Patent Description:
Since the creation of the first electric motors, constructors have been trying to create ever new structures designed to eliminate or reduce the deficiencies of the previous solutions. We can identify a number of motor features, i.e. general features similar for all drives, such as engine performance that can be defined for each drive which usually ranges from <NUM>% to <NUM>%, and special features which in some cases differ by several orders of magnitude, such as power, revolutions per minute, weight or production cost. In recent times, it becomes more and more important not only to use electricity to assist us in all our activities but also the method it is used, i.e. we naturally prefer to clean the floor with a vacuum cleaner rather than with a brush and for some time it has become important that the vacuum cleaner is equipped with a highly efficient motor with low power but high suction capacity. This is mainly because we have appreciated drive parameters which were once considered insignificant and sometimes even negligible. These features include e.g. energy efficiency, work culture (e.g. low noise operation, reduced electromagnetic interference) and recyclability. The object subject to this patent is the electric motor displaying extremely high performance in converting electrical energy into mechanical energy. This motor can also operate as a power generator. Electrical drive with extremely high efficiency has many very favourable characteristics which are now beginning to be observable, yet not too apparent, such as:.

Currently, various electric motors are used, and the main criterion in the selection of the motor is the type and nature of the work. A different drive will be used in the air conditioning fan and a different one to maneuver the position of a robot arm. After all, the final criterion of the drive selection is always the economics, i.e. cost of purchasing, installing and operating of the drive. In all types of electric drives and in most applications, one can notice more designs with enhanced performance and their more frequent utilization. The trend will continue until we discover the electrical drive operating with no loss.

In the present state of technical advancement, we can observe the following sources of energy loss in motor drives:.

Patent description No <CIT> discloses a similar design. However, attention should be given to the following problems:.

Document <CIT> discloses a machine comprising a plurality of axial field rotor stages each comprising a plurality of magnet segments arranged around a driven hub in a pre-stressed assembly in which encompassing hoop means exerts sufficient compressive stress on the magnets and hub assembly to counter centripetal forces generated by speeds of up to <NUM>,<NUM> rpm. Alternative methods of stressing the hoop means is described.

Description <CIT> discloses a design which contains most of the above solutions. However, attention should be given to the following problems:.

The invention claimed herein is to design the electrical machine with minimum energy loss during operation.

The present invention is an electrical machine as defined in the independent claim <NUM>. Further embodiments of the invention are defined in the dependent claims <NUM> - <NUM>.

An electrical machine consisting of a stator with front and rear bearing plates comprising bearings wherein the stator is located between the bearings, a rotor. The stator comprising windings conducting electric current and embedded in a composite material and shaped into winding segments forming a section of a ring. The winding segments are inserted between external discs and internal discs of the rotor, made of non-magnetic composite and reinforced with fibres, in which magnetic poles consisting of at least one permanent magnet are embedded and magnetised towards the axial direction of the internal discs. The magnetic poles are separated from each other with a spacing made of the non-magnetic composite material of the internal and external discs structure. The electrical machine is characterized in that said external disc and internal disc are reinforced with fibres of a strength exceeding <NUM> GPa. Each external disc and internal disc has on the circumference an external reinforcing ring, respectively, made of a non-magnetic composite material reinforced with fibres of a strength exceeding <NUM> GPa, formed by winding the fibres together with resin on the cylindrical surface of the discs, while the first and last external discs of the rotor have a ring closing the magnetic circuit made of ferromagnetic material. Said winding segments forming a section of a ring have an angular span of <NUM> degrees or <NUM> degrees. Preferably, the machine contains a sensor measuring the shaft rotation angle consisting of an angular position sensor coding disc permanently fixed on the shaft of the machine, rotating together with the discs of the machine and photosensitive elements or magnetic pole sensors cooperating with the sensor coding disc, attached to the stator of the motor.

In addition, a preferably non-magnetic composite reinforced with fibres of tensile strength exceeding 1GPa is the composite based on epoxy resins.

Preferably, the shaft rotation angle measurement sensor exhibits a higher resolution than the number of magnetic poles on a single disc.

