DE102018121058A1 - Compressor unit, compressed air supply system, in particular for a vehicle with a compressed air supply system - Google Patents

Abstract

The invention relates to a compressor unit (356) comprising a compressor (K) and a direct current motor (M, 100, 200) for driving the compressor (K), the direct current motor (100, 200) being connected to a housing (102, 202) has a crankcase of the compressor (K), the housing (102, 202) being formed in three parts. According to the invention, a middle housing part (102c, 202c) has a dimension (L1) that is axially on the end side in a range (b) between a longer upper dimension limit (oL1) and a shorter lower dimension limit (uL1), the lower dimension limit (uL1) essentially being a final axial end position (L2) of a stator (108) is formed and the upper dimension limit (oL1) is essentially formed from a final axial end position (L3) of a rotor (104), - the frame (110, 210) of a pot-like final housing part (102b, 202b) has an extension (L6) which completely overlaps a brush holder (112, 212) of a commutator (114, 214) on a shaft, and - a brush holder (112, 212) and the pot-like end-side housing part (102b, 202b) is formed in each case as a lightweight construction and the lightweight construction is formed with a light metal.

Description

The invention relates to a compressor unit comprising a DC motor for coupling to a crankcase of the compressor, in particular a brushed, permanently excited DC motor, for coupling to a crankcase of the compressor. Furthermore, the invention relates to a compressed air supply system, in particular a vehicle with a compressed air supply system comprising the compressor unit for supplying compressed air to a compressed air connection.

Compressors for generating compressed air in vehicles are typically driven by electric motors, preferably by direct current motors. An electric motor is an electromechanical converter that converts electrical power into mechanical power. When compressed air is needed, the DC motor is turned on. When a sufficient amount of compressed air has been generated, the DC motor is usually switched off.

DE 10 2008 052 779 A1 describes an electric motor for driving a compressor of an air supply unit of a vehicle. The electric motor has at least one semiconductor switch for controlling the electric motor.

Typically, electric motors, such as, for example, direct current motors, in particular mostly brushed, permanently excited direct current motors of the type mentioned at the beginning, have a housing made of steel. The DC motor includes a rotor rotatably mounted on a shaft in a stator. The stator is a fixed part of the DC motor and is often also part of the housing. The stator carries permanent magnets attached to it.

However, the use of steel also has structural disadvantages. These constructional disadvantages include, in particular, a relatively high weight and a thermal behavior of the DC motor that is in need of improvement.

Compressors, in particular compressed air compressors for vehicles, are always subject to high weight reduction requirements, along with high availability and low costs. In addition, the thermal behavior of the DC motor depends on its on-time. The duty cycle of a DC motor is referred to as the maximum permissible operating interval of the DC motor after which there must be a break in order not to damage or destroy the DC motor, and is implicitly used as a criterion for estimating the load capacity and thus also for quality assessment.

It is desirable to enable increased load capacity even for a weight-reduced DC motor.

The invention is therefore based on the object of providing a compressor unit with a weight-reduced direct current motor which is nevertheless designed for a higher thermal load. In particular, the construction of the direct current motor in the context of the compressor unit should be advantageously designed.

The invention solves this problem by a compressor unit of claim 1.

For this purpose, the invention relates to a compressor unit comprising a compressor and a direct current motor for driving the compressor, the direct current motor having a housing for coupling to a crankcase of the compressor, in particular for a compressed air supply system. The housing is formed in three parts and comprises a first crankcase-side housing part for coupling to the crankcase of the compressor, a second end-side housing part and a third middle housing part, which is connected between the first and second housing parts. Furthermore, the DC motor comprises a rotor which is rotatably mounted on a shaft in a stator for use of a magnetic field during operation, the shaft being held on the crankcase-side housing part and the end-side housing part, and the stator on the middle housing part. Furthermore, the middle housing part is made of steel. In particular, the middle housing part is made of steel. The end-side housing part is pot-shaped with a frame.

