DE102017201389A1 - Rotor of a claw-pole machine - Google Patents

Abstract

A rotor of a claw-pole machine has a plurality of intermeshing claws, in the outer side of which a plurality of parallel grooves are introduced, wherein the width-distance ratio of groove width to the distance between adjacent grooves for a plurality of grooves is within a defined size range.

Description

The invention relates to a rotor of a claw-pole machine according to the preamble of claim 1.

State of the art

Claw pole machines are known whose rotor has a shaft with a pole core, intermeshing claws and a coil wound on the pole core, which is delimited by the claws. The electromagnetic excitation occurs via slip rings on the rotor shaft, which are electrically connected to the coil on the pole core.

Moreover, it is known to introduce on the outside of the claw a plurality of parallel grooves, whereby the claw surface is increased to improve the cooling and also the rotor iron losses are reduced by interrupting the current path. A corresponding rotor of a claw pole machine, for example, in the JP 8-149762 A described.

Disclosure of the invention

The rotor according to the invention of a claw-pole machine has, in a manner known per se, several interlocking claws which form north-south poles and in particular embrace an electrically energizable coil, which is usually wound on a pole core which is mounted on a rotor shaft of the rotor. The claws have on their outside a plurality of parallel, groove-shaped grooves, which preferably extend at a right angle to the claw longitudinal axis. The grooves are in particular in an axial region which is covered by the stator of the claw-pole machine. The grooves increase the claw surface, which significantly improves rotor cooling. On the other hand, the grooves reduce the rotor iron losses by interrupting the current path of the eddy currents.

Adjacent grooves on a claw have a ratio of groove width to the distance between these grooves ranging between 0.035 and 0.2. This width-to-width ratio of groove width to groove spacing of immediately adjacent grooves increases the claw surface for improved cooling and reduces rotor iron losses due to eddy currents. The distance between adjacent grooves is advantageously measured from a groove side wall, a first groove to the opposite side wall of the adjacent groove, so for example from the right side wall of the first groove to the right side wall of the second, immediately adjacent groove. This width-distance ratio represents an optimized groove geometry with which the electric power of the claw-pole machine is not or only slightly reduced by the introduction of the grooves.

According to an advantageous embodiment, at least three grooves, which are arranged on the outside of the same claw, have a different width-distance ratio. Advantageously, all the grooves on the same jaw have a different width-to-depth ratio, for example, in that all the grooves have the same width but the groove-to-groove pitch changes. For example, a gap that varies continuously from groove to groove is possible.

Furthermore, it is also possible to additionally or alternatively vary the width of the groove. In any case, the width-to-space ratio is in the size range between 0.035 and 0.2.

According to a further expedient embodiment, a plurality of grooves on a jaw, optionally all grooves on a jaw on an identical width-distance ratio and in particular several or all grooves are provided with an identical width and an identical distance to each other. It is also possible, however, to provide several or all grooves on a jaw different widths and different spacing of the grooves with identical width-distance ratio.

According to yet another advantageous embodiment, which relates to grooves on a claw with different width-spacing ratio, the width-to-width ratio of the grooves to the claw tip decreases. The claws advantageously have a trapezoidal geometry in plan view, which tapers towards the tip, which forms the free end face of the claw. As the width-to-distance ratio decreases toward the claw tip, the distance between adjacent grooves toward the claw tip increases and / or the width of the grooves increases toward the claw tip. Advantageously, the groove width of all grooves of a claw remains constant. Thus, as the width-to-width ratio changes, the distance between adjacent grooves is varied.

In a further expedient embodiment, the grooves on the outside of the jaws on a defined width-to-depth ratio to each other. The ratio of groove width to groove depth of all grooves on a claw is in a size range between 0.07 and 0.5. The width of the groove refers to the dimension of the groove in the transverse direction to its longitudinal extension, the depth of the extension between the bottom of the groove-shaped groove and the External surface on the claw, measured in the radial direction to the claw longitudinal axis.

This width-to-depth ratio preferably applies to the grooves on all claws of the rotor, whereby different width-depth ratios of the grooves are possible both from claw to claw and within a claw groove-to-groove, but the size range of the width-depth Ratio of 0.07 to 0.5 is not fallen below or exceeded. Also, this width-depth ratio of groove width to groove depth represents an optimized groove geometry with which the electrical power of the claw-pole machine is not or only slightly reduced by the introduction of the grooves. Thus, the advantages of the larger cooling surface and the reduction of the rotor iron losses due to eddy currents can also be realized without this being accompanied by a relevant electrical power reduction.

