Title of Invention | ELECTRIC MOTOR HAVING A CO-AXIALLY ARRANGED PUMP FOR A COOLANT CIRCUIT |
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Abstract | The invention relates to an electric motor (1) having a coaxially arranged pump (6) for a coolant circuit in particular, in a system with temperature transfer or heat transfer. Within housing parts (7, 10) which are configured as a hermetically sealed pressure enclosure, a shaft assembly (5) transmits a torque from the electric motor (1) to at least one impeller (8) which is arranged in the pump housing (7), and a flywheel (12) is arranged between the electric motor (1) and the pump housing (7). All the rotating parts are arranged within a hermetically sealed motor/pump assembly, and the motor/ pump assembly is filled with fluid. Here, the flywheel (12) comprises a flywheel body (13) having a multiplicity of cavities (14, 15) and having heavy-metal inserts (16, 17) which are arranged in the cavities. A heavy metal having a density of greater than 11.0 (kg/dm3) forms the heavy-metal inserts or is arranged therein, and the flywheel body (13) is composed of a high-strength material. |
Full Text | KSB Aktiengesellschaft Description. Electric motor having a coaxially arranged pump The invention relates to an electric motor having a coaxially arranged pump for a coolant circuit, in particular in a system with temperature transfer and/or heat transfer, within housing parts, which are configured as a hermetically sealed pressure enclosure, a shaft assembly transmits a torque from the electric motor to at least one impeller, which is arranged in the pump housing, and a flywheel is arranged between the electric motor and the pump housing, all the rotating parts are arranged within a hermetically sealed motor/pump assembly, and the motor/pump assembly is filled with fluid. In power station systems equipped with heat generators and having temperature transfer and/or heat transfer devices, it is known to use motor/pump assemblies, which are equipped with a flywheel. This is a safety measure in order to be able to guarantee that, in the event of a possible fault, a coolant circulation is maintained through the pump for a minimum time due to the inertia of a flywheel. Due to the moment of inertia of a flywheel, such an electric motor continues to run even when the power has failed, and in doing so the motor/pump assembly pumps a quantity of coolant. Although reduced, such a quantity of coolant is sufficient to guarantee a dissipation of heat in a heat transfer device until the heat generator has been safely switched off. A so-called dry electric motor has been disclosed as a result of US-A 3 960 034 in which the motor and the flywheel are cooled with air. Here, the flywheel is additionally equipped with a protective device in order to prevent possible damage to the environment due to a disintegrating flywheel in the event of overspeeds. However, in the case of motor/pump assemblies without shaft seals, disclosed by DE-C 2 807 876 or US-A 4 084 87 6, there is a hydrodynamic friction resistance due to the motor filled with coolant and due to a flywheel rotating in the coolant. The rotation of the flywheel in the coolant, frequently water, causes a high power loss due to the hydrodynamic friction and the generation of heat energy. This reduces the overall efficiency of pump, motor and flywheel. This motor/pump assembly has a thermal barrier with a thin housing neck between the pump section and the motor section in order to keep the heat conduction between the hot pump housing and the cooled motor housing as low as possible. A flywheel driven by the shaft assembly is located behind the thermal barrier on the face of the motor housing and within a pressure-tight common housing. Furthermore, to reduce the hydrodynamic friction losses, the flywheel is surrounded by a sleeve, which is rotatably mounted in the housing and has inlet openings for the fluid in the motor housing. In operation, the sleeve assumes an average speed, which is less than the speed of the flywheel, due to the hydrodynamic friction surfaces between housing, sleeve and flywheel. This is intended to give rise to a reduction in the friction losses at the flywheel, which is arranged in the cooler motor section. An electric motor in the form of a canned motor for a motor/pump assembly with a flywheel is disclosed by EP 0 351 488 B1 or US-A 4 886 430. The flywheel is designed as a bearing element within