COOLANT ELEMENT, COOLING SYSTEM AND ELECTRICAL MACHINE

Description

[0001] The invention relates to a coolant guide element for a cooling system for cooling an electrical machine. Furthermore, the invention relates to a corresponding cooling system and an electrical machine.

[0002] An electrical machine often has a stator that heats up during operation. To prevent the stator and thus the electrical machine from overheating, the electrical machine has a cooling system through which the stator and thus the electrical machine can be cooled. A coolant guide element is provided to guide a coolant along a cooling path of the cooling system. It is desirable that a homogeneous flow along the cooling path can be achieved by means of a gap defined by the coolant guide element for the coolant to flow through between the coolant guide element and the cooling path.

[0003] For manufacturing, it is known to cast the coolant guide element, which is usually ring-shaped, or to join two parts together with a weld. However, such coolant guide elements have high manufacturing tolerances, which means that the size of the gap formed for the coolant to flow through can vary considerably, which can also cause the cooling effect to fluctuate significantly. Furthermore, these designs do not allow for tolerance compensation of the stator tolerances.

[0004] A cooling system for motor-driven pumps is known from US 3,127,530 A. DE 10 2011 056838 A1 discloses a cooling device for an auxiliary unit of an internal combustion engine, preferably for an electrical auxiliary unit, comprising a double-walled cooling housing connected to a cooling circuit in which a cooling fluid flows. The cooling housing has an inlet connection and a return connection. The double-walled cooling housing is formed from a first cooling section and a second cooling section, which are connectable to one another and are designed such that they bear against at least one outer wall of the auxiliary unit.

[0005] From DE 15 01 498 A1 a heat exchanger is known, in particular a rigid, resilient heat exchange plate which is stretched around containers of various dimensions, whereby their contents are heated or cooled.

[0006] US Pat. No. 4,573,329 A discloses a machine for producing ice cream and similar cold products. It comprises a freezing container that can be inserted into and removed from a substantially cylindrical cooling chamber. The chamber is elastically deformable and has a circular cross-section that is not completely closed due to the presence of a passage. The passage is closed by a pair of shields and by a substantially bellows-like part made of elastically yielding and heat-insulating material. This improves the thermal efficiency of the machine.

[0007] From US 2,625,804 A the cooling and dispensing of beverages, in particular beer and similar brews, is known and relates in particular to a device and a method for cooling brews that are filled in metal barrels.

[0008] From US 4 535 604 A an ice cream machine with an ice cream container is known, with a substantially cylindrical cooling chamber with a substantially cylindrical cooling space of circular cross-section, which is not completely closed due to the presence of a slot extending along a circumferential surface of the cylinder.

[0009] The invention is based on the object of providing a coolant guide element, a cooling system and an electrical machine in which a flow gap that is as defined as possible can be formed.

[0010] The object of the invention is achieved by the features of the independent claims. Preferred embodiments and further developments of the invention are specified in the dependent claims.

[0011] The coolant conducting element according to the invention comprises a base body on which at least one guide element for guiding a coolant is arranged on a radially inward-facing circumferential surface of the base body, wherein the base body has a first end section and a second end section, wherein in a connected state of the first end section with the second end section, the base body forms an annular shape. Furthermore, the coolant conducting element according to the invention comprises a bracing element which, in a state fastened to the base body, extends along a radially outward-facing circumferential surface of the base body and is fastened to the base body in such a way that the first end section and the second end section are held braced relative to one another.

