DE102017011989A1 - Rotor for an electric machine - Google Patents

Abstract

The invention relates to a rotor for an electric machine, comprising two sheet-metal packages (9, 11) consisting of a plurality of rotor segment sub-packages (13), which are mounted on a rotor shaft (1). In a rotor which can also be used at high speeds and rotational speeds and is nevertheless inexpensive to produce, the rotor shaft (1) has an outer toothing (3) for receiving the two laminated cores (9, 11) whose side by side extending axially obliquely receiving grooves (5, 7) are mirrored.

Description

The invention relates to a rotor for an electric machine, comprising at least one laminated core, which is mounted on a rotor shaft.

From the DE 10 2015 215 614 A1 a rotor for an electrical machine is known, which has a rotor shaft on which a laminated core is arranged, which consists of a plurality of mutually axially arranged rotor segment sub-packages. The rotor has a rotor cage consisting of a plurality of axially extending rods and two shorting rings disposed on axial ends of the laminated core, the laminated core having apertures formed by stamping the rotor segment sub-packages and receiving the rods therein wherein the rods are produced by pouring a casting material into the openings and the shorting rings by casting the casting material against the laminated core.

The object of the invention is to provide a rotor for an electric machine, which is to manufacture with the least possible effort and still achieved very high speeds without a failure of the electric machine occurs as a result of centrifugal forces occurring.

The invention results from the features of the independent claims. Advantageous developments and refinements are the subject of the dependent claims. Other features, applications and advantages of the invention will become apparent from the following description, as well as the explanation of embodiments of the invention, which are illustrated in the figures.

The object is achieved with a rotor characterized in that the rotor shaft has an outer toothing for receiving the two laminated cores, whose juxtaposed axially extending obliquely to each other receiving grooves are mirrored. This has the advantage that a simple mounting of two counter-rotating laminated cores on the rotor shaft is possible. The symmetrical external toothing of the rotor shaft thus allows a balancing advantage with simultaneous precise centering of the electric blades by function separation. The first function is a reliable toothing for the torque transmission, while the second function of the residual cylinder is used for centering. Thus, a cost-effective teeth for the rotor shaft can be used. Furthermore, the form-fitting between rotor shaft and laminated core ensures the representation of the rotor bevel.

Advantageously, an amount of an oblique angle of both receiving grooves is the same size. The skew angle of the two receiving grooves differs only in the sign, the skew angle is arbitrary, which brings greater flexibility with it. By this arrangement, higher speeds and higher torques are possible, which brings a greater functional advantage for the electric machine.

In one alternative, the amounts of the skew angle of the juxtaposed receiving grooves differ from each other. Such an asymmetrical rotor is used in difficult NVH (noise vibration roughness) ratios.

In one embodiment, the first laminated core is placed from one side onto the rotor shaft and helically guided in the first receiving groove, while the second laminated core is placed from an opposite side to the rotor shaft and helically in the second, second receiving groove extending axially adjacent to the first receiving groove is guided. This helical guide allows an offset in the circumferential direction toothing, all rotor blades of the laminated core are formed identically. Costs can be reduced through this common parts strategy. Since the positioning of the segmented laminated cores takes place via a positive connection, it is not possible to rotate the rotor segment sub-packages during the operation of the rotor. As a result, higher speeds of the electric machine can be realized.

In a variant, the individual rotor segment sub-packages of each laminated core are twisted, pre-oriented and fixed in order to form a helical internal toothing. This allows a particularly simple helical mounting of the rotor segment sub-packages of the laminated cores on the rotor shaft. However, such a pre-coding is not absolutely necessary.

In one embodiment, the at least two receiving grooves of the external teeth extend to the middle of the rotor shaft. Through these shortened receiving grooves, the assembly of the individual laminated cores is supported by the two opposite sides of the rotor shaft. The recording grooves can also intersect.

In a further development, the laminated cores are mutually fixed axially on a respective fuse element. Such an axial fixation supports the form-fitting of the laminated cores with the rotor shaft and prevents lifting of the laminated cores at high speeds.

Advantageously, for use in a permanently excited electric machine, the securing element is designed as an overreached locking ring, wherein the attack by a the Internal teeth having stop disc takes place. By means of this stop disc, the laminated core is reliably centered axially and simultaneously held in position during operation of the rotor. The securing ring forms the stop of the rotor shaft 1 for the laminated core.

