Switched reluctance motor and connection method for sensor shutter thereof

The present invention relates to a switched reluctance motor and a connection method for a sensor shutter thereof. The switched reluctance motor in accordance with the present invention includes a stator; a rotor rotating with respect to the stator centering around a rotational shaft; and a sensor shutter having a sensing part through which a light can be passed and connected to an end portion of the rotational shaft, and a stopping ring is connected to the end portion of the rotational shaft so as to prevent the sensor shutter from being separated. Accordingly, the sensor shutter can be quickly and easily connected and the length of the rotational shaft can be decreased.

TECHNICAL FIELD

The present invention relates to a switched reluctance motor, and more particularly, to a switched reluctance motor which is capable of easily connecting a sensor shutter and of decreasing a length thereof in an axial line direction, and a connection method for the sensor shutter thereof.

BACKGROUND ART

As known, the switched reluctance motor rotates a rotor by using a reluctance torque according to a change in the magnetic reluctance and has advantages in that its fabrication cost is low, it does not need much maintenance and has such high reliability that its life span is substantially permanent.

FIG. 1is a sectional view of the related art switched reluctance motor, andFIG. 2is a sectional view taken along line II-II inFIG. 1. As shown in the drawings, the switched reluctance motor includes a housing11, a stator21fixed within the housing11, a rotor31rotatably disposed with respect to the stator21, and a rotor position detecting unit41that detects a rotational position of the rotor31.

A plurality of through holes13are formed at side portions of the housing11to allow the interior and exterior to communicate with each other, and a stator21is fixedly disposed within the housing11. The rotor31is installed to be rotatable centering around a rotational shaft33within the stator21. The rotational shaft33is rotatably supported by a bearing35fixed at the housing11.

Meanwhile, the rotor position detecting unit41includes a sensor disk43integrally and rotatably connected to the rotational shaft33, and a sensor unit51interworks with the sensor disk43to detect a rotational position of the rotor31.

The sensor disk43has a disk shape and includes a plurality of protrusions45formed to be outwardly protruded in a radial direction at the circumference thereof. A support member47is connected at one side of the sensor disk43and connected to the rotational shaft33to support the sensor disk43.

The sensor unit51includes a plurality of PCBs53, a PCB fixing member55for fixing the PCBs53at the housing11, and a photo-interruptor57having a light emitting part58and a light receiving part59that are disposed to be spaced apart with the protrusions45of the sensor disk43interposed therebetween in the axial line direction at one side of each PCB53. Here, the PCBs53and the photo-interruptors57are provided by the number corresponding to each phase (three-phase) of a coil of the stator21and connected at each pre-set position.

The related art switched reluctance motor has the following problems. That is, because the sensor unit51is connected in the through holes13formed at the lateral portion of the housing11, the stator21needs to be precisely inserted within the housing11in consideration of the position of the sensor unit51during assembling, so much attention and time are required for the assembling of the stator21.

In addition, as in case used for a motor of a vacuum cleaner, because the light emitting part58and the light receiving part59are disposed within the housing11in which temperature is relatively high and there is much dust, the life span and sensitivity of the light emitting part58and the light receiving part59are negatively affected.

In addition, because the sensor disk43is connected to the support member47by using a screw or the like, time duration for assembling is extended, and the length of the rotational shaft33and the size of the housing are increased, thereby being disadvantageous in a compact configuration.

DISCLOSURE OF THE INVENTION

Technical Problem

Therefore, one object of the present invention is to provide a switched reluctance motor which is capable of quickly and easily connecting a sensor shutter and of decreasing a length of a rotational shaft thereof, and a connection method for the sensor shutter thereof.

Another object of the present invention is to provide a switched reluctance motor which is capable of firmly fixing a sensor shutter to a rotational shaft and a connection method for the sensor shutter thereof.

Technical Solution

To achieve these and other advantages and in accordance with an aspect of the present invention, there is provided a switched reluctance motor comprising: a stator; a rotor rotating with respect to the stator centering around a rotational shaft; a sensor shutter having a sensing part through which a light can be passed and connected to an end portion of the rotational shaft; a stopping ring connected to the end portion of the rotational shaft so as to prevent the sensor shutter from being separated.

Here, a sensor shutter connecting unit that is reduced in a radial direction to allow the sensor shutter to be connected to is formed at the end portion of the rotational shaft, and the stopping ring may be connected to the sensor shutter connecting unit.

Further, a concave-convex part may be formed at the sensor shutter connecting unit to prevent an gap in an axial line direction of the stopping ring.

Preferably, a shaft hole is formed at the sensor disk to allow the sensor shutter connecting unit to be inserted into, and a rotation restraining part that restrains a relative rotation is formed at the sensor shutter connecting unit and the shaft hole.