[0012] According to the invention, it is no longer provided that the coolant guide element is rigid, but rather the coolant guide element has a defined flexibility in an installed state in which the coolant guide element is arranged in the electrical machine, so that manufacturing tolerances can be compensated for by the coolant guide element and thus a defined and constant gap for the coolant to flow through can be formed between the coolant guide element and a cooling track. For this purpose, the coolant guide element has a base body which preferably has an axially formed slot, wherein the base body has a first end section and a second end section through the axially formed slot, wherein the two end sections are connected to one another, so that the base body has a ring shape in a connected state and thus also in the state installed in the electrical device.According to the invention, the two end sections are connected to one another in such a way that they are resiliently braced when connected. As a result, the base body and thus the coolant guide element has a spring effect, whereby a resilient tolerance compensation can be formed by connecting the two end sections to one another when the coolant guide element is installed. The resilient bracing of the two end sections to one another ensures that, when installed, the guide elements for guiding the coolant rest against the cooling track of the cooling system, thereby creating a defined, constant flow gap. The guide elements preferably also form spacer elements, so that the coolant guide element can be held at a defined distance from the cooling track, thus creating the gap or flow gap for the coolant to flow through.The resilient bracing of the two end sections is achieved according to the invention in that the coolant conducting element has a bracing element in addition to the base body, wherein the bracing element thus preferably forms a component of the coolant conducting element that is designed separately from the base body. In order to brace the two end sections of the base body together, the bracing element is preferably detachably fastened to the base body, in particular to a radially outward-facing circumferential surface of the base body, so that the bracing element extends along the radially outward-facing circumferential surface of the base body in the fastened state. By holding the two end sections of the base body braced relative to one another by means of the bracing element, the formation of a constant, as small as possible gap orA flow gap for the coolant to flow through can be ensured, whereby the gap can be kept constant by means of the clamping element, regardless of geometric and physical tolerances, such as temperature influences.

[0013] In order to reliably ensure the formation of a constant gap or flow gap under various geometric and physical influences, the bracing element can preferably be made of a resilient and / or elastic material. By constructing the bracing element from a resilient and / or elastic material, it can have a defined flexibility with a simultaneous restoring effect in order to be able to compensate for tolerances in a defined manner. Spring steel or spring wire, for example, can be used as the resilient material. Rubber or caoutchouc material and / or an elastic plastic material can be used as the elastic material. The material of the bracing element preferably has high media compatibility, in particular high media compatibility with the coolant, and high extensibility.

[0014] According to the invention, the bracing element is designed such that, in the fastened state, i.e. when the bracing element is fastened to the base body, it extends over more than one third of the radially outward-facing circumferential surface of the base body. If the bracing element extends over more than one third of the radially outward-facing circumferential surface of the base body, the tolerances to be compensated by the bracing element can be distributed over a relatively large length of the bracing element. Due to the distribution over a relatively large length, relatively small expansions are necessary in the bracing element itself in order to be able to ensure a sufficiently large preload at all times to hold the two end sections of the base body. The bracing element therefore preferably has an elongated design. The bracing element preferably extends over approximately half of the radially outward-facing circumferential surface of the base body.

[0015] To fasten the bracing element to the base body, according to the invention, a first fastening element and a second fastening element are arranged on the base body on the radially outward-facing circumferential surface of the base body. The two fastening elements are preferably formed integrally on the base body. Preferably, the two fastening elements are designed such that the bracing element can be detachably fastened to the base body, so that the bracing element can be replaced if necessary. Preferably, the two fastening elements are structurally identical to one another. However, it is also possible for the two fastening elements to have different shapes and configurations.

[0016] To achieve a particularly reliable positioning of the bracing element on the base body, the first fastening element is arranged opposite the second fastening element according to the invention. The two fastening elements are thus preferably arranged at a 180° angle to each other on the base body. When the two fastening elements are positioned opposite each other, the bracing element can extend approximately over half of the radially outward-facing circumferential surface of the base body.

[0017] In an embodiment not belonging to the invention, it is possible that the two fastening elements are not arranged opposite one another, for example if the available installation space requires that they are arranged at an angle of less than or greater than 180° to one another on the base body.

[0018] According to the invention, the first fastening element and / or the second fastening element are hook-shaped. With a hook-shaped design, the bracing element can be hooked onto the fastening element(s) in a simple and quick manner in order to be fastened to the base body. Quick release of the bracing element from the fastening elements is then also possible. Other configurations of one or both fastening elements are also possible. For example, the first fastening element and / or the second fastening element can be designed in the form of an eyelet through which the bracing element is passed for fastening.

[0019] In a first alternative according to the invention, the bracing element is designed in the form of a rubber ring. An O-ring, for example, can be used as the rubber ring. The rubber ring can then, for example, be attached to the base body in such a way that it forms two 180° bends in the region of its attachment to the base body, so that the rubber ring extends like a double-guided cord along the radially outward-facing circumferential surface of the base body. If the bracing element is designed in the form of a rubber ring, the bracing element is preferably made of an elastic plastic material. By designing the bracing element in the form of a rubber ring, it can also be very lightweight.

