EP3394962A1

EP3394962A1 - Electrical working machine

Info

Publication number: EP3394962A1
Application number: EP16815538.0A
Authority: EP
Inventors: Guido Kochsiek
Original assignee: Iprotec Maschinen und Edelstahlprodukte GmbH
Current assignee: Iprotec Maschinen und Edelstahlprodukte GmbH
Priority date: 2015-12-21
Filing date: 2016-12-21
Publication date: 2018-10-31
Also published as: RU2018124639A; DE202016008922U1; WO2017108967A1; JP2019503643A; CN108432101A; US20180358864A1

Abstract

The aim of the invention is to simplify electrical working machines with respect to their structure and assembly and to improve their power. In order to achieve said aim, the invention proposes to equip an electrical working machine with elements for transmitting torques, in which at least one pair of elements is designed as a non-circular connection.

Description

Electric working machine

Electric machines are electric motors, power generators and the like.

Within the electric motor or even with power generators, a number of compounds are included that need to transmit torque. Depending on the engine, different engine concepts are used. In all engines but on the motor shaft components are required, which are responsible for the drive of the engine or for the generation of electricity at the generator. These must be permanently connected to the motor / generator shaft in a rotationally stable manner. In certain engines, additional components are required, which must also be rotationally connected to the motor shaft. The components to be connected to the motor shaft are, for example, collector, armature (winding), rotor core, commutator, etc.

Most connections in the generator and Eiektromotorenbau are designed as spline, feather key or as a shrink joint.

In particular, the shrink joints ensure a high assembly cost with corresponding costs (heating or cooling of the components, unfavorable handling of hot or cold components, high energy costs during assembly, possible distortion of the components when heated, high Beschädigungspotenzia! Assembly (loss of run when joining long joints due to snow! Cooling during assembly). A correction-disassembly possibility is no longer possible when the shrink connection has cooled down once. In case of service, non-destructive disassembly is possible.

Other connections (splines, keyways) have technical disadvantages and use the space usually not optimal. splines For example, they forgive the barrel when they need to be hardened. Keyway connections are among the worst types of connection in the industry (imbalance, notch effect, expensive production, expensive assembly, unfavorable torque behavior, backlash).

The present invention is based on the invention to simplify electrical machines with regard to their construction and assembly.

To solve this problem, the invention proposes an electric working machine with the features of claim 1. In the following description further independent inventive solutions are shown.

The aim of this invention is to optimize the manufacturing processes, to reduce the manufacturing costs and to optimize the connections so that space or weight can be saved, as well as assembly advantages can be achieved and the service friendliness is increased.

The invention proposes to design at least one of the connections for torque transmission in such a way that the elements to be connected-usually shaft / hub arrangements-have a non-circular cross-section. One speaks of so-called non-circular connections, in the special case of polygon connections. For the purposes of the present invention, the term "undround connections" is used in general for non-circular elements, ie those which do not have a circular cross-section, and polygon connections, in turn, are special non-circular connections, for example, they can produce contours called cycloids. Epicycloids, shortened and lengthened and the like

This is understood by novel production technologies, in particular the non-circular manufacturing of manufactured elements. These have no circular cross-section, but a different cross section, which may also be polygonal. It is obvious that an example octagonal hub on the one hand, which accommodates an octagonal end of a shaft, a much simpler installation and maintenance allows, but beyond also a much better torque transmission. In the production by the novel non-circular turning process also reduces the material requirements for production, as well as allows a faster processing time. In addition, less production energy is needed.

These compounds are characterized by: unbalance freedom, freedom from backlash, self-centering, low notch effect, optimum torque behavior in the smallest space, easy installation, high running quality even with hardened connections.

Through the use of polygonal stages or conical polygon connections can be almost all compounds in the electric motor or generator as

Make non-circular connections.

For the replacement of the shrink joints polygonal (non-round) step connections are particularly suitable because the heating or cooling of the components is not required. The assembly can be greatly simplified. Alternatively, a conical non-circular profile can be used. By using non-circular connections, the connection length can be reduced and space can be saved or space for additional functions (such as fits, ...) can be released.

The advantages of such a connection are: greatly simplified assembly with significantly lower costs (no heating of the components required), shortening of the connection length by non-round positive locking instead of round frictional connection or by non-round shape and friction, gain of space, reduction of weight (energy efficiency, better efficiency, better performance), high running quality (no imbalance) after the greatly simplified installation. Components can be dismantled and then reassembled (significantly cheaper repair costs of an engine).

