DE102010050934A1 - Electromotor has bundle of laminations assembled from punch-packetized single metal sheets with projection in stacking or rotor axis direction, and bonded with one another through external thread screw - Google Patents

Abstract

The electromotor has a bundle of laminations assembled from punch-packetized single metal sheets with a projection in stacking or rotor axis direction, and bonded with one another through an external thread screw. Each metal sheet is provided with one or more recesses for reduction of moment of inertia of the rotor. Several planar faces at the outer perimeter of the bundle of laminations are formed with detent in circumferential direction. Independent claims are included for the following: (1) method for manufacture of rotor of electromotor; and (2) use of rotor and stator bundles of laminations of electromotor.

Description

The invention relates to an electric motor, a method for manufacturing a rotor of an electric motor and a use.

It is generally known to assemble a rotor from a rotor shaft and a laminated core. Depending on the type of engine, the active part, which may be a short-circuit cage and / or a permanent magnet arrangement, is provided on the laminated core.

The invention is therefore the object of developing an electric motor, with a simple cost-effective production is to be achieved.

According to the invention the object is achieved in the electric motor according to the claim 1, in the method according to the in claim 12 and in the use according to the features indicated in claim 15.

Important features of the invention in the electric motor with a rotor shaft and a laminated core, which is connected to the rotor shaft, that the rotor shaft has an external thread, wherein the laminated core has a screwed onto the external thread internal thread, in particular so that the laminated core with the rotor shaft at least is schraubverbindbar.

The advantage here is that a low-force or force-free connection is possible. Because when screwing only such small amounts of force are necessary that no deformation of the rotor shaft occurs and thus no reworking is necessary.

In an advantageous embodiment, rotor shaft and laminated core are at least screw-connected with each other. The advantage here is that a simple manufacture is possible. In particular, the rotor shaft is finished before joining - at least in the connection region with the laminated core.

In an advantageous embodiment, rotor shaft and laminated core are connected to each other at least cohesively. The advantage here is that an automatic unscrewing is avoided during operation. In addition, the security is improved by a double connection. In particular, by means of the screw connection, a simultaneous positive connection takes place, which ensures the function even in the event of a failure of the adhesive bond.

In an advantageous embodiment, the package movement is relative to the shaft on the one hand by an axial stop of the package or by the outlet of the thread additionally positively prevented, on the other side by a circumferential groove, which receives a circlip

The preferably continuous thread on the rotor shaft in conjunction with the interrupted thread on the laminated core acts as a pump for the adhesive when making the connection. In particular, the effect of a suction pump, which sucks the adhesive from the entry point into the thread during the joining, ie rotational movement of the thread equalizes the effect. The adhesive is pumped into the connection area, whereby there is a continuous application of adhesive between the rotor shaft and the laminated core. The connection of the laminated core to the rotor shaft is made by material connection. By screwing, so a rotational movement, the adhesive is applied evenly. At the same time the threads are evenly applied with adhesive.

In an advantageous embodiment, the laminated core is composed of stanzpaketierten individual sheets, in particular wherein each individual sheet has a directed in the stacking direction and / or Rotorachsrichtung survey. The advantage here is that a simple centering of the individual sheet packages is executable to each other. In this way, a stanzpaketiertes laminated core is produced. The laminated core is optionally also divided into partial laminated cores and can be assembled from them.

In an advantageous embodiment, each next to each other adjacent individual sheets are arranged rotated by an angle contract, in particular wherein the individual sheets of the laminated core are made similar. The advantage here is that an internal thread can be generated in a simple manner by twisting arranged inner knobs. Because by the rotation of the directly adjacent inner knobs to each other an arrangement of the inner knobs on an imaginary helix is possible with a constant thickness of the individual sheet metal parts, wherein the helix has a constant radius and a consistently uniform pitch. The helix is thus represented by a uniform circular motion, ie with a constant rotational speed, and a superimposed uniform linear motion, ie at a constant speed, in the normal direction to the plane containing or parallel to the circular motion.

In an advantageous embodiment, each individual sheet has one, two or more inner knobs for forming the internal thread. The advantage here is that a catchy, double-threaded or multi-threaded thread, for example standard trapezoidal thread, for the production of Shaft usable us is thus the connection force can be increased accordingly. When using standard thread contours, manufacturing costs can be reduced by using standard tools.

In an advantageous embodiment, the nubs form the internal thread, in particular in a discrete manner, ie in particular a point of each nub is arranged such that the amount of these respective points are substantially on an imaginary helix, in particular with a predetermined pitch, in particular where the point of Noppe is that surface point of the nub which has the smallest radial distance. The advantage here is that a screw in a simple manner can be produced. In particular, no internal thread must be screwed into the laminated core.

