JP2010124517A - Sr motor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To overcome the problem of a conventional SR (switched reluctance) motor that the efficiency of using a magnetic force is poor, the motor may not operate actually when used and the accuracy is not sufficient. <P>SOLUTION: This SR motor has a stator in which a plurality of ribs are provided with an equal pitch, wherein magnets having the same polarity of magnetic poles adjacently opposite are provided between the tips of the ribs. In the SR motor, the coils are fitted respectively between the ribs, the magnets are positioned on the end where the each of the coils is arranged, and a combined value of magnetic flux density of the two magnets which are to sandwich one rib is set at ≤1.2 times the saturated magnetic flux of the ribs of the stator. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an SR (Switched Reluctance) motor, and more particularly to an SR motor that is more efficient and more accurate than conventional ones, and that can be further reduced in size and vibration.

  In general, an SR motor is a motor that rotates using a magnetic resistance, that is, a ratio of magnetomotive force and magnetic flux, and resistance to magnetic flux of a magnetic circuit without using an expensive permanent magnet. The phase winding is wound so that the opposing ribs (saliency poles) of the stator are opposite to N and S, and the phases are switched by a semiconductor power switch.

  There is no phase winding in the rotor of this SR motor, and the rotational operation principle of this SR motor requires an encoder signal for detecting the position of the rotor in order to synchronize with the pulse signal of the phase current. With this position detection signal, the rotor is rotated under the control of synchronizing the phase winding pulse signal of the stator by the semiconductor switch.

  And since this SR motor does not use a permanent magnet for the rotor, the motion efficiency is improved without considering the scattering of the magnet, and the manufacturing cost is greatly advantageous compared to a brushless DC motor or the like. ing.

However, since this SR motor is vibrated and difficult to downsize, the application range of use is limited. Focusing on this point, the technique shown in Patent Document 1 has been disclosed, but this structure has not yet been able to use the magnetic flux more efficiently and has not been completed in terms of accuracy.
JP 2004-229404 A

  The problem to be solved by the present invention is that the SR motor having the conventional structure has a low use efficiency of the magnetic force, and may not be able to operate for practical use as a motor and lacks its accuracy. It is.

  In order to solve the above-described problems, the SR motor according to the present invention has a stator having a plurality of ribs provided at an equal pitch, and magnets whose adjacent opposing magnetic poles have the same polarity are provided between the tips of the ribs. In the arranged SR motor, each coil is fitted between the ribs, and the magnet is positioned on an installation end face of each coil. The rib has an outer surface formed flat. It is characterized by that.

  In addition, the SR motor according to the present invention has a structure in which the above-described stator is disposed on the outer periphery of the rotor, the ribs protrude in the direction of the rotor, and the gap between the ribs is a wedge shape that becomes narrower inward. The rotor has a rotating shaft at the center, and the tip longitudinal cross-sectional area of the protrusion (pole) formed on the outer peripheral surface of the rotor is the longitudinal section of the tip of the rib (pole) described above. It is characterized by being equal to or greater than the surface area.

  Furthermore, the SR motor according to the present invention is characterized in that the above-described magnet can be attached and detached, and the magnetic force in the sense including the material, width, length and number of the magnet can be selected and changed according to the required torque, The combined magnetic flux density of the two magnets that sandwich one rib is 1.2 times or less than the saturation magnetic flux density of the stator rib.

  In the SR motor according to the present invention, the magnet described above has a trapezoidal cross section that matches the gap structure between the ribs described above, and prevents the magnet from popping out and falling off even if it is attracted to the rotor side. It is characterized by being.

  The SR motor according to the present invention is configured as described above. Therefore, SR motors that do not use magnets basically do not have a magnetic field, but when a magnet is interposed, a magnetic field is generated. When a coil is energized, a reverse magnetic force is obtained. The magnetic force passes through the stator ribs. In general, the saturation magnetic flux density in the rib is 1.5 to 2.0 Tesla. If the inside of the rib is saturated, the electromagnetic force does not increase so much even if more current is supplied. However, by intervening the magnet, the magnetic flux generated by the magnet and the magnetic flux generated when electricity is applied cancel each other, and the saturation magnetic flux density of the rib increases as much as the magnet is inserted. Therefore, the current can be used more effectively than the conventional current, and a motor with high efficiency and output can be provided.

  According to the sixth aspect of the present invention, if the magnetic force of the magnet is too strong, it can be prevented that the magnetic force leaks and adversely affects the rotation of the rotor.

  Furthermore, according to the structure of the SR motor according to the present invention, even if the magnet between the ribs of the stator is attracted to the rotor side, it can be prevented from popping out and falling off.

