SI20172A - Liquid-cooled electric machine - Google Patents

Abstract

The invention seeks to create an electric machine with a cooling element, which enables an optimal economical design of said machine. The machine comprises a stator (1) and a rotor (2). The stator (1) has a winding (3) and is enclosed by a double-walled machine housing (4) for a liquid-surface cooling. The end shields (5) and the bearings (6) delimit the machine laterally. In this jacket cooling, cooling liquid is fed via the connectors (13). In addition, a cooling pipe (14) is fitted inside the machine, in the region of the winding (3) of the stator (1), in particular parallel to the faces of the winding (3) heads. The cooling pipe (14) can be connected with the jacket cooling via connectors (15) on configuration of the jacket cooling. The invention innovatively enables heat loss produced by the rotor winding or the stator winding to be carried directly to the exposed areas. This results in increased exploitation potential of the machine, which in turn enables smaller construction dimensions of the machine under certain circumstances.

Description

Liquid-cooled electric machine

The invention relates to an electrical machine consisting of a stator, a rotating shaft with a rotor rigidly attached thereto, and a housing in which the stator is attached, and having a housing on either side of a bearing end plate with a bearing through which the shaft, and the housing and / or shaft is liquid cooled if necessary.

Electric machines of the above type generate heat due to losses, which are mostly necessary to remove. This can be done by cooling with fresh air, distinguishing between automatic cooling with air movement or radiation without the aid of a fan, automatic ventilation with a fan attached to the rotor or driven by it, and external cooling. The effect of automatic cooling and self-cooling depends on the rotational speed of the machine, and the external cooling is independent of this. It is also possible to indirectly cool the liquid by means of fluid circulating within the walls of the housing, which is also independent of the rotational speed. Furthermore, rotor shaft cooling is known, e.g. with a high speed electric machine. In addition, a further method of cooling is known, circuit cooling in which a refrigerant, e.g. air, hydrogen, or the like, flows in the circuit through the machine and through the proper cooler. Circulating cooling can be stated as depending on the rotational speed or as independent of the rotational speed.

There are also machine types where certain types of refrigeration cannot be used for construction reasons. This occurs, for example. for sliding ring rotors with high rotor losses. However, with this type of machinery, shaft cooling is only regularly complicated, if at all possible, because shaft cooling requires a sliding ring portion of the shaft. In order to cope with the rotor heat loss now, the machine had to be over-dimensioned.

It is an object of the invention to make an electric machine of the type mentioned above, which exhibits cooling, which enables the best design of the machine economically.

The electrical machine according to the invention is characterized by the fact that at least one coolant coolant pipe is installed in the inner space of the housing near the winding provided in the stator and / or in the bearing area. By the invention, it is possible, for the first time, to direct the heat of losses caused by the rotor and / or rotation in exposed places. stator winding. This ensures that the utilization of the machine can be increased appropriately, which again allows the construction of smaller machines under certain conditions.

Installing a cooling pipe in the bearing area is a viable alternative to shaft cooling. In view of this, the installation of a cooling pipe in the area of the front sides of the threaded heads of the stator winding is an alternative to cooling the surface of the housing. Of course, all variations are possible.

According to a further feature of the invention, the cooling tube has ribs on its surface. By increasing the cooling surface, an improvement in efficiency is to be achieved. In a particular embodiment of the invention, the cooling tube is parallel and / or concentric to the front faces of the threaded heads in the stator of the intended winding. As mentioned earlier, the front or front. only the threaded head area is most suitable for extracting heat losses from active parts of the machine. With cooling pipe or. with a preparation similar to a cooling snake, this is easily possible.

According to a further embodiment of the invention, the cooling tube is arranged parallel and / or concentrically with respect to the shaft bearing. This area is also well-suited for the extraction of heat generated from shaft losses. In addition, it is worth trying to keep the bearing area from overheating.