the housing part, which forms a pressure enclosure, in the area of a pressure-side pump housing cover of the encapsulated and fluid-filled motor/pump assembly. It undertakes the radial bearing function for the shaft assembly in the area of the pump housing. Furthermore as the flywheel is also designed as an axial bearing, in contrast to the solution according to DE-C 2 807 876, this has enabled an axial bearing arrangement at the end of the motor remote from the pump to be dispensed with. A pot-shaped insert is arranged in the housing between the pump housing and the flywheel absorbing the bearing forces as an integral thermal barrier. It is provided with insulating air chambers on the outside and opposite the pump section. An additional external fluid cooling is arranged on its inside facing the flywheel face. A further wall element absorbing the bearing forces is arranged between the fluid cooling and the face of the flywheel near the pump. Due to the design of the canned motor/pump assembly, the flywheel chamber and the rotor chamber of the electric motor are filled with the pumping fluid to be pumped, and these chambers are at the same pressure as the pump housing, while the stator chamber of the motor is designed to be dry. The motor is enclosed by a heat exchanger, through which the same water flows that lubricates and cools the bearing elements abutting the flywheel. This cooling circulation from the motor, radial and axial bearing as well as the flywheel also flows through the flywheel itself. This therefore weakens the hub/shaft bonding of the flywheel. The invention is based on the problem of achieving an improved solution for motor/pump assemblies equipped with a flywheel, in which the design of a flywheel, its operational safety and also its power loss as a result of hydrodynamic friction are improved. The solution to this problem provides that the flywheel comprises a flywheel body having a multiplicity of cavities and having heavy-metal inserts, which are arranged in the cavities, that a heavy metal having a density of greater than 11.0 (kg/dm3) forms the heavy- metal inserts or is arranged therein, and that the flywheel body is composed of a high-strength material. This solution offers the advantage of easier and better adaptability to different operating situations. By simple selection and arrangement of the cavities, different heavy-metal inserts can be inserted therein. For those applications in which the pumping fluid in the motor/pump assembly can undergo unfavorable reactions with the heavy-metal inserts, means are provided for shielding the heavy-metal inserts against a surrounding fluid. These means can be arranged on the flywheel body. Additionally or alternatively, the inserts are provided with means for separating the heavy-metal inserts from a surrounding fluid. It has been shown to be particularly advantageous when the heavy-metal inserts are designed in the form of a cartridge and fixed in the flywheel body by means, which are known in themselves. In this respect, the inserts can be safely manufactured at an alternative place and are therefore easy to transport and can also be stored. Later, when the machining of a flywheel body is complete, they can be inserted into said flywheel in the simplest manner. The retention of the heavy-metal inserts in the flywheel body can be carried out using technical means, which are known in themselves. These would be welded joints, screwed joints, soldering, gluing, shrink or press joints and the like. The type of joint is chosen depending on the particular operating conditions. It is also possible to design the heavy-metal inserts in the form of filler material placed in the cavities and to retain them there using means, which are known in themselves. This would be a solution for those cases in which the heavy metal is stocked as a pourable, granular material or similar and is to be handled accordingly. According to another embodiment of the invention, it has been shown to be advantageous when the flywheel body does not have a hole for feeding through the shaft assembly. With electric motors having very high drive powers, such as are used in large power stations, very large forces act on such a flywheel. Here, there is a risk that unfavorable hub stresses occur in the area of the transition between flywheel body and shaft assembly starting from a through-hole for a shaft assembly. In the extreme case, for example in overload operation, this