In an alternative, the fuse element is realized by die casting a short circuit cage for use with an asynchronous machine. The solidified casting material, which was introduced into openings of the rotor segment sub-packages of the laminated cores, acts as a tie rod, so that they are axially fixed via the opposing teeth of both laminated cores.

Further advantages, features and details will become apparent from the following description in which - where appropriate, with reference to the drawings - at least one embodiment is described in detail. Described and / or illustrated features may form the subject of the invention itself or in any meaningful combination, optionally also independent of the claims, and in particular may also be the subject of one or more separate application / s. The same, similar and / or functionally identical parts are provided with the same reference numerals.

• 1 ein Ausführungsbeispiel einer Rotorwelle des erfindungsgemäßen Rotors,
• 2 ein Ausführungsbeispiel des erfindungsgemäßen Rotors mit zwei Blechpaketen,
• 3 ein Ausführungsbeispiel eines Blechpaketes für eine permanent erregte Elektromaschine,
• 4 ein Ausführungsbeispiel für einen Asynchronmotor.

Show it:

• 1 An embodiment of a rotor shaft of the rotor according to the invention,
• 2 An embodiment of the rotor according to the invention with two laminated cores,
• 3 an embodiment of a laminated core for a permanently excited electric machine,
• 4 An embodiment of an induction motor.

In 1a is an embodiment of a rotor shaft according to the invention 1 shown, which has an external toothing 3 has, in the axial direction obliquely to each other receiving grooves 5 . 7 having. These obliquely extending receiving grooves 5 . 7 form a mirrored helical gearing.

1b shows a plan view of the rotor shaft 1 in an enlarged view, in which the inclination of the receiving grooves 5 . 7 the external toothing 3 is shown more clearly. For example, the first outer groove has 5 an oblique angle of -2 °, while the second receiving groove 7 has a skew angle of + 2 °. These recording grooves 5 , 7 can be at a corresponding tooth length on the rotor shaft 1 also cross. In the 1c is a cross section through the double-toothed rotor shaft 1 represented, from which these different angles of skewness emerge more clearly. Here are the first and the second recording groove 5 . 7 alternately formed.

2 shows the embodiment of the rotor shaft 1 on which two laminated cores 9 , 11 are set up. The laminated cores 9 . 11 are from different sides on the rotor shaft 1 applied. The left-hand laminated core 9 , which consists of four rotor segment subpackets 13 exists, is from the left side to the rotor shaft 1 into the recording groove 5 pressed and helically guided in the helical gearing. This also consists of four rotor segment subpackets 13 existing right laminated core 11 is a mirror image helical and is from the right into the receiving groove 7 screwed in helically. In the middle of the rotor shaft 1 hit the right and the left laminated core 9 . 11 on each other and lie against each other. The external toothing 3 the rotor shaft 1 can be made by forming or machining processes such as rolling or milling or by very small, intersecting teeth by knurling in the rotor shaft 1 be introduced.

To realize the helical configuration, have the laminated cores 9 . 11 an internal toothing 15 on, in which the individual rotor segment sub-packages 13 twisted are preoriented. This can be done, for example, with baked enamel or stamped packet. 2 B shows the sheet metal package twisted to the left 11 , which leads into the left-hand external toothing 3 intervenes. In 2c is the second laminated core 9 shown, which is twisted to the right and the outer toothing twisted to the right 3 intervenes.

In 3 is an embodiment of a laminated core 17 for a permanently energized electric machine, showing twisted rotor segment sub-packages 19 having. This can be seen from the fact that the internal teeth 15 the rotor segment subpackets 19 offset from each other ( 3a ). In 3b is the laminated core 17 of the permanently energized electric motor twisted to the right while in 3c a laminated core 17 the permanently energized electric machine is shown, which is twisted to the left.

For non-twisted rotor segment sub-packages 13 become the first rotor segment sub-package at the one tooth flank and the second rotor segment sub-package 13 applied to the opposite tooth flank for torque transmission. If this is the case, it is also possible to use magnets with a cost-effective rectangular basic shape, which can also be axially secured better. Such axial locking takes place in a permanently excited electric machine overlapped circlips, the attack being made by offset stop or balancing discs, which also have internal teeth. In these thick sheet metal parts, the internal toothing is preferably punched obliquely with a fine cutting process.

