ELECTRIC MOTOR

Description

[0001] The invention relates to an electric motor in conjunction with a pump and an electronic component.

[0002] An electric motor and its associated power electronics generate greater or lesser losses during operation depending on the load, resulting in the release of heat. Excessive heating leads to damage to the motor and electronics. To increase the power density of the drive, the designer of a controlled drive regularly seeks suitable measures to dissipate heat from the drive.

[0003] US 2005 0047 933 A1 shows a motor pump in which the pumped medium is passed through a multi-walled pump housing.

[0004] WO 2015 / 195 411 A1 shows an arrangement of the power electronics in a pump housing, which is intended to ensure cooling by means of the pumped medium.

[0005] JP 2007 211 695 A shows the cooling of a heat sink that absorbs the heat of the power electronics and is cooled with a pumping medium.

[0006] GB 2 401 487 A discloses an electrically driven liquid pump assembly. The assembly comprises a liquid pump and an electric motor with an electronic control unit. A cooling channel is provided in the electric motor through which a liquid is pumped from a high-pressure area to a low-pressure area of ​​the pump.

[0007] The object of the invention is to further develop a cooling system for an electric motor in conjunction with power electronics and a pump, which can be manufactured easily and cost-effectively.

[0008] This object is achieved by an electric motor with connected power electronics and a pump, comprising the features of claim 1.

[0009] According to the invention, the cooling system is implemented as a liquid cooling system, with the cooling fluid being provided by the pumped fluid. This has the advantage that the fluid acts as a cooling fluid with a high heat capacity compared to the ambient air typically used when cooled by a fan.

[0010] A coolant channel is provided to guide the coolant in or around the power electronics. This has the advantage of allowing the coolant to be directed to individual components.

[0011] The cooling fluid flows from the pressure-side connection of the pump housing through the coolant channel to the suction-side connection of the pump housing. This causes the cooling fluid to be forced into the coolant channel by the pressure created by the pump, while simultaneously being drawn into the coolant channel by the suction of the pump's suction side. The heated pumped fluid, which served as the cooling fluid, is mixed with the remaining pumped fluid on the suction side of the pump.

[0012] Cooling of the electric motor is provided, with a coolant channel being provided in or on the electric motor. The coolant channel preferably branches off at the bearing plates of the electric motor and—in an embodiment not forming part of the invention—runs as parallel axial channels through the stator housing or is directly adapted to it. In each case, it is necessary to consider the influence of a coolant channel on the electromagnetic properties of the electric motor or the power electronics and the benefits of targeted cooling of specific locations.

[0013] The coolant channels can be interconnected in the two bearing plates, which can also consist of multiple parts. The path of the coolant through individual areas of the drive can be determined during the drive design.

[0014] According to the invention, heat pipes can be provided on components of the power electronics and / or the electric motor that are remote from the coolant channel. These heat pipes are connected to the coolant channel for heat dissipation. This allows for the cooling of specific hot spots, i.e., locations with increased heat input that may not be easily accessible for a coolant channel, with the cold part of the heat pipe being able to dissipate heat into the coolant.

[0015] Furthermore, an actuator for determining the flow rate, in particular a thermostatic valve, is provided in the supply line. This has the advantage that only as much coolant is diverted from the conveying fluid as is required due to the heating of the electric motor or the power electronics.

[0016] In a further embodiment, the suction and pressure-side connections can be retrofitted to existing pump housings using adapters. This has the advantage that a cooling system according to the invention can be retrofitted; in particular, in pumps, adapters can be attached to the nozzles on the suction and pressure sides, which have the connections for branching off the coolant.

[0017] Further features and advantages of the invention will become apparent from the description of embodiments with reference to drawings and from the drawings themselves.

[0018] It shows: The Figure 1 the basic structure of a pump according to the invention in longitudinal section, the Figure 2 a first embodiment of a pump according to the invention in longitudinal section, the Figure 3 an associated cross-section, the Figure 4 a pump not belonging to the invention in longitudinal section, the Figure 5a second, not part of the invention, associated cross-section, the Figure 6 a third, not part of the invention, associated cross-section, the Figure 7 a fourth, not part of the invention, associated cross-section, the Figure 8 a fifth, associated cross-section not belonging to the invention.

[0019] Figure 1shows an electrically driven pump equipped with an electric motor 1 and power electronics 2. The pump can be a centrifugal pump, for example, although other pump types are also possible. The pump shown has a pump housing 3 that is flanged to one of the bearing plates 4 of the electric motor. Furthermore, according to the invention, connections for fluid lines are provided on the pump housing 3, one connection each for the pressure side 5 and the suction side 6. The supply line 7 and the return line 8 of the cooling system are provided at these connections. On the pressure side 5, cold pumping fluid is injected into the coolant channel, and on the suction side 6, the pumping fluid is then fed back into the flow of pumping fluid. The supply line 7 and the return line 8 of the cooling system can be located both inside and outside the pump housing.