can lead to the flywheel body breaking. On the other hand, it is more advantageous to join the flywheel body to the shaft assembly by means of single or multi-part flange joints. This considerably reduces the risk of the flywheel body breaking. The spur gears, which serve to transfer the torque and which form the joining means between flywheel body and shaft assembly, are also advantageous. As the electric motor and the hermetically sealed motor/pump assembly driven thereby are filled with pumping fluid, there is the additional problem here that a flywheel rotating in the fluid also generates a high power loss due to the fluid friction. For economic or safety reasons it can nevertheless be expedient to deliberately leave such a power loss in the area of the flywheel in order to achieve the hermetic sealing and to be able to dispense with the use of shaft seals, which are prone to failure. For this purpose, it is provided that at least one heat exchanger surrounding the outside diameter of the flywheel is arranged within the pressure enclosure and forms a radial wall surface of a flywheel chamber, that a high-pressure zone of the pump chamber is connected by means of one or more flow paths fed over the outside of the heat exchanger to a side of the flywheel chamber remote from the pump, that a ring gap between heat exchanger and flywheel forms a first return flow path between the flywheel chamber remote from the pump and the flywheel chamber near the pump, and that a second return flow path arranged in the area of the shaft assembly connects the flywheel chamber near the pump to the pump chamber. With this solution, a defined high but nevertheless operationally safe temperature is guaranteed in the flywheel chamber. Here, the knowledge is based on the fact that at higher fluid temperatures within the flywheel chamber the power losses occurring here are greatly reduced, as the density of the fluid and its viscosity are reduced as a result of the effect of temperature, and therefore the friction losses are minimized. The arrangement of the heat exchanger on the larger diameter around the flywheel results in a particularly efficient cooling action. An improved cooling action occurs when a pumping fluid taken from the pump chamber flows away via the largest diameter of the heat exchanger and enters the flywheel chamber on the side remote from the pump. The pumping fluid will flow back into the pump chamber via the flow and return flow paths as a result of the pressure gradient in the pump housing between a low pressure at the impeller inlet and a high pressure after the impeller, after a guide device or in a spiral chamber. As there are no holes in the flywheel, the cooled pumping fluid will flow back in the opposite direction through the gap between the outside diameter of the flywheel and the inside diameter of the cylindrical heat exchanger. In doing so, it will additionally and for a second time be subjected to the cooling action of the heat exchanger and at the same time absorbs the lost heat of the flywheel. The pumping fluid leaves the flywheel chamber on the smaller diameter in the area of the shaft assembly and at its other side near the pump. It flows back into the main pump stream through relief holes arranged in the impeller. The pressure difference between the removal opening and the inlet opening in the pump housing can be sufficient for driving this internal fluid flow. The cooling action can be improved in that several heat exchangers surround the flywheel coaxially on the larger diameter, and between these heat exchangers a ring gap or several channels form the flow path to the flywheel chamber remote from the pump. The heat exchanger(s) is/are connected to an external cooling water source and can be designed in the form of a cylinder, for example. In addition, a further embodiment of the invention provides that at least one pumping device driven by the shaft assembly is arranged in the second return flow path. This makes it possible to increase the flow rate of the cooling liquid flow. These can be known means in the form of a small additional impeller, which is provided with holes or blades, a fluid circulation screw or other known devices. According to other embodiments, a motor cover on the pump side forms the wall of the flywheel chamber remote from the pump, and a cooling device is arranged in the motor cover. This cooling device can be designed as a low-pressure cooling device or