The rotation restraining part may comprise protrusions protruding at an inner side of the shaft hole in the radial direction, and protrusion receiving recesses formed at the sensor shutter connecting unit to receive the protrusions.

Here, the protrusions may be formed by making a pair.

Meanwhile, in accordance with another aspect of the present invention, there is provided a switched reluctance motor comprising: a stator; a rotor rotating with respect to the stator centering around a rotational shaft; a sensor shutter having a sensing part through which a light can be passed and connected to the rotational shaft with a pre-set assembling position; and a rib connected to the sensor shutter and then curved at the end portion of the rotational shaft so as to prevent the sensor shutter from being separated.

Here, a concave-convex part may be formed at the end portion of the rotational shaft connected to the sensor shutter in a circumferential direction.

A shaft hole penetrated to insert the end portion of the rotational shaft may be formed at the sensor shutter, and a rotation restraining part may be formed at the end portion of the shaft hole and the rotational shaft so as to restrain a relative rotation.

The rotation restraining part may comprise protrusions protruding at any one of the end portion of the rotational shaft and the shaft hole toward another one, and protrusion receiving recesses formed at another one to receive the protrusions.

Preferably, the rib is formed in plural spaced from each other by intervals for inserting the protrusions in the axial line direction.

Meanwhile, in accordance with still another aspect of the present invention, there is provided a connection method for a sensor shutter of a switched reluctance motor in which the sensor shutter having a sensing area passing a light and a shaft hole at a center thereof is connected to one end portion of a rotational shaft of a rotor, the connection method comprising: forming a rib at the one end portion of the rotational shaft to be protruded in an axial line direction; connecting the rotational shaft to the sensor shutter so as for the rib to pass through the shaft hole; and fixing the sensor shutter by curving the rib.

Here, prior to the step of connecting the rotational shaft to the sensor shutter, it may further comprise forming a concave-convex part at an outer surface of the rotational shaft to which the sensor shutter is connected in a circumferential direction.

Effect of the Invention

As aforementioned in detail, in accordance with the present invention, because the stopping ring is connected or the rib is curved after the connection of the sensor shutter, the sensor shutter can be quickly and easily connected, besides, because a screw connecting means, such as a screw, a bolt, a nut or the like, which relatively spends much time on connecting and needs a relatively long length of the axial line, is not used, the length of the rotational shaft can be decreased and the size of the motor with respect to the axial line direction can be smaller overall.

Further, in accordance with the present invention, the sensor shutter can be firmly fixed to the rotational shaft and there is no concern to be loosen by vibrations while rotating, accordingly enabling the reliability of an apparatus to be enhanced.

Further, in accordance with the present invention, because air flows into the housing in the axial line direction of the motor, the temperature is relatively high, and the sensor disk and the sensor can be installed by being separated from the inside of a motor housing having dust or the like, thereby being capable of preventing the sensor from being negatively affected by the temperature and the dust, and of reducing the size of the motor housing.

MODES FOR CARRYING OUT THE PREFERRED EMBODIMENTS

Hereinafter, the present invention will be described in detail with reference to accompanying drawings.

As shown inFIG. 3, the switched reluctance motor includes: a stator120; a rotor130rotating with respect to the stator120centering around a rotational shaft131; a sensor shutter140having a sensing part141, as shown inFIG. 5, through which a light can be passed and connected to an end portion of the rotational shaft131; a stopping ring151connected to the end portion of the rotational shaft131so as to prevent the sensor shutter140from being separated.

The stator120is provided with a plurality of salient poles123therein, and the rotor130is provided with salient poles133formed to be outwardly protruded in a radial direction so as to be rotatably connected to an interior of the stator120centering around the rotational shaft131. A pair of bearings132are connected to the rotational shaft131.

The stator120and the rotor130are receivedly installed inside of a motor housing110having the interior formed in a receiving space having one opened side, and a bearing connecting unit113to allow the bearings132to be connected to is formed at a closed end112aof the motor housing110. A shaft hole115is formed at the bearing connecting unit113so that the end portion of the rotational shaft131can be exposed outwardly.

Meanwhile, the sensor shutter140, as shown inFIG. 5, is provided with sensing parts141and blocking parts142which have the different length in the radial direction so that light can be passed through or blocked, and the shaft hole143is formed at a central area thereof so as to insert the rotational shaft131. Protrusions145are protrudingly formed inside of the shaft hole143so as to be integrally rotated with the rotational shaft131when connecting to the rotational shaft131.

At the end portion of the rotational shaft131, as shown inFIG. 4, recesses135cut in a diameter direction are formed to insert the protrusions145when connecting the sensor shutter140. Here, the outer surface of the end portion of the rotational shaft131may be cut to be flattened and the shaft hole of the sensor shutter140may be formed to correspond to a shape of a cross section of the rotational shaft131. A stopping ring151is coupled to one side of the sensor shutter140so as to prevent the sensor shutter140from being separated.

