EP1132623B1 - Submersible motor pump unit - Google Patents

Description

The invention relates to a motor assembly for a submersible pump unit with the features specified in the preamble of claim 1.

Motor assemblies of this type are used for submersible pump assemblies which have a slender and substantially cylindrical shape and are adapted to the given narrow bore hole dimensions. Such submerged pump units are known, for example, from the closest prior art of Technick DE 3642727 A1 or also from DE 38 20 005 C1 or EP 0 346 730 B1. In these submersible pump units, a frequency converter is integrated, which makes it possible to drive the pump unit substantially independent of the frequency and voltage of the electrical supply network high speed and thus to achieve a high flow rate even with a relatively small pipe diameter or aggregate diameter.

A certain problem with such units, which have a built-in frequency converter, it is regularly to dissipate the heat generated in the power section of the frequency converter heat loss. In the case of the pumps according to the prior art mentioned at the beginning, this takes place via the pumped medium, in which a partial flow is formed within the unit, which is used essentially to dissipate the heat generated in the frequency converter. The design-related expenses required for this purpose are quite high, which is why it is now also transferred to dissipate the heat not to the pumped liquid, but to the housing of the unit, as this large area with the surrounding fluid is connected and therefore particularly predestined for the removal of this heat loss.

A problem, however, is to dissipate the heat loss to the usually formed from sheet metal housing or the housing shell. In DE 197 27 202 A1, this is done by assigning to the heat generating assemblies of the frequency converter elastic cushions which are filled with a thermally conductive agent and which release the heat from the corresponding assembly via the pad to an inner housing or inner shell, in turn is inserted into the formed from sheet metal housing jacket. Although this design has proven its worth, but manufacturing technology is quite expensive, since a dimensionally stable inner casing is required, on which the heat-conducting cushion can be supported to allow an intense heat transfer. This inner housing is made of light metal profiles and inserted as a whole together with the assemblies therein in the metallic housing shell. The latter can also be problematic because to achieve a large heat dissipation as close as possible investment of the inner housing on the housing shell is required, which leads to high forces during insertion or pressing of the inner housing in the housing shell. Since the housing shell is a sheet metal part that is not machined, are, albeit minor, misalignment over the length of the housing can not be completely ruled out, which can lead to significant problems during insertion of the inner housing in the jacket.

Before this state of the art, the invention has the object, a generic engine assembly so educate that it can be produced inexpensively, especially in mass production and the pre-recorded mounting problems are avoided.

This object is achieved according to the invention by the features specified in claim 1. Advantageous embodiments are the subclaims as well as the following description and the drawing.

The basic idea of the present invention is to dispense with the heat-conducting contact between the inner casing and the casing casing and instead to provide one or, if required, a plurality of heat distributors, which deliver the heat directly to the casing casing. To achieve this, the heat spreaders are adapted in their outer contour of the inner contour of the housing shell, so that they rest over substantially its entire circumference on the housing shell and thus grant a large-scale heat transfer. Since a heat-conducting system is required only in the area of the heat spreader, the remaining parts of the drawer can be designed freely. So can be largely dispensed with an inner housing or this made of plastic or other materials. In addition, these other insertion parts can be arranged with play within the housing shell, which facilitates the assembly, since upon insertion, only the friction between the heat spreader and the heat spreaders and the housing is overcome.

Preferably, the heat spreader, which is heat-conducting connected to the first component, ie the component which includes the power section of the frequency converter, arranged at the motor end of the frequency converter. Under power unit is not necessarily only the power circuit, but possibly also to understand the power electronics of the input circuit. This results in short cable connections from the power unit to the motor. In addition, the line connection can then be formed in a particularly advantageous embodiment of the invention by the first component itself.

If due to the size or other requirements require additional components of the frequency converter of a separate cooling, it is expedient to provide a further heat spreader, which is also in the Substantially rests against the housing shell over its entire circumference and its outer contour corresponds substantially to the inner contour of the housing shell. Advantageously, when providing a plurality of heat spreaders these are not arranged directly one behind the other, but with a clear distance from each other to facilitate the assembly of the insert. In one embodiment, which provides two heat spreaders, they are advantageously arranged at both ends of the insert, wherein the heat spreader for the first component, that is expediently arranged adjacent to the engine for the power unit.