as a high-pressure cooling device. It is also possible to design this cooling device as part of a high-pressure motor cooling system. In order to reduce mixing, a shaft seal is arranged between motor chamber and flywheel in the area of the shaft assembly. This can be designed as a restrictor section, labyrinth seal or similar. An exemplary embodiment of the invention is shown in the drawings and is described in more detail below. In the drawings Fig. 1 shows a cross section through a motor/pump assembly, Fig. 2 shows a perspective view of a flywheel body and heavy-metal inserts, Fig. 3 & 4 show enlarged views of the flywheel chamber, and Fig. 5 shows a diagram of a temperature distribution at the flywheel. Fig. 1 shows a liquid-cooled motor 1 having a housing 2, which is designed as a pressure enclosure. The inside of the motor 1 is filled with fluid, and a high- pressure cooling system 3 is connected to the ends of the motor in order to dissipate the electrical power loss. A radial and an axial bearing are arranged at the one end of the motor 4, the axial bearing at the same time serving as a pumping device for the cooling water circulating within the motor and through the cooler 3. The driving force of the motor acts on a shaft assembly 5 and thus transmits a torque to a pump 6, which is coaxially arranged with respect to the electric motor 1. An impeller 8 with downstream guide device 9 is arranged within a pump housing 7, and the pump housing 7 is sealed by means of a cover element 10 and connected to the housing 2 of the motor 1 by means of tie rods 11. A flywheel 12, the moment of inertia of which ensures a further rotational movement of the shaft assembly 5 with the connected impeller 8 and therefore a pumping capacity of the pump 6 in the event of a power failure, is located within the cover element 10, which is here designed in several parts. Those housing parts 2, 4, 7, 10 of pump and motor, which define an inner chamber with respect to a surrounding atmosphere, form a so-called pressure enclosure. This is designed for a very high system pressure, which prevails in a heat transfer system, in which this motor/pump assembly is installed for circulating a pumping fluid. As such an assembly is designed for drive powers greater than 600 kW and therefore has a disproportionate size, the representation in Fig. 1 is only of a schematic type. Details are shown in the following Figures 2 and 3 in an enlarged view. Fig. 2 shows a view of a flywheel 12 in perspective. It consists of a flywheel body 13, which is shown in light gray in Figure 2. The flywheel body 13 also has a multiplicity of cavities 14, 15 shown in dark gray. These cavities 14, 15 serve to accommodate heavy-metal inserts 16, 17 with which the moment of inertia of a fully assembled flywheel 12 is increased. The cavities 14, 15 have different diameters, as a result of which it is guaranteed that the flywheel body 13, which is made of a high-strength material, is resistant to the centrifugal forces prevailing during an operation. Due to the arrangement, size and number of the cavities 14, 15, a safe stress characteristic is guaranteed in the flywheel body 13 under the effect of high temperatures. An adequate reserve of strength is therefore ensured even under critical operating conditions, for example in the event of turbine operation caused by an operational fault or overload operation of the pump, as a result of which the speed is higher than the rated speed. A flange joint 19, with which the connection to the shaft assembly 5 is made, is fixed to the face 18 of the cylindrical flywheel body 13. The spur gear 20 shown here acts together with an appropriate design of the shaft assembly 5 to thus guarantee a reliable transmission of torque. Other frictional and/or interlocking forms of connection can also be used. In doing so, however, it should be ensured that these types of connection do not have a negative effect on the stress characteristic within the flywheel body 13. Furthermore, it can be seen from Fig. 2 that correspondingly sized heavy-metal inserts 16, 17 are arranged in the different sized cavities 14, 15. Here, the heavy metal can be arranged as inserts in the form of rods or filler material. The heavy-metal inserts 16, 17 shown here illustrate a variant in which the heavy metal is to be found within a cartridge 21, 22. Such a cartridge is simple to manufacture, easy to handle, to store and to transport, and thus fulfils the