Air compressor for conveying air, comprising an air guiding path with different channel cross-sections

Abstract

The invention relates to an air compressor (100) for conveying air, said air compressor (100) comprising: - a stator (101), - a sleeve (103), - and an air guiding path (105), said air guiding path (105) being configured so as to guide an air mass flow along the stator (101), wherein the air guiding path (105) comprises a plurality of channels (107) which form a main region (111) extending radially about the inner region (115) of the stator (101) and a plurality of auxiliary regions (113) extending from the main region (111) in the direction of the inner region (115) of the stator (101), and each channel (107) of the plurality of channels (107) differs in terms of the cross-section thereof. The air guiding path (105) overlaps with the stator (101) at least at the end face.

Description

[0001] Description

[0002] title

[0003] Air compressor for conveying air with an air guide path with different channel cross-sections

[0004] The presented invention relates to an air compressor for conveying air, a manufacturing method for an air compressor and a fuel cell system according to the appended claims.

[0005] State of the art

[0006] Air compressors for conveying air are usually designed as auxiliary units in a particularly compact manner for reasons of installation space.

[0007] Due to the compact design, thermal problems arise particularly in the area of ​​the stator of an electrical machine for driving an air compressor.

[0008] Disclosure of the invention

[0009] Within the scope of the invention presented, an air compressor for conveying air, a manufacturing method for an air compressor, and a fuel cell system are presented. Further features and details of the invention emerge from the respective subclaims, the description, and the drawings. Features and details described in connection with the air compressor according to the invention naturally also apply in connection with the manufacturing method according to the invention, the fuel cell system according to the invention, and vice versa, so that with regard to the disclosure of the individual aspects of the invention, reference is or can always be made to each other. The invention presented serves, in particular, to provide a possibility for robust operation of an air-conducting system, in particular a fuel cell system.

[0010] Thus, according to a first aspect of the invention presented, an air compressor for conveying air is presented.

[0011] The presented air compressor comprises a stator, a shell and an air guide path, wherein the air guide path is configured to guide an air mass flow along the stator, wherein the air guide path comprises a plurality of channels which form a main region extending radially around an inner region of the stator and a plurality of secondary regions extending from the main region in the direction of the inner region of the stator, wherein respective channels of the plurality of channels differ from one another in their cross section and wherein the air guide path overlies the stator at least at the front side.

[0012] In the context of the invention presented, an end face is understood to be a short side of a cylindrical stator.

[0013] In the context of the present invention, a casing is understood to mean a housing, in particular a housing with a bearing plate. Accordingly, the casing can include a bearing plate.

[0014] The presented invention is based on an air guide path comprising a plurality of channels. To form the channels, the air guide path can comprise air guide elements, such as protrusions, indentations, cavities, fins, pin-fin structures, throttle elements, or any other technically suitable form of air guide elements. The channels can be integrated into the stator and / or the casing of the air compressor and / or into a cooling device provided in addition to the stator and the casing.

[0015] It is provided that respective channels of the plurality of channels overlap the stator at least at its front side, so that an air mass flow is guided along the stator through the channels. This means that the plurality of channels extend, in particular, over the entire length of the front side of the stator, in particular over the entire length of a short side of the stator, in particular over a winding head of the stator, so that the winding head is cooled by the air guide path at least at its front side.

[0016] An air mass flow flowing through the air guide path dissipates heat radiated by the air compressor, particularly by the stator, e.g., by the bearing shells supporting the stator. Accordingly, thermal energy is transferred from the air compressor, particularly the stator, to the air mass flow and dissipated, so that the stator is cooled and can be loaded with particularly high power.

[0017] The air guide path may comprise a number, in particular a plurality of partial air paths, each of which guides a partial air mass flow to a predetermined location of the air compressor.

[0018] To provide the air mass flow through the air guide path, ambient air can flow into the air guide path and be guided through the air guide path via convection.

[0019] Furthermore, for example, a partial air mass flow can be diverted after the compressor of the air compressor and optionally cooled beforehand, so that the air compressor is cooled more dynamically as the load and correspondingly increasing speed increase.

[0020] Alternatively, a partial air mass flow of a main air mass flow provided by a turbine of the air compressor can be guided into the air guide path, so that the stator is cooled more intensively or dynamically as the air compressor's power increases. For this purpose, the casing can comprise at least one inlet opening that introduces an air mass flow into the air guide path or respective channels and at least one outlet opening that discharges the air mass flow from the air guide path or respective channels. According to the invention, respective channels of the plurality of channels differ from one another in their cross-section.