The DC motor is further characterized in that the middle housing part has a dimension that is axially on the end side in a range between a longer upper dimension limit and a shorter lower dimension limit. The lower dimension limit is formed by the axial end position of the stator at the end.

The upper dimension limit is formed by the axial end position of the rotor at the end. In addition, the frame of the pot-like end-side housing part has an extension which completely engages over a brush holder of a commutator on the shaft. Furthermore, the DC motor is characterized in that the brush holder and the pot-like end-side housing part are each formed as a lightweight construction with a light metal that is selected from one Group of light metals consisting of aluminum and magnesium.

According to the present invention, a DC motor having a stator and a rotor has a three-part housing. The middle housing part is made of steel and forms a steel ring, which serves as a magnetic yoke in order to achieve a magnetic circuit for the magnetic field during operation. The middle housing part has an axial dimension that is axially on the end side between an end side axial end position of the stator and an end side axial end position of the rotor.

The middle housing part therefore has a dimension which on the end side extends beyond an axial dimension of the stator and essentially extends to a dimension of the rotor. Compared to conventional DC motors of more similar dimensions, the axial dimension of the housing part made of steel is shorter and therefore enables the weight of the DC motor of the present invention to be reduced. Nevertheless, this dimension of the housing part made of steel, which goes beyond an axial dimension of the stator at the end, is weighed against the weight reduction - according to the invention, both the brush holder and the pot-like end part of the housing are formed as a lightweight construction with a light metal - balanced by a predetermined amount to achieve sufficient magnetic return for the magnetic circuit for the magnetic field during operation. Specifically, it is particularly preferred that the middle part made of steel is only as long as is absolutely necessary in order to achieve a sufficient magnetic conclusion.

The invention also achieves the object by means of a compressed air supply system with the compressor unit according to the invention.

The invention thus also relates to a compressor unit comprising a compressor and a direct current motor in the context of a compressed air supply system, in particular a vehicle with a compressed air supply system, comprising a compressor unit according to the invention for supplying compressed air.

Advantageous developments of the invention can be found in the subclaims and specify in particular advantageous possibilities for realizing the concept explained above in the context of the task and with regard to further advantages.

In the case of such mostly brushed, permanently excited DC motors, the rotor, if necessary also the stator with so-called electrical sheet, can advantageously be used in any case. H. be formed with soft magnetic, corrosion-protected steel sheet. In particular, only the rotor, e.g. B. for cost reasons, be formed with electrical sheet. The stator housing, on the other hand, can be made from deep-drawn or rolled sheet steel. It has been shown that a design laminated in lamellae would not bring any noteworthy advantage due to the absence of pole changes or the eddy currents that hardly occur. Electrical sheet is one of the most important soft magnetic materials for magnetic cores in terms of quantity and value.

Both the brush holder and the pot-like end-side housing part are advantageously formed as lightweight structures with aluminum or magnesium or aluminum and magnesium. In particular, the crankcase-side housing part is formed as a lightweight construction with a light metal. The light metal is preferably selected from a group of light metals consisting of: aluminum, magnesium or alloys thereof. Alternatively, the lightweight construction can also consist of the light metal, in particular of an aluminum and / or magnesium based alloy.

Aluminum and magnesium have better thermal conductivity than steel. This fact is used by the DC motor of the invention to better dissipate the heat generated in the commutator from an area of the brush holder. Since the on-time is limited primarily by self-heating in the area of the brush holder, the advantageous choice of material and the advantageous geometry of the pot-like end part of the housing enable the on-time of the DC motor according to the invention to be increased.

In an alternative development, the lightweight construction is formed from a composite material, the composite material being formed from a plastic and the light metal.

In a further development, the composite material is formed as a layer material with a first layer made of plastic and a second layer made of light metal. In particular, in a preferred development, the composite material has a supporting structural body with a coating, the coating being formed from the light metal.