requirement for trouble-free stocking of such heavy- metal inserts 16, 17. In addition, such a cartridge 21, 22 protects a heavy metal arranged therein against the effect of the fluid, which surrounds a flywheel 12 for cooling purposes, or vice versa. The sealing of such a cartridge, which in this case is designed in the form of a cylinder, is carried out by means of known techniques, and is possible on normal machine tools. Special machines are not required for this. Such a cartridge 21, 22 can be retained within the flywheel body 13 with the known techniques. It is also possible to design the cavities 14, 15 in the flywheel body 13 as through-holes or blind holes and to arrange a heavy metal directly therein. In order to secure the position of a heavy metal, which is located directly in the cavities 14, 15, the cavities can be sealed by means of individual cover elements or by one large cover element, the size of which corresponds to the diameter of the flywheel. Fig. 3 and 4 show an enlarged view of the arrangement of the flywheel in the shaft assembly and its position between pump and motor. The impeller 8 with a downstream guide device 9 can be seen within the pump housing 6. A single or multi-stage design can be used depending on the type of pump. In the single or last pump stage shown here, a removal pipe can be seen in a zone with the highest pressure within the pump housing 7 - here after the guide device 9. This is used as flow path 23 for a pumping fluid and guides this within the pressure enclosure into the flywheel chamber 24. A pump cover 10 and a motor cover 25 near the pump form the flywheel chamber 24. The pressure and fluid-tight contact surface 26 of the two cover parts 10, 2 5 lies in the area of a face 18 of the flywheel 12 remote from the pump. The two-part flywheel housing so formed makes manufacture and assembly easier. All parts are held together by tie rods 11, which are screwed into the pump housing 7 and find their counter support in a flange of the motor housing 2. A heat exchanger 27, which surrounds the flywheel 12 and which is connected to a low-pressure cooling system A-B which penetrates the pressure enclosure, is arranged within the flywheel chamber 24. The flow path 23 connecting the pump inner chamber to the flywheel chamber 24 carries a pumping fluid over the outside 28 of the heat exchanger 27 to the side of the flywheel chamber 24 remote from the pump. A further low-pressure cooling system C-D is arranged at the face of the flywheel chamber 24 remote from the pump in the area of the motor cover 25, with the help of which an appropriate temperature gradient is achieved in the area of the face 18 of the flywheel remote from the pump. Furthermore, it can be seen that the motor cover 25 has a connector for a high-pressure motor cooling system E, which is connected to the motor cooler 3. The arrows show the direction of flow of the motor cooling fluid around the stator end windings. At the same time, they serve as lubricating fluid for the motor bearing 3 0 near the pump. The heated motor cooling fluid is removed via channels 31 in the motor cover 25 and cooled down by means of the motor cooler 3 shown in Fig. 1 and fed into the motor 1 once more at the motor cover 4 remote from the pump. Pumping fluid entering the flywheel chamber 24 at its end remote from the pump flows through a ring gap 32 between the inside 33 of the heat exchanger 27 and the outside diameter of the flywheel 12 to the flywheel chamber 24.1 near the pump. This ring gap 32 forms a first return flow path for the pumping fluid, which is simultaneously subjected here to the effect of the heat exchanger 27. It flows via the flywheel chamber 24.1 near the pump to the face 34 of the flywheel 12 near the pump towards the shaft assembly 5. From the area of the shaft assembly 5, it flows back via the second return flow path arranged there to the impeller 8 of the pump 6. In doing so, a pump bearing 35 is lubricated at the same time. The direction of flow is determined by the pressure gradient between the high- pressure zone in the pump housing 7 and the lower- pressure zone in the area of the impeller 8, which is defined by the axial thrust relief openings 36. When designing such a motor/pump assembly, the size and number of flow paths is determined for the specified operating conditions in order to achieve a basic setting for the cooling pumping fluid for the appropriate powers. It is also possible to provide