According to a further feature of the invention, the cooling tube is connected to the cooling of the housing surface and / or to the cooling of the shaft. As the cooling of the internal space of the machine can be established with the help of the cooling pipe as a real alternative to the possible cooling of the shaft, but also the liquid cooling of the surface of the housing, the coolant for cooling the shaft or the cooling fluid can be advantageously used. for surface cooling also use for cooling pipe. The cooling pipe connections may be connected directly to the corresponding cooling circuit.

The invention will be explained in more detail by way of the embodiment illustrated in the drawing.

FIG. 1 shows a section through an electrically rotating machine and FIG. 2 cooling pipe.

According to FIG. 1 is an electric rotating machine a three-phase asynchronous machine, in this embodiment, with a rotor with a sliding ring. Such a machine can be e.g. used as a generator in windmills or windmills. wind turbine plants. The machine consists of a stator 1 and a rotor 2. The stator 1 has a winding 3 and is enclosed by machine casings 4, with machine ends resting on the sides 5 with bearings 6. The machine housing 4 is made double-skinned for liquid surface cooling.

In bearings 6, the shaft 7 of the rotor 2 is mounted. In addition, on one side of the machine, the shaft 7 is guided through the bearing end plate 5 and sliding rings 8 are provided at the extended end of the shaft. The sliding rings 8 are provided with a cover 9 that is attached to the bearing. end plate 5, wherein a cover box may also be provided on the cover 9.

The rotor 2 consists of layered rotor plates 10, with these mounted on the shaft

7. This rotor 2 has a winding 11 of a rotor with a sliding ring which is guided to the sliding rings 8 through the holes 12 in the shaft 7.

As mentioned above, the case 4 of the machine is double-sided for liquid cooling. In this case cooling coolant is supplied through the terminals 13. In addition, a cooling tube 14 is provided in the interior of the machine, which is located in the stator winding area 3, in particular parallel to the front faces of the winding winding heads 3. This cooling tube 14 may be connected to the cooling jacket via the cooling 15 through the case 15. . However, it is entirely within the scope of the invention to provide for its own coolant connections.

For a type of machine with a rotor with a slip ring, it is advisable not to provide for cooling of the shaft due to the structure of the slip ring. As a real alternative to this, it is possible to install a cooling tube 16 near the bearings 6. As shown above, the cooling tube 16 may be connected to the cooling jacket or via cooling ports 16. own connections could be provided.

It is, however, within the scope of the invention that the cooling pipes are 14 or. 16 When shaft cooling is present, they connect via shaft connections to the shaft cooling.

According to FIG. 2 is a 14 oz cooling tube. 16 provided with ribs on its surface to increase the surface area. As a material for the cooling tube 14 oz. 16 is provided e.g. aluminum or also stainless materials. Of course, the decision on the cooling pipe material is 14 oz. 16 depends on the refrigerant used.

Claims (3)

Patent claims An electric machine existing from a stator (1), a rotating shaft (7) with a rigidly mounted rotor (2) and a housing (4) in which the stator (1) is attached, and the housing (4) shows on both sides a bearing end plate (5) with a bearing through which the shaft (7) is mounted and, if necessary, the housing (4) and / or the shaft (7) is liquid cooled, with the inner space of the housing close to the winding (3), which provided in the stator (1), a cooling tube is arranged concentrically with respect to the front face of the threaded heads, characterized in that the cooling pipe (14) is arranged parallel to the front faces of the threaded heads in such a way that it essentially forms the first open ring so that In the area of the bearing (6), a further cooling tube (16) is mounted in parallel and concentrically with respect to the bearing of the shaft (7) and essentially forms a second open ring and the rings show different diameters. Electric machine according to claim 1, characterized in that the cooling tube (12, 16) exhibits ribs (18) on its surface. Electric machine according to claim 1 or 2, characterized in that the cooling pipes (14, 16) are connected to the cooling of the housing surface and / or to the cooling of the shaft.