized to different polarities, and which rotates around a rotating shaft, and the rotational position of the rotor within the aperture are magnetically detected to determine the current direction of the stator windings. In a small electric motor that has a control unit that switches between It has a hole into which it is fitted and an arm whose tip touches the stator core, and a board that is held between the support part of the bracket and the stator core. It is attached to the board so that it is located between the two.

(E) Function When a small electric motor is configured as described above, the electric motor can be made smaller and more efficient, and at the same time, the positioning of the board can be easily performed, making it easier to assemble the electric motor.

(f) Examples Below, examples of the present invention will be explained based on the drawings.
The figure is a sectional view of the main parts of the electric motor, Figure 2 is a front view with the bracket and rotor removed and seen from the ■ direction in Figure 1, and Figure 3 is a front view of the electric motor.
The figure is a perspective view of this electric motor, and the same components are given the same reference numerals. First, (1) is the stator core, which is an opening in which a yoke (3) and a rotor (4) are inserted into which a single stator winding (2) is wound by laminating multiple rectangular iron plates. (5)
are formed facing each other. The rotor +41 includes a permanent magnet (7) magnetized to two poles on the outer periphery of a rotor core (6), and is fixed to a rotating shaft (8). (9), 00) are a first bracket and a second bracket, the first bracket (9) has a through hole (11) through which the rotating shaft (8) passes, a bearing metal (1), and a bearing metal bearing is a material. α3), spring 0
4) A self-aligning section consisting of an oil cap Q5) performs automatic centering of the rotating shaft (8).

Note that the oil cap α5) is press-fitted into the first bracket (9), and this oil cap group 0 and the first bracket (9)
) is filled with an oil-impregnated material such as a wick to supply oil to the bearing metal (121).

Further, (16) is a thrust washer.

The second bracket 00) includes a thrust seat 07) that receives the end of the rotor (8), a bearing metal (I8), a bearing metal receiver, a spring (2t1), an oil cap (2
1), which performs automatic centering of the rotating shaft (8). In addition, the oil cap (21) is
This oil cap (2) is press-fitted into the bracket QO).
In the space created between 1) and the second bracket (tel), an oil-bearing material such as a wick is placed to supply oil to the bearing metal α barrel.Furthermore, (221 is a support part,
It is in contact with a substrate that will be described later.

Q (to) is a control part in which a control circuit is molded, and a position detection element C241 for magnetically detecting the rotational position of the rotor (4) in the aperture (5) <for example, a Hall element, Hall I
The current direction to the stator winding (2) is switched based on the output of the C1 magnetic diode, magnetic wire, etc.).

The control unit (23) and the position detection element (goods) are layered on a substrate (2!5+), and this substrate 051 has an engagement hole (to) into which a protrusion to be described later fits, 07) (substrate (251). ), and the tip of the stator core (1
), which are in contact with the stator core (1) and the second bracket (00), are provided with arm parts (for example, board pins whose lengths are adjusted). Position detection element (
24) can be installed in 2 to 3 places along the circumference of the hole (5), depending on the specifications of the motor (high-speed rotation, low-speed rotation). This allows the phase timing of current energization switching to be appropriately selected. In addition, this control section (c) controls the stator core (1) and stator winding (2).
It is located between.

(30) is a bobbin on which the stator winding (2) is wound;
The yoke (3) is molded with resin.

The yoke (3) of this bobbin (311) has ends 01), 0
21 has a different shape, and this bobbin (to) is the stator core (1
) prevents it from being press-fitted in the opposite direction. In addition, between the protrusions that fit into the engagement holes (26) of the board (251), C
34) is molded.

09, (The penalty is the lead wire connected to the DC power supply.

In the electric motor constructed in this manner, the shape of the aperture (5) of the stator core (1) is a combination of circular arcs Gη, (to) having the same radius and different center points. In this way, the permanent magnet (7) of the rotor (4) and the stator core (1)
) and the stator winding (2) becomes uneven.
When the rotor (4) is not energized, the rotor (4) always stops at a fixed position (or at a position rotated by 180 degrees). Also, C3! l
(4[) is a polar separation groove.

In addition, (41) is the first bracket (9) attached to the stator core (1).
) and the second bracket 00). (
Row 4 (44) is a hole for attaching the electric motor to other equipment.