• - das mittlere Gehäuseteil eine Abmessung, die kurbelgehäuseseitig axial über einer kürzeren Abmessungsuntergrenze liegt, wobei die Abmessungsuntergrenze im Wesentlichen von der kurbelgehäuseseitig axialen Endposition des Stators gebildet ist, und/oder
• - das mittlere Gehäuseteil hat eine Abmessung, die kurbelgehäuseseitig axial unter einer längeren Abmessungsobergrenze liegt, wobei die Abmessungsobergrenze im Wesentlichen von der kurbelgehäuseseitig axialen Endposition des Rotors gebildet ist.

To allow further weight loss, has

• - The middle housing part has a dimension that is axially on the crankcase side above a shorter dimension lower limit, the lower dimension limit being essentially formed by the axial end position of the stator on the crankcase side, and / or
• - the middle housing part has a dimension which is axially below a longer upper dimension limit on the crankcase side, the upper dimension limit being essentially formed by the axial end position of the rotor on the crankcase side.

• - abschlussseitig axial mit einem ersten Überstand über einer kürzeren Abmessungsuntergrenze liegt und/oder
• - kurbelgehäuseseitig axial mit einem zweiten Überstand über einer kürzeren Abmessungsuntergrenze liegt. Dies hat den Vorteil, dass ein optimierter Magnetkreis und gleichzeitig eine vorteilhafte Gewichtsreduktion erzielbar ist, wobei das aus Stahl gebildete mittlere Gehäuseteil, welches als magnetischer Rückschluss dient, axial beidseitig einen angemessenen Überstand hat. Vorzugsweise ist der erste und/oder zweite Überstand derart bemessen ist, dass abschlussseitig axial und/oder kurbelgehäuseseitig axial über das mittlere Gehäuseteil aus Stahl ein magnetischer Rückschluss des Magnetfeldes im Betrieb gegeben ist. Insbesondere ist der erste und/oder zweite Überstand derart minimiert bemessen, dass Streuverluste des Magnetfeldes im Betrieb lediglich unter einer vorbestimmt akzeptablen Obergrenze gehalten sind.

The middle housing part preferably has a dimension that

• - Is axially at the end with a first protrusion over a shorter dimension lower limit and / or
• - Axial side of the crankcase with a second protrusion is above a shorter dimension lower limit. This has the advantage that an optimized magnetic circuit and at the same time an advantageous weight reduction can be achieved, the middle housing part, which is made of steel and serves as a magnetic yoke, has an appropriate overhang on both sides of the axis. The first and / or second protrusion is preferably dimensioned such that the end side axially and / or the crankcase side axially provides a magnetic inference of the magnetic field during operation via the middle housing part made of steel. In particular, the first and / or second protrusion is dimensioned to be minimized such that leakage losses of the magnetic field during operation are only kept below a predetermined, acceptable upper limit.

Preferably, the dimension of the middle housing part on the end side is longer than the dimension on the end side relative to the dimension with less than 5% protrusion, in particular with less than ten millimeters protrusion, of the stator. Additionally or alternatively, the dimension of the middle housing part on the crankcase side relative to the dimension with less than 5% projection, in particular with less than ten millimeters projection, is preferably longer than the axial dimension of the stator on the crankcase side.

Thus, the dimension of the middle housing part on one side can be up to approximately ten millimeters longer than an axial dimension of the stator than for achieving an improved magnetic yoke. For this reason, in a development of the DC motor of the invention, the dimension of the middle housing part on the end side is essentially ten millimeters longer than the end-side axial dimension of the stator. In addition, in this development, the dimension of the middle housing part on the crankcase side is essentially ten millimeters longer than the axial dimension of the stator on the crankcase side. For the value of ten millimeters, a deviation of 10% is tolerated according to the concept of the invention.

In particular, as part of a further development, a length of tension screws on the housing can be adapted to the dimension of the middle housing part; this results in a further advantageous weight reduction.

A further development, which enables an advantageous further increase in the duty cycle, comprises a housing part at the end which has a heat sink. In particular, the heat sink serves to enlarge a heat-emitting surface of the pot-like end-side housing part. This further prevents possible damage to the DC motor due to overheating. The heat sink has the task of dissipating heat loss by heat conduction from heat-generating components such as the brush holder and the commutator and then dissipating this to an environment by means of heat radiation and convection. In order to keep the thermal resistance as low as possible, the heat sink is made of the heat-conducting light metal. The heat sink is preferably mounted vertically in order to support the air circulation during operation due to the chimney effect.

