Patent ID: 12224651

DETAILED DESCRIPTION

As illustrated in the Figures, the electric motor according to an example embodiment of the present invention has a rotatably mounted rotor shaft5, onto which an active part4is inserted and non-rotatably connected, e.g., with the active part4having a squirrel-cage or permanent magnets, depending on whether the electric motor is arranged as an asynchronous motor or as a synchronous motor.

At least one of the bearings rotatably supporting the rotor shaft5is accommodated in a bearing flange11which is releasably but, e.g., non-rotatably connected to a housing part7. A stator winding6is arranged radially inside the housing part7and is non-rotatably connected to the housing part7.

On the side of the bearing flange11facing away from the stator winding6, a fan guard9is fastened to the bearing flange11, which radially surrounds a fan8which is non-rotatably connected to the rotor shaft5.

The fan guard9does have a fan grille, e.g., passing-through recesses arranged in a grille, so that the air flow conveyed by the fan can be guided through the fan grille. On the other hand, the fan guard9performs a protective function by preventing people from touching rotatably mounted parts.

The fan guard9is made either from plastic as a plastic injection molded part or from sheet metal as a stamped and bent part.

An angle sensor for detecting the angular position of the rotor shaft5has a shaft3which is rotatable relative to a housing2of the angle sensor, e.g., mounted rotatably relative to a housing2of the angle sensor.

The housing2of the angle sensor is connected to a torque support1which is connected to the fan guard9.

This torque support1is configured such that the torque support1is more rigid against a rotation between the housing part2of the angle sensor and the fan guard9in relation to the rotor shaft5in the circumferential direction, e.g., against a torsion-type rotation, than against an axially directed displacement and also against a radially directed displacement.

In this manner, manufacturing tolerances of the components, for example, the fan guard together with the bearing flange11and/or the rotor shaft5together with the shaft3of the angle sensor, can be compensated for. For example, tolerances in the axial extent or in the axial direction lead to incorrect axial positioning of the housing2, which can, however, be compensated for by the torque support1, which is less rigid in the axial direction.

The torque dissipation cannot be influenced by this, since the torsional rigidity of the torque support1is very high and the housing2is therefore connected to the bearing flange via the fan guard9in a sufficiently non-rotatable manner.

The shaft3of the angle sensor is non-rotatably connected to the rotor shaft5. A non-positive connection such as, for example, an expanded shaft connection or a conical shaft connection is, for example, used for this purpose.

The angle sensor generates a sensor signal that encodes the angular position of the rotor shaft5relative to the housing part7. The angle sensor is configured according to either a magnetic or an optical operating principle.

The bearing of the rotor shaft5accommodated in the bearing flange11is arranged, for example, as a fixed bearing. An arrangement as a floating bearing is possible, since the torque support1couples the housing of the angle sensor to the fan guard9.

The torque support1bears against a, e.g., planar, fan grille of the fan guard9and is non-rotatably fastened to the fan guard9with at least one fastening device or fastener10, e.g., a screw with a nut.

A shaft sealing ring is accommodated in the bearing flange axially between the housing2and the fixed bearing and seals the bearing flange relative to the rotor shaft5. For this purpose, the sealing lip of the shaft sealing ring rests on the rotor shaft5and touches it.

The torque support1has on its radially outer edge radially outwardly protruding tab regions22, through which one of the fastening devices10, e.g., a screw, is guided, which also protrudes through the grille of the fan guard9, e.g., so that the screw head of the fastening device10, e.g., a screw, and a nut which is screwed onto a threaded portion of the fastener10press the torque support1against the fan guard9.

At its radially inner end region, the torque support1has an inner ring23which is connected to the tab regions22via, e.g., four, e.g., meandering, webs24.

In the example embodiment illustrated inFIGS.2and3, two of the webs24are connected to the inner ring23in a first connecting region, which covers a first circumferential angle region, with an axially pass-through recess25being arranged in this first connecting region, through which another fastening device is passed, which connects the torque support1to the housing2of the angle sensor, e.g., by pressing thereon. The further fastening device is, for example, also arranged as a screw part, the screw head of which presses the torque support1against the housing2when the screw part is screwed into an axially directed threaded bore of the housing2.

Likewise, a second connecting region is formed on inner ring23diametrically opposite to the first connecting region, which second connecting region covers a second circumferential angle region, with a second axially pass-through recess25being arranged in this second connecting region, through which a second further fastening device is passed, which also connects, e.g., presses, the torque support1to the housing2of the angle sensor. The further fastening device is, for example, in turn arranged as a screw part, the screw head of which presses the torque support1against the housing2when the screw part is screwed into a further axially directed threaded bore of the housing2.

Two of the webs24are connected with their radially inner end region to the first connecting region and with their radially outer connecting region to a first of the tab regions22.