The use of polygonal / non-circular connections in the electric motor or generator leads to significant improvements and increases the reliability of the drive, since positive connections can be used in all connections. The use of non-circular connections open up further possibilities for the engine developer in the same installation space, or more To accommodate functionality. Through the use of non-circular connections, the production costs can be significantly reduced, the energy efficiency increases.

As a further independent solution according to the invention, it is also proposed to make the output shaft end likewise non-circular. If non-circular connections are used anyway, this connection can be manufactured in one clamping, which has a positive effect on the manufacturing quality and the production costs. The same applies to the machining of round sections of the motor shaft (for example, bearing seats) and non-circular connections in one setting in order to improve the running quality between the individual sections. As a result, higher speeds can be achieved on the finished product. The technical advantages of a non-circular connection also at the output shaft end are: no imbalance, self-centering, more compact design with the same performance, freedom from backlash, etc.

In addition, it is also proposed as a separate invention erfindungsgermäße solution to connect the fan of a motor / generator also polygonal / out of round with the shaft. Again, a non-circular step design or conical Unrundprofil offers as a connection form.

According to the invention, extended trochoidal are particularly interesting when it comes to the connection of laminated cores and rotor shaft. This particular because the counterpart is a sheet metal part.

The solution according to the invention is characterized by a high level of economy through the use of non-circular turning processes. This allows great precision, so that connections can be created that are no longer subject to play, as is the case, for example, with splines. Also, there are no imbalances such as feather key connections. The non-circular turning process makes it possible to produce torsionally stiff, secure oversize joints. The joining can be implemented without heating or cooling, in particular when using a step design, conical connections or similar compounds are sefbstzentrierend and compared to conventional plug-in tooth connections, these aufrgund better power transmission properties in a smaller space be housed or allow for the same space a higher reliability and / or the transmission of larger forces. The connecting elements (shaft and hub) can be manufactured according to the same procedure.

In particular, in the combination of laminated core to the rotor core, extended shapes can be used, for example, an extended trochoid, because the counterpart, i. The laminated core, can not be produced by machining.

According to the invention, the individual elements of a polygonal connection can be formed of different materials, which also results in simplifications and possibilities for improvement.

Further advantages and features of the invention will become apparent from the following description with reference to FIGS. Showing:

Fig. 1 is a schematic representation of a non-circular shaft-hub connection in the

Output shaft range of an electric motor

Fig. 1 a with respect to the shaft-hub connection of Fig. 1 a

Force distribution curve;

Fig. 2 is a schematic representation of a non-circular shaft-hub connection between

Laminated core and motor shaft (rotor);

Fig. 2a with reference to the shaft-hub connection of Fig. 2 a

Force distribution curve and

3 is a schematic representation of the non-circular shaft-hub connection according to the invention in the viewing direction III according to FIG. 2.

1 shows a shaft-hub connection with a hub seat 2 provided by a while 1 and a hub of a component 5, for example a toothed wheel, received by the hub seat 2. The hub seat 2 and the hub of the component 5 form a polygon connection, that is, the hub seat 2 has a polygonal cross-sectional outer contour, wherein the component 5 has a trained example as a bore receptacle with a corresponding to the outer contour of the hub seat 2 inner contour. For example, the polygon profile used may be a five-corner. Basically, of course, that the polygonal profile as Unrundprofil over as needed according to many corners may have. The invention is not limited to a five-cornered polygonal profile.

As can be seen from the illustration according to FIG. 1, the hub seat 2 and the component 5 received therefrom are of equal length in the longitudinal direction 1 1 of the shaft 1 or equally wide with respect to the plane of the sheet according to FIG. 1. With reference to the plane of the drawing according to FIG. 1, the hub seat 2 is delimited on the left as well as on the right by a connecting region 3 or a connecting region 4, which connecting regions 3 and 4 are circular in cross section in contrast to the hub seat 2.

2, the hub seat 2 in the illustrated embodiment has two further radial shoulders 9 and 10, so that a total of a three-stage hub seat 2 with the three stages I, II and III is formed. The hub of the component 5 a laminated core, is formed according to the invention multi-stage of the hub seat 2 accordingly.

The individual stages I, II and III of the hub seat are the same width with respect to the plane of the drawing of FIG. 2, that is, the same length with respect to the longitudinal direction 1 of the motor shaft 1.

