DE102019215223A1 - Thrust gas bearings - Google Patents

Abstract

The invention relates to an axial gas bearing (30) with at least one gas bearing gap (58, 59) which is designed to form a supporting gas film between an axial bearing disk (33) and a support surface (48, 49) ) To improve functionally, the support surface (48, 49) is provided on a support body (38, 39) made of an aluminum material.

Description

The invention relates to an axial gas bearing with at least one gas bearing gap which is designed to form a load-bearing gas film between an axial bearing disk and a support surface.

State of the art

From the American Offenlegungsschrift US 2012/0207414 A1 an axial bearing designed as an air bearing with a spring foil and a cover foil is known. Because of the foils used, such air bearings are also referred to as foil bearings.

Disclosure of the invention

The object of the invention is to functionally improve an axial gas bearing with at least one gas bearing gap which is designed to form a supporting gas film between an axial bearing disk and a support surface.

In the case of an axial gas bearing with at least one gas bearing gap, which is designed to form a supporting gas film between an axial bearing disk and a support surface, the support surface is provided on a support body made of an aluminum material. When the axial gas bearing is in operation, the axial bearing disk, which is formed, for example, on a rotor, rotates about an axis of rotation. With the aid of bearing elements such as foils, this rotary movement generates a gas flow in the gas bearing gap which runs essentially in the circumferential direction and which builds up the load-bearing gas film between the axial bearing disk and the support surface. The gas for the supporting gas film is supplied, for example, via appropriate openings. The design and arrangement of these openings is known and will not be further explained here. The gas is, for example, air. The thrust gas bearing is therefore also referred to as an axial air bearing. The term axial refers to the axis of rotation of the rotor. Axial means in the direction or parallel to the axis of rotation of the rotor. Depending on the application, large axial forces and / or high speeds can occur during operation of the axial gas bearing. The support body made of the aluminum material enables efficient cooling of the axial gas bearing in a simple manner. This ensures that a machine equipped with the axial gas bearing will function properly even with high axial forces and high speeds. The aluminum material has a significantly greater thermal conductivity compared to a steel material used in conventional axial gas bearings. In this way, the heat that occurs during operation of the axial gas bearing can be better dissipated from the axial gas bearing. In addition, the aluminum material is easier to process in terms of production technology, for example by cutting.

A preferred exemplary embodiment of the axial gas bearing is characterized in that the support body made of the aluminum material is provided with a hard material layer to protect the support surface from wear. The axial gas bearing is preferably designed as a foil bearing. Such a film store comprises, for example, at least one spring film and at least one cover film. The spring foil is clamped between the cover foil and the support surface. The hard material layer prevents the spring foil from digging into the support body made of the relatively soft aluminum material. With the hard material layer, similar accuracies can advantageously be achieved as with steel components. The hard material layer is applied to the aluminum material, for example by anodizing. Alternatively, the hard material layer can be formed from titanium nitride.

Another preferred exemplary embodiment of the axial gas bearing is characterized in that the support body is combined with at least one annular body which is arranged radially outside the axial bearing disk. The ring body delimits a receiving space of the axial gas bearing. The axial bearing disk of the axial gas bearing is rotatably mounted in the receiving space which is delimited by the ring body and the support body. Depending on the design, the ring body can also be connected in one piece to the support body.

Another preferred embodiment of the axial gas bearing is characterized in that the ring body is formed from an aluminum material. As a result, the heat dissipation of the heat occurring during operation from the receiving space of the axial gas bearing can be further improved. The ring body is fastened, for example with suitable fastening means, to a housing body of a machine equipped with the axial gas bearing.

Another preferred exemplary embodiment of the axial gas bearing is characterized in that a further support surface is provided on a housing body of a machine equipped with the axial gas bearing. The machine is, for example, an air compressor, which is preferably used in a fuel cell system to provide air that contains oxygen, which is converted to water when the fuel cell is in operation. The air compressor comprises, for example, a housing made of an aluminum material, to which the housing body with the further support surface belongs. A second support body can thus advantageously be dispensed with.

Another preferred embodiment of the axial gas bearing is characterized in that the housing body is formed from an aluminum material. The housing body is preferably formed from the same aluminum material as the support body. The housing of the air compressor equipped with the axial gas bearing is particularly advantageously made entirely of aluminum material.