[0021] By means of channels with different cross-sections, i.e., different effective cross-sections for guiding an air mass flow, a multitude of partial air mass flows with different strengths or speeds can be generated, so that, for example, a turbulent overall flow is formed at the end or at the outlet of the multitude of channels.

[0022] Alternatively, the cross-section of the respective channels can be designed differently in such a way that a loss of force or a loss of speed of an air mass flow flowing through the air guide path is compensated with the course of the main area, so that, for example, a laminar overall flow is formed at the end or at the outlet of the plurality of channels.

[0023] It can be provided that at least a part of respective channels forming the secondary regions comprises a throttle element which adjusts a cross-section of a respective channel.

[0024] To adjust a cross-section of a respective channel, the channel may comprise a material projection or a throttle element inserted into the channel.

[0025] A throttle element can, for example, comprise an outer circumference corresponding to a cross-section of a respective channel and a specific inner cross-section, so that the inner cross-section of the throttle element specifies or determines an effective cross-section of the channel for conducting an air mass flow.

[0026] In particular, by using a plurality of throttle elements with different cross-sections, i.e., different internal cross-sections, an air guide path with a plurality of channels, each of which has the same cross-section, can be implemented, creating a flow geometry with different cross-sections in respective secondary areas. For this purpose, respective throttle elements can be inserted into respective channels, in particular, glued, clamped, and / or welded.

[0027] It can further be provided that the throttle element is detachably connected to the respective channel.

[0028] A throttle element detachably connected to a respective channel enables the throttle element to be replaced and, as a result, the flow geometry of the air guide path to be changed.

[0029] It can further be provided that throttle elements arranged in respective channels of the secondary areas successively enlarge or reduce an effective cross-section of the respective channels in the course of the main area.

[0030] By changing secondary areas in the course of the main area, the flow behavior of an air mass flow formed at the exit or outlet of the secondary areas can be influenced, so that it is forced, for example, into a turbulent or laminar flow movement.

[0031] It can be provided that the air compressor comprises a cooling device which forms at least part of the air guide path, wherein the cooling device comprises a base body in which at least part of the plurality of channels is formed, wherein the cooling device overlies the stator in a region between a winding head of the stator and the casing at least on the front side and forms the air guide path together with the winding head and / or the casing.

[0032] An additional element in the form of a cooling device, which is added to the stator and the casing of the air compressor, enables a complex geometry of the air guide path, which directs an air mass flow from a thermally favorable, i.e., particularly cold, location to particularly thermally stressed areas of the air compressor, such as the winding head and / or bearing shells for supporting the stator. In particular, a cooling device can interact with the stator and / or the casing to form the air guide path, allowing the air compressor to be designed particularly compactly.

[0033] The cooling device can be manufactured from a large number of parts, for example, in a 3D printing process or in an injection molding process.

[0034] It can further be provided that the cooling device overlays the winding head at least in part, both at the front and laterally in the direction of the respective stator slots of the stator.

[0035] By superimposing the winding head on the front and sides, a surface for transferring thermal energy from the winding head to a fluid flowing in the cooling device is maximized and the winding head is protected from mechanical stress on the front and sides.

[0036] It can further be provided that the base body of the cooling device consists of a material whose thermal conductivity is higher than the thermal conductivity of air and whose electrical conductivity is less than 1% of the electrical conductivity of aluminum.

[0037] A high thermal conductivity of the base body of the cooling device results in a high heat transfer from the winding head to a fluid flowing in the cooling device and a correspondingly good cooling effect or high cooling performance.

[0038] An electrical conductivity of the base body that is less than 1% of the electrical conductivity of aluminum suppresses eddy currents between the stator shell and the stator, thus maximizing the performance of the air compressor.

[0039] It can also be provided that the base body of the cooling device is made entirely or partially of ceramic. Ceramics such as Al2O3 with a thermal conductivity of 20W / mK or AlN with a thermal conductivity of 170W / mK have proven particularly advantageous for dissipating heat from a winding head and are electrically insulating.

[0040] It can further be provided that at least some of the plurality of channels are formed in the shell and / or the stator.

[0041] Channels that run partially or completely through the shell and / or the stator allow the shell and / or the stator to be cooled efficiently.