In one development, the end housing part is formed with a light metal, the light metal being a deep-drawn light metal. In addition or instead, in another development, the crankcase-side housing part is formed with a light metal, the light metal being a deep-drawn light metal.

In an alternative development, the end housing part is formed with a light metal, the light metal being a die-cast light metal. In addition or instead, in another development, the crankcase-side housing part is formed with a light metal, the light metal being a die-cast light metal.

In another development, the housing part on the end is formed with a deep-drawn light metal and the housing part on the crankcase side is formed with a die-cast light metal. In another alternative development, the end-side housing part is formed with a die-cast light metal and the crankcase-side housing part with a deep-drawn light metal.

In comparison to a steel housing part, die-cast light metal offers numerous geometrical design options, in particular for attaching additional components outside and inside for attaching a brush bridge. For example, an additional work step to create the position of the brush bridge is An embossing on the housing part made of steel is required. Die-casting enables the same function to be achieved in a cost-neutral manner, for example by gripping a shaped rib between the magnets and establishing the position. In this case, it is no longer necessary to install the housing with the magnets in the correct position, since the magnetization only takes place after assembly.

In particular, the use of die-cast light metals enables the corresponding housing part to be freely designed, which additionally influences the visual appearance. Deep-drawn light metals enable the manufacture of lighter housing parts, whereby the free formability is limited compared to die casting. The use of a composite material, in particular of metal-coated plastics, increases the electromagnetic compatibility of the DC motor and enables a further weight reduction in comparison with housing parts made of light metal. In contrast, the thermal conductivity of metal-coated plastics is generally poorer.

Embodiments of the invention will now be described below with reference to the drawing. This is not necessarily to show the embodiments to scale, rather the drawing, where useful for explanation, is carried out in a schematic and / or slightly distorted form. With regard to additions to the teachings which can be seen directly from the drawing, reference is made to the relevant prior art. It should be taken into account here that various modifications and changes regarding the form and the detail of an embodiment can be made without departing from the general idea of the invention. The features of the invention disclosed in the description, in the drawing and in the claims can be essential for the development of the invention both individually and in any combination. In addition, all combinations of at least two of the features disclosed in the description, the drawing and / or the claims fall within the scope of the invention. The general idea of the invention is not limited to the exact form or detail of the preferred embodiment shown and described below, or limited to an object that would be limited compared to the object claimed in the claims. For the specified design ranges, values within the stated limits should also be disclosed as limit values and can be used and claimed as required. For the sake of simplicity, the same reference numerals are used below for identical or similar parts or parts with identical or similar functions.

• 1 ein Schema eines Gleichstrommotors gemäß dem Konzept der Erfindung;
• 2a eine Außenansicht einer bevorzugten Ausführungsform eines Gleichstrommotors zur Ankopplung an ein Kurbelgehäuse eines Kompressors;
• 2b einen Querschnitt des Gleichstrommotors der 2a;
• 3 ein Schema eines Fahrzeugs mit einem Druckluftversorgungssystem umfassend ein Kompressoraggregat und Druckluftfeder.

Further advantages, features and details of the invention emerge from the following description of the preferred exemplary embodiments and with reference to the drawing; this shows in:

• 1 a schematic of a DC motor according to the concept of the invention;
• 2a an external view of a preferred embodiment of a DC motor for coupling to a crankcase of a compressor;
• 2 B a cross section of the DC motor 2a ;
• 3 a schematic of a vehicle with a compressed air supply system comprising a compressor unit and compressed air spring.