Another preferred exemplary embodiment of the axial gas bearing is characterized in that the housing body made of the aluminum material is provided with a hard material layer to protect the support surface from wear. The axial gas bearing is preferably designed as a foil bearing. Such a film store comprises, for example, at least one spring film and at least one cover film. The spring foil is clamped between the cover foil and the support surface. The hard material layer prevents the spring foil from digging into the housing body made of the relatively soft aluminum material. With the hard material layer it is advantageously possible to achieve accuracies similar to those with steel components, in particular by grinding the hard material layer. The hard material layer is applied to the aluminum material, for example by anodizing. Alternatively, the hard material layer can be formed from titanium nitride.

Another preferred exemplary embodiment of the axial gas bearing is characterized in that a cooling system is integrated into the housing body. The cooling comprises, for example, a cooling water jacket with cooling channels through which a coolant, such as water, is passed in order to dissipate heat that occurs during operation of the axial gas bearing. By using the highly thermally conductive aluminum material to represent the support body or two support bodies or a support body and the housing body, the heat from the axial gas bearing can be dissipated particularly effectively.

The invention also relates to an air compressor with a rotor which is supported by an axial gas bearing described above. The axial bearing disk is attached to the rotor.

The axial gas bearing described above is preferably used in an air compressor or air compressor for the axial bearing of a rotor. The air compressor or air compressor, in turn, is preferably used in a fuel cell system in order to compress a gas, in particular air, which is then fed to a fuel cell.

The invention also relates to a method for operating an axial gas bearing described above.

The invention also relates to a support body, a housing body and / or an annular body for an axial gas bearing described above. The named bodies can be traded separately.

Further advantages, features and details of the invention emerge from the following description, in which various exemplary embodiments are described in detail with reference to the drawing.

Figure list

• 1a eine schematische Schnittdarstellung eines Axial-Gaslagers mit einem ersten Ausführungsbeispiel;
• 1b die gleiche Darstellung wie in 1a gemäß einem zweiten Ausführungsbeispiel des Axial-Gaslagers;
• 2 eine schematische Schnittdarstellung eines Verdichters mit einem Rotor, der durch drei Lager radial und axial drehbar gelagert ist; und
• 3 eine schematische Darstellung eines Brennstoffzellensystems mit einem Luftverdichter, wie er in 2 dargestellt ist.

Show it:

• 1a a schematic sectional view of an axial gas bearing with a first embodiment;
• 1b the same representation as in 1a according to a second embodiment of the axial gas bearing;
• 2 a schematic sectional view of a compressor with a rotor, which is radially and axially rotatably supported by three bearings; and
• 3 a schematic representation of a fuel cell system with an air compressor, as shown in 2 is shown.

Description of the exemplary embodiments

In 3 is a fuel cell system 1 shown schematically. Fuel cell systems are known per se, for example from the German Offenlegungsschrift DE 10 2012 224 052 A1 . The fuel cell system 1 includes a fuel cell 3 which is only indicated by a dashed rectangle. The fuel cell 3 includes at least one stack 2 , which is shown alternatively with a valve symbol.

By an arrow 4th an air mass flow is indicated, which is carried out via an air supply device designed as an air compressor 5 the fuel cell 3 is fed. By an arrow 6th is a compressed air mass flow 6th indicated, from which a cooling air mass flow 7th is branched off. The cooling air mass flow 7th is also only indicated by an arrow and is part of a cooling air path 19th over which the air compressor 5 via a cooling air inlet 23 Cooling air is supplied.

The one via the cooling air path 19th supplied cooling air is used, for example, to cool air bearings with which a shaft of the air compressor 5 is rotatably mounted. The cooling air mass flow 7th represents one Loss in the compressed air mass flow 6th because the branched off cooling air mass flow 7th no longer in the stack 2 the fuel cell 3 is available.

Since the cooling air mass flow 7th via the air compressor 5 is provided for internal cooling, energy, in particular electrical energy, is necessary to generate it. This energy has a negative effect on the overall efficiency of an electric drive machine of a motor vehicle that is powered by the fuel cell system 1 is driven.

The remaining air mass flow 6th is via an air supply line 8th the fuel cell 3 fed. The fuel cell 3 is a galvanic cell that converts the chemical reaction energy of a fuel supplied via a fuel supply line (not shown) and an oxidizing agent into electrical energy.

The oxidizing agent is the air coming through the air supply line 8th the fuel cell 3 is fed. The fuel can preferably be hydrogen or methane or methanol. Accordingly, water vapor and carbon dioxide are produced as exhaust gas. The exhaust gas is in the form of an exhaust gas mass flow 10 via an exhaust pipe 9 led away as if by an arrow 10 is indicated.