In an advantageous embodiment, the contact lines between the external thread of the rotor shaft and a respective nub on a circular arc portion whose center is not on the central axis but has a non-vanishing radial distance thereto. Thus, it is ensured that on each individual sheet not only a point but a line contact with the external thread of the rotor shaft takes place. Thus, the surface pressure is reduced and allows a groove-free movement when screwing.

In a first Fertigugnsschritt the outer diameter of the rotor shaft, so the outer cylindrical surface of the rotor is processed, in particular by grinding and / or turning.

In a second production step, therefore, a thread with generous contours is produced after machining the rotor shaft. Thus, a game between sheets and screwed thread exists. In this case, the game is so large or the contours are designed such that they are suitable to receive the later introduced adhesive by means of adhesion to the shaft.

The centering of the laminated core is advantageously taken over by the smooth area of the outer surface of the rotor shaft, in which no thread is cut, because this is vorbearbeitbar by the exact executable turning or grinding and thus highly accurately manufacturable.

Despite the above-mentioned game, a highly accurate centering can be achieved by applying adhesive over the entire circumference of the central recess of the laminated core and thus forming an adhesive film, which causes the good centering.

By screwing the shaft in the package, the distribution of the adhesive can be done in a simple manner by being applied to the shaft at the entry point - with multiple threads at the entry points - of the thread in the package. For this purpose, a metering device can be arranged in a stationary manner, which enables automated production, in particular by means of a controlled and / or regulated supply of adhesive. Preferably, the metering device has a plurality of openings, is pressed out of the adhesive.

In a further development, it is advantageous first to wet the laminated core with one with an activator or primer, whereby on the one hand improved adhesion of the subsequently introduced adhesive can be achieved and, on the other hand, the penetration of adhesive into capillary gaps of the laminated core is prevented.

After introduction of the adhesive, good utilization of the adhesive is achievable, since it can no longer penetrate into the capillary gaps and thus effects adhesive bonding only in the bonding area. It is thus also prevented that too much adhesive diffuses by capillary action without effect for the compound in the laminated core.

In an advantageous embodiment, each individual sheet outer nubs on to limit adhered to the laminated core permanent magnet. The advantage here is that an increased security in the connection of the permanent magnets can be achieved.

In an advantageous embodiment, each individual sheet has one or more recesses. The advantage here is that this contributes to the reduction of the moment of inertia of the rotor and thus more dynamic movements by the. Electric motor be enabled.

In an advantageous embodiment, the external thread is more continuous, wherein the number of gears corresponds to the number of internal knobs of a single sheet. The advantage here is that an increased connection force in the connection between the laminated core and rotor shaft can be achieved. In addition, a more even force distribution in the connection area is possible.

In an advantageous embodiment, internal thread and external thread are not designed to be self-locking. The advantage here is that a low-force or force-free connection is possible.

In an advantageous embodiment, the external thread is designed as a trapezoidal thread or has a trapezoidal cross-section. The advantage here is that an easy to manufacture Thread type is usable. A movement thread is particularly advantageous in terms of the screwing speed.

Important features in the method for producing a rotor of an electric motor are that first the rotor shaft is finished and then the laminated core is connected to the rotor shaft, in particular screwed, is. The advantage here is that after connecting the laminated core no post-processing of the rotor shaft is necessary. Thus, the finishing of the rotor shaft is possible even before connecting and therefore feasible in a cost effective manner.

As an assurance of the axial position, an end stop of the laminated core is advantageously used on a shaft collar of the rotor shaft. On the opposite side a circlip groove is provided, in which a circlip prevents the reverse rotation after the application of the adhesive.

In an advantageous embodiment, individual sheet metal parts are stanzpaketiert when producing the laminated core, wherein the die of the punching machine is rotated by an angular amount when punching the inner knobs of a respective single sheet stack. The advantage here is that the helical arrangement of the inner knobs is easily manufacturable by a known Stanzpaketierverfahrensschritt is changed only by the die is rotated in successive punching operations, in particular by a constant amount to produce a correspondingly uniform helical arrangement of the inner knobs.

In an advantageous embodiment, dies are used in the punching, so other cutouts are punched out before punching out the inner knobs in another punching step. The advantage here is that different complex structures can be produced.

