Air compressor for conveying air with position-stable stator

Abstract

The presented invention relates to an air compressor (100) for conveying air, wherein the air compressor (100) comprises: - a stator (101), - a cooling device (103) and - a casing (105) surrounding the stator (101), comprising the cooling device (103): - a basic body (107) and - a number of air guide elements (109) formed on a surface of the base body (107) wherein the cooling device (103) overlaps a winding head (111) of the stator at least at its end face in an area between the winding head (111) and the casing (105), wherein the shell (105) has a number of shell receptacles (113, 115) by which the cooling device is mechanically coupled to the shell, wherein the stator has a number of stator mounts (117, 119) through which the cooling device is mechanically coupled to the stator (101), and wherein the shell (105) together with the air guide elements (109) and the base body (107) forms an air guide path configured to direct a mass air flow along the stator (101).

Description

[0001] The presented invention relates to an air compressor for conveying air, a manufacturing method for manufacturing the air compressor and a fuel cell system according to the appended claims. State of the artDisclosure of the invention

[0002] Air compressors for conveying air are usually designed as auxiliary units in a particularly compact manner for reasons of installation space.

[0003] Due to the compact design, thermal problems arise particularly in the area of ​​the stator of an electrical machine for driving an air compressor. Disclosure of the invention

[0004] Within the scope of the invention presented, an air compressor for conveying air, a manufacturing method for producing the 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 for producing the air compressor or 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 always made to each other.

[0005] The invention presented serves in particular to provide a possibility for robust operation of an air-conducting system, in particular a fuel cell system.

[0006] Thus, according to a first aspect of the invention presented, an air compressor for conveying air is presented.

[0007] The presented air compressor comprises a stator, a cooling device and a shell surrounding the stator.

[0008] The cooling device comprises a base body and a number of air guiding elements formed on a surface of the base body, wherein the cooling device overlies a winding head of the stator in a region between the winding head and the shell at least on the end face, wherein the shell has a number of shell receptacles by means of which the cooling device is mechanically coupled to the shell, wherein the stator has a number of stator receptacles by means of which the cooling device is mechanically coupled to the stator, and wherein the shell, together with the air guiding elements and the base body, forms an air guiding path which is configured to guide an air mass flow along the stator.

[0009] In the context of the invention presented, an end face is understood to be a short side of a cylindrical stator.

[0010] The invention presented is based on a cooling device that is arranged in a region between the winding head of the stator of the air compressor presented and a stator casing, and that overlaps the stator at least at its front end. This means that the cooling device extends, in particular, over the entire length of the front end of the winding head, so that the winding head is cooled by the cooling device at least at its front end.

[0011] Due to the arrangement of the cooling device between the winding head and the stator shell, the air compressor presented can be designed to be particularly compact.

[0012] To cool the stator or the winding head, the cooling device, together with the casing surrounding the stator, forms an air flow path that directs an air mass flow through the air compressor to areas of the stator subject to particularly high thermal stress, particularly to the winding head. Accordingly, thermal energy is transferred from the stator to the air mass flow and dissipated, cooling the stator and allowing it to be loaded with particularly high power.

[0013] 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.

[0014] The shell of the proposed air compressor can have one or more shell receptacles, through which the cooling device is mechanically coupled to the shell and positioned relative to the shell. Furthermore, the shell can form a housing of the air compressor, in particular a housing with a bearing plate. Accordingly, the shell can include a bearing plate.

[0015] The stator of the presented air compressor can have one or more stator receptacles through which the cooling device is mechanically coupled to the stator and positioned relative to the shell.

[0016] Accordingly, the number of sleeve receptacles and the number of stator receptacles act together for the mechanical coupling of the cooling device to the air compressor or for positioning, in particular for centering the cooling device in the air compressor.

[0017] The cooling device may, for example, comprise a circular part that overlies the stator at the front and optionally engages in an inner region of the stator in order to guide an air mass flow to the stator or through the stator.

[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, or 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 power of the air compressor increases. For this purpose, the cooling device can comprise at least one inlet opening that introduces an air mass flow into the air guide path and at least one outlet opening that discharges the air mass flow from the air guide path.