The exhaust gas mass flow 10 is via an exhaust turbine 11 to an exhaust gas outlet 12th dissipated, which is indicated by an arrow. The air compressor 5 is in the air supply line 8th arranged. The exhaust turbine 11 is in the exhaust pipe 9 arranged. The air compressor 5 and the exhaust turbine 11 are mechanically connected via a shaft.

The shaft is by an electric motor 14th electrically driven. The exhaust turbine 11 serves to support the electric motor 14th when driving the air compressor 5 . The air compressor 5 who have favourited the exhaust turbine 11 , the shaft and the electric motor 14th together form a turbo compressor 15th , which is also known as a turbo machine.

The fuel cell system 1 also includes a bypass line 13th , in which a bypass valve 16 is arranged. Via the bypass line 13th with the bypass valve 16 can be a bypass air mass flow 17th to lower the pressure of the air supply line 8th bypassing the stack 2 the fuel cell 3 into the exhaust pipe 9 be discharged. This is advantageous, for example, to lower the pressure in the air supply line 8th the fuel cell 3 to effect supplied air mass flow.

The fuel cell system 1 further comprises an intercooler 18th , which is indicated by a dashed rectangle. The intercooler 18th serves to control the compressed air mass flow 6th to cool before the cooling air mass flow 7th via the cooling air path 19th is branched off.

In 2 is a compressor 100 a fuel cell system shown schematically. The compressor 100 includes a housing 101 in which an electric motor 102 is arranged. The electric motor 102 serves to drive a rotor 103 of the compressor 100 .

The rotor 103 of the compressor 100 is with the help of two foil bearings or radial gas bearings 104 , 105 radially in the housing 101 stored. For the axial bearing of the rotor 103 a foil bearing or thrust gas bearing is used 106 .

At the in 2 left end of the rotor 103 is a compressor wheel 107 appropriate. The compressor wheel 107 is used to compress air that is provided in the fuel cell system when the compressor wheel 107 about the rotor 103 by the electric motor 102 is driven.

The gas storage 104 , 105 ; 106 are designed as foil bearings and each include a housing body 108 , 109 ; 110 . The rotor 103 includes two rotor sections, also called the rotor body 111 , 112 are referred to with which the rotor 103 in the radial gas bearings 104 , 105 is mounted radially.

The rotor 103 also includes a rotor collar, which also acts as a rotor body 113 referred to as. About the rotor body 113 is the rotor 103 through the thrust gas bearing 106 axially in the housing 101 stored. The rotor body 113 is also known as a thrust bearing washer.

In the 1a , 1b is a thrust gas bearing 30th shown schematically in section. The thrust gas bearing 30th is an embodiment of the in 2 with 106 designated axial gas bearing. The thrust gas bearing 30th includes a rotor 31 that the rotor 103 in 2 corresponds to.

The rotor 31 includes a rotor body 32 , which is integral with a thrust bearing washer 33 connected is. The rotor 31 with the rotor body 32 and the thrust washer 33 is around an axis of rotation 34 rotatable, as in the 1a , 1b by an arrow 35 is indicated.

The thrust gas bearing 30th is in a housing body 36 integrated in an air compressor, for example in 2 is shown schematically. To the housing body 36 is a bearing housing 37 of the thrust gas bearing 30th cultivated. The bearing housing 37 of the thrust gas bearing 30th comprises two support bodies 38 , 39 .

Between the support bodies 38 and 39 are an annular body in the axial direction 40 and an auxiliary ring body 41 arranged. With a dashed line 50 at least one fastening means is indicated with which the bearing housing 37 of the thrust gas bearing 30th to the housing body 36 is grown.

Between the thrust bearing washer 33 and the support surface 48 are a feather foil 53 and a cover sheet 54 arranged. Analog are between the axial bearing washer 33 and the support surface 49 a feather foil 55 and a cover sheet 56 arranged. The slides 53 to 56 are in the 1a , 1b as well as gas bearing column 58 , 59 shown only schematically and greatly simplified.

Gas, in particular air, to form the supporting gas film in the gas bearing gaps 58 , 59 is made, for example, by interruptions or holes in the foils 53 to 56 into the gas storage column 58 , 59 drawn in. The gas supply for the formation of the supporting gas film in the gas bearing gaps 58 , 59 is in the 1a , 1b not shown.