an additional pumping device 37 in the area of the second flow path, which is driven by the shaft assembly 5. In this exemplary embodiment, a fluid circulation screw is shown, but it could equally well be an appropriate impeller or other known auxiliary pumping device 37. This can improve the cooling performance of the pumping fluid circulating in the flywheel chamber 24, 24.1. The lost heat produced by the flywheel 12 due to the hydrodynamic friction in the fluid is thus dissipated in an extremely effective manner by mass transport. Due to the specific guidance of the internal cooling flow from the pump chamber to the flywheel chamber 24, 24.1, the temperature level in the flywheel chamber and also within the flywheel 12 can be influenced such that a homogenous temperature level develops during operation. The development of the homogenous temperature level in the flywheel 12 is assisted by the heat exchanger performance at the outer circumference of the flywheel 12 and the cooling action at the face 18 of the flywheel remote from the pump. Controlling this heat exchanger performance enables the homogeneity of the temperature level to be maintained. This has the decisive advantage that material stresses caused by temperature differences are prevented within the flywheel 12. With this solution, heat can even be fed back into the pump circuit for that operating condition in which the temperature level in the flywheel chamber is higher than the temperature level of the pumping fluid. By this means, it is possible to partially recover the lost heat. In any case, however, the temperature in the flywheel chamber 24, 24.1 is limited to a maximum, which does not have a negative effect on the strength of the flywheel body. Fig. 4 shows a variant of Fig. 3 in which only the lower-pressure cooling system C-D in the area of the face 8 of the flywheel 12 remote from the pump has been dispensed with. Instead of this, the high-pressure motor cooling system E is used simultaneously to also affect the temperature level in the flywheel chamber 24. Depending on the specified operating conditions of such a motor/pump assembly, the necessary homogenous temperature level in the flywheel 12 is also ensured with this solution. The wall 29 of the flywheel chamber 24 remote from the pump, formed by the pump-side motor cover 25, is here subjected to the high-pressure motor cooling system E with the help of a connection 39. A shaft seal 38, which reduces mixing of the fluids, is arranged in the area of the wall 25. A first locus σA, which shows a determining strength characteristic of the material of the flywheel body as a function of temperature, is illustrated in the diagram of Fig. 5. This strength characteristic, for example 80% of the elastic limit, includes an adequate safety margin with respect to material failure. The overall efficiency of the motor/pump assembly is plotted against temperature in a second locus nges. The temperature corresponds to that, which can prevail in the flywheel chamber. The point of intersection A of the two loci corresponds to the operating point of the motor/pump assembly with all cooling systems operating. The optimum operating temperature Topt prevails at this point A. Here, a homogenous temperature level Topt is established in the flywheel chamber and in the flywheel. In addition, this operating point A has a further high safety margin S compared with those operating conditions in which a failure of an external cooling system was expected. If such a condition occurs in which one or more external cooling systems fail, which constitutes a fault situation, then because of the internal fluid friction within the flywheel chamber the temperature will rise and establish itself at a maximum temperature T0. The consequence of such a temperature rise is that the viscosity of the pumping fluid reduces as a result of the increasing temperature, and therefore the power loss in the flywheel chamber decreases. As a result of this, the overall efficiency nges of the motor/pump assembly increases. The negative effect of a temperature rise, however, is a reduction in the material strength of the flywheel body to a lower value aL at the temperature T0. This gives rise to a fault situation operating point B in the flywheel chamber at the higher temperature level T0 in the event of a failure of an external cooling. The strength of the flywheel body is still guaranteed at this operating point B, however, due to