Two of the webs24are connected with their radially inner end region to the first connecting region and with their radially outer connecting region to a second of the tab regions22.

The first tab region22is arranged diametrically opposite the second tab region22, e.g., spaced apart substantially by approximately 180° in the circumferential direction.

The meandering configuration of the respective web24is arranged within the plane defined by the torque support1, which is, for example, arranged as a stamped sheet metal part.

The meandering region is, for example, arranged such that as the radial distance increases, a first of the two webs24initially has a circumferential angle that increases up to a maximum value and then has a circumferential angle that decreases to a minimum value, whereupon the circumferential angle then increases again until it reaches the circumferential angle region covered by the tab region22.

In further exemplary embodiments, the meandering course of the web24varies more frequently with an increasing radial distance from the axis of rotation of the rotor shaft and correspondingly more frequently reaches the maximum value or minimum value.

As illustrated inFIGS.2and3, the meandering course of the second web24of the two webs24in the circumferential direction is mirror-symmetrical to the plane containing the axis of rotation of the rotor shaft and the center point of the recess26and/or the barycenter of the first tab region22.

For example, the other two webs24are also mirror-symmetrical to the aforementioned webs24.

Since the torque support1is a flat and planar stamped part made of sheet metal, the respective meander, e.g., the respective meander-like web24, is arranged in a plane, the normal direction of which is aligned parallel to the axis of rotation of the rotor shaft, and the torsional rigidity with respect to a torsion relative to the axis of rotation is very high. Thus, the detection of the angle with the angle sensor can be carried out with few errors.

In the axial direction, a deflection of the tab regions22relative to the axial position of the inner ring23is possible with a low force, since the torque support1does not have a high level of rigidity with respect to such deflections. Manufacturing tolerances can thus be compensated for without the angle detection being impaired.

Likewise, radial deviations can be accommodated by elastic deflection of the tab regions22relative to the inner ring23.

The webs24are, for example, regularly spaced apart from one another in the circumferential direction.

The inner ring23is, for example, in contact with the housing2of the angle sensor.

Each web24covers, e.g., with its meandering course, a circumferential angle region which covers more than 60° and which, for example, is less than 90°.

There is therefore an angular distance of more than 60° between the maximum value and the minimum value, with the angular distance being less than 90°.

The webs24are, for example, regularly spaced apart from one another in the circumferential direction.

The fan guard9itself, e.g., the grille of the fan guard9, is made more rigid than the torque support1.

The radial distance region covered by the webs24is arranged between the radial distance region covered by the inner ring23and the radial distance region covered by the tab regions22.

The angular circumferential angle region covered by the first tab region22is quantitatively spaced more than 60° apart from the circumferential angle region covered by the first connecting region. The circumferential angle region covered by the first tab region22is spaced more than 60° apart from the circumferential angle region covered by the first connecting region.

This permits the meander to be shaped in an optimized manner, e.g., as many meander loops as possible in a small radial distance region.

Correspondingly, an angle between the connecting line connecting the barycenters of the two tab regions22and the connecting line connecting the barycenters of the two connecting regions amounts to more than 60°, e.g., 90°.

If the two connecting lines are, for example, aligned perpendicular to one another, a highly precise detection of the angle values by the angle sensor is provided, since the torsional rigidity has the same values both in the circumferential direction and counter to the circumferential direction, e.g., there is no preferential direction. This also applies if there are axial and radial tolerance deviations.

The torque support1, e.g., a torque support part, is arranged as a one-piece stamped part.

As illustrated inFIG.4andFIG.5, nuts40are welded on the side of the torque support1facing the fan guard9. Thus, the nuts40are integrally connected to the torque support1. Screws42protruding through recesses41in the fan guard are screwed into the nuts40. The respective screw head of the respective screw42thus presses the fan guard9onto the respective nut40and the torque support is thus positively connected to the fan guard9by screws42.

The housing part2of the angle sensor is positively and thus non-rotatably connected in the circumferential direction, by pins43that pass through the torque support1. The pins43are, for example, inserted into bores in the housing2in a non-positive manner.

Since the fan guard9is also positively connected to the housing part7, e.g., the stator housing, by screws, the torque is transmitted from the housing2of the angle sensor via the torque support1and via the fan guard9to the housing part7.

The torque support1is therefore arranged on the inside of the fan guard9and is therefore protected by the fan guard9against the effects of the external environment.

LIST OF REFERENCE NUMERALS

1torque support2housing, e.g., stator, of the angle sensor3shaft, e.g., rotor shaft, of the angle sensor4active part5rotor shaft6stator winding7housing part8fan9fan guard10fastening device, e.g., screw with nut11bearing flange22tab region23inner ring24meander-like web25recess26recess40nut41recess42screw43pin