[0042] Furthermore, the integration of respective channels into the casing and / or the stator minimizes the installation space required for the air compressor.

[0043] To integrate the respective channels into the shell and / or the stator, these can be milled into the shell or, for example, a casing surrounding the stator and shaped in a primary forming process.

[0044] It can further be provided that the air guide path is formed by a number of air guide elements which comprise at least one structure from the following list of structures: channel, receptacle, recess, protuberance, cavity, air guide plate, cooling fin, pin-fin structure.

[0045] Air guiding elements can be arranged as separate components on, for example, the casing, the stator or a base body of a cooling device and / or incorporated into them.

[0046] It can further be provided that the air guide path runs inclined by an air guide angle in the direction of the stator.

[0047] A path inclined at an air guide angle toward the stator, in which the air guide path is inclined to an auxiliary axis perpendicular to the stator's rotational axis, in particular overlying the frontal area of ​​the stator, results in an air mass flow from a point above the stator toward an inner part of the stator. The air guide path can be configured, for example, in a helical or spiral shape, so that the air guide path itself already forms a vortex.

[0048] It can further be provided that the plurality of secondary areas connect the inner area of ​​the stator with the main area in an air-conducting manner.

[0049] Through a main area, which is filled with a fresh or cold air mass flow, for example, through a number of inlet openings, respective secondary areas can be flowed into, which divide the entire air mass flow into partial mass flows and, as a result, control the flow behavior of the air mass flow.

[0050] It can further be provided that the air guide path comprises a plurality of secondary regions, each of which extends with mutually different flow geometries from the main region in the direction of the inner region of the stator.

[0051] For example, the secondary regions can be designed in such a way that the partial mass flows are combined at the exit of the secondary regions to form a vortex that flows through the inner part of the stator.

[0052] In the context of the present invention, a flow geometry is understood to mean, for example, an angle to the main area, a length, a thickness, a throttle point, or a path of the air guiding elements between respective secondary areas. Accordingly, a specific flow geometry can be used to control the flow path of the air mass flow flowing through the air guiding path, for example, by locally accelerating or decelerating it.

[0053] It may also be provided that a flow geometry of the main area changes in its course.

[0054] A main area whose course changes can, for example, locally accelerate or decelerate an air mass flow flowing through the main area, creating an air mass flow that flows with the same strength or speed throughout the main area. It can also be provided that the main area forms a circle or is closed at one end.

[0055] A circular main area allows the air mass flow flowing into the main area to be divided into two oppositely flowing and correspondingly strong partial mass flows.

[0056] A main area closed at one end causes a flow movement of an air mass flow flowing through the main area in only one direction, since a division of the air mass flow into two oppositely flowing partial mass flows is prevented.

[0057] It can further be provided that the air guide path overlaps the winding head at least in part, both at the front and laterally in the direction of the respective stator slots of the stator.

[0058] By superimposing the winding head on the front and sides, a surface for transferring thermal energy from the winding head to a fluid flowing in the cooling device is maximized and the winding head is protected from mechanical stress on the front and sides.

[0059] It can further be provided that the air guide path comprises an interface which is configured to receive the air to be guided through the air guide path from an environment and to release it to the environment or to receive a partial air mass flow of a compressor and / or a turbine of the air compressor and to release it to the turbine or the environment.

[0060] An interface, such as a number of inlet channels and a number of outlet channels, allows cold air to be introduced at a location that is particularly thermally favorable, i.e., cold, and air to be discharged at a location that is particularly mechanically favorable, i.e., thermally resilient. It can further be provided that a first air guide path is formed at a first end face of the stator, and a second air guide path is formed at a second end face of the stator opposite the first end.

[0061] Two air guide paths at each end of the stator provide a particularly high cooling capacity for tempering the stator, so that it can be subjected to a particularly high power.

[0062] According to a second aspect, the presented invention relates to a manufacturing method for an air compressor.

[0063] The presented manufacturing method comprises providing a stator, providing a shell, providing an air guide path which is configured to guide an air mass flow along the stator, wherein the air guide path comprises a plurality of channels which form a main region extending radially around an inner region of the stator and a plurality of secondary regions extending from the main region in the direction of the inner region of the stator and forming at least one throttle element in at least some of the plurality of channels, so that respective channels of the plurality of channels differ from one another in their cross section and wherein the air guide path overlies the stator on the front side.

