JPH08275462A - Motor with speed sensor - Google Patents

Abstract

PURPOSE: To hold speed detecting magnets and a speed detecting element for the detection of rotational speed of a rotor using a simple structure, and prevent damage to the speed detecting magnets and stator coil ends. CONSTITUTION: A speed detecting element 10 is installed on a bracket 12. Recesses 5 are formed on the end faces of vanes 4 on a rotor end ring 3 in a position corresponding to the speed detecting element 10. Speed detecting magnets 1 are fit and bonded into the recesses 5.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a motor with a speed detector which can be constructed with a simple structure.

[0002]

2. Description of the Related Art Generally, in a motor with a speed detector, a speed detecting magnet for detecting the rotation speed of a rotor is provided directly on the outer circumference of a rotary shaft by an adhesive or the like, or is fixedly mounted via a mounting member. Then, a speed detecting element such as a hall element that detects the rotational speed of the rotor by the magnetic force of the speed detecting magnet is fixedly supported on the inner surface of the bracket through a support tool.

[0003]

In the above structure, the speed detecting magnet may hit the fixed portion during the assembling of the electric motor and may be damaged, or the coil end of the stator may be damaged by the support of the speed detecting element. There was a drawback that the number of parts increased and the structure became complicated. In order to eliminate the above-mentioned drawbacks, the present invention holds a speed detecting magnet and a speed detecting element for detecting the rotational speed of a rotor with a simple structure and prevents damage to the speed detecting magnet and the stator coil end. The present invention provides an electric motor with a speed detector that is capable of performing the above.

[0004]

SUMMARY OF THE INVENTION In order to solve the above-mentioned conventional problems, the present invention provides a bracket with a speed detecting element, and a blade end surface on a rotor end ring at a position corresponding to the speed detecting element. To provide a recess. Then, a speed detecting magnet is inserted into this recess and fixed by adhesion.

[0005]

[Work] With the above construction, it is not necessary to provide a special mounting member for the speed detecting magnet, and not only the structure is simplified but also the speed detecting magnet and the coil end are prevented from being damaged during assembly. it can.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment in which the present invention is applied to a squirrel cage phase control induction motor will be described below with reference to the drawings. FIG. 1 is a sectional view of an essential part of an induction motor with a speed detector showing a fixed structure of a speed detecting element and a speed detecting magnet using an embodiment of the present invention. Reference numeral 1 is a speed detecting magnet, and 2 is a rotor. A recess 5 for fitting the speed detecting magnet 1 is provided on the end surface of the blade 4 on the end ring 3 of the rotor 2. The fixing of the speed detecting magnet 1 will be described first.
An adhesive is applied to the concave portion 5 provided on the end surface of the blade 4 on the rotor end ring, and the speed detecting magnet 1 is inserted and fixed.
Further, at the fitting portion of the speed detecting magnet 1 and the concave portion 5 provided on the end face of the rotor end ring, the outer peripheral portion of the speed detecting magnet and the end face of the blade on the rotor end ring are provided. 1 on at least one of the inner circumferences of the recess
By forming the groove for accumulating the adhesive at a place or a plurality of places, the area of contact with each other is increased and the fixing strength by adhesion is further increased. Reference numeral 6 is a stator, and 7 is a coil end of the stator. The rotor 2 is fixed to the rotary shaft 8 and is rotatably fixed to the stator 6 via a bearing 9.

Next, the fixing of the speed detecting element 10 will be described. First, a support 11 made of a resin molded product for fixing and supporting the speed detecting element 10 is incorporated in the lower specified position of the speed detecting element 10 to form a bracket 12. It is inserted into the support tool mounting hole 13 provided in the end face, and the groove portion 14 provided in the support tool 11 and the end surface of the support tool mounting hole 13 provided in the bracket are fitted to each other so that left and right positioning can be performed. It can be positioned in the vertical direction by fixing with the stopper portion 15 provided on the. By filling the space 17 between the support 11 and the speed detecting element 10 and the connector 16 with resin, airtightness and insulation can be maintained and the speed detecting element 10 and the connector 16 can be fixed.
As a result, the speed detecting element 10 can be arranged at a position facing the speed detecting magnet 1. When the rotor 2 rotates with the above configuration, the speed detecting magnet 1 also rotates at the same speed, and the speed detecting element 10 mounted on the bracket 12 obtains a speed signal. By inputting this speed signal to the phase control circuit and controlling the phase control induction motor with the output of this phase control circuit, a phase control induction motor with high speed accuracy can be obtained. In the embodiment of the present invention, the case where the speed detecting magnet is provided on the blade end surface of the rotor has been described, but the present invention is not limited to this and may be provided on the end ring end surface of the rotor end surface, and the gist is changed. Of course, it can be changed within the range not to be.

[0008]

As is apparent from the above description, according to the present invention, the concave portions are formed in the blade end faces on the rotor end ring,
Apply adhesive to this recess and insert the speed detection magnet,
The following effects can be obtained by fitting and fixing the both. 1. No special parts are required to fix the speed detecting magnet, and the cost can be reduced. 2. By fixing the speed detecting magnet directly to the blade end surface on the rotor end ring, the size of the electric motor can be reduced. 3. The contact area between the speed detecting magnet and the concave portion provided on the end face of the blade on the rotor end ring increases, and the adhesion strength by adhesion increases. 4. The speed detection magnet and the speed detection element can be held by a simple structure with a small number of parts, and the speed detection magnet and the coil end can be prevented from being damaged during assembly.

[Brief description of drawings]

FIG. 1 is a sectional view of an essential part of an electric motor with a speed detector according to an embodiment of the present invention.

[Explanation of symbols]

 1 Speed Detecting Magnet 2 Rotor 3 End Ring 4 Blades 5 Recess 6 Recess 7 Coil End 8 Rotating Shaft 9 Bearing 10 Speed Detecting Element 11 Support Tool 12 Bracket 13 Support Tool Mounting Hole 14 Groove 15 Stopper 16 Connector 17 Space Department

Claims (3)

[Claims] 1. A speed detecting element is disposed on a bracket, and a recess for disposing a speed detecting magnet is formed on a blade end surface on a rotor end ring at a position corresponding to the speed detecting element,
An electric motor with a speed detector in which the speed detecting magnet is fitted in the recess and fixed by adhesion. 2. The speed detecting device according to claim 1, wherein a support tool for fixedly supporting the speed detecting element on the inner surface of the bracket via the support tool has a stopper portion and a groove portion for fitting with the bracket. Electric motor with a device. 3. At least one of an outer peripheral portion of the speed detecting magnet and an inner peripheral portion of the concave portion at a fitting portion between the speed detecting magnet and the concave portion provided on the blade end surface on the rotor end ring. The electric motor with speed detector according to claim 1 or 2, wherein a groove is formed in the groove.