EP3853976A1

EP3853976A1 - Motor terminal for quick connection shift

Info

Publication number: EP3853976A1
Application number: EP19748525.3A
Authority: EP
Inventors: Hasim OTUNC; Caglar ACAR; Evren SOYDAN; Cem DOGAN; Goknur TIKIC
Original assignee: Arcelik AS
Current assignee: Arcelik AS
Priority date: 2018-09-17
Filing date: 2019-07-30
Publication date: 2021-07-28
Also published as: WO2020057823A1

Abstract

The present invention relates to an electric motor (1) wherein the connection type is easily and correctly changed as delta or star connection by means of the terminal block plate (8) comprising the slide plate (9) without using any tools.

Description

MOTOR TERMINAL FOR QUICK CONNECTION SHIFT

The present invention relates to an electric motor wherein the shift to the desired connection (star or delta connection) in the terminal box can be quickly and correctly performed.
Industrial type electric motors are basically composed of the fixed stator and rotating rotor. The stator is formed by stacking laminations with different thicknesses in special molds and then the windings are passed through the slots thereof. Similar to the stator, the rotor is also formed by stacking laminations one above the other, and preferably aluminum rods are hammered into the slots thereof. By means of the electrical energy supplied to the stator windings, a rotating magnetic field is generated. The rotating magnetic field intercepts the rods in the rotor and provides the flow of alternative current. The rotating magnetic field applies a force onto the conductor through which current flows and as a result of this force the rotor is enabled to be rotated. The basic function of the electric motor is to convert electrical energy to mechanical energy. The electrical energy is received via the terminal box and the output power is taken from the rotor (end of the shaft).
While the electrical energy is supplied to the motor, there can be two types of connection on the terminal plate. The first of these connections is the delta connection and the other is the star connection. The main difference between the star and delta connections is the difference between the current and voltage drawn by the motor without changing the motor power. In the star connection the voltage is high while the current is low. On the other hand, in the delta connection the voltage is low while the current is high. According to the field of application, said two types of connection are needed, and it is required to shift between the connections and change the bridges.
The problem addressed by the present invention is the different positions of the bridge components in the star and delta connections. Because there is a neutral point in the delta connection, which should be formed on the terminal plate. When the connection is desired to be changed, the connection between the mains electricity and the motor is cut off. The bridge components, nuts and washers on the motor terminal plate are removed. According to the new connection type (shift from the star to delta or from the delta to star connection), the bridge components are repositioned, the connection to the mains electricity is established, and the nuts and washers are tightened again.
In the state of the art Patent Application No. CN 203014721 U in 2013, Patent Application No. CN 104009677 in 2014, Patent Document No. WO 2015/056271 in 2015, a motor terminal is disclosed wherein switching over between the connections (star or delta connection) can be performed.
The aim of the present invention is the realization of a terminal wherein the connection type (star or delta connection) of the electric motor can be quickly and correctly changed without using any tool (wrench, screwdriver, etc.) or without demounting any component.
In the electric motor realized in order to attain the aim of the present invention, explicated in the first claim and the respective claims thereof, the transmission between the connection points is provided by means of a slide plate on the terminal. According to the type of this transmission, the connection type can be adjusted as delta or star connection.
Thus, the time required for changing the conventional electric connection in motors not under load is decreased. Moreover, the need for removing nuts, washers and mains connection and reattaching the same for the new connection is eliminated, the system allows shifting between two defined connection types, and thus the risk of the operators making wrong connections is eliminated.
An electric motor realized in order to attain the aim of the present invention is illustrated in the attached figures, where:
Figure 1 - is the view of the main sections of industrial electric motors.
Figure 2 - is the perspective view of the connection type in the sliding system of the present invention.
The elements illustrated in the figures are numbered as follows:
1. Electric motor
2. Body
3. Rotor shaft and core group
4. Cover
5. Terminal box
6. Fan cover
7. Foot
8. Terminal block plate
9. Slide plate
10. Conductive plates
11. Pin
The electric motor (1) comprises

a rotor shaft and core group (3) which provides the rotational movement,
a body (2) wherein the rotor shaft and core group (3) is disposed,
a cover (4) which covers the open parts of the body (2),
a terminal block plate (8) for making electrical connections,
a terminal box (5) wherein the terminal block plate (8) is disposed,
a fan cover (6) which covers the rear side of the motor (1),
two feet (7) for mounting the body (2) in place.

The terminal block plate (8) comprise a slide plate (9), a conductive plate (10) and a plurality of pins (11).
The basic function of the electric motor (1) is to convert electrical energy to mechanical energy. The electrical energy is supplied to the electric motor (1) via the terminal block plate (8) in the terminal box (5). The electrical connections are connected to the pins (11) on the terminal block plates (8) via connection elements. Said connections can be made in two different types, that is delta and star connection. Depending on the type of connection, the current and voltage values of the motor may vary.
The pins (11) on the terminal block plate (8) are in contact with the conductive plates (10). The conductive plates (10) are located on the slide plate (9). The delta or star connection is realized by providing transmission between the pins (11) according to the position of the slide plate (9). The marks on the slide plate (9) indicate the type of the connection, whether delta or star connection.
The electrical energy supplied to the electric motor (1) generates a magnetic field on the windings in the body (2).
By means of the magnetic field generated in the body (2), the rotor shaft and core group (3) is enabled to be rotated. The rotational movement is transmitted outside the body (2) by means of the rotor shaft and core group (3).
In an embodiment of the present invention, as the connection type can be changed as star or delta connection without removing any electrical connections connected to the pins (11), the problems arising from the erroneous connections due to human error are prevented.
In another embodiment of the present invention, since the established electrical connections are not required to be removed to change the connection type, the need for any tool or equipment (wrench, screwdriver, etc.) is eliminated.
The electrical energy is transmitted to the windings in the body (2) of the electric motor (1) via the electrical connection to the pins (11), the conductive plates (10) and the slide plate (9). Without detaching the cables connected onto the pins (11) via connection elements, the desired delta or star connection is made by sliding the slide plate (9) right or left. Thus, by eliminating the need for removing the connection elements while changing the connection type, labor costs are decreased and assembly errors which may arise due to labor are prevented.

Claims

An electric motor (1) comprising a rotor shaft and core group (3) which provides the rotational movement, a body (2) wherein said rotor shaft and core group (3) is disposed, a cover (4) which covers the open parts of the body (2), a terminal block plate (8) for making electrical connections, a terminal box (5) wherein the terminal block plate (8) is disposed, a fan cover (6) which covers the rear side of the motor (1), and two feet (7) for mounting the body (2) in place.
An electric motor (1) as in Claim 1, characterized by a stator which is stationary in the body (2) and the rotor shaft and core group (3) which makes rotational movement by means of the magnetic field generated in the body (2).
An electric motor (1) as in Claim 1, characterized by the terminal box (5) which is mounted onto the body (2) and which comprises the terminal block plate (8) for making the electrical connections.
An electric motor (1) as in Claim 3, characterized by the terminal block plate (8) which is fixed into the terminal box (5) by means of fixing members and by a plurality of pins (11) wherein the electrical connections on the terminal block plate (8) are made by means of connection elements.
An electric motor (1) as in Claim 4, characterized by the terminal block plate (8) comprising conductive plates (10) which are continuously in contact with the pins (11), a slide plate (9) and the conductive plate (10) which is in contact at different parts depending on the position of the slide plate (9).
An electric motor (1) as in Claim 4, characterized by the slide plate (9) which can slide right or left depending on the connection type and which can move on the terminal block plate (8).