[0020] In a second alternative according to the invention, it is provided that the bracing element is designed in the form of a spring plate or in the form of a spring wire. The bracing element is then preferably made of a metal material. Whether the bracing element is designed in the form of a spring plate or in the form of a spring wire, it preferably has a very small thickness, preferably a thickness of less than 10 mm, so that here too the bracing element can be lightweight while simultaneously being highly stable and having a good spring effect. When designed in the form of a spring plate or in the form of a spring wire, the bracing element is preferably bent in such a way that its shape is adapted to the annular outer contour of the base body.

[0021] When using a spring wire as a bracing element, the bracing element is designed according to the invention as a spiral spring. The bracing element can have several coils along its length, which allows the bracing element to exhibit a particularly good spring effect.

[0022] The invention further provides a cooling system for cooling an electrical machine, which has an inlet opening for supplying a coolant, an outlet opening for discharging a coolant, and a cooling path along which coolant emerging from the inlet opening flows during a cooling process and along which the coolant flows to the outlet opening during the cooling process, wherein a coolant guide element according to the invention is formed on the cooling path, which can be designed and developed as described above, wherein a gap is formed between the cooling path and the coolant guide element, through which gap the coolant flows from the inlet opening to the outlet opening during the cooling process.

[0023] The coolant guide element can radially cover or encompass the cooling track, allowing the coolant to be guided in a controlled manner between the cooling track and the coolant guide element. A gap for the coolant to flow through can then be formed between the coolant guide element and the cooling track. The cooling track can, for example, be a cooling jacket that can surround a housing, for example, of a stator of an electrical machine.

[0024] The object of the invention is further achieved by means of an electric machine having a housing, wherein a cooling system is arranged on an outer peripheral surface, which cooling system can be designed and developed as described above. The electric machine can further have a further housing that radially encloses the cooling system and thus also the coolant conducting element.

[0025] The electrical machine can, for example, be designed as an electric motor of a motor vehicle.

[0026] Further measures improving the invention are presented in more detail below with reference to the description of preferred embodiments of the invention with reference to the following figures.

[0027] They show: Fig. 1 a schematic representation of a coolant guide element according to the invention, Fig. 2 a schematic representation of a section of the Fig. 1 shown coolant guide element in the area of ​​the fastening of the bracing element to the base body, Fig. 3 a schematic plan view of one side of the Fig. 1shown coolant guide element, Fig. 4 a schematic representation of a coolant guide element according to a further embodiment of the invention, Fig. 5 a schematic representation of a coolant guide element according to a further embodiment of the invention, Fig. 6 a sectional view of a part of an electrical machine with a cooling system and a along the in Fig. 1 drawn line AA cut coolant guide element, Fig. 7 a schematic detailed representation of the Fig. 6 shown sectional view, and Fig. 8 a schematic detailed view of a transition area between the two end sections of the base body of the Fig. 1 shown coolant guide element.

[0028] Fig. 1 shows a coolant guide element 100 which can be arranged in an electrical machine 400.

[0029] The coolant guide element 100 comprises a base body 10, which has a plurality of guide elements 12 for guiding a coolant on its radially inward-facing circumferential surface 11. The guide elements 12 are each designed in the form of ribs that protrude from a radially inward-facing circumferential surface 11 of the base body 10. The guide elements 12, designed in the form of ribs, are formed here by embossing the base body 10, so that the guide elements 12 are formed from the base body 10.

[0030] The base body 10 has an axially extending slot 13, so that the base body 10 has two opposite end sections 14, 15. In a connected state of the two end sections 14, 15 with each other, the base body 10 has a ring shape, as in Fig. 1 can be seen. The two end sections 14, 15 are held clamped to each other when connected.

[0031] To create the bracing, a bracing element 16 is provided, which is designed as a separate component from the base body 10. In the attached state, the bracing element 16 is fastened to the base body 10 in such a way that the first end section 14 and the second end section 15 of the base body 10 are held braced relative to one another by means of the bracing element 16. In the attached state, the bracing element 16 extends along a radially outward-facing circumferential surface 17 of the base body 10. The bracing element 16 thus encompasses the base body 10 over at least a partial length of the base body 10.