The second stage II of the hub seat 2 forming radial shoulder 9 projects beyond the first stage I of the hub seat 2 in the radial direction depending on the embodiment and application by at least some μιτι up to several millimeters. In the same way, the third step III formed by the radial shoulder 10 projects beyond the second step II of the hub seat 2 provided by the radial shoulder 9 in the radial direction.

Fig. 3 shows the shaft-hub connection according to the invention in the direction of view III of FIG. 2. From this illustration, the individual radial paragraphs 9 and 10 and the individual Steps I, II and III of the hub seat are clearly visible. It can be seen in particular from this representation that the hub seat 2 forms a polygonal polygonal profile, whereas the connecting areas 3 and 4 adjoining the hub seat 2 with reference to the illustration according to FIG. 2 on the left and right sides have a circular cross-section.

If, in the loading case, a force, for example, with respect to the plane of the drawing according to FIG. 2, acts on the same side as shown in FIG. 3 on the basis of the force arrow F, the shaft 1 will be subjected to a load in the region of the hub seat 2, as shown by way of example is shown in Fig. 2a. FIG. 2 a shows a diagram showing the force or stress distribution 8 in the region of the hub seat 2 of the shaft 1, wherein the force introduced into the shaft 1 on the y-axis 7 extends over the axial extent of the hub seat 2 according to the x-axis 6 is worn away. As can be seen from this diagram, a force or voltage curve 8 results, which increases with respect to the plane of the drawing according to FIG. 2 per stage I, II and III of the hub seat 2 from left to right. The maximum stress results in each case with reference to the plane of the drawing according to FIG. 2 on the right side of each stage I, II and III of the hub seat 2.

At this point, it should be emphasized that FIGS. 1 a and 2 a are merely illustrative and should not be scientifically and technically correct in any way.

The force peaks also define an average force, which corresponds approximately to the mean value between 0 and F _max . This average force is the measure of the efficiency of the shaft-hub connection and this average value is shown as a dashed line.

In a shaft-hub connection according to the prior art results in a power or voltage distribution 8, as shown in Fig. 1 a. In a comparison of the diagrams of Fig. 1a and Fig. 2a shows that either the total force introduced into the hub seat 2 is equal, but that a force distribution with respect to the maximum force acting on the individual stages I, II and III of the Hub seat 2 is achieved according to the embodiment of the invention. Or the other way around the shaft-hub connection according to the invention is more resilient and can be a larger average power transmitted. This results in the result that in the embodiment of the invention a minimized in comparison to the prior art with the same force introduction maximum load on the shaft 1 acts. The minimization of the maximum load is achieved in that a distribution of the maximum forces and / or stresses on the individual stages I, II and III of the hub seat 2 takes place according to the embodiment of the invention. Due to this stress distribution, an improved, that is reduced, contact corrosion compared to the prior art can be achieved. Or alternatively, the shaft-hub connection according to the invention can be regarded as significantly more efficient, ie, it represents a significant improvement in every respect. By targeted different excesses in the stages, further optimizations can be achieved in terms of the function of the compound.

The application of this shaft-hub technology to the torque-transmitting connections in an electrical machine is the subject of the present patent application. It is apparent from the general illustrations based on the embodiments, which advantages arise here for electric machines.

LIST OF REFERENCE NUMBERS

1 motor shaft

2 hub seat / hub-hub connection

3 connection area

4 connection area

5 component

6 x axis

7 y axis

8 force distribution

9 Radial paragraph

10 Radial paragraph

1 1 longitudinal direction

I level

II level

III level

force

maximum strength

Claims

claims

1 . Electric machine with elements provided for the transmission of torques, characterized in that at least one element has a connection region with a rounded cross-section.

2. Electric machine according to claim 1, characterized in that the output shaft end has a non-circular cross-section.

3. Electric drive machine according to one of the preceding claims, characterized in that the region is made with a non-circular cross-section using a non-rounding process.

A method according to claim 3, characterized in that the non-circular cross-section area is made using a round-bottom turning method in the same setting for rotating round areas.

5. The method according to any one of the preceding claims, characterized in that the region having a non-circular cross section has a cycloidal contour.

6. Electric drive machine according to one of the preceding claims, characterized in that the region with a non-circular cross-section is polygonal and over the length has steps of different diameters.

7. Electric drive machine according to one of the preceding claims, characterized in that the region is formed with a non-circular cross-section conical.

8. Electric drive machine according to one of the preceding claims, characterized in that it comprises a plurality of elements with regions having a non-circular cross-section.