Figure 4 is a diagram of the electric circuit molded into the control unit (2 (support)), and the same components as in Figures 1 to 3 are given the same reference numerals. (45) is a constant voltage diode. Yes, and supplies a constant voltage to the position detection element (24). (46)
is a comparator which detects the rotational position of the rotor (4) and switches its output between an H level voltage and an L level voltage every time the rotor (4) rotates 180 degrees. Comparator (46)
When the output is H level voltage, the transistor (4 current (48
) is in the on state, and the transistor (4 special, I!501 is in the off state. When the output of the comparator (46) is an L level voltage, the transistor (47), (the 4 camphor is in the off state), the transistor (49), I !50) is turned on. By switching between the on and off states of the transistor (4η to bag) in this way, the direction of the current flowing to the stator winding (2) is alternately switched.

6υ is an overcurrent detection resistor that detects the overcurrent flowing in the stator winding (2), and the voltage generated across this resistor 6υ is the resistor 52.
When the voltage becomes higher than the voltage generated at the connection point of 1.531, an H level voltage is output from the comparator 64), turning off the transistor 651 and causing the transistors (47) to ff1O) and the stator winding (2) to burn out. is prevented.

Therefore, by using such a control circuit, the direction of energization to the stator winding (2) can be switched in accordance with the rotational position of the rotor (4), and continuous rotation of the rotor (4) can be obtained. It is. The details of this operation are similar to the energization switching of a normal brushless motor, so a detailed explanation will be omitted.

When assembling such a motor, after positioning the board (251) by fitting the engagement hole (26) of the board (251) to the protrusion C34 of the bobbin (toward), this board e
If l'51 is held between the stator core (1) and the support part (c) of the second bracket 00), the board (c) can be easily and accurately attached. That is, the position detection element (24) mounted on the substrate (c) is also mounted at an accurate position at the same time.

(G) Effects of the Invention The present invention provides a small electric motor having a skeleton-type stator core, which includes a bobbin for winding a stator winding, an engagement hole into which a protrusion of the bobbin is fitted, and an arm portion whose tip is in contact with the stator core. Since the control unit is mounted on this board, the board can be easily and accurately attached when assembling the electric motor.

In addition, if the control unit is mounted on the board between the stator windings and the stator core, the control unit can be protected, and at the same time, the motor get space can be used effectively, making the motor more compact. It is something.

[Brief explanation of the drawing]

1 is a sectional view of the main parts of a small electric motor showing an embodiment of the present invention, FIG. 2 is a front view of the main parts of the electric motor shown in FIG. FIG. 4 is a perspective view showing an example of the external appearance of a motor using the parts shown in FIG. 2, and FIG. 4 is an electric circuit diagram showing an example of the control section shown in FIGS. 1 and 2. (1)...Stator core, (2)...Stator winding,
(3)...Yoke, (4)...Rotor, (5
)...Opening hole, (8)...Rotating shaft, (9), αQ・
... Bracket, (2Z... Support part, @... Control part, I24)... Position detection element, (251...
・Platform board, (261, (5)...Engagement hole, (to), 翰...arm, modified...bobbin, (to), (34)...
·protrusion. Applicant Sanyo Electric Co., Ltd. and 1 other agent Patent attorney Masatoshi Sano

Claims (2)

[Claims] (1) A stator core made of stacked rectangular iron plates with a yoke for winding a single stator winding and an opening into which a rotor is inserted facing each other, the surfaces of which are magnetized to different polarities. A small electric motor that has a rotor that has magnetic poles and rotates around a rotating shaft, and a control unit that magnetically detects the rotational position of the rotor within an aperture and switches the energization direction of the stator winding, A bracket that has a bearing part that supports the rotating shaft and is fixed to the stator core, a bobbin that is provided on the yoke and around which the stator winding is wound, an engagement hole into which the protrusion of this bobbin fits, and a tip that is connected to the stator core. A substrate having an arm portion in contact with the iron core and sandwiched between the support portion of the bracket and the stator iron core,
A small electric motor characterized by having a control section mounted on this board. (2) The small electric motor according to claim 1, wherein the control section is mounted on the board so as to be located between the stator winding and the stator core.