During operation of the thrust gas bearing 30th builds up in the gas bearing crevices 58 , 59 between the cover sheets 54 , 56 and the thrust washer 33 each has a supporting gas film. Between the cover sheets 54 , 56 and the support surfaces 48 , 49 are the feather foils 53 , 54 arranged, which is on the support bodies 38 , 39 prop up.

Via the additional ring body 41 can be an axial distance between the support bodies 38 , 39 and thus a bearing play of the axial gas bearing 30th can be set. Depending on the design, at least one of the support bodies can also be used 38 , 39 , which are also known as support plates, with the ring body 40 and / or the additional ring body 41 can be combined into one component.

During operation of the thrust gas bearing 30th builds up in the gas bearing crevices 58 , 59 between the cover sheets 54 , 56 and the thrust washer 33 a supporting gas film. Under the cover sheets 54 , 56 are the feather foils 53 , 55 that are on the support surfaces 48 , 49 prop up.

The in 1a illustrated embodiment of the axial gas bearing 30th are the two support bodies 38 , 39 , which are also referred to as support disks, are formed from an aluminum material. On the support surfaces 48 , 49 are the supporting bodies 38 , 39 Made of the aluminum material with a hard material layer around the support surfaces 48 , 49 to protect against wear. For this purpose, at least at the contact points between the spring foils 53 , 55 and the support bodies 38 , 39 Hard material layers provided.

The case body 36 is part of a compressor housing in which a cooling system 60 is integrated. The cooling includes cooling channels 61 , 62 through which a coolant such as cooling water is passed. About the support body 38 , 39 from the aluminum material can be combined with the water cooling 16 significantly more heat from the thrust gas bearing 30th than with conventional axial gas bearings. According to a further aspect of the invention, the ring bodies are also 40 and the additional ring body 41 formed from an aluminum material. As a result, the heat dissipation during operation of the axial gas bearing can be further improved.

In 1b a second embodiment is shown in which, in contrast to that in 1a illustrated first embodiment of the axial gas bearing 30th the additional ring body 41 not applicable. In addition, the in 1a with 39 designated support body in the housing body 36 integrated into the compressor housing.

The case body 36 the compressor housing has a cooling system 70 provided, the cooling channels 71 , 72 includes. Through the cooling channels 71 , 72 a coolant, such as cooling water, is passed through which the axial gas bearing is in operation 30th resulting heat is dissipated.

The cooling duct 71 is near the support surface 49 arranged. The cooling duct 72 is near the ring body 40 arranged. The arrangement of the cooling channels 71 , 72 can be advantageous, as can the arrangement of the cooling channels 61 , 62 in 1a , are effectively placed near areas that are in operation during the operation of the thrust gas bearing 30th heat particularly strongly. This can reduce the effectiveness of the cooling 60 , 70 to be further improved.

QUOTES INCLUDED IN THE DESCRIPTION

This list of the documents listed by the applicant was generated automatically and is included solely 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

• US 2012/0207414 A1 [0002]
• DE 102012224052 A1 [0018]

Claims (10)

Axial gas bearing (30) with at least one gas bearing gap (58,59) which is designed to form a supporting gas film between an axial bearing disk (33) and a support surface (48,49), characterized in that the support surface (48,49) is provided on a support body (38, 39) made of an aluminum material. Axial gas bearing according to Claim 1 , characterized in that the support body (38, 39) made of the aluminum material is provided with a hard material layer to protect the support surface (48, 49) from wear. Axial gas bearing according to Claim 2 , characterized in that the support body (38, 39) is combined with at least one ring body (40, 41) which is arranged radially outside the axial bearing disk (33). Axial gas bearing according to Claim 3 , characterized in that the ring body (40,41) is formed from an aluminum material. Axial gas bearing according to one of the preceding claims, characterized in that a further support surface (49) is provided on a housing body (36) of a machine (100) equipped with the axial gas bearing (30). Axial gas bearing according to Claim 5 , characterized in that the housing body (36) is formed from an aluminum material. Axial gas bearing according to Claim 6 , characterized in that the housing body (36) made of the aluminum material is provided with a hard material layer to protect the support surface (49) from wear. Axial gas bearing according to Claim 6 or 7th , characterized in that a cooling system (60; 70) is integrated in the housing body (36). Air compressor (100) having a rotor (31) which is supported by an axial gas bearing (30) according to one of the preceding claims. Support body (38,39), housing body (36) and / or ring body (40,41) for an axial gas bearing (30) according to one of the Claims 1 to 8th .

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