According to an advantageous embodiment, at least two grooves, which are arranged on the outside of the same claw, have a different width-to-depth ratio. Advantageously, all of the grooves on the same jaw have a different width-to-depth ratio, for example, in that all the grooves have the same width but a different depth. Furthermore, it is also possible to additionally or alternatively vary the width of the groove. In any case, the width-to-depth ratio is in the size range between 0.07 and 0.5.

According to yet another expedient embodiment, a plurality of grooves on a jaw, optionally all grooves on a jaw on an identical width-to-depth ratio and are in particular provided with an identical width and an identical depth. But it is also possible to provide different widths and depths of the grooves with identical width-to-depth ratio of several or all grooves on a claw.

According to yet another advantageous embodiment, which relates to grooves on a claw of different width-to-depth ratio, the width-to-depth ratio of the grooves towards the claw tip increases. The claws advantageously have a trapezoidal geometry in plan view, which tapers towards the tip, which forms the free end face of the claw. Accordingly, as the width-to-depth ratio increases toward the claw tip, the depth of the grooves decreases toward the claw tip and / or the width of the grooves increases toward the claw tip. Advantageously, the groove width of all grooves of a claw remains constant. With a changing width-depth ratio, the depth of the grooves is thus varied. It is convenient that the depth of the grooves decreases towards the tip of the claw, thereby avoiding restrictions on the stability of the claws. In addition, by means of different deep grooves, the rotor iron losses can be reduced, in particular by a greater depth of the grooves in the wider, the claw tip facing away portion of the claws.

According to yet another expedient embodiment, the various jaws are grooved in the same way. Claws pointing in the same direction have the same groove pattern. Opposing directed, interlocking claws are accordingly provided with a mirror-symmetrical groove pattern.

The grooves on the outside of the claws advantageously extend over the entire or at least approximately the entire width of the claws.

According to yet another expedient embodiment, the grooves are formed as grooves, which are optionally introduced later in the claw outer side. The grooves may assume different cross-sectional shapes, for example U-shaped or V-shaped cross-sectional shapes. Advantageously, all grooves have the same cross-sectional shape.

• 1 in perspektivischer Darstellung einen Rotor einer Klauenpolmaschine, wobei auf der Außenseite der Klauen parallel verlaufende Rillen angeordnet sind,
• 2 in schematischer Darstellung eine Klaue des Rotors mit eingebrachten Rillen,
• 3 einen Schnitt durch eine Klaue mit den darin eingebrachten Rillen,
• 4 einen Schnitt durch eine Klaue mit Rillen, deren Tiefe sich zur Klauenspitze hin verringert,
• 5 einen Schnitt durch eine Klaue mit Rillen, deren Tiefe sich zur Klauenspitze hin vergrößert,
• 6 ein Ausschnitt eines Rotors einer Klauenpolmaschine, wobei in die Klauen Rillen eingebracht sind, deren Abstand zueinander sich zur Klauenspitze hin vergrößert,
• 7 ein Schaubild mit dem Verlauf der Wirbelströme und der Rotoreisenverluste in Abhängigkeit von der Rillenbreite,
• 8 ein Schaubild mit dem Verlauf der Wirbelströme und der Rotoreisenverluste in Abhängigkeit von dem Abstand benachbarter Rillen,
• 9 ein Schaubild mit dem Verlauf der Wirbelströme und der Rotoreisenverluste in Abhängigkeit von der Rillentiefe.

Further advantages and expedient embodiments can be taken from the further claims, the description of the figures and the drawings. Show it:

• 1 3 is a perspective view of a rotor of a claw-pole machine, with grooves running parallel on the outside of the claws;
• 2 a schematic view of a claw of the rotor with grooves introduced,
• 3 a section through a claw with the grooves introduced therein,
• 4 a section through a claw with grooves whose depth decreases towards the tip of the claw,
• 5 a section through a claw with grooves whose depth increases towards the claw tip,
• 6 a section of a rotor of a claw-pole machine, wherein grooves are made in the claws whose distance from each other increases towards the claw tip,
• 7 a graph with the course of the eddy currents and the rotor iron losses as a function of the groove width,
• 8th a diagram with the course of the eddy currents and the rotor iron losses as a function of the distance between adjacent grooves,
• 9 a graph showing the course of the eddy currents and the rotor iron losses as a function of the groove depth.