[0064] It can be provided that the air guide path is provided by air guide elements formed in a cooling device and / or the stator and / or the casing.

[0065] To form the air guide path, respective air guide elements can be formed, in particular cast, together with the cooling device or the stator or the casing, for example, in a primary forming process or can be introduced into the cooling device or the stator or the casing in a separate forming process, for example by milling.

[0066] According to a third aspect, the presented invention relates to a fuel cell system for converting energy. The presented fuel cell system comprises a fuel cell stack and a possible embodiment of the presented air compressor for supplying the fuel cell stack with air.

[0067] Advantages described in detail with respect to the air compressor for conveying air according to the first aspect of the invention equally apply to the manufacturing method for an air compressor according to the second aspect of the invention and the fuel cell system for converting energy according to the third aspect of the invention.

[0068] Further advantages, features, and details of the invention will become apparent from the following description, which describes exemplary embodiments of the invention in detail with reference to the drawings. The features mentioned in the claims and in the description may be essential to the invention individually or in any combination.

[0069] They show:

[0070] Figure 1 is a schematic representation of a possible design of the presented air compressor in a sectional side view,

[0071] Figure 2 shows a possible embodiment of the air guide path provided according to the invention in a sectional plan view,

[0072] Figure 3 shows a possible design of the presented fuel cell system,

[0073] Figure 4 shows a possible design of the presented manufacturing process.

[0074] Figure 1 shows an air compressor 100 for conveying air. The air compressor 100 includes a stator 101, a casing 103, and an air guide path 105.

[0075] The air guide path 105 is configured to direct an air mass flow to the stator

[0076] 101. For this purpose, the air guide path 105 comprises a plurality of channels 107, which form a main region extending radially around an inner region of the stator 101 and a plurality of secondary regions extending from the main region toward the inner region of the stator 101.

[0077] Respective channels 107 of the plurality of channels 107 differ from one another in their cross-section.

[0078] The air guide path 105 overlies the stator 101 at least on its front side 109 and is partially formed by a cooling device 121 which interacts with the stator 101 and the casing 103.

[0079] Air guiding elements 123 are formed on the cooling device 121, which form a main region 111 shown in Figure 2 and a plurality of secondary regions 113.

[0080] Figure 2 shows a top view of the air guide path 105. It can be seen that the air guide path 105 comprises the main area 111 and a plurality of secondary areas 113.

[0081] The main region 111 extends radially or circularly around an inner region 115 of the stator 101.

[0082] The secondary regions 113 connect the main region 111 with the inner region 115, so that an air mass flow flows through an inlet 117 into the main region 111 and further through the secondary region 113 into the inner region 115 of the stator 101 and cools or cools the stator at the front and in its inner region 115.

[0083] A first throttle element 203 is arranged in a first channel 201, and a second throttle element 207 is arranged in a second channel 205. The first throttle element 203 and the second throttle element 207 differ from each other in their cross-section.

[0084] Due to the narrower cross section of the first throttle element 203 compared to the second throttle element 207, an air mass flow flowing through the first throttle element 203 flows more strongly than an air mass flow flowing through the second throttle element 207.

[0085] Figure 3 shows a fuel cell system 300 for converting energy.

[0086] The fuel cell system 300 comprises a fuel cell stack 301 and an air compressor 100 according to Figure 1 for supplying the fuel cell stack 301 with air.

[0087] Figure 4 shows a manufacturing method 400 for an air compressor.

[0088] The manufacturing method 400 comprises a first provision step 401 in which a stator is provided, a second provision step 403 in which a shell for receiving the stator is provided, a third provision step 405 in which an air guide path is provided which is configured to guide an air mass flow along the stator, wherein the air guide path comprises a plurality of channels which form a main region extending radially around an inner region of the stator and a plurality of secondary regions extending from the main region towards the inner region of the stator.

[0089] Furthermore, the manufacturing method 400 comprises a formation step 407 in which at least one throttle element is formed in at least a part of the plurality of channels, so that respective channels of the plurality of channels differ from one another in their cross section, wherein the air guide path overlies the stator on the front side.