  As described above, the SR motor according to the present invention effectively uses the magnetic force, can obtain the operation as a motor with high accuracy, can suppress vibration and can be downsized, and is necessary by exchanging magnets. It can be matched to the torque to be mounted and can be mounted corresponding to a wide range of products.

  This was realized by configuring as illustrated in the drawings and described in the examples.

  Next, an example of a preferred embodiment of the present invention will be described with reference to the drawings. 1 is a plan view showing an SR motor embodying the present invention, FIG. 2 is a longitudinal sectional view, FIG. 3 is a bottom view, FIG. 4 is a plan view showing the stator, FIG. 5 is a sectional view, and FIG. Fig. 7 is a plan view showing the rotor, Fig. 7 is a longitudinal sectional view, Fig. 8 is a front view showing the magnet, and Fig. 9 is a plan view.

  In these drawings, reference numeral 1 denotes a stator. The stator 1 has a square shape with rounded corners in plan view, and a plurality of tips are concentrated in the form of concentrating the tip toward the center on the inside thereof. The ribs 2, 2,... Are integrally formed with an equal pitch, in this embodiment, a pitch of 30 degrees.

  The stator 1 is formed by laminating and adhering soft magnetic materials having a saturation magnetic flux density of about 2.15 Tesla particularly in the ribs 2, 2. In this lamination, the shafts 4 with the female threads at both ends are inserted into the shaft holes 4, 4... Into the flange portions 3, 3.

  Further, positioning holes 7 and 7 are formed in the vicinity of the diagonal positions of the shaft holes 4, 4..., And are fixed to the fixing holes 7 and 7 together with a casing to be described later. A pin (not shown) is fitted. As a result, when the stator 1 is simply laminated and screwed, it is possible to prevent backlash due to the gap that allows for the screwing and the contact with it, and to suppress vibration and noise as a whole of the motor. By increasing the number of 2, vibration and noise can be further suppressed in addition to suppressing torque ripple.

  Each of the ribs 2, 2... Has a flat outer surface without a wing-like projection at the tip as in the prior art, and the tip surface is slightly concave when viewed in plan. The space | gap 6,6 ... between 2 ... is made into the wedge shape which becomes narrow toward the center. In the gaps 6, 6..., Coils 8, 8,... Wound around the outer periphery of the frame-shaped core are press-fitted or inserted from the open side on the inner side where the width is narrow. At this time, since the number of turns on the inner side of the coil 8 is reduced, the coil 8 is deformed so as to be crushed and closely fitted according to the shape of the gap 6. In the figure, reference numeral 9 denotes an insulating material for completely preventing energization of the coil 8 with the core.

  Further, magnets 10, 10... Are arranged at the tip portions of the gaps 6, 6. The magnet 10 has a trapezoidal shape with a narrow tip in accordance with the shape of the gap 6 and can be attached and detached. The magnets 10, 10... Can be exchanged selectively. In addition, because of the trapezoidal shape, there is no possibility of popping out and dropping off even if it is detachable or sucked to the rotor side described later.

  The two magnets 10 and 10 sandwiching one rib 2 are arranged such that the opposite magnetic poles have the same polarity, and the sandwiched rib 2 is excited so as to have the same polarity. This enhances the force acting on the rotor described later. Further, the combined value of the magnetic flux densities of the two magnets 10 and 10 sandwiching the rib 2 is 1.2 times or less than the saturation magnetic flux density of the rib 2. This prevents the magnets 10 and 10 from being too strong and causing a loss, and also prevents adverse effects on the rotation of the rotor.

  On the other hand, reference numeral 11 in the figure denotes a rotor, and this rotor 11 is also formed by laminating thin sheets of silicon steel or pure iron, which is a soft magnetic material. The area is larger than that of the stator 1. The rotor 11 is concentrically provided with three pin holes 12, 12... At a pitch of 120 degrees, and is positioned by inserting pins into the pin holes 12, 12..

  The rotor 11 is integrally formed with eight protrusions (poles) 13, 13... At an equal pitch on the outer periphery, and in the case of this embodiment, at a pitch of 45 degrees. The end surface vertical cross-sectional area of each of the protrusions 13, 13... Is equal to or greater than the end surface vertical cross-sectional area of the rib 2 of the stator 1. However, in this embodiment, the number of laminated thin plates of the rotor 11 is larger than that of the stator 1. As a result, the cross-sectional area is secured to that extent. Thus, the protrusion 13 can receive the magnetic flux passing through the rib 2 of the stator 1 more effectively.

  Further, an insertion hole 15 of the rotating shaft 14 is formed in the center of the rotor 11 so as to penetrate vertically. The rotary shaft 14 has a lower diameter at the upper and lower ends than the center.