In the figures, the same components are provided with the same reference numerals.

In 1 is an electrically energizable rotor 1 a Klauenpolmaschine shown, a rotor shaft and distributed on the rotor shaft over the circumference a plurality of alternately counter-directed jaws 2 which enclose an exciting coil of the rotor. The rotor longitudinal axis of the rotor is denoted by the reference numeral 3 characterized. Between adjacent claws 2 are permanent magnets 4 in the rotor 1 arranged, which serve to increase performance by leakage flux compensation of the electric machine.

As 1 combined with 2 to extract, have the claws 2 in plan view, a trapezoidal, approximately triangular geometry, wherein the free end face of the claw 2 the tapered claw tip 2a forms. On the outside of the claw 2 are grooves 5 introduced, which are perpendicular to the claw longitudinal axis 6 extend. The claw longitudinal axis 6 runs at a small angle to the rotor longitudinal axis 3 wherein the angle is preferably less than 30 °. The grooves 5 are in the form of depressions or grooves in the outside of the claws 2 brought in. The grooves 5 may be over the entire width of the claw 2 extend. In longitudinal direction - relative to the rotor's longitudinal axis 3 or the claw longitudinal axis 6 - are the grooves 5 along a section on the outside of the claw 2 which is covered by the stator. This is an area on the claw 2 with the distance both to the tip of the claw 2a is arranged as well as the opposite side of the claw with maximum width.

The grooves 5 are preferred on all claws 2 arranged in the same way. Intermeshing jaws extending into the interstices from opposite sides are in view of the grooves 5 formed mirror-symmetrically.

In 3 is a longitudinal section through a claw 2 shown. The width of the grooves 5 is w, the depth of the grooves 5 denoted by t. The distance a between two adjacent grooves 5 refers to the distance between like sidewalls of the adjacent grooves, for example in the illustration according to FIG 3 the distance between the right sidewalls of adjacent grooves 5 ,

The grooves 5 are formed as grooves in the outside of the claws 2 are introduced. All grooves 5 on a claw 2 lie parallel to each other and are orthogonal to the claw longitudinal axis. The grooves 5 have in the exemplary embodiment on a U-shaped cross-sectional shape, whereby other cross-sectional shapes, for example, V-shaped cross-sectional shapes come into consideration. Advantageously, all grooves have 5 the same cross-sectional shape.

The grooves 5 on the claws 2 are subject to a defined ratio of their width w to their depth t: $$\mathrm{0:07}\le w/t\le 0.5$$

This width-depth ratio w / t applies to all grooves 5 on all claws 2 of the rotor 1 , However, it is possible that the width-to-depth ratio between different grooves 5 on a common claw 2 differs as long as the range for the width-to-depth ratio w / t is not undershot or exceeded. Furthermore, it is also possible that, as in 3 represented, all grooves 5 on a claw 2 have the same width-depth ratio w / t, in particular each have the same width w and each have the same depth t. In addition, it is possible to have an equal width-depth ratio w / t between different grooves 5 in that the width w and the depth t respectively increase or decrease proportionally.

In the 4 and 5 are exemplary embodiments of a changing width-to-depth ratio w / t between the various grooves 5 on a claw 2 shown. According to 4 have the grooves 5 on the claw 2 the same width w, but they differ in their depth t, the tip of the claw 2a decreases so that the width-to-depth ratio w / t increases towards the tip of the claw. Accordingly, the groove has 5 in which the claw tip 2a opposite area the greatest depth t. The rotor iron losses due to eddy currents in this area can be effectively reduced by the greater depth t.

In 5 is a variant of a claw 2 with grooves whose width-to-depth ratio w / t changes from one groove to the next groove. at 4 takes the groove depth t to the tip of the claw 2a down continuously, whereas at 5 the groove depth t to the claw tip 2a continuously increases, so that at 5 corresponding to the width-depth ratio w / t of the grooves 5 to the tip of the claw 2a decreases.

