DE102019211896A1 - Electric motor - Google Patents

Abstract

An electric motor (1) is proposed, comprising a rotor (2) and a stator (3), in which the rotor shaft (4) is supported in a radially overhung manner.

Description

The present invention relates to an electric motor comprising a rotor and a stator according to the preamble of patent claim 1.

It is known from the prior art to use electric motors comprising a rotor and a stator in vehicles. Here, roller bearings and / or slide bearings are used to support the rotor, which disadvantageously results in a limitation of the performance of the electric motors. In particular, in the case of the electric motors known from the prior art, the maximum achievable rotor speeds are limited due to the roller and / or slide bearings of the rotor, the efficiency being negatively influenced due to the bearing losses. In addition, the use of roller and / or plain bearings results in a relatively large dimensioning of the electric motors.

The present invention is based on the object of specifying an electric motor by means of which the described disadvantages known from the prior art are avoided.

This object is achieved by the features of claim 1. Further configurations and advantages according to the invention emerge from the subclaims.

Accordingly, an electric motor comprising a rotor and a stator is proposed, in which the rotor shaft is supported in a radially overhung manner.

According to one embodiment of the invention, the rotor shaft has external toothing at one or both ends, each external toothing meshing with two gearwheels fixedly arranged in rotation on different, fixedly mounted shafts assigned to the respective end of the rotor shaft, the longitudinal axes of the rotor shaft and the respective Fixed shafts assigned to the end of the rotor shaft are arranged parallel to one another and preferably lie in one plane.

The gear wheels arranged on the fixedly mounted shafts preferably have a helical toothing such that at least some of the axial forces can be absorbed.

According to an advantageous embodiment of the invention, the rotor shaft has an external toothing at both ends, two fixed shafts are provided, on each of the ends of which a gear is rotatably arranged, which meshes with the external toothing of one end of the rotor shaft, the longitudinal axes of the The rotor shaft and the fixedly mounted shafts are arranged parallel to one another and preferably lie in one plane. The two fixed shafts are assigned to both ends of the rotor shaft.

With this configuration and with gears having helical teeth, the advantage is achieved that the axial forces cancel each other out, so that no additional axial bearing of the rotor shaft is required. This embodiment also advantageously means that, in comparison to the embodiment in which two fixedly mounted shafts are assigned to each end of the rotor shaft, only two shafts have to be fixedly mounted.

The bearings for mounting the fixed shafts can be bearings known from the prior art and, for example, be designed as roller or ball bearings.

As part of a further development of the invention, it is proposed to design the output of the electric motor in such a way that an internally toothed ring gear connected to an output shaft of the electric motor is driven via the gears that mesh with the external toothing of the end of the rotor shaft facing the output shaft.

The concept according to the invention makes it possible to achieve higher rotor speeds in an advantageous manner compared to the prior art, according to which roller bearings and / or slide bearings are used to support the rotor. Furthermore, the efficiency of the electric motor is increased, since bearing losses due to bearing friction on the rotor shaft are eliminated. Furthermore, by eliminating the roller and / or sliding bearings, a compact design is achieved, in particular with a smaller diameter compared to the prior art, so that installation space can be made available for further components. Furthermore, by expanding the speed range, a further gear step can be saved, which results in a significant reduction in manufacturing, maintenance and assembly costs.

• 1: Eine schematische Darstellung einer ersten Ausgestaltung der Erfindung;
• 1: Eine schematische Darstellung einer weiteren Ausgestaltung eines Elektromotors gemäß der Erfindung; und
• 3: Eine schematische Darstellung einer erfindungsgemäßen Ausgestaltung des Abtriebs eines Elektromotors.

The invention is explained in more detail below with reference to the accompanying figures. The general structure and the mode of operation of electric motors are very well known to the person skilled in the art, so that the features that are important for the present invention are described in detail below. Show it:

• 1 : A schematic representation of a first embodiment of the invention;
• 1 : A schematic representation of a further embodiment of an electric motor according to the invention; and
• 3 : A schematic representation of an embodiment according to the invention of the output of an electric motor.

In 1 is an electric motor 1 shown, which has a rotor 2 and a stator 3 includes; the rotor shaft is identified by the reference number 4th designated. According to the invention, the rotor 2 of the electric motor 1 Radially overhung via gear stages. The in 1 example shown has the one with the rotor 2 rotatably connected rotor shaft 4th external teeth at both ends 5 , 5 ' on, each external toothing 5 , 5 ' each with two on different, the respective end of the rotor shaft 4th assigned fixed shafts 6th , 7th , 8th , 9 non-rotatably arranged gears 10 , 11 , 12 , 13 combs.