[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] It can be provided that the number of sleeve receptacles comprises elevations which are elevated relative to a base body of the sleeve or that the number of sleeve receptacles comprises depressions which are recessed relative to the base body of the sleeve.

[0021] In particular, the cooling device can form a number of counter-sleeve receptacles which form a positive connection with the number of sleeve receptacles.

[0022] Elevations, such as material projections, effectively limit the cooling device's movement space and force it into a predetermined position. For this purpose, the elevations can be slanted or curved, for example.

[0023] Envelope receptacles designed as elevations can engage with the cooling device or surround the cooling device in order to mechanically couple it to the envelope.

[0024] Recesses, such as cutouts in the casing material, effectively limit the cooling device's movement space and force the cooling device into a predetermined position when the cooling device engages the recesses. For this purpose, the recesses can be slanted or curved, for example.

[0025] It can further be provided that the number of stator receptacles comprises elevations which are elevated relative to a base body of the stator or that the number of stator receptacles comprises depressions which are recessed relative to the base body of the stator.

[0026] In particular, the cooling device can form a number of counter-stator receptacles which form a positive connection with the number of stator receptacles.

[0027] Elevations, such as material projections, effectively limit the cooling device's movement space and force it into a predetermined position. For this purpose, the elevations can be slanted or curved, for example.

[0028] Stator receptacles designed as elevations can engage with the cooling device or surround the cooling device in order to mechanically couple it to the casing.

[0029] Recesses, such as recesses in the stator material, such as in the resin surrounding the stator winding head, effectively limit the cooling device's movement space and force the cooling device into a predetermined position when the cooling device engages the recesses. For this purpose, the recesses can be slanted or curved, for example.

[0030] It may further be provided that the number of stator receptacles and the number of sleeve receptacles are configured to align the cooling device relative to a longitudinal axis of the stator.

[0031] A secure positioning of the cooling device relative to the stator requires a reliable air mass flow to areas of the stator that are subject to particularly high thermal stress, so that the stator is reliably cooled and accordingly fail-safe and resilient.

[0032] 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.

[0033] By superimposing the winding head on the front and sides, a surface for transferring thermal energy from the winding head to the cooling device or from the cooling device to an air mass flow flowing along the cooling device is maximized and the winding head is protected from mechanical stress on the front and sides.

[0034] 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.

[0035] A high thermal conductivity of the base body of the cooling device results in a high heat transfer from the winding head to the cooling device, through the cooling device and to an air mass flow flowing along the cooling device and a correspondingly good cooling effect or high cooling performance.

[0036] An electrical conductivity of the base body that is less than 10%, especially less than 1% of the electrical conductivity of aluminum, suppresses eddy currents between the stator shell and the stator, so that the performance of the air compressor is maximized.

[0037] It can also be provided that the base body of the cooling device consists entirely or partially of ceramic.

[0038] Ceramics such as Al2O3 with a thermal conductivity of 20W / mK or AlN with a thermal conductivity of 170W / mK have proven to be particularly advantageous for dissipating heat from a winding head and are electrically insulating.

[0039] It can further be provided that air guiding elements are formed on the surface of the base body, which consist of at least one material from the following list of materials: silicone, thermoplastic and duroplastic.

[0040] Air guide elements or a cooling device made of silicone, thermoplastic or thermoset have an electrically insulating effect and can be manufactured particularly cost-efficiently.

[0041] It can further be provided that the shell comprises a base part and a bearing plate, wherein a first number of shell receptacles is formed in the base part and a second number of shell receptacles is formed in the bearing plate, and wherein a geometry of the first number of shell receptacles differs from a geometry of the second number of shell receptacles.

[0042] By using different sleeve mounts on the base part and the bearing plate, the cooling device can be shaped differently on the base part and the bearing plate, allowing a position-specific or side-specific air mass flow to be provided through the cooling device, which, for example, corresponds to a specific stator geometry. For example, the geometry of the sleeve mounts on the base part can provide a supply line for an air mass flow.

