Lohr Electromecanique

Lohr Industrie

Pierre Dumas

Daniel Scheer

Laurent Verdier

The invention relates to a synchronous machine () including a stator () and a rotor (). Said machine is provided with at least one sensor () of the angular position of the rotor () and is characterized in that the stator () includes a winding provided such as to be supplied with polyphase current by an electronic power device. The rotor (), which includes permanent magnets (), is provided such as to rotate about the stator (). The angular position sensor () extends away from the rotor () and is in alignment with the latter at the permanent magnets (). The angular position sensor () includes at least two sensors () for measuring magnetic induction and are provided for detecting variation in the axial magnetic field of the rotor () in the form of voltage, and the angular position sensor () moreover includes at least one electronic unit provided for receiving the voltages of the magnetic induction measurement sensors () such as to absolutely deduce therefrom the angular position of the rotor () and send corresponding information, in real time, to the electronic power device.

Synchronous machine provided with an angular position sensor

The invention relates to a stator tooth () for an electrical machine, the stator tooth being intended for holding an electrical wire winding (). The tooth includes a central portion () formed with a contiguous assembly of precut magnetic metal sheets (). The metal sheets are secured to one another. The tooth is characterized in that the central portion () is enclosed between two longitudinal end portions () which are secured to the central portion () and each have a radial attachment bolt () passing therethrough. The longitudinal end portions () have a rounded outer shape () for forming, on the ends of the tooth, a continuous contact surface for the electrical wire(s) wound onto the tooth.

Stator, and electrical machine comprising such a stator

The invention relates to a method for measuring ageing of permanent magnets of a synchronous machine comprising a stator and a rotor, the machine being fitted with at least one angular position sensor of the rotor, the rotor comprising the permanent magnets provided to move said rotor around the stator, the angular position sensor comprising at least two fixed magnetic induction measurement sensors extending to an axial end of the rotor, facing and immediately adjacent to the axial edges of the permanent magnets, characterized in that the method consists of: j1) determining, while stopped or during a laden or unladen rotation phase of the synchronous machine, the maximum value of the magnetic induction using the magnetic induction measurement sensors and the electronic unit; j2) comparing the measured maximum magnetic induction value with a reference value; and j3) if the maximum magnetic induction value is less than the reference value, presenting a difference determined with respect to said reference value in order to generate warning information S using the electronics unit and, if this is not the case, returning to step j1).

Method for measuring the ageing of permanent magnets of a synchronous machine fitted with an angular position sensor

The moving part, designed to move past a fixed rotor with coils, comprises a metallic chassis to which magnets, arranged in parallel rows of alternating polarity, are bonded. Non-metallic fixing strips, screwed to the chassis, are positioned longitudinally between each row of magnets, extend along the entire length of these rows and mechanically immobilize the magnets. Each fixing strip comprises a bearing base with convex rounded flanks which immobilize the magnets vertically and collaborates with a concave rounded portion, formed in the adjacent edge face of the magnets over at least half of the height thereof. The strip also comprises a longitudinal upper extension acting as a spacer between the rows of magnets and immobilizing the magnets laterally. The invention is of benefit to the manufacturers of rotary or linear electrotechnical machines such as motors or generators.

Magnet-bearing moving part for permanent magnet synchronous machine

The invention relates to a method for detecting a short circuit between the phases of a polyphase synchronous machine () comprising a stator () and a rotor (), said machine being fitted with at least one angular position sensor () of the rotor (), the rotor () comprising means for generating a magnetic induction provided to move said rotor around the stator (), the angular position sensor () comprising at least two magnetic induction measurement sensors (), the induction measurement sensors () extending to an axial end () of the rotor (), facing and immediately adjacent to the axial edges () of the means for generating a magnetic induction, characterized in that said method consists of: i1) using the values measured and supplied by the induction measurement sensors, i2) calculating the gradient of the curve of the measured values as a function of time, i3) comparing the calculated gradient with a threshold value, Vs, and i4) if the calculated gradient is greater than or equal to the threshold value, Vs, generating a warning signal, S, using an electronic unit and, if this is not the case, returning to step i1).

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Strasbourg, France

Pierre Dumas