Important features in the use of a rotor lamination stack of an electric motor are that it is used as a nut screwed onto an external thread of the rotor shaft of the electric motor. Because a nut is thus formed in the form of a laminated core, this nut can be screwed onto the rotor shaft and thus the laminated core is screw-connected to the rotor shaft. The advantage here is that a low-force or force-free connection is possible.

Further advantages emerge from the subclaims. The invention is not limited to the combination of features of the claims. For the skilled person, further meaningful combination options of claims and / or individual claim features and / or features of the description and / or figures, in particular from the task and / or posing by comparison with the prior art task.

Instead of laminated core of the rotor, the invention can also be used for connecting a laminated core of the stator to the stator housing, wherein the stator housing has a corresponding internal thread.

The invention will now be explained in more detail with reference to figures: In the 1 is a rotor shaft according to the invention 1 shown, wherein the laminated core is not yet connected.

In the 2 the rotor shaft is shown with the laminated core screwed on.

In the 3 is a plan view of the laminated core shown.

In the 4 is an oblique view of the laminated core shown.

As in 1 shown is the rotor shaft 1 in an axial region 2 designed with screw thread, which has a slope S, which has a value from the value range between 2 and 20 mm, for example, 5 mm.

As in 2 The laminated core is shown on the rotor shaft 1 unscrewed, the laminated core one from inside nubs 40 having formed quasi-internal thread. For this purpose, the inner knobs are arranged along one or more imaginary helical lines, which also has or have the slope S.

The laminated core is as stacking 3 composed of sheet metal parts to form the laminated core, wherein the stack 3 are stanzpaketiert.

At the outer periphery, the laminated core on a number n of flat surfaces, which are limited in the circumferential direction by means of boundaries, which from Außennoppen 32 the sheet metal parts 30 are formed.

To form the pile one turns off 3 apparent sheet metal part 30 made as a stamped and bent part, with recesses 31 and outside naps 32 as well as inner knobs 33 be punched out of a blank.

The punching process can also be carried out in several steps, that is to say with separate follow-on tools, with the die in the last step, which comprises punching out the inner knobs successive parts is rotated by an angle value, for example, 360 ° / n. At the in 3 shown, in the circumferential direction successively arranged, ten adhesive surfaces for permanent magnets so a rotation is performed by each 36 ° after each punching operation.

In this way, during production in successive sheet metal parts, the inner knobs 33 arranged twisted to each other. This results in that the inner knobs 33 are arranged on an imaginary helical line. However, this applies mathematically exact only for the point of the inner knob, which has the minimum radial distance to the rotor axis. The remaining part of the inner knob 33 runs in the circumferential direction, so not exactly in the helical direction.

That through the inner knobs 33 generated screw thread is realized so to speak discretely, so always at spaced locations of the imaginary screw thread is an inner knob 33 arranged.

By attaching two or more inner knobs 33 a corresponding two- or multi-threaded screw thread is generated.

The sheet metal part also has punched out recesses 31 so that the moment of inertia of the rotor is reduced. There are also surveys 34 on the sheet metal part 30 arranged, with which a punched package is executable.

For each magnetic adhesive surface are external nubs 32 provided for limiting the permanent magnets in the circumferential direction.

That through the inner knobs 33 formed internal thread 40 is more usable if there are several inner knobs 33 on the sheet metal part 30 be formed. In the 3 are two inner knobs 33 shown so that a zweigängiges screw thread is generated discretely.

Leg of a sheet thickness of 0.5 mm and circumferentially successively arranged ten permanent magnets results in a thread pitch of 5 mm, the half pitch of the double-threaded thread is 2.5 mm.

The screw thread is preferably not selected to be self-locking.

It may be designed as a trapezoidal thread or other thread, so with a different profile.

Overall, the stanzpaketierte laminated core by means of the inner knobs 33 formed discrete internal thread like a nut on the provided in the rotor shaft, in particular machined external thread screwed.

Preferably, the thread on the rotor shaft is rotated, knurled and / or milled.

A particular advantage of the invention is that the screwing force-free or at least low-energy takes place and thus the rotor shaft can be finished with the laminated core even before assembly, so screwing.

Since the rotor shaft is made of steel, a particularly simple production can be carried out.

It is even possible to first glue the permanent magnets on the adhesive surfaces on the outer circumference of the laminated core and then perform only the screwing of the laminated core to the rotor shaft.

Since there is no special force acting on the rotor shaft when screwing on, a deformation of the rotor shaft and thus required reworking, for example grinding, is not necessary. Thus, the manufacturing is particularly simple and inexpensive executable.