the remaining 20% elastic limit reserve in this example. The shaded area C on the right in the diagram adjacent to the fault situation operating point B denotes an inadmissible operating range. As a result of deliberately forgoing an improvement in the overall efficiency nes, a significant improvement in the operational safety is achieved. Safe operation of the motor/pump assembly is still guaranteed even in the event of a failure of an external cooling device. Even then, there is no fear that the flywheel will fail due to inadmissible stress conditions in the material of the flywheel body. Consequently, this enables elaborate protection devices for the flywheel to be dispensed with, which leads to a significant cost reduction and an increase in the operational safety of such a motor/pump assembly. CLAIMS 1. An electric motor (1) having a coaxially arranged pump (6) for a coolant circuit, in particular in a system with temperature transfer and / or heat transfer, wherein within housing parts (7, 10), which are configured as a hermetically sealed pressure enclosure, a shaft assembly (5) transmits a torque from the electric motor (1) to at least one impeller (8), which is arranged in the pump housing (7), and a flywheel (12) is arranged between the electric motor (1) and the pump housing (7), all the rotating parts are arranged within a hermetically sealed motor/ pump assembly, and the motor / pump assembly is filled with fluid, characterized in that the flywheel (12) comprises a flywheel body (13) having a multiplicity of cavities (14, 15) and having heavy-metal inserts (16, 17), which are arranged in the cavities (14, 15), that a heavy metal having a density of greater than 11.0 (kg/ dm3) forms the heavy-metal inserts (16, 17) or is arranged therein, and that the flywheel body (13) is composed of a high-strength material. 2. The electric motor as claimed in claim 1, wherein the means are arranged for shielding the heavy-metal inserts (16,17) against a surrounding fluid. 3. The electric motor as claimed in claim 1 or 2, wherein the heavy-metal inserts (16, 17) are designed in the form of a cartridge (21, 22) and fixed in the flywheel body (13) by means, which are known in themselves. 4. The electric motor as claimed in claim 1 or 2, wherein the heavy-metal inserts (16, 17) are designed in the form of filler material placed in the cavities (14, 15) and are retained in the flywheel body (13) using means, which are known in themselves. 5. The electric motor as claimed in one of claims 1 to 4, wherein the flywheel body (13) does not have a hole for feeding through the shaft assembly (5). 6. The electric motor as claimed in one of claims 1 to 5, wherein the flywheel body (13) is joined to the shaft assembly (5) by means of single or multi-part flange joints (19, 20). 7. The electric motor as claimed in one of claims 1 to 6, wherein spur gears (20) from the joining means between flywheel body (13) and shaft assembly (5). 8. The electric motor as claimed in the pre-characterizing clause of claim 1, characterized in that at least one cylindrical heat exchanger (27) surrounding the outside diameter of the flywheel (12) is arranged within the pressure enclosure and forms a radial wall surface of a flywheel chamber (24), that a high-pressure zone of the pump chamber is connected by means of one or more flow paths (23) fed over the outside of the exchanger (27) to a side of the flywheel chamber (24) remote from the pump, that a ring gap (32) between heat exchanger (27) and flywheel (12) forms a first return flow path between the flywheel chamber remote from the pump and the flywheel chamber (24. 1) near the pump, and that a second return flow path arranged in the area of the shaft assembly (5) connects the flywheel chamber (24.1) near the pump to the pump chamber. 9. The electric motor as claimed in claim 8, wherein several cylindrical heat exchangers (27) surround the flywheel (12) coaxially, and between the heat exchangers (27) a ring gap or several channels from the flow path to the flywheel chamber (24) remote from the pump. 10. The electric motor as claimed in claim 8 or 9, wherein at least one pumping device (37) is arranged in the second return flow path, which pumping device is driven by the shaft assembly (5). 11. The electric motor as claimed in one of claims 1 to 10, wherein the cylindrical heat exchanger (27) is connected to an external cooling water source (A-B). 