Preferably, the rotor discs have holes letting cooling air and made perpendicularly to the discs surface between the area with magnetic poles and rotor shaft as well as the holes supplying cooling air to the windings that allow air to pass from the mentioned holes to the space between the discs, where the motor winding segments are located, cooling them during operation.

Preferably, the winding segments are combined into winding packets filling the spaces between the multiple discs.

Preferably, the housing has two connectors in the rear bearing plate for pneumatic hoses through which the air cooling the internal parts of the machine is supplied and extracted.

The subject of the invention is presented on the figure, where <FIG> is a cross-section of the main machine, <FIG> is a cross section of the main machine with the holes for external air cooling, <FIG> is a cross-section of the rotor, <FIG> presents the view of the external disc and its cross-section along the A-A line, <FIG> presents the view of the internal disc, <FIG> the view of the packet of winding segments, <FIG> the view of the winding segment, <FIG> the view of a single winding phase, <FIG> the view of various shapes of the magnetic poles made of a single magnet.

An electrical machine of the external diameter of <NUM> and length of <NUM> consisting of the stator with a side cover <NUM>, front bearing plate <NUM> with the seated front bearing <NUM> of the motor shaft <NUM>, the rear bearing plate <NUM> with the seated rear bearing <NUM> of the motor shaft <NUM> and the winding conducting electric current embedded in glass-epoxy composite and shaped into the winding segments <NUM>, <NUM> thick, constituting a ring section of <NUM> degrees. Three phases of winding are within the segments and embedded in epoxy composite <NUM>: phase A <NUM>, phase B <NUM> and phase C <NUM> made of multicore stranded copper of <NUM> x <NUM>. Forty five segments of the winding <NUM> are divided into three winding segment packets <NUM> with fifteen segments for each packet within the winding segment packet frame <NUM>. These packets are inserted between the rotor discs. The rotor consists of the motor shaft <NUM>, two external discs <NUM> and fourteen internal discs <NUM> made of glass-epoxy composite, thickness: <NUM>, constituting the body of the internal disc <NUM> and body of the external disc <NUM>, in which twenty four magnetic poles <NUM> are embedded, magnetised towards the axial direction of the internal discs <NUM>, and consisting of one cuboid neodymium magnet of dimensions: <NUM> x <NUM> x <NUM> each, magnetised along the dimension of <NUM>, magnetic material N42. The external discs <NUM>, external diameter <NUM>, and internal discs <NUM> reinforced with the reinforcing external rings <NUM> and <NUM> respectively, made of the glass-epoxy composite formed by winding glass fibres together with resit around the cylindrical surface of the discs, whereas the external discs <NUM> (the first and last disc) of the rotor also have the ring closing up the magnetic circuit <NUM>, made of magnetically soft steel. All rotor discs with magnetic poles are dimensionally protected against the rotation in relation to the motor shaft <NUM> and are axially maintained within their position by the bearing surface on the motor shaft <NUM> from one side and on the other side by the nut <NUM> fixing the rotor discs,. Both the external discs <NUM> and internal discs <NUM> have in their structure holes <NUM>, diameter: <NUM>, providing cooling air during operation to gaps <NUM> supplying cooling air to the windings which, as a result of centrifugal force, is forced into the space around the winding section <NUM>. The motor shaft rotation angle measurement sensor <NUM> consists of the coding disc <NUM> permanently fixed on the machine shaft, and the photosensitive sensors <NUM> cooperating with the sensor coding disc <NUM>, permanently fixed to the motor stator with resolution <NUM> pulses per one rotation of the motor shaft <NUM>.

The machine supplied from an external controller, operating in the motor mode, generated mechanical power of <NUM> kW when supplied under voltage equal to <NUM> V. The current was <NUM> A and at rotational speed: <NUM><NUM> rpm, the torque reached <NUM>. Efficiency of the machine in this mode was <NUM>% ± <NUM>%.

In the generator mode, the machine with very similar rotational speed and driving torque at <NUM> kW power, attained the efficiency of conversion of mechanical energy into electrical energy equal to <NUM>% ± <NUM>%. The results obtained by the prototype confirm the advisability of the application of the aforementioned solutions. insignificant losses, at the level of <NUM>%, allowed to construct an electrical machine generating high power and remaining small dimensions, which was the initial goal.