The longitudinal axes of the rotor shaft 4th and that of the respective end of the rotor shaft 4th assigned fixed shafts 6th , 7th or. 8th , 9 are arranged parallel to each other and lie in one plane. The ones on the fixed shafts 6th , 7th , 8th , 9 arranged gears 10 , 11 , 12 , 13 preferably have a helical toothing such that at least some of the axial forces can be absorbed.

The one end of the rotor shaft 4th According to further embodiments, assigned gears can be dimensioned differently compared to the gears assigned to the other end, in which case the diameter of the respective external toothing of the rotor shaft and / or the distance between the fixed shafts assigned to the respective end and the rotor shaft can vary accordingly .

When designing according to 1 a separate axial bearing is preferably not required. According to a further embodiment of the invention, only one of the two ends of the rotor shaft can 4th have an external toothing which meshes with two fixedly mounted shafts which are fixedly arranged in a rotationally fixed manner on different shafts assigned to this end of the rotor shaft. In this case, in addition to a conventional radial bearing, an axial bearing is required at the other end of the rotor shaft.

This in 2 The embodiment shown differs from the embodiment according to 1 by the fact that only two fixed shafts 14th , 15th are provided, each of the two ends of the rotor shaft 4th assigned. With this configuration and the helical gears 10 , 11 , 12 , 13 the advantage achieved is that the axial forces cancel each other out, so that there is no additional axial bearing for the rotor shaft 4th is required.

Subject of 3 is an advantageous embodiment of the output of the electric motor 1 according to the invention, in which the at least one end of the rotor shaft 4th of the electric motor 1 associated shafts 6th , 7th and the fixed gears arranged on these shafts 10 , 11 for driving an output shaft 16 of the electric motor 1 can be used.

Here is a with the Abtrieswelle 16 of the electric motor 1 connected internal toothed ring gear 17th provided, which is rotatably fixed on the fixed shafts 6th , 7th arranged gears 10 , 11 that with the external teeth 5 of the end of the rotor shaft facing the output shaft 18 4th comb, is driven. In the event of an arrangement according to 1 and 2 can be from one or both ends of the rotor shaft 4th one output shaft can be driven.

List of reference symbols

1

Electric motor

2

rotor

3

stator

4th

Rotor shaft

5, 5 '

External toothing

6

fixed shaft

7th

fixed shaft

8th

fixed shaft

9

fixed shaft

10

gear

11

gear

12

gear

13

gear

14th

fixed shaft

15th

fixed shaft

16

Output shaft of the electric motor

17th

internally toothed ring gear

Claims (6)

Electric motor (1), comprising a rotor (2) and a stator (3), characterized in that the rotor shaft (4) is supported in a radial overhung manner. Electric motor (1) Claim 1 , characterized in that the rotor shaft (4) has an external toothing (5, 5 ') at one or both ends each external toothing (5, 5 ') each with two fixedly mounted shafts (6, 7, 8, 9, 14, 15) arranged in a rotationally fixed manner on different shafts (6, 7, 8, 9, 14, 15) which are fixedly mounted on different ends of the rotor shaft (4). 12, 13), the longitudinal axes of the rotor shaft (4) and the fixedly mounted shafts (6, 7), (8, 9) assigned to the respective end of the rotor shaft (4) being arranged parallel to one another and lying in one plane. Electric motor (1) Claim 1 or 2 , characterized in that the rotor shaft (4) has external toothing (5, 5 ') at both ends, two fixedly mounted shafts (14, 15) assigned to both ends of the rotor shaft being provided, each of which has a gear wheel ( 10, 12), (11, 13), which meshes with the external toothing (5, 5 ') at one end of the rotor shaft (4), the longitudinal axes of the rotor shaft (4) and the fixedly mounted shafts (14, 15) are arranged parallel to each other and lie in one plane. Electric motor (1) Claim 2 or 3 , characterized in that the gear wheels (10, 11, 12, 13) arranged on the fixedly mounted shafts (6, 7, 8, 9, 14, 15) have helical teeth. Electric motor (1) Claim 2 , 3 or 4th , characterized in that an output shaft (16) of the electric motor (1) is driven in that an internally toothed ring gear (17) connected to the output shaft (16) in a rotationally fixed manner is provided, which via the fixedly mounted shafts (6, 7 ), (8, 9), (14, 15) arranged gears (10, 11, 12, 13), which mesh with the external toothing (5) of the end of the rotor shaft (4) facing the output shaft (18), is driven. Electric motor (1) Claim 6 , characterized in that one output shaft can be driven by one or both ends of the rotor shaft (4).

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