1 shows a schematically illustrated DC motor M supercharged K , wherein in the scheme an embodiment of the DC motor 100 according to the concept of the invention is shown in detail. The DC motor 100 includes a housing 102 for coupling to a crankcase of a compressor. The housing is formed in three parts with a first housing part on the crankcase side 102a for coupling, with a second housing part at the end 102b and with a middle housing part connected between the first and second housing parts 102c , The DC motor also has a rotor 104 on that on a wave 106 in a stator 108 is rotatably attached. The wave 106 is on the crankcase-side housing part 102a and on the end part of the housing 102b held. The stator is on the middle part of the housing 102c held. The middle part of the housing 102c of the DC motor 100 is made of steel. In alternative embodiments, the middle housing part is made of steel.

The middle part of the housing 102c has a dimension L1 , the end side axially in one area b between a longer upper limit of dimensions oL1 and a shorter dimension lower limit uL1 is the lower dimension limit uL1 essentially from a final axial end position L2 of the stator 108 is formed and the upper dimension limit oL1 essentially from a final axial end position L3 of the rotor 104 is formed. In addition, the middle housing part 102c a dimension L1 , the crankcase side axially over a shorter dimension lower limit UL1 is the lower dimension limit UL1 essentially from the axial end position on the crankcase side L4 of the stator 108 is formed, and here has the middle housing part 102c also a dimension L1 , the crankcase side axially below a longer upper limit OL1 lies, the Dimensional upper limit OL1 essentially from the axial end position on the crankcase side L5 of the rotor 104 is formed.

• - abschlussseitig axial mit einem ersten Überstand ü über einer kürzeren Abmessungsuntergrenze uL1 liegt und
• - kurbelgehäuseseitig axial mit einem zweiten Überstand Ü über einer kürzeren Abmessungsuntergrenze UL1 liegt. Der erste und/oder zweite Überstand ü, Ü ist derart bemessen, dass abschlussseitig axial und/oder kurbelgehäuseseitig axial über das mittlere Gehäuseteil 102c aus Stahl ein magnetischer Rückschluss des Magnetfeldes im Betrieb gegeben ist. Dazu ist der erste und/oder zweite Überstand ü, Ü derart minimiert bemessen, dass Streuverluste des Magnetfeldes im Betrieb lediglich unter einer vorbestimmt akzeptablen Obergrenze gehalten sind.

That is, here has the middle housing part 102c a dimension L1 , the

• - axially at the end with a first protrusion ü over a shorter dimension lower limit uL1 lies and
• - Axially with a second overhang on the crankcase side Ü over a shorter dimension lower limit UL1 lies. The first and / or second supernatant ü . Ü is dimensioned such that axially on the end side and / or on the crankcase side axially via the middle housing part 102c a magnetic inference of the magnetic field during operation is given from steel. To do this, the first and / or second supernatant ü . Ü dimensioned so minimized that leakage losses of the magnetic field are only kept below a predetermined acceptable upper limit during operation.

The middle part of the housing is concrete here 102c made of steel only as long as absolutely necessary in order to generate a sufficient magnetic return. From the point of view of the magnetic circuit, the minimum length of the middle part corresponds to something more (approx. 10mm per side overhang) than the length of the magnets. It turns out that in the event that one wanted to build shorter than the magnets - despite the fact that they depend on the geometry - the losses increase disproportionately,

For this purpose, in the present embodiment the dimension of the middle housing part on the end side is essentially ten millimeters longer than the end side axial end position L2 of the stator. Furthermore, the dimension of the middle housing part on the crankcase side is essentially ten millimeters longer than the axial end position on the crankcase side L4 of the stator.

The end part of the housing is pot-like with a frame 110 formed, the frame an extension L6 has and a brush holder 112 a commutator 114 on the wave 106 and an associated brush 116 completely overlaps.

In addition, the brush holder 112 and the pot-like end part of the housing 102b is each formed as a lightweight construction with a light metal. The light metal is selected from a group of light metals consisting of aluminum and magnesium.