The electrical machine mentioned in Embodiment <NUM> was made using magnetic poles <NUM> in the form of singular neodymium magnets of the trapezoid shape <NUM>, wherein shorter base of the trapezoid is positioned at the disc axis side. The dimensions of each magnet <NUM> were: longer base of the trapezoid: <NUM>, shorter base of the trapezoid: <NUM>, height of the trapezoid: <NUM>, thickness of pole: <NUM>. Following these dimensions the pole was magnetised, magnetic material N42. The above described magnetic poles <NUM> were applied both in the fourteen internal discs <NUM> as well as in the two external discs <NUM>.

The machine, as previously mentioned, supplied from an external controller, operating in the motor mode, generated mechanical power of <NUM> kW when supplied with voltage equal to <NUM> V. The current was <NUM> A and at the rotational speed of <NUM><NUM> rpm the obtained torque was <NUM>. The efficiency of the machine in this mode was <NUM>% ± <NUM>%.

In the generator mode, the machine with very similar rotational speed and driving torque at <NUM> kW power, attained the efficiency of converting mechanical energy into electrical energy equal to <NUM>% ± <NUM>%. The higher efficiency confirms the positive effect of reshaping the magnetic poles <NUM> on the machine operation.

The electrical machine described in Embodiment <NUM> was constructed using the magnetic poles <NUM> of singular neodymium magnets in the shape of a ring section <NUM> with a smaller radius of the ring positioned at the disc axis side. The dimensions of each magnet <NUM> were: external radius: <NUM>, internal radius: <NUM>, angular span of the ring: <NUM>°, and thickness of pole: <NUM>. According to this dimension the pole was magnetised, magnetic material N42. The magnetic poles <NUM> were applied both in the fourteen internal discs <NUM> as well as in the two external discs <NUM>.

The machine, as previously mentioned, supplied from an external controller, operating in the motor mode, generated <NUM> kW of mechanical power when supplied with voltage equal to <NUM> V. The current was <NUM> A and at the rotational speed of <NUM><NUM> rpm, and the torque reached <NUM>. The efficiency of the machine in this mode was <NUM>% ± <NUM>%.

In the generator mode, the machine at very similar rotational speeds and driving torque of <NUM> kW power, attained the efficiency of converting mechanical energy into electrical energy equal to <NUM>% ± <NUM>%. As in Embodiment <NUM>, the higher efficiency confirms a positive effect of reshaping the magnetic poles <NUM> on the machine operation.

Claim 1:
An electrical machine consisting of:
a stator with front and rear bearing plates (<NUM>, <NUM>) comprising bearings (<NUM>, <NUM>) wherein the stator is located between the bearings (<NUM>, <NUM>);
a rotor;
wherein the stator comprising windings conducting electric current and embedded in a composite material and shaped into winding segments (<NUM>) forming a section of a ring, wherein the winding segments (<NUM>) are inserted between external discs (<NUM>) and internal discs (<NUM>) of the rotor, made of non-magnetic composite (<NUM>,<NUM>) and reinforced with fibres, in which magnetic poles (<NUM>) consisting of at least one permanent magnet are embedded and magnetised towards the axial direction of the internal discs (<NUM>), whereas the magnetic poles (<NUM>) are separated from each other with a spacing made of the non-magnetic composite material (<NUM>, <NUM>) of the internal (<NUM>) and external (<NUM>) discs structure;
characterized in that said external disc (<NUM>) and internal disc (<NUM>) are reinforced with fibres of a strength exceeding <NUM> GPa;
each external disc (<NUM>) and internal disc (<NUM>) has on the circumference an external reinforcing ring (<NUM>) and (<NUM>), respectively, made of a non-magnetic composite material reinforced with fibres of a strength exceeding <NUM> GPa, formed by winding the fibres together with resin on the cylindrical surface of the discs, while the first and last external discs (<NUM>) of the rotor have a ring closing the magnetic circuit (<NUM>) made of ferromagnetic material; and in
that said winding segments (<NUM>) forming a section of a ring have an angular span of <NUM> degrees or <NUM> degrees.