JPS60194734A - Motor - Google Patents

Abstract

PURPOSE:To provide efficient cooling function by twisting slots formed on a rotor core with respect to a rotor shaft. CONSTITUTION:A rotor core 6b formed with slots 9b is press-fitted into a rotor shaft 8b, and formed at a twisting angle alpha with respect to the shaft 8b. In this construction, when the shaft 8b is rotated, the core 6b performs as a fan to generate an axial air flow mainly through the slots 9b, thereby suppressing the temperature rise of a rotor winding.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to an electric motor having a rotor core fixed to a rotor shaft and made of laminated steel plates.

Conventional Structure and Problems Conventionally, this type of motor, a commutator motor, has a field winding 1 attached to a field core 2, and a bearing portion 3 attached to the field core 2, as shown in FIG. 2 is installed inside a bracket 4, and a rotor shaft 8 to which a rotor core 6 having a rotor winding 6 and a commutator 7 are press-fitted and fixed is pivotally supported on the bearing part 3. there were.

Still, the rotor core 6 is composed of laminated steel plates, and there is no need to twist the rotor teeth relative to the rotor shaft 8 in order to increase the starting torque or to determine the direction of rotation, as in an induction motor. As shown, a slot 9 for receiving one winding is arranged parallel to the rotor axis 8.

Furthermore, home appliances such as juicers and mixers are rarely used under stable load conditions like blowers, but are used under a wide variety of load conditions depending on the user. Sometimes, electric motors are used under harsh conditions, and as a result, the value of current flowing through the field winding 1 and rotor winding 5 increases, the temperature of both windings rises, and ultimately the windings burn out. Connect with.

The temperature rise value of this winding is one element for evaluating the performance of the motor, but in the above conventional configuration, the field winding 1 and the rotor winding 6 transfer heat to the field core 2 and the rotor core 6. The amount of heat dissipated from each iron core was sufficient to reduce the temperature rise of each winding, and the motor itself did not have any special configuration for cooling.

Therefore, there was a problem in that it was necessary to install a fan or use an unnecessarily large electric motor just for the purpose of lowering the temperature of the winding.

OBJECTS OF THE INVENTION The present invention solves the above-mentioned conventional problems and provides an electric motor that can suppress the temperature increase of the windings without using special parts.

Structure of the Invention In order to achieve the above object, the present invention includes a rotor core made of laminated steel plates provided with a plurality of slots for rotor windings, and a rotor shaft into which the rotor core is press-fitted. The slots provided in the rotor core are configured to have a torsion angle with respect to the rotor shaft. According to this configuration, when the rotor shaft rotates, the slots are twisted due to the torsion of the slots. The air inside the slot is pushed out of the slot under pressure, which allows the air to flow through the slot, thereby keeping the temperature rise low.

DESCRIPTION OF EMBODIMENTS Hereinafter, a commutator motor which is an embodiment of the present invention will be described based on the accompanying drawings. In FIG. 3, 6b is a rotor core provided with a slot 9b, which is press-fitted into the rotor shaft 8b. This slot 9b is formed at a helix angle α with respect to the rotor shaft 8b. In this configuration, as the rotor shaft 8b rotates, the rotor core 6b acts as a fan, causing air to flow mainly through the slots 9b in the axial direction. Also, in commutator motors,
The winding specifications are usually designed so that the temperature rise value of the rotor winding is higher than that of the field winding, and from this point of view, air flow is created inside the slot where the rotor winding is installed. , suppressing the temperature rise of the rotor windings leads to improved motor characteristics.

Furthermore, the operating speed of commutator motors ranges from 10,000 to 20,000 revolutions per minute.
It is often used at 10,000 rotations, and it is difficult to create air flow in the axial direction through the inside of the rotor (slots) with wind applied from the outside, and the outer surface must be cooled. It is a good idea to provide the child core itself with a fan function, and it is also significantly advantageous from a cost perspective.

Effects of the Invention As is clear from the above embodiments, the electric motor of the present invention has a slot provided in the rotor core that is twisted with respect to the rotor axis, so that the electric motor has the same cost as the conventional motor. Well, the electric motor itself can have an efficient cooling function.

[Brief explanation of drawings]

Fig. 1 is a sectional view of essential parts of a conventional commutator motor, Fig. 2 is a front view of the rotor of the commutator motor, and Fig. 3 is a front view of the rotor of a commutator motor according to an embodiment of the present invention. It is a diagram. 6b... Rotor core, 8b... Rotor shaft, 9
a. 9b...Slot. Name of agent: Patent attorney Toshio Nakao and 1 other person 1st
Figure 2 Figure 3

Claims (1)

[Claims] It has a rotor core made of laminated steel plates provided with a plurality of slots for rotor windings, and a rotor shaft into which this rotor core is press-fitted, and the slots are arranged at a torsion angle with respect to the rotor shaft. The electric motor I had.