2a shows a DC motor M with a schematically illustrated compressor K , specifically an external view of a preferred embodiment of a DC motor 200 for coupling to a crankcase of a compressor K is shown. 2 B shows a cross section of the DC motor 200 the 2a ,

Here, too, has the middle part of the housing 202c a dimension L1 , the end side axially in one area b between a longer upper limit of dimensions oL1 and a shorter dimension lower limit uL1 is the lower dimension limit uL1 essentially from a final axial end position L2 of the stator 208 is formed and the upper dimension limit oL1 essentially from a final axial end position L3 of the rotor 204 is formed; in the present embodiment, the upper dimensional limit falls oL1 and the final axial end position L3 of the rotor 204 together. In addition, the middle housing part 202c , one dimension L1 , the crankcase side axially over a shorter dimension lower limit UL1 is the lower dimension limit UL1 essentially from the axial end position on the crankcase side L4 of the stator 208 . 208 is formed.

• - abschlussseitig axial mit einem ersten Überstand ü über einer kürzeren Abmessungsuntergrenze uL1 liegt und
• - kurbelgehäuseseitig axial mit einem zweiten Überstand Ü über einer kürzeren Abmessungsuntergrenze UL1 liegt. Der erste und/oder zweite Überstand ü, Ü ist derart bemessen, dass abschlussseitig axial und/oder kurbelgehäuseseitig axial über das mittlere Gehäuseteil 202c aus Stahl ein magnetischer Rückschluss des Magnetfeldes im Betrieb gegeben ist. Dazu ist der erste und/oder zweite Überstand ü, Ü derart minimiert bemessen, dass Streuverluste des Magnetfeldes im Betrieb lediglich unter einer vorbestimmt akzeptablen Obergrenze gehalten sind.

Ie here has the middle housing part 202c a dimension L1 , the

• - axially at the end with a first protrusion ü over a shorter dimension lower limit uL1 lies and
• - Axially with a second overhang on the crankcase side Ü over a shorter dimension lower limit UL1 lies. The first and / or second supernatant ü . Ü is dimensioned such that axially on the end side and / or on the crankcase side axially via the middle housing part 202c a magnetic inference of the magnetic field during operation is given from steel. To do this, the first and / or second supernatant ü . Ü dimensioned so minimized that leakage losses of the magnetic field are only kept below a predetermined acceptable upper limit during operation.

As in 2a A length is also recognizable L of lag screws Z to the dimension L1 of the middle part of the housing 202c adjusted, which leads to weight loss.

The middle part of the housing is concrete here 202c made of steel only as long as absolutely necessary in order to generate sufficient magnetic inference. From the point of view of the magnetic circuit, the minimum length of the middle part corresponds to something more (approx. 10mm per side overhang) than the length of the magnets. It turns out that in the event that one wanted to build shorter than the magnets - despite the fact that they depend on the geometry - the losses increase disproportionately,

The following discussion focuses on other technical features that the DC motor 100 of 1 from the DC motor 200 of 2a and 2 B differentiate. Those technical features found in both DC motors 100 and 200 Similar, are denoted by the same reference numerals (with the exception of the first digit, the "1" for the DC motor 100 the 1 is and "2" for the DC motor 200 the 2a and 2 B is).

The middle part of the housing 202c is made of steel. To achieve a magnetic circuit, only this area has to be made of steel. The rest of the case is made of light metal. The crankcase-side housing part is specific 202a and the end housing part 202b formed as a lightweight construction with a light metal. Compared to conventional direct current motors, the joint levels move in this embodiment 218a . 218b towards each other, shortening the length of the connecting screws 220 enables.

Overall, the entire DC motor can be further reduced in weight 200 also easier assembly. In addition, the pot-like end-side housing part 202b of the DC motor 200 a heat sink 222 on. The heat sink 222 serves to provide a heat-emitting surface of the pot-like end-side housing part 202b to enlarge. The heat sink 222 has the task of dissipating heat by conduction of heat-generating components such as the brush holder 212 and the commutator 214 away and then emit them to the environment by heat radiation and convection. In order to keep the thermal resistance as low as possible, the heat sink is made of light metal with good thermal conductivity. The heat sink is preferably mounted vertically in order to support the air circulation during operation due to the chimney effect.