12. The electric motor as claimed in one of claims 1 to 11, wherein a motor cover (25) on the pump side forms the wall (29) of the flywheel chamber (24) remote from the pump, and that a cooling device (C-D, F) is arranged in the motor cover (25). 13. The electric motor as claimed in claim 12, wherein the cooling device (C-D) is designed as a low-pressure cooling device. 14. The electric motor as claimed in claim 12, wherein the cooling device (E) is designed as a high-pressure cooling device. 15. The electric motor as claimed in one of claims 11 to 14, wherein the cooling device is designed as part of a high-pressure motor cooling system. 16. The electric motor as claimed in one of claims 1 to 15, wherein a shaft seal is arranged between motor chamber and flywheel in the area of the shaft assembly. ABSTRACT ELECTRIC MOTOR HAVING A CO-AXIALLY ARRANGED PUMP FOR A COOLANT CIRCUIT The invention relates to an electric motor (1) having a coaxially arranged pump (6) for a coolant circuit in particular, in a system with temperature transfer or heat transfer. Within housing parts (7, 10) which are configured as a hermetically sealed pressure enclosure, a shaft assembly (5) transmits a torque from the electric motor (1) to at least one impeller (8) which is arranged in the pump housing (7), and a flywheel (12) is arranged between the electric motor (1) and the pump housing (7). All the rotating parts are arranged within a hermetically sealed motor/pump assembly, and the motor/ pump assembly is filled with fluid. Here, the flywheel (12) comprises a flywheel body (13) having a multiplicity of cavities (14, 15) and having heavy-metal inserts (16, 17) which are arranged in the cavities. A heavy metal having a density of greater than 11.0 (kg/dm3) forms the heavy-metal inserts or is arranged therein, and the flywheel body (13) is composed of a high-strength material. |
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00221-kolnp-2008-correspondence others.pdf
00221-kolnp-2008-description complete.pdf
00221-kolnp-2008-international publication.pdf
00221-kolnp-2008-international search report.pdf
00221-kolnp-2008-pct priority document notification.pdf
221-KOLNP-2008-(13-12-2012)-ABSTRACT.pdf
221-KOLNP-2008-(13-12-2012)-AMANDED PAGES OF SPECIFICATION.pdf
221-KOLNP-2008-(13-12-2012)-ANNEXURE TO FORM 3.pdf
221-KOLNP-2008-(13-12-2012)-CLAIMS.pdf
221-KOLNP-2008-(13-12-2012)-CORRESPONDENCE.pdf
221-KOLNP-2008-(13-12-2012)-DESCRIPTION (COMPLETE).pdf
221-KOLNP-2008-(13-12-2012)-DRAWINGS.pdf
221-KOLNP-2008-(13-12-2012)-FORM-1.pdf
221-KOLNP-2008-(13-12-2012)-FORM-2.pdf
221-KOLNP-2008-(13-12-2012)-FORM-5.pdf
221-KOLNP-2008-(13-12-2012)-OTHERS.pdf
221-KOLNP-2008-CANCELLED PAGES.pdf
221-KOLNP-2008-CORRESPONDENCE OTHERS 1.1.pdf
221-KOLNP-2008-CORRESPONDENCE OTHERS 1.2.pdf
221-KOLNP-2008-CORRESPONDENCE-1.1.pdf
221-KOLNP-2008-CORRESPONDENCE-1.2.pdf
221-KOLNP-2008-CORRESPONDENCE-1.3.pdf
221-KOLNP-2008-EXAMINATION REPORT.pdf
221-KOLNP-2008-FORM 18-1.1.pdf
221-KOLNP-2008-FORM 26-1.1.pdf
221-KOLNP-2008-GRANTED-ABSTRACT.pdf
221-KOLNP-2008-GRANTED-CLAIMS.pdf
221-KOLNP-2008-GRANTED-DESCRIPTION (COMPLETE).pdf
221-KOLNP-2008-GRANTED-DRAWINGS.pdf
221-KOLNP-2008-GRANTED-FORM 1.pdf
221-KOLNP-2008-GRANTED-FORM 2.pdf
221-KOLNP-2008-GRANTED-FORM 3.pdf
221-KOLNP-2008-GRANTED-FORM 5.pdf
221-KOLNP-2008-GRANTED-SPECIFICATION-COMPLETE.pdf
221-KOLNP-2008-INTERNATIONAL PRELIMINARY REPORT.pdf
221-KOLNP-2008-INTERNATIONAL PUBLICATION.pdf
221-KOLNP-2008-INTERNATIONAL SEARCH AUTHORITY REPORT 1.1.pdf
221-KOLNP-2008-INTERNATIONAL SEARCH REPORT & OTHERS.pdf
221-KOLNP-2008-PCT REQUEST.pdf
221-KOLNP-2008-REPLY TO EXAMINATION REPORT.pdf
221-KOLNP-2008-TRANSLATED COPY OF PRIORITY DOCUMENT.pdf
Patent Number | 257858 | |||||||||||||||
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Indian Patent Application Number | 221/KOLNP/2008 | |||||||||||||||
PG Journal Number | 46/2013 | |||||||||||||||
Publication Date | 15-Nov-2013 | |||||||||||||||
Grant Date | 12-Nov-2013 | |||||||||||||||
Date of Filing | 16-Jan-2008 | |||||||||||||||
Name of Patentee | KSB AKTIENGESELLSCHAFT | |||||||||||||||
Applicant Address | JOHANN-KLEIN-STRASSE 9 67227 FRANKENTHAL | |||||||||||||||
Inventors:
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PCT International Classification Number | F04D 29/04 | |||||||||||||||
PCT International Application Number | PCT/EP2006/006644 | |||||||||||||||
PCT International Filing date | 2006-07-07 | |||||||||||||||
PCT Conventions:
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