[0043] It can further be provided that a first cooling device is arranged at a first front end of the stator and a second cooling device is arranged at a second front end of the stator opposite the first end.

[0044] Two cooling devices at each end of the stator provide a particularly high cooling capacity to temper the stator, so that it can be subjected to a particularly high power.

[0045] According to a second aspect, the presented invention relates to a fuel cell system for converting energy.

[0046] The presented fuel cell system comprises a fuel cell stack and a possible design of the presented air compressor for supplying the fuel cell stack with air.

[0047] It can be provided that the cooling device of the air compressor is fluidly coupled to a cooling system of the fuel cell system.

[0048] According to a third aspect, the presented invention relates to a manufacturing method for producing a possible embodiment of the presented air compressor.

[0049] The presented manufacturing method comprises forming a shell, wherein the shell comprises a number of shell receptacles, forming a stator, wherein the stator comprises a number of stator receptacles, inserting the stator into the shell, and inserting a cooling device into the shell, wherein the cooling device is inserted into the shell in such a way that the cooling device is mechanically coupled to both the number of stator receptacles and the number of shell receptacles.

[0050] To form the number of shell receptacles, these can be formed as an integral part of the shell in a primary forming process of the shell, such as a casting process, or they can be subsequently introduced into the shell after primary forming in a machining process, e.g. by milling.

[0051] To form the number of stator receptacles, these can be formed as an integral component in the shell in a primary forming process of the stator, such as a casting process of a shell of the stator, or can be subsequently introduced into the shell or the stator after a primary forming process in a machining process, e.g. by milling.

[0052] Advantages described in detail for the air compressor for conveying air according to the first aspect of the invention apply equally to the fuel cell system for converting energy according to the second aspect of the invention and the manufacturing method for manufacturing a possible embodiment of the presented air compressor according to the third aspect of the invention.

[0053] 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.

[0054] They show: Fig. 1 a schematic representation of a possible design of the presented air compressor in a sectional side view, Fig. 2 a plan view of the cooling device arranged on the stator of the air compressor according to Fig. 1, Fig. 3 a possible design of the presented fuel cell system, Fig. 4 a possible design of the presented manufacturing process.

[0055] In Fig. 1 shows an air compressor 100 for conveying air. The air compressor 100 includes a stator 101, a cooling device 103, and a casing 105 surrounding the stator 101.

[0056] The cooling device 103 comprises a base body 107 and a number of air guiding elements 109 formed on a surface of the base body 107.

[0057] The cooling device 103 overlies a winding head 111 of the stator 101 in a region between the winding head 111 and the shell 105.

[0058] Furthermore, the casing 105 comprises a number of casing receptacles 113, 115, by means of which the cooling device 103 is mechanically, in particular firmly, coupled to the casing 105.

[0059] Furthermore, the stator 101 comprises a number of stator receptacles 117, 119, through which the cooling device 103 is mechanically, in particular permanently, coupled to the stator 101. On a first side 121, the stator receptacle 117 is configured as an elevation or material protrusion in a casing of the winding head 111, and the sleeve receptacle 113 is configured as a recess or depression in the casing 105.

[0060] On a second side 123 opposite the first side 121, the stator receptacle 119 is designed as a recess or depression in a material of the winding head 111 and the sleeve receptacle 115 is designed as an elevation or material protrusion of the sleeve 105.

[0061] The sleeve 105 forms, together with the air guiding elements 109 and the base body 107, an air guiding path 125 which guides an air mass flow to the winding head 111.

[0062] In Fig. 2, the cooling device 103 according to Fig. 1 is shown in a top view. Here, inlets 201 and 203 for the air mass flow into the cooling device 103 can be seen.

[0063] The air mass flow is guided through the air guide elements 109 to the winding head 111 and through an inner part 205 of the stator 101.

[0064] In Fig. 3 shows a fuel cell system 200 for converting energy.

[0065] The fuel cell system 200 comprises a fuel cell stack 201 and an air compressor 100 according to Fig. 1 for supplying the fuel cell stack 201 with air.

