Danfoss Compressors Gmbh

Niels Christian Weihrauch

Peter Scavenius Andersen

The invention concerns a rotor of an electrical machine, particularly a driving motor for a hermetically enclosed refrigerant compressor with a body () comprising a magnetically conductive material, the rotor having a plurality of axially extending slots (), which are filled with an electrically conductive material. It is endeavored to achieve a good performance. For this purpose, it is ensured that an extension section () of a first group of slots () extends further radially inwards than a second group of slots (), and that between two slots () of the first group at least one slot () of the second group must be arranged, a first flow cross-section being formed between neighboring extension sections () at the circumferentially shortest distance (a) between the two extension sections (), a second flow cross-section being formed between neighboring slots () at the circumferentially shortest distance (b) between the slots (), the first flow cross-section corresponding to the sum of the second flow cross-sections between the two slots (5) of the first group.

Rotor of an electrical machine and motor with such a rotor

The invention provides a rotor for an electrical motor. The rotor comprises both a squirrel cage and a number of magnets and can be inserted e.g. in a line-start motor. To secure the magnets in cavities in a core of the rotor, an end plate is attached to one axial end face by rivet means, and to simplify manufacturing of the rotor, the rivet means forms part of at least one of the short circuit rings of the squirrel cage.

Rotor for an electrical motor

The invention provides a rotor for an electrical motor, e.g. a line-start motor. The rotor comprises a magnet located in a cavity in a rotor core. The core is laminated from sheets of magnetically conductive material and the magnet is secured in the cavity by an end plate which covers the end face. To avoid short circuiting of the magnet, an aperture is provided in the end plate such that a first portion of the opening into the cavity is in communication with the aperture and such that a remaining, second, portion of the cavity is covered by the end plate to secure the magnet in the cavity independently upon the orientation of the end plate around the center axis.

Rotor with a cover plate for securing a magnet in the rotor

The invention provides a rotor for an electrical motor, a tool for making a rotor core and a method of making the rotor. The rotor could be incorporated e.g. in a line-start motor and comprises a squirrel cage and magnet located in a rotor core. The magnets are, in one end of the rotor, secured by an end plate with apertures which are larger than the magnet openings, and the end plate is indexed relative to the magnet slots such that a first portion of openings into the magnet slots is in communication with the aperture and such that a remaining, second, portion of the magnet slots is covered by the end plate. In one aspect, the end plate forms an integrated part of the rotor core and comprises openings cooperating with conductor slots to form through-going passages for conductors of the squirrel cage. In that way, the end plate is held in a completely fixed position by the squirrel cage which is moulded directly onto the core and into the conductor slots.

The invention concerns a starter for a line start electric motor having at least one main winding () and at least one start winding () and which start winding is connected in series with a run capacitor () with which a start capacitor () and a PTC-thermistor () are connected in parallel. In order to make a simply constructed starter for a line start electric motor the start capacitor () and the PTC-thermistor () are connected in series with a switch mechanism (). The series connected circuit made up of the start capacitor (), the PTC-thermistor () and the switch mechanism () is connected in parallel with the run capacitor ().

Starter for a line start electric motor

The invention relates to a rotor for an electric motor, especially an electric line-start motor, comprising spaces (to) which receive permanent magnets (to) and extend in an axial direction, and spaces (to) that accommodate conductor rods and extend in an axial direction. In order for the rotor to run as regularly as possible, the spaces (to) accommodating the conductor rods are provided with a substantially elongate cross-section in at least one sector of the rotor while being embodied in a curved manner along the longitudinal axis thereof in said sector when viewed from a cross-sectional perspective.

Rotor for an electric motor

The invention relates to a rotor for an electric motor, particularly an electric line-start motor, comprising axially accommodating spaces (to) for conductor rods, and axially extending receiving spaces () for permanent magnets (), which are-designed and located in such a way that they generate a permanent magnet field with a magnet axis () and a neutral axis (). The aim of the invention is to ensure that the rotor runs as regularly as possible during the operation of the electric motor. To this end, the diameter of the rotor along the magnet axis is larger than that along the neutral axis ().

The invention concerns a stator for a line-start electric motor, with a rotor accommodating chamber, in which a rotor is accommodated to be rotatable, and which has accommodating chambers for conducting rods and accommodating chambers for permanent magnets, and with a stator winding comprising several windings, which, during operation of the line-start electric motor under the influence of the rotor, generate a magnetic field with a main axis. In order to increase the efficiency of the line-start electric motor, the rotor accommodating chamber has no constant inner radius, but, in the area of a vertical to the main axis, has a larger inner radius than in the adjacent areas.

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Flensburg, Germany

Niels Christian Weihrauch