3 shows a schematic representation of a vehicle 350 , in the form of a car. The vehicle has a pneumatic compressed air supply system 352 to supply compressed air. The pneumatic compressed air supply system has a compressed air supply system 354 on which is a compressor unit 356 with a schematically illustrated DC motor M supercharged K according to the concept of the invention. Furthermore, the pneumatic compressed air supply system 352 a pneumatic system designed as an air suspension system 358 on. In the case of vehicles in the car sector in particular, rapid provision of compressed air for level control in operation is of great importance, since breaks, in particular for carrying out an air pressure measurement, can be perceived by the driver of the vehicle. That is why here, without limitation of the applicability also for trucks or other commercial vehicles, exemplarily shown car vehicle 350 has four wheels 360 , of which the two wheels assigned to a vehicle side are shown here on the basis of the sectional illustration. The air suspension system has the same number of wheels 358 over four air springs 362 , of which the two air springs assigned to a vehicle side are analogous to the wheels due to the sectional view 362 are shown. The four air springs 362 , each of the four wheels 360 are assigned as part of the air suspension system 358 by means of the compressor unit 356 the compressed air supply system 358 supplied with compressed air. The compressed air supply system 358 is on the supply line 364 and the compressed air connection 366 connected to a compressed air collector; in this case via the gallery 368 with the components of the pneumatic system 358 , in this case the four air springs 362 connected.

Reference list

100, 200, M

DC motor;

102.202

Casing;

102a, 202a

crankcase-side housing part;

102b, 202b

end-side housing part;

102c, 202c

middle housing part;

104.204

Rotor;

106.206

Wave;

108.208

Stator;

110, 210

Frame of the end housing part;

112, 212

Brush holder;

114, 214

Commutator;

116,

Brush;

218a, 218b

Joint level;

220

Connecting screw;

222

Heat sink;

350

Vehicle;

352

Compressed air supply system;

354

Compressed air supply system;

356

Compressor unit;

358

Pneumatic system designed as an air suspension system;

360

Wheel;

362

Air spring;

364

Supply line;

366

Compressed air connection;

368

Gallery;

K

compressor

L

Long a lag screw

L1

axial dimension of the middle housing part;

L2

end-side axial end position of the stator;

L3

end-side axial end position of the rotor;

L4

axial end position of the stator on the crankcase side;

L5

axial end position of the rotor on the crankcase side;

L6

axial extension of the frame,

b, B

Areas;

ü, Ü

Got over;

uL1, UL1, oL1, OL1

first and second lower dimensions, first and second upper dimensions;

Z

Lag screw.

QUOTES INCLUDE IN THE DESCRIPTION

This list of documents listed by the applicant has been generated automatically and is only included 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.

Patent literature cited

• DE 102008052779 A1 [0003]

Claims (15)