Claims

Claims 1. An air compressor (100) for conveying air, the air compressor (100) comprising: a stator (101), a shell (103), and an air guide path (105), the air guide path (105) being configured to guide an air mass flow along the stator (101), the air guide path (105) comprising a plurality of channels (107) forming a main region (111) extending radially around an inner region (115) of the stator (101) and a plurality of secondary regions (113) extending from the main region (111) in the direction of the inner region (115) of the stator (101), respective channels (107) of the plurality of channels (107) differing from one another in their cross-section, and the air guide path (105) overlying the stator (101) at least at its end face.

2. Air compressor (100) according to claim 1, characterized in that at least a part of respective channels (107) forming the secondary regions (113) comprises a throttle element (202, 207) which adjusts a cross section of a respective channel (107).

3. Air compressor (100) according to claim 2, characterized in that the throttle element (203, 207) is detachably connected to the respective channel (107).

4. Air compressor (100) according to one of the preceding claims, characterized in that that throttle elements (203, 207) arranged in respective channels (107) of the secondary regions (113) successively enlarge or reduce an effective cross-section of the respective channels (107) in the course of the main region (111).

5. Air compressor (100) according to one of the preceding claims, characterized in that the air compressor (100) comprises a cooling device (121) which forms at least part of the air guide path (105), wherein the cooling device (121) comprises a base body in which at least part of the plurality of channels (107) is formed, wherein the cooling device (121) overlies the stator (101) in a region between a winding head of the stator (101) and the casing (103) at least on the end face and forms the air guide path (105) together with the winding head and / or the casing (103).

6. Air compressor (100) according to one of the preceding claims, characterized in that at least some of the plurality of channels (107) are formed in the casing (103) and / or the stator (101).

7. Air compressor (100) according to one of the preceding claims, characterized in that the air guide path (105) is formed by a number of air guide elements (123) which comprise at least one structure from the following list of structures: channel, receptacle, recess, protuberance, cavity, air guide plate, cooling fin, pin-fin structure.

8. Air compressor (100) according to one of the preceding claims, characterized in that the air guide path (105) is inclined by an air guide angle in the direction of the stator (101).

9. Air compressor (100) according to one of the preceding claims, characterized in that that respective channels (107) forming the plurality of secondary regions (113) connect the inner region (115) of the stator (101) to respective channels (107) forming the main region (111) in an air-conducting manner.

10. Air compressor (100) according to one of the preceding claims, characterized in that the air guide path (105) comprises a plurality of secondary regions (113), each of which extends with mutually different flow geometries from the main region (111) in the direction of the inner region (115) of the stator (101).

11. Air compressor (100) according to one of the preceding claims, characterized in that a flow geometry of the main region (111) changes over the course of the main region (111).

12. Air compressor (100) according to one of the preceding claims, characterized in that the main region (111) forms a circle or is closed at one end.

13. Air compressor (100) according to one of the preceding claims, characterized in that the air guide path (105) at least partially overlies a winding head of the stator (101) both at the front and laterally in the direction of respective stator slots of the stator (101).

14. Air compressor (100) according to one of the preceding claims, characterized in that the air guide path (105) comprises an interface (109) which is configured to receive air to be guided through the air guide path (105) from an environment and to release it to the environment or to receive a partial air mass flow of a compressor and / or a turbine of the air compressor and to release it to the turbine or the environment.

15. Air compressor (100) according to one of the preceding claims, characterized in that a first air guide path is formed at a first front end of the stator (101) and a second air guide path is formed at a second front end of the stator (101) opposite the first end.

16. Manufacturing method (400) for an air compressor, the manufacturing method (200) comprising: Providing (401) a stator (101), Providing (403) a cover (103), Providing (405) an air guide path (105) configured to guide an air mass flow along the stator (101), wherein the air guide path (105) comprises a plurality of channels (107) forming a main region (111) extending radially around an inner region (115) of the stator (101) and a plurality of secondary regions (113) extending from the main region (111) toward the inner region (115) of the stator (101), Forming (407) at least one throttle element (203, 207) in at least a part of the plurality of channels (107), so that respective channels (107) of the plurality of channels (107) differ from one another in their cross section and wherein the air guide path (105) overlaps the stator (101) on the front side.

17. Manufacturing method (400) according to claim 16, characterized in that the air guide path (105) is provided by air guide elements (123) formed in a cooling device (121) and / or the stator (101) and / or the casing (103).

18. A fuel cell system (300) for converting energy, the fuel cell system (300) comprising: a fuel cell stack (301), an air compressor (100) according to any one of claims 1 to 15 for supplying the fuel cell stack (301) with air.

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