[0020] Figure 2shows an axial view of a pump according to the invention with spiral-shaped coolant channels 11, which are directly connected to the supply line 7 and the return line 8. The coolant channel 11 is guided around the electric motor, wherein the coolant channel 11 is arranged on the outside of the housing of the electric motor 1 and / or between the electric motor 1 and the power electronics 2.

[0021] Figure 3 shows a section through the electric motor 1 and the power electronics 2, highlighting the arrangement of the spiral coolant channels 11 in the motor housing 15 around the stator 13. The rotor 14 of the electric motor is also shown schematically. The spiral coolant channel 11 has two connections: supply line 7 and return line 8.

[0022] Figure 4shows - not belonging to the invention - an axial representation of the pump with axial coolant channels 12. In the pump-side A-end shield 4a, the still cool pumping fluid is distributed to the individual areas of the coolant channels 12 via a central cold water collecting ring 9, which is provided on the pressure side 5. In the opposite B-end shield 4b of the electric motor, the coolant flow is redirected and guided via the coolant lines 12 back into the A-end shield 4a, where it is fed to the return line 8 by means of a hot water collecting ring 10. From here, the coolant is fed back to the pumping medium via the suction side 6, whereby, depending on the flow rate, good mixing can already be achieved quickly and easily.

[0023] Figure 5shows a section through the electric motor (not part of the invention) and the power electronics 2 with axial coolant channels 12 in the motor housing 15. Depending on requirements and manufacturability, the coolant channels 12 can be arranged closer to the stator 13 or further away. Here and in the following examples, as shown above, the distribution of the cooling medium can be achieved via special configurations of the line routing in the bearing shields. In particular, the cold and hot water collection rings shown can be used. Corresponding bearing shields can be manufactured using 3D printing processes if required, or alternatively, they can be equipped with pipes located outside the housing.

[0024] Figure 6shows a section through the electric motor - not belonging to the invention - and the power electronics 2 with axial coolant channels 12 partly in the motor housing 15 and / or partly in the motor feet 16 and / or partly in the electronics housing 2. The production of such coolant channels is simple and cost-effective, and in addition, the areas to be cooled are very well thermally connected.

[0025] Figure 7 shows a section through the electric motor (not part of the invention) and the power electronics 2 with axial coolant channels 12, partly in the motor housing 15 and / or partly in the electronics housing 2. Here, too, cooling can be provided where it appears specifically necessary. For example, a control electronics module does not require special cooling, while a power electronics module may require special cooling.

[0026] Figure 8shows a section through the electric motor and the power electronics 2 with axial coolant channels 12 - not belonging to the invention - in the stator 13 of the motor. Reference symbol

[0027] 1 Electric motor 2 Power electronics 3 Pump housing 4 Bearing shield 5 Pressure side 6 Suction side 7 Supply line 8 Return line 9 Cold water collecting ring 10 Hot water collecting ring 11 Spiral coolant channel 12 Axial coolant channel 13 Stator 14 Rotor 15 Motor housing 16 Motor feet

Claims

1. Electric motor (1) having connected power electronics (2) and a pump (3), comprising a pump chamber (3) having a suction-side (6) and a pressure-side (5) connection, and a cooling device of the power electronics (2) and the motor, which cooling device is connected to the pump chamber (3), wherein the cooling device is realized as liquid cooling and the cooling liquid is provided by the delivery fluid delivered by the pump (3), wherein a coolant channel (11) is provided, which is routed around the electric motor (1), wherein the coolant channel (11) is arranged externally on the casing of the electric motor (1) and between the electric motor (1) and the power electronics (2), wherein the cooling liquid runs from the pressure-side connection (5) of the pump casing (3) through the coolant channel (11) to the suction-side connection (6) of the pump casing (3), wherein the connections for fluid lines are provided on the pump casing and the coolant channel (11) has the two connections: supply line (7) and return line (8), wherein the supply line (7) is connected to the pressure-side connection (5) and wherein the return line (8) is connected to the suction-side connection (6), characterized in that the cooling channel (11) is spiral-shaped, wherein heat pipes are provided on components of the power electronics (2) and / or the electric motor (1) which are remote from the coolant channel (11), which heat pipes are connected to the coolant channel (11) for cooling purposes, wherein a control element for establishing the flow rate is provided in the supply line (7) and / or the coolant channel (11).

2. Electric motor (1) according to Claim 1, characterized in that the control element for establishing the flow rate is a thermostat valve.

3. Electric motor (1) according to either of the preceding claims, characterized in that the suction-side (5) and pressure-side (6) connections can be retrofitted on existing pump casings by means of adapters.