The stopping ring151has a ring shape, and is provided with a plurality of protrusions152inwardly protruded at inner surface thereof. Here, it is preferable that the stopping ring151is formed in a circular shape to attenuate a generation of vibrations, because a large vibration can be generated by a small vibration generating element when the rotor130rotates in a high speed (for example, approximately 30000 rpm to 80000 rpm).

As shown inFIG. 4, a concave-convex part136having a cross section of which top parts137aand bottom parts137bare alternately disposed in the axial line direction is formed at the outer surface of the rotational shaft131so as to prevent the stopping ring151from being separated by engaging with the protrusions152of the stopping ring151.

A sensor housing160is connected to the closed end112aof the motor housing110so as to receive the sensor shutter140therein. A female screw part116is formed at the motor housing110so that a connecting member170such as a screw, or the like can be connected, and a through hole168is formed at the sensor housing160so that the connecting member170can pass through. Sensors165having a light emitting part166and a light receiving part167which are spaced apart with the sensor shutter140interposed therebetween in the axial line direction is disposed at the sensor housing160.

With such configuration, when the stator120and the rotor130are connected in the motor housing110, the end portion of the rotational shaft131is exposed outwardly through the shaft hole115. The sensor shutter140is connected to the rotational shaft131so as to insert the protrusions145into the recesses135of the rotational shaft131, and a stopping ring151is connected to the concave-convex part136so that the sensor shutter140can be prevented from separating and be fixed. After the stopping ring151is connected, the sensor housing160is connected to the end portion of the motor housing110, and the sensors165are connected to the corresponding positions of the sensor housing160, respectively.

Hereinafter, the switched reluctance motor in accordance with a second embodiment of the present invention will be described with reference toFIGS. 7 to 13. The same or equivalent features with aforementioned description are referenced by the same numerals for convenient description of the drawings, and the detailed description will be omitted. As shown inFIG. 7, the switched reluctance motor includes: the stator120; the rotor130rotating with respect to the stator centering around a rotational shaft171; a sensor shutter140having a sensing part141through which a light can be passed and connected to the rotational shaft171with a pre-set assembling position; a rib173connected to the sensor shutter140and then curved at the end portion of the rotational shaft171so as to prevent the sensor shutter140from being separated.

The stator120is provided with the plurality of salient poles123therein, and the rotor130is provided with salient poles133formed to be outwardly protruded in the radial direction so as to be rotatably connected to the interior of the stator120centering around the rotational shaft171. The pair of bearings132are connected to the rotational shaft171.

The stator120and the rotor130are receivedly installed inside of the motor housing110having the interior formed in the receiving space having one opened side, and the bearing connecting unit113provided with the shaft hole115is formed at the closed end112aof the motor housing110so that the bearings132is connected thereto and the end portion of the rotational shaft171can be exposed.

The sensor shutter140is provided with the sensing parts141and the blocking parts142, and the shaft hole143is formed at the central area thereof. The protrusions145are protrudingly formed inside of the shaft hole143so as to be integrally rotated with the rotational shaft171when connecting to the rotational shaft171.

Meanwhile, at the end portion of the rotational shaft171, as shown inFIGS. 7 and 8, a pair of ribs173which are curved to contact the surface of the sensor shutter140is formed at the end portion of the rotational shaft171so as to prevent the sensor shutter140from being separated after the connection of the sensor shutter140. The ribs173are formed to have an arch shape and be spaced apart in insertion intervals174of the protrusions145. Recesses175cut in the diameter direction are formed at the end portion of the rotational shaft171so that the protrusions145can be respectively received when connecting the sensor shutter140. Here, at the outer surface of the rotational shaft171, as shown inFIGS. 11 and 12, a concave-convex part186having the cross section of which top parts187aand bottom parts187bare alternately disposed in a circumferential direction is formed, which is preferable to increase a connecting force of the sensor shutter140.

With such configuration, when the stator120and the rotor130are connected in the motor housing110, the end portion of the rotational shaft171is exposed outwardly through the shaft hole115. After inserting the protrusions145of the sensor shutter140into the intervals174between the ribs173, the sensor shutter140is moved in the axial line direction so that the protrusions145are inserted into the recesses175.

Then, as shown inFIGS. 9 and 10, a tool181having an inclined end portion is disposed at the end portion side of the rib173, and the rib173is pressed in the axial line direction. When the rib173is pressed by the tool181, the rib173is curved adjacent to the sensor shutter140and outwardly split. As shown inFIG. 13, after the pressing, the rib173undergoes a plastic deformation to be adhered on the surface of the sensor shutter140, accordingly preventing the sensor shutter140from being separated. Meanwhile, when curving of the rib173is completed, the sensor housing160is connected thereto, and the sensors165are respectively connected to the positions pre-set for the sensor housing160.