In 6 is a further embodiment of a rotor 1 a Klauenpolmaschine shown, which in principle in the same way as the rotor according to 1 is constructed and interlocking claws 2 each having a plurality of parallel grooves 5 provided on the claws outside. The grooves 5 have a defined width-to-space ratio w / a of groove width b to the distance a between immediately adjacent grooves 5 , wherein the width b and the distance a as in 3 are defined shown.

The width-to-distance ratio w / a is in a size range between 0.035 and 0.2: $$0035\le w/a\le 0.2$$

This width-to-space ratio w / a also enables a reduction in the rotor iron losses and increases the cooling surface without this being accompanied by a significant reduction in electrical power.

As in 6 shown, the distance a increases from groove to groove in the direction of the claw tip 2a , When the groove width w is advantageously constant, the width-distance ratio w / a of the grooves accordingly increases towards the tip of the claw 2a down. It is particularly expedient that the grooves 5 on all claws 2 have the same width distance ratio w / a on the claw outer side. Accordingly, the claws are constructed identically or are the interlocking claws with mirror-symmetrical grooves 5 Mistake.

In the embodiment according to 6 assign all the neighboring grooves 5 on a claw 2 a differing width-to-space ratio w / a. This may be towards the claw tip 2a steadily decrease. The groove width w is preferably constant, whereas the distance a between the grooves 5 increases continuously towards the tip of the claw.

However, it is also possible to have a constant width-to-spacing ratio either between part of the grooves 5 on a claw 2 or between all grooves 5 on a claw 2 , In the case of a changing width-distance ratio as well as a constant width-distance ratio, this lies in the aforementioned range between 0.035 and 0.2.

In the 7 and 8th are graphs with the course of the eddy currents 7 and the rotor iron losses 8th as a function of the groove width w or represented by the distance a of adjacent grooves. The losses due to eddy currents 7 decrease both with increasing groove width w and with increasing distance a between adjacent grooves, as well as take the rotor iron losses 8th tends to decrease with increasing groove width w and increasing distance a between adjacent grooves. With respect to the groove width w, there is a preferred groove width range w _p within which the eddy currents 7 and rotor iron losses 8th have already fallen significantly in relation to a lower starting range. Analog exists in 8th a preferred distance range a _p between adjacent grooves, within which the losses due to eddy currents 7 and the rotor iron losses 8th have dropped significantly compared to an initial range. From the ratio of the preferred groove width range w _p to the preferred distance range a _p between adjacent grooves, the above-described width-to-spacing ratio w / a results.

9 shows a graph with the course of the eddy currents 7 and the rotor iron losses 8th depending on the groove depth t. The losses due to eddy currents 7 and the rotor iron losses 8th decrease with increasing groove depth t. There is a preferred groove depth range t _p within which the eddy currents 7 and rotor iron losses 8th are significantly reduced relative to a lower exit area. From the ratio of the preferred groove width range w _p ( 7 ) to the preferred groove depth range t _p results in the above-described width-depth ratio w / t.

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• JP 8149762 A [0003]

Claims (10)

Rotor of a claw-pole machine, with intermeshing claws, in the outside of which a plurality of parallel grooves are inserted, characterized in that the width-distance ratio (w / a) of groove width (w) to the distance (a) between adjacent grooves for several or all Grooves in a size range between 0.035 and 0.2 are: $$0035\le w/a\le 0.2$$

Rotor after Claim 1 , characterized in that at least two grooves on a claw have a different width-spacing ratio (w / a). Rotor after Claim 2 , characterized in that all the grooves on a claw have a different width-to-spacing ratio (w / a). Rotor after Claim 2 or 3 , characterized in that the width-to-spacing ratio (w / a) of the grooves decreases toward the claw tip. Rotor after Claim 4 , characterized in that the distance (a) between the grooves towards the claw tip decreases towards. Rotor after one of Claims 1 to 5 , characterized in that all the grooves of a claw have a constant groove width (w). Rotor after one of Claims 1 to 6 , characterized in that all the grooves of a claw extend at right angles to the claw longitudinal axis. Rotor after one of Claims 1 to 7 , characterized in that intermeshing claws are provided with mirror-symmetrical grooves. Rotor after one of Claims 1 to 8th , characterized in that the width-depth ratio (w / t) of groove width (w) to groove depth (t) of all grooves is in a size range between 0.07 and 0.5: $$\mathrm{0:07}\le w/t\le 0.5$$

Claw pole machine, with a rotor after one of the Claims 1 to 9 ,

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