Compressor unit (356) comprising a compressor (K) and a DC motor (M, 100, 200) for driving the compressor (K), the DC motor (100, 200) having a housing (102, 202) for coupling to a crankcase of the compressor (K), wherein - the housing (102, 202) is formed in three parts with a first crankcase-side housing part (102a, 202a) for coupling and with a second end-side housing part (102b, 202b) and with one connected between the first and second housing parts middle housing part (102c, 202c), wherein - a rotor (104) is rotatably mounted on a shaft (106, 206) in a stator (108) for use of a magnetic field in operation, the shaft (106, 206) on the crankcase side housing part (102a, 202a) and end-side housing part (102b, 202b) is held and the stator (108) is held on the middle housing part (102c, 202c), wherein - the middle housing part (102c, 202c) is made of steel, in particular The other consists of steel, and wherein - the end-side housing part (102b, 202b) is pot-shaped with a frame (110, 210), characterized in that - the middle housing part (102c, 202c) has a dimension (L1) on the end side axially in a range (b) between a longer upper dimension limit (oL1) and a shorter lower dimension limit (uL1), the lower dimension limit (uL1) being essentially formed by an axial end position (L2) of the stator (108) at the end and the upper dimension limit ( oL1) is essentially formed by an axial end position (L3) on the end of the rotor (104), - the frame (110, 210) of the pot-like end-side housing part (102b, 202b) has an extension (L6) which has a brush holder (112, 212) of a commutator (114, 214) completely engages on the shaft, and - the brush holder (112, 212) and the pot-like end-side housing part (102b, 202b) each as a lightweight u is formed and the lightweight construction is formed with a light metal. Compressor unit (356) after Claim 1 , wherein the crankcase-side housing part (102a, 202a) is formed as a lightweight construction with a light metal. Compressor unit (356) after Claim 1 or 2 , wherein - the light metal is selected from a group of light metals consisting of: aluminum, magnesium or alloys thereof, or - the lightweight construction consists of the light metal, in particular consists of an aluminum and / or magnesium-based alloy. Compressor unit (356) after Claim 1 or 2 , wherein the lightweight construction is formed from a composite material (, the composite material being formed from a plastic and the light metal. Compressor unit (356) after Claim 4 , wherein the composite material is formed as a layer material with a first layer of plastic and a second layer of light metal. Compressor unit (356) after Claim 5 , wherein the composite material has a supporting structural body with a coating, the coating being formed from the light metal. Compressor unit (356) according to any one of the preceding claims, wherein - The middle housing part (102c, 202c) has a dimension (L1) which is axially above a shorter dimension lower limit (UL1) on the crankcase side, the dimension lower limit (UL1) essentially from the crankcase side axial end position (L4) of the stator (108, 208 ) is formed, and / or - The middle housing part (102c, 202c) has a dimension (L1) which is axially below a longer upper dimension limit (OL1) on the crankcase side, the upper dimension limit (OL1) essentially from the end position (L5) of the rotor (104, 204) on the crankcase side ) is formed. Compressor unit (356) according to any one of the preceding claims, wherein the central housing part (102c, 202c) has a dimension (L1) which - Axially at the end with a first protrusion (ü) over a shorter dimension lower limit (uL1) and / or - Axial side of the crankcase with a second protrusion (Ü) is above a shorter dimension lower limit (UL1). Compressor unit (356) after Claim 8 , wherein the first and / or second overhang (ü, Ü) is dimensioned such that there is a magnetic inference of the magnetic field during operation axially and / or axially on the crankcase side axially via the central steel housing part (102c, 202c). Compressor unit (356) after Claim 8 or 9 , wherein the first and / or second projection (ü, Ü) is dimensioned so minimized that leakage losses of the magnetic field during operation are only kept below a predetermined acceptable upper limit. Compressor unit (356) according to one of the Claims 8 to 10 , in which - the dimension (L1) of the middle housing part (102c, 202c) on the end relative to the dimension (L1) with less than 5% overhang (ü), in particular with less than ten millimeters overhang (ü), is longer than the end-side axial dimension (L2) of the stator (108, 208), and / or - the dimension (L1) of the middle housing part (102c, 202c) on the crankcase side relative to the dimension (L1) with less than 5% projection (Ü), in particular with less than ten millimeters projection ( Ü), is longer than the axial dimension (L2) of the stator (108, 208) on the crankcase side. Compressor unit (356) according to one of the Claims 1 to 11 , wherein the end-side housing part (102b, 202b) has a heat sink (222). Compressor unit (356) according to one of the preceding claims, wherein the end-side housing part (102b, 202b), or the crankcase-side housing part (102a, 202a), or the end-side housing part (102b, 202b) and the crankcase-side housing part (102a, 202a) with one Light metal is formed, the light metal being a deep-drawn or die-cast light metal, in particular the light metal consisting of aluminum, magnesium and / or an aluminum and / or magnesium-based alloy. Compressor unit (356) according to one of the preceding claims, characterized in that a length (L) of tension screws (Z) is adapted to the dimension (L1) of the central housing part (102c, 202c). Compressed air supply system (352), in particular for a vehicle (350), comprising a compressor unit (356) according to one of the Claims 1 to 14 for supplying a compressed air connection (366) with compressed air.

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