Alternatively, also a straight laminated core 9 . 11 with twisted internal toothing 15 conceivable.

In 4 an asynchronous motor is shown, which also counter-twisted laminated cores 9 . 11 which, by the mutually twisted receiving grooves 5 . 7 the external toothing 3 the rotor shaft 1 are positioned. The short circuit kä 21 an integrated axial lock dar. Such Kurzschlusskä 21 is in 4b clarified in more detail. By die casting through the openings 23 the laminated cores 9 . 11 guided shorting bars 25 becomes a short circuit kä 21 generated with a V-shape. The thereby bent kinked short rods 25 serve as tie rods. Diecasting can be done by aluminum or copper. The case-molded outer short-circuit discs 27 connect to the short-circuit bars 25 to the Kurzschlusskä 21 , To reduce the machining time when milling or rolling both external gears 3 these are only up to the middle of the rotor shaft 1 introduced and have a machining spout in the form of a tool radius that can extend to below the opposite rotor segment sub-packages.

The described solution allows cost-effective toothing of the laminated cores on the rotor shaft.

Although the invention has been further illustrated and explained in detail by way of preferred embodiments, the invention is not limited by the disclosed examples, and other variations can be derived therefrom by those skilled in the art without departing from the scope of the invention. It is therefore clear that a multitude of possible variations exists. It is also to be understood that exemplified embodiments are really only examples that are not to be construed in any way as limiting the scope, applicability, or configuration of the invention. Rather, the foregoing description and description of the figures enable one skilled in the art to practice the exemplary embodiments, and those of skill in the knowledge of the disclosed inventive concept may make various changes, for example, to the operation or arrangement of particular elements recited in an exemplary embodiment, without Protection area defined by the claims and their legal equivalents, such as further explanations in the description.

LIST OF REFERENCE NUMBERS

1

rotor shaft

3

external teeth

5

receiving groove

7

receiving groove

9

laminated core

11

laminated core

13

Rotor segment subpacket

15

internal gearing

17

laminated core

19

Rotor segment subpacket

21

Squirrel cage

23

openings

25

Shorting bars

27

Short disc

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

• DE 102015215614 A1 [0002]

Claims (9)

Rotor for an electric machine, comprising two laminated core assemblies (9, 11) consisting of a plurality of rotor segment subpackets (13), which are mounted on a rotor shaft (1), characterized in that the rotor shaft (1) has an outer toothing (3) for receiving the two laminated cores (9, 11), whose juxtaposed axially extending obliquely receiving grooves (5, 7) are mirrored. Rotor after Claim 1 , characterized in that an amount of an oblique angle of the adjacent receiving grooves (5, 7) is the same size. Rotor after Claim 1 , characterized in that the amounts of the skew angle of the juxtaposed receiving grooves differ from each other. Rotor after Claim 1 . 2 or 3 , characterized in that the first laminated core (9) is attached from one side to the rotor shaft (1) and in the first receiving groove (5) is helically guided, while the second laminated core (11) from an opposite side to the rotor shaft (1 ) is mounted and in the second, axially adjacent to the first receiving groove (5) extending receiving groove (7) is guided helically. Rotor after Claim 4 , characterized in that the individual rotor segment sub-packages (13) of each laminated core (9, 11) to form a helical internal toothing (15) are twisted pre-oriented and fixed. Rotor according to at least one of the preceding claims, characterized in that extending the at least two receiving grooves (5, 7) of the external toothing (3) of the rotor shaft (1) to the center of the rotor shaft (1). Rotor according to at least one of the preceding claims, characterized in that the laminated cores (9, 11) are axially fixed on both sides via a respective securing element (21, 27). Rotor after Claim 6 , characterized in that for use in a permanently energized electric machine, the securing element is designed as an overreached locking ring, wherein the overlap by a the internal toothing (15) having stop disc. Rotor after Claim 6 , characterized in that for use in an asynchronous machine, the securing element is realized by die casting a short-circuit cage (21).

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