GB2200263A

GB2200263A - Single phase induction motor

Info

Publication number: GB2200263A
Application number: GB08729147A
Authority: GB
Inventors: Samy Akbar
Original assignee: Individual
Current assignee: Individual
Priority date: 1986-12-22
Filing date: 1987-12-14
Publication date: 1988-07-27
Also published as: DE3643999A1; GB8729147D0

Abstract

A single phase induction motor with a short-circuited rotor has a three-phase series wound stator 1, 2, 3 which operates with a single operating capacitor 5 and, in dependence on the selected connection points of the AC source 11 (to point 7 or 8), makes rotation in the one or other direction of rotation possible with high initial torque and low noise generation. The stator windings are said to be in a star arrangement. <IMAGE>

Description

s SINGLE PHASE INDUCTION MOTOR IN A STAR ARRANGEMENT The invention relates to a three-phase induction motor with a short-circuited rotor and a three-phase winding in a star arrangement with three inner (star) connections and three outer connections.

A single phase induction motor of this kind is described in the patent application P 36 32 512.0 and is characterised by a high initial torque, good power endurance and low noise.

The present invention represents a further improvement of this single phase induction motor and leads, above all, to minimisation of the capacitive effort and expense and thus to a further increase in the profitability of the motor.

The solution in accordance with the present invention is characterised in that the three phases of the stator winding together with the operating capacitor are so connected in series to form a closed circuit that from this circuit in each case a first connection terminal outer+inner results from the combination of the outer connection of a first phase winding with the inner connection of a second phase winding and, furthermore, a second connection terminal star+star results from the laying together of the star connection of the first phase winding with the same named connection of the third phase winding, including a capacitor connection with the outer connection of the second phase winding and a further one with the outer connection of the third phase winding, with the connection to the single phase network taking place on the one hand through the terminal outer+inner and, on the other hand, through the terminal star+star for the one direction of rotation and, through the connection point of the capacitor with the second phase winding for the other direction of rotation.

An embodiment of the invention will now be described in more detail with reference to the drawing.

The drawing shows, in each case with an outer connection and a star connection, the phase I with the reference numeral (1), the phase II with the reference numeral (2) and the phase III with the reference numeral (3) of the stator winding in a star arrangement.

The outer connection of the phase II (2) is connected to one terminal 11 of a power or mains supply voltage u, while the star connection of this phase II (2) is brought together with the star connection of the phase III (3) at a common terminal point (7) (terminal star+star).

The outer connection of the phase III (3) is connected with one plate of an operating capacitor (5), the other plate of which is connected to the outer connection (8) of the phase I (1). The star connection of the phase I (1) is fixedly connected to the outer connection of the phase II (2) (terminal star+outer) and is thus likewise connected to the connection point (11) for the mains supply voltage u.

The setting of the motor into operation takes place in dependence on the desired direction of rotation by connecting the terminal point (7) or the terminal point (8) with the mains terminal (12) as shown in the drawing by broken lines.

Claims

Patent Claims:

1. Single phase- induction motor with a short-circuited rotor and a three phase winding in a star arrangement with three inner (star) connections and three outer connections, characterised in that the three phases (1, 2, 3) of the stator winding together with the operating capacitor (5) are so connected in series to form a closed circuit that from this circuit in each case a first connection terminal outer+inner results from the combination of the outer connection of a first phase winding (2) with the inner connection of a second phase winding (1) and, furthermore, a second connection terminal star+star (7) results from the laying together of the star connection of the first phase winding (2) with the same named connection of the third phase winding (3), including a capacitor connection with the outer connection (8) of the second phase winding (1) and a further one with the outer connection of the third phase winding (3); with the connection to the single phase power supply (11, 12) taking place on the one hand through the terminal outer+inner and, on the other hand, through the terminal star+star for the one direction of rotation and through the connection point (8) of the capacitor (5) with the second phase winding (1) for the other direction of rotation.

2. A single phase induction motor comprising a short-circuited rotor and a three phase stator winding in substantially a star arrangement, with each phase of the stator winding having an inner star connection and an outer connection, characterised in that a) the outer connection of the first phase winding is connected to the inner connection of the second phase winding to form a first terminal for connection to one terminal of a single phase power supply; b) the star connection of the first phase winding is connected to the star connection of the third phase winding to form a second terminal for connection to said single phase power supply; c) a capacitor having first and second plates is connected between the outer connection of the third phase winding and the outer connection of the first phase winding.

3. A single phase induction motor comprising a short-circuited rotor and a three phase stator winding in substantially a star arrangement with each phase of the stator winding having an inner star connection and an outer connection, characterised in that a) the outer connection of the first phase winding is connected to the inner connection of the second phase winding to form a first terminal for connection to one terminal of a single phase power supply; b) the star connection of the first phase winding is connected to the star connection of the third phase winding; c) a capacitor having first and second plates is connected between the outer connection of the third phase winding and the outer connection of the first phase winding to form a second terminal for connection to said single phase power supply.

4. A single phase induction motor substantially as herein illustrated and described.