[0032] As in Fig. 1As can be seen, the bracing element 16 extends in the attached state over more than one third of the radially outwardly facing circumferential surface 17 of the base body 10, so that a spring effect applied by the bracing element 16 can be distributed over the greatest possible length of the bracing element 16, so that even small expansions of the bracing element 16 can apply a sufficiently large preload to the base body 10 by means of the bracing element 16 and a high tolerance compensation is possible. As shown in the Fig. 3 shown side view of the Fig. 1 As shown in the coolant guide element 100 shown, the bracing element 16 extends over approximately half of the radially outward-facing circumferential surface 17 of the base body 10. However, it is also possible for the bracing element 16 to extend by more or less than half of the radially outward-facing circumferential surface 17 of the base body 10, if required.

[0033] The bracing element 16 is detachably fastened to the base body 10. For fastening, a first fastening element 18 and a second fastening element 19 are arranged on the base body 10, wherein the bracing element 16 is fastened to the first fastening element 18 and to the second fastening element 19 in the fastened state. The two fastening elements 18, 19 are arranged on the radially outward-facing circumferential surface 17 of the base body 10. The two fastening elements 18, 19 are designed and arranged on the base body 10 in such a way that they each protrude from the radially outward-facing circumferential surface 17 of the base body 10.

[0034] At the Fig. 1 In the embodiment shown, the fastening elements 18, 19 are both hook-shaped, so that the bracing element 16 can be hooked onto the fastening elements 18, 19 in the fastened state, as in Fig. 2can be seen.

[0035] As further stated in Fig. 1 and 3 As can be seen, the two fastening elements 18, 19 are arranged opposite one another so that they are arranged at a 180° angle to one another on the base body 10.

[0036] At the Fig. 1 to 3In the embodiment shown, the bracing element 16 is in the form of a rubber ring. An O-ring, for example, can be used as the rubber ring. The bracing element 16, designed as a rubber ring, is fastened to the base body 10 in such a way that it forms two 180° bends in the region of its attachment to the base body 10, so that the bracing element 16, designed as a rubber ring, extends like a double-guided cord along the radially outward-facing circumferential surface 17 of the base body 10. In the region of the two 180° bends, the bracing element 16, designed as a rubber ring, forms a type of loop 20, each of which can hook onto one of the two fastening elements 18, 19.

[0037] At the Fig. 4In the embodiment shown, the bracing element 16 is designed in the form of a spring plate. The spring plate, and thus the bracing element 16, is bent in such a way that its shape is adapted to the radius of the base body 10. The bracing element 16, designed as a spring plate, has the smallest possible thickness in order to achieve a good spring effect.

[0038] At the Fig. 5 In the embodiment shown, the bracing element 16 is designed in the form of a spring wire, with the spring wire here being shaped as a spiral spring. The bracing element 16, designed as a spring wire or spiral spring, has a plurality of turns along its length, through which a good spring effect can be achieved over the length of the bracing element 16.

[0039] The bracing element 16, which is designed as a spring plate or spring wire, can also have a loop or a hook at each of its two ends in order to fasten the bracing element to the fastening elements 18, 19 of the base body 10.

[0040] In order to achieve a tight fit of the two end sections 14, 15 of the base body 10 against each other, the first end section 14 can have a first sealing surface 33 and the second end section 15 can have a second sealing surface 34, wherein the two sealing surfaces 33, 34 together can form a labyrinth seal, as in Fig. 1 and 8can be seen. The first sealing surface 33 can be designed in the form of an edge surface protruding from the first end section 14, and the second sealing surface 34 can be designed in the form of an edge surface protruding from the second end section 15, wherein in the connected state of the two end sections 14, 15 with one another, the second sealing surface 34 can lie flat on the first sealing surface 33.

[0041] The base body 10 shown here further comprises a resilient seal 35, which can interact with a housing 200 surrounding the coolant guide element 100 in an installed state, as shown in Fig. 6can be seen. The resilient seal 35 protrudes toward the surrounding housing 200 so that it can interact with the housing 200 without affecting the remaining function of the coolant conducting element 100. The resilient seal 35 is formed on a circumferential edge 36 of the base body 10, so that the resilient seal 35 is also formed circumferentially on the base body 10.

[0042] In the area of ​​the seal 35 or the edge 36, the base body 10 has a venting gap 37, which is arranged in the area of ​​the connection of the two end sections 14, 15 to each other, as for example in Fig. 1 can be seen.

[0043] Furthermore, fastening hooks 39 are formed on the base body 10, which are directed radially outwards and which hook into the housing 200 when installed, as shown in Fig. 6can be seen, in order to secure the coolant guide element 100 against axial and radial displacement. The fastening hooks 39 are resiliently formed on the base body 10 by slots 40 being formed in the base body 10 in the region where the fastening hooks 39 are connected to the base body 10. The fastening hooks 39 are formed on the edge 41 of the base body 10 opposite the edge 36.