Preferably, before the screw connection with the rotor shaft, the inner knobs are each rounded and flat so that each knob is circumferentially at least three times or at least five times longer than in the radial direction. Each knob is in a deviation from the circular shape. When screwing on the laminated core, the inner knobs are partially deformed. This applies in particular in material areas of the nub remote from the imaginary helix. This material deformation causes a further improved connection force.

In a further embodiment according to the invention, when the sheet-metal package is screwed on, additional adhesive is additionally introduced into the connection area, thus creating an additional cohesive connection.

LIST OF REFERENCE NUMBERS

1

rotor shaft

2

screw thread

3

Stack of sheet metal parts to form the laminated core

30

sheet metal part

31

recess

32

External knobs for limiting the permanent magnets in the circumferential direction

33

Inner knobs for forming an internal thread

40

inner thread formed from inner knobs

Claims (15)

Electric motor with a part, such as rotor shaft or stator housing, and a laminated core, which is connected to the part, characterized in that the part has an external thread or internal thread, wherein the laminated core has an on the thread screwed internal thread or external thread, in particular so that Sheet metal package with the part at least schraubverbindar. Electric motor according to at least one of the preceding claims, characterized in that part and laminated core are at least screw-connected with each other. Electric motor according to at least one of the preceding claims, characterized in that part and laminated core are connected to each other at least cohesively. Electric motor according to at least one of the preceding claims, characterized in that the laminated core is composed of stanzpaketierten individual sheets, in particular wherein each individual sheet has a directed in the stacking direction and / or Rotorachsrichtung survey. Electric motor according to at least one of the preceding claims, characterized in that each next to each other adjacent individual sheets are arranged rotated by an angle contract, in particular wherein the individual sheets of the laminated core are made similar. Electric motor according to at least one of the preceding claims, characterized in that each individual sheet has one, two or more inner knobs for forming the internal thread, in particular wherein the inner knobs are made rounded, so the deviation from the circular shape in the circumferential direction is longer than in the radial direction. Electric motor according to at least one of the preceding claims, characterized in that the studs form the internal thread or external thread, in particular in a discrete manner, in particular a point of each knob is arranged such that the amount of points lie on an imaginary helix, in particular with a predetermined Pitch, in particular wherein the point of the nub is that surface point of the nub which has the smallest radial distance. Electric motor according to at least one of the preceding claims, characterized in that the contact line between a knob and the external thread or internal thread of the part is a circular arc portion whose center has a non-vanishing radial distance from the central axis of the part. Electric motor according to at least one of the preceding claims, characterized in that each single sheet has outer knobs for limiting permanent magnets adhered to the laminated core, and / or that each individual plate has one or more recesses for reducing the moment of inertia of the rotor or the mass of the electric motor, and / or that the external thread or internal thread is more continuous, wherein the number of gears corresponds to the number of internal knobs of a single sheet. Electric motor according to at least one of the preceding claims, characterized in that the mutually engaged threads, in particular internal thread and external thread, are not self-locking, and / or that the thread is designed as trapezoidal thread, buttress thread or round thread or has a trapezoidal cross-section, and / or that the package movement relative to the shaft on one side by an axial stop, insbeosndere by an arranged on the rotor shaft stop, the package or through the outlet of the thread, insbeosndere in the laminated core, in addition positively prevented and / or that on one side, in particular on the other side, by a recess running around the part, in which a securing ring is arranged. A method for producing a rotor of an electric motor, in particular according to at least one of the preceding claims, characterized in that in a first manufacturing step, the part is finished and in a final manufacturing step, the laminated core is connected to the part, in particular screwed, is. Method according to at least one of the preceding claims, characterized in that in the first step, such a thread is incorporated into the part that a non-vanishing clearance between the laminated core and part is present in the circumferential direction, and / or that in a second manufacturing step on the laminated core an activator or primer is applied in the last Manufacturing step additionally adhesive is introduced into the intermediate region between the part and the laminated core, in particular by a controlled or at least controlled operated metering device, wherein the adhesive forms a chemical compound with the activator or primer. Method according to at least one of the preceding claims, characterized in that individual sheet metal parts are stanzpaketiert when producing the laminated core, wherein the punch of the punching machine is rotated by an angular amount during punching of the inner knobs of a respective single sheet stack. Method according to at least one of the preceding claims, characterized in that dies are used during punching, so other holes are punched out before punching out the inner knobs in another punching step. Use of a rotor core of an electric motor as screwed onto an external thread of the rotor shaft of the electric motor nut or use of a stator core of an electric motor as screwed onto an internal thread of the stator housing of the electric motor mother.

Images