  Further, in the figure, 16 indicates an upper casing and 17 indicates a lower casing. The casings 16 and 17 are adapted to the outer shape of the stator 1, and the portions corresponding to the flange portions 3, 3... Are stepped portions 16a and 17a. As shown in FIG. Then, screws 18 and 18 are screwed and fixed to the shaft 5 from outside the casings 16 and 17.

  A through hole is formed in the center of the upper casing 16 and the lower casing 17 so that the rotary shaft 14 protrudes, and a small diameter portion of the rotary shaft 14 is supported by bearings 19 and 19 inside the vicinity of the opening. Yes.

  A circuit board 20 is disposed on the lower surface of the rotor 11 and an encoder 21 for detecting the rotational position of the rotor 11 is provided. The encoder 21 detects the rotational position of the rotor 11 and is automatically controlled to synchronize the pulse signal of the coil 8. Reference numeral 22 denotes a harness for connecting to the control unit of the encoder 21, and 23 denotes a cord. The cord 23 is provided through a cord hole 24 formed in the lower casing 17.

  Further, in the figure, reference numeral 25 denotes a harness for connecting to a control unit for energizing the coil 8, and cords 26a and 26b are connected to this harness in this embodiment, and cord holes formed in the lower casing 17 are connected. 27 through. Reference numeral 27a denotes a spare cord hole. When the cords 26a and 26b are thick or there are many cords, the spare cord hole 27a can be passed therethrough.

  The SR motor according to the present embodiment is configured as described above. From the arrangement configuration of the coil 8 and the magnet 10 with respect to the ribs 2, 2,... Of the stator 1, the magnetic force can be used more efficiently, and a large power can be exhibited as a motor. Further, there is no loss in the magnetic force, it is possible to obtain a highly accurate operation, and it is possible to realize downsizing by controlling the vibration, and the application range of use can be greatly expanded.

  The SR motor according to the present embodiment is configured as described above. In this embodiment, the stator 1 is on the outside and the rotor 11 is on the inside. However, the stator 1 can be replaced without being particular, and the shape of the stator 1 is not limited to this embodiment. The fixing structure with 16, 17 can be replaced with other forms.

It is a top view which shows the SR motor which implemented this invention. It is a longitudinal cross-sectional view. It is a bottom view. It is a top view which shows a stator. It is sectional drawing. It is a top view which shows a rotor. It is a longitudinal cross-sectional view. It is a front view which shows a magnet. It is a top view.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Stator 2 Rib 3 Flange part 4 Shaft hole 5 Shaft 6 Space | gap 7 Retaining hole 8 Coil 9 Insulating material 10 Magnet 11 Rotor 12 Pin hole 13 Protrusion 14 Rotating shaft 15 Insertion hole 16 Upper casing 16a Step part 17 Lower casing 17a Step part 18 Screw 19 Bearing 20 Circuit board 21 Encoder 22 Harness 23 Cord 24 Cord hole 25 Harness 26a Cord 26b Cord 27 Cord hole 27a Spare cord hole

Claims (7)

  In an SR motor having a stator in which a plurality of ribs are provided at equal pitches, and magnets in which adjacent magnetic poles having the same polarity are arranged between the rib tips, coils are fitted between the ribs. The SR motor is characterized in that the magnet described above is located on the installation end face of each coil.   The SR motor according to claim 1, wherein the rib has an outer surface formed flat.   The above-described stator is structured to be disposed on the outer periphery of the rotor, the ribs protrude in the rotor direction, and the gap between the ribs has a wedge shape that becomes narrower inward. The SR motor according to claim 1 or 2.   The rotor has a rotation shaft at the center, and the tip vertical cross-sectional area of the protrusion (pole) formed on the outer peripheral surface of the rotor is equal to or larger than the tip vertical cross-sectional area of the rib (pole) described above. The SR motor according to claim 1, claim 2, or claim 3.   The above-described magnet is detachable, and the magnetic force in the meaning including the material, width, length, and number of the magnet can be selected and changed according to the required torque. The SR motor according to claim 3 or claim 4.   The combined value of the magnetic flux densities of the two magnets that sandwich one rib with respect to the saturation magnetic flux density of the ribs of the stator is 1.2 times or less. The SR motor according to claim 2, claim 3, claim 4 or claim 5.   2. A magnet according to claim 1, wherein the magnet has a trapezoidal cross section that matches the gap structure between the ribs, and prevents the magnet from popping out and falling off even if it is attracted to the rotor side. The SR motor according to claim 1, claim 3, claim 4, claim 5, or claim 6.

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