[0044] Fig. 6 shows a sectional view of a part of an electrical machine 400 with a cooling system 300 and a along the Fig. 1 drawn line AA cut coolant guide element 100. The cooling system 300 is arranged radially outward and circumferentially around a housing 50 of the electrical machine 400, wherein the housing 50 can be, for example, a housing 50 of a stator.

[0045] The cooling system 300 has an inlet opening 60 for supplying a coolant and an outlet opening 61 for discharging the heated coolant. The cooling system 300 further has a cooling path 62, along which coolant exiting from the inlet opening 60 flows during a cooling process and along which the coolant flows to the outlet opening 61 during the cooling process, as indicated by the arrows. The cooling path 62 is arranged radially inward of the coolant guide element 100, so that a gap 63 is formed between the cooling path 62 and the coolant guide element, through which gap the coolant flows. The guide elements 12 of the coolant guide element 100 lie flat on the cooling path 62, so that a defined height H of the gap 63 is formed by the height of the guide elements 12, as shown in Fig. 7 is shown, wherein the height H of the gap 63 remains constant over the entire circumference of the coolant guide element 100.

[0046] The invention is limited in its implementation to the subject matter defined in the claims. List of reference symbols

[0047] 100Coolant guide element 200Housing 300Cooling system 400Electric machine 10Base body 11Circumferential surface 12Guide element 13Slot 14First end section 15Second end section 16Clamping element 17Circumferential surface 18First fastening element 19Second fastening element 20Loop 33First sealing surface 34Second sealing surface 35Seal 36Edge 37Venting gap 39Fastening hook 40Slot 41Edge 50Housing 60Inlet opening 61Outlet opening 62Cooling track 63Gap Height

Claims

1. Coolant conducting element (100) for a cooling system (300) for cooling an electrical machine (400), comprising a base body (10), on which at least one guide element (12) for guiding a coolant is arranged on a radially inwardly facing circumferential surface (11) of the base body (10), wherein the base body (10) has a first end portion (14) and a second end portion (15), wherein the base body (10) forms a ring shape when the first end portion (14) is connected to the second end portion (15), and comprising a bracing element (16) which, when fixed to the base body (10), extends along a radially outwardly facing circumferential surface (17) of the base body (10) and is fixed to the base body (10) in such a way that the first end portion (14) and the second end portion (15) are held together in a braced manner, wherein the bracing element (16), in the fixed state, extends over more than one third of the radially outwardly facing circumferential surface (17) of the base body (10), wherein a first fixing element (18) and a second fixing element (19) for fixing the bracing element (16) to the base body (10) are arranged on the radially outwardly facing circumferential surface (17) of the base body (10), wherein the first fixing element (18) is arranged opposite the second fixing element (19), wherein the first fixing element (18) and / or the second fixing element (19) are hook-shaped, or the first fixing element (18) and / or the second fixing element (19) are designed in the form of an eyelet, wherein the bracing element (16) is designed in the form of a rubber ring, that the bracing element (16) is designed in the form of a spring plate or in the form of a spring wire, or that a bracing element (16) designed as a spring wire is designed as a spiral spring.

2. Coolant conducting element (100) according to claim 1, characterized in that the bracing element (16) is made of a resilient and / or elastic material.

3. Cooling system (300) for cooling an electrical machine (400), comprising an inlet opening (60) for supplying a coolant, an outlet opening (61) for discharging the coolant, a cooling path (62) along which coolant emerging from the inlet opening (60) flows during a cooling process and along which the coolant flows to the outlet opening (61) during the cooling process, wherein a coolant conducting element (100) is arranged on the cooling path (62), which coolant conducting element is designed according to either of claims 1 or 2, wherein a gap (63) is formed between the cooling path (62) and the coolant conducting element (100), through which gap the coolant flows from the inlet opening (60) to the outlet opening (61) during the cooling process.

4. Electrical machine (400) comprising a housing (50), wherein a cooling system (300) is arranged on an outer peripheral surface of the housing (50), which cooling system is designed according to claim 3.

5. Electrical machine (400) according to claim 4, wherein the electrical machine (400) is designed as an electric motor of a motor vehicle.