[0066] In Fig.4 shows a manufacturing method 300 for producing a possible embodiment of the presented air compressor.

[0067] The manufacturing method 300 comprises a first molding step 301 in which a shell is molded such that the shell comprises a number of shell receptacles, a second molding step 303 in which a stator is molded such that it comprises a number of stator receptacles.

[0068] Furthermore, the manufacturing method 300 comprises a first insertion step 305 in which the stator is inserted into the shell, and a second insertion step in which a cooling device is inserted into the shell in such a way that the cooling device is mechanically coupled to or engages with both the number of stator receptacles and the number of shell receptacles.

Claims

[1] Air compressor (100) for conveying air, wherein the air compressor (100) comprises: - a stator (101), - a cooling device (103) and - a shell (105) surrounding the stator (101), wherein the cooling device (103) comprises: - a base body (107) and - a number of air guiding elements (109) formed on a surface of the base body (107) wherein the cooling device (103) overlies a winding head (111) of the stator in a region between the winding head (111) and the sleeve (105) at least on the front side, wherein the casing (105) has a number of casing receptacles (113, 115) by means of which the cooling device is mechanically coupled to the casing, wherein the stator has a number of stator receptacles (117, 119) through which the cooling device is mechanically coupled to the stator (101), and wherein the shell (105) with the air guiding elements (109) and the base body (107) forms an air guiding path which is configured to guide an air mass flow along the stator (101). [2] Air compressor (100) according to claim 1, characterized by that the number of sleeve receptacles (113, 115) comprises elevations which are elevated relative to a base body of the sleeve (105) or the number of sleeve receptacles (113, 115) comprises depressions which are recessed relative to the base body of the sleeve (105). [3] Air compressor (100) according to claim 1 or 2, characterized by that the number of stator receptacles (117, 119) comprises elevations which are elevated relative to a base body of the stator (101) or the number of stator receptacles (117, 119) comprises depressions which are recessed relative to the base body of the stator (101). [4] Air compressor (100) according to one of the preceding claims, characterized bythat the number of stator receptacles (117, 119) and the number of sleeve receptacles (113, 115) are configured to align the cooling device (103) relative to a longitudinal axis of the stator (101). [5] Air compressor (100) according to one of the preceding claims, characterized by that the cooling device (103) overlies the winding head (111) both at the front and laterally in the direction of the respective stator slots of the stator (101) at least in some areas. [6] Air compressor (100) according to one of the preceding claims, characterized by that the air guiding elements (109) consist of at least one material from the following list of materials: silicone, thermoplastic and duroplastic. [7] Air compressor (100) according to one of the preceding claims, characterized byin that the shell (105) comprises a base part and a bearing plate, wherein a first number of shell receptacles (113) is formed in the base part and a second number of shell receptacles (115) is formed in the bearing plate, and wherein a geometry of the first number of shell receptacles (113) differs from a geometry of the second number of shell receptacles (115). [8] Air compressor (100) according to one of the preceding claims, characterized by that a first cooling device (103) is arranged at a first front end of the stator (101) and a second cooling device (103) is arranged at a second front end of the stator (101) opposite the first end (115). [9] Fuel cell system (200) for converting energy, the fuel cell system (200) comprising: - a fuel cell stack (201), - an air compressor (100) according to one of claims 1 to 8 for supplying the fuel cell stack (201) with air. [10] A manufacturing method (300) for manufacturing an air compressor (100) according to any one of claims 1 to 8, wherein the manufacturing method (100) comprises: - forming (301) a sleeve (105), wherein the sleeve (105) comprises a number of sleeve receptacles (113, 115), - forming (303) a stator (101), wherein the stator (101) comprises a number of stator receptacles (117, 119), - inserting (305) the stator (101) into the casing (105), and - introducing (307) a cooling device (103) into the casing, wherein the cooling device (103) is introduced into the casing (105) in such a way that the cooling device (103) is mechanically coupled both to the number of stator receptacles (117, 119) and to the number of casing receptacles (113, 115).

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