The first heat spreader for the power unit expediently has a transverse wall, against which the first component bears in a planar and thermally conductive manner in order to ensure heat dissipation towards the housing jacket. This transverse arrangement of the first unit offers particular advantages, which are described in detail below.

In addition to the first component, which is usually formed as a semiconductor component or Umgossener semiconductor device is still free in particular in the coils of the frequency converter heat, which is dissipate. These coils of the frequency converter are preferably incorporated in each case in an axial recess of a heat spreader heat-conducting. Thus, for example, in the heat spreader for the power section on the other side of the transverse wall by providing such an axial recess also a coil can be incorporated.

The component forming the intermediate circuit, which may possibly also comprise the input circuit or parts of the input circuit, and the control electronics (this is to be understood control electronics in a broader sense, including the components required for the control) are advantageously arranged on boards, which are located in Lengthwise extend the engine assembly. Conveniently, a respective circuit board is provided for each of the two components. The boards are arranged approximately parallel and one above the other. This arrangement has the particular advantage in that all line connections between the first component and the second component, between the second and the third component and between the first component and the third component can be formed by the first component itself. Such an arrangement is particularly favorable in terms of production and assembly since a large part of the line connections within the frequency converter can be formed by the first component, which considerably reduces the number of assembly steps. In addition, the reliability is improved by such an arrangement, since the number of solder or connectors can be reduced to a minimum. Preferably, these outgoing from the first component line connections are formed by sheet metal sections which are mechanically connected and held together by a Kunststoffvergusskörper, as will be described in detail with reference to the embodiment. This Kunststoffvergusskörper is advantageously used for attachment of the first component to the heat spreader. It can enclose or also completely accommodate the semiconductor element comprising the power section of the frequency converter.

The invention is explained in more detail with reference to an embodiment shown in the drawing. The figure shows a greatly simplified exploded view of a part of the structure of a motor assembly according to the invention.

Not shown for reasons of clarity is formed of sheet metal cylindrical housing shell, which accommodates all components shown in the figure and, moreover, does not differ from the known Gehäusemänteln for units of this kind from the design principle.

The motor assembly has a motor, the stator 1 is visible in the figure bottom left. The associated rotor is not shown for reasons of clarity. At this stator is followed on the side facing away from the drive shaft, a first heat spreader 2, which has the same circular outer contour as the stator 1 and in alignment with this in the (not shown) housing shell is pressed. The heat spreader 2 has a substantially cylindrical shape and has, on the side facing the stator 1, a recess 3 which has a substantially round cross-section and is delimited by a transverse wall 4 in its axial extent. This recess 3 has a longitudinal groove 5, which passes through the transverse wall 4 in the form of a substantially rectangular opening. The recess 3 is provided for receiving a coil 6, which is pressed into this recess 3 such that a good heat transfer from the coil 6 to the heat spreader 2 takes place. It is a coil for reactive current compensation. Electrically connected to this coil 6 via two terminals 7, which are performed by the longitudinal groove 5, the transverse wall 4 enforce and on the side facing away from the stator 1 of the heat spreader 2 are led out. The heat generated in the coil 6 is delivered to the heat spreader 2, which is pressed into the (not shown) consisting of sheet metal cylindrical housing shell and with substantially its entire peripheral surface is thermally conductive with this housing shell in connection.

On the side facing away from the stator 1 of the heat spreader 2, a relatively shallow depression in the end face of the heat spreader is provided, which is bounded by the transverse wall 4. This recess is provided for receiving a first component 8, which includes the power section of the frequency converter. This component 8 comprises the six power switches, the freewheeling diodes and the braking resistors. These are integrated in a common discrete component in the form of a semiconductor device. The electrical leads and terminals of this semiconductor device are formed by stamped or otherwise manufactured sheet metal sections, which are held in a common potting body 10 and mechanically connected to each other. The potting body 10 surrounds the semiconductor component 9 and fixes the lines or connections of the first component 8 formed by the sheet metal sections. This potting body 10 simultaneously serves for fastening of the semiconductor device 9 on the heat spreader. For this purpose, 10 bores 11 are provided in the potting body, which are penetrated by (not shown) stud bolts formed of light heat spreader 2 and are deformed after the incorporation of the component 8 in the heat spreader 2 to a rivet head, the component 8 with the form-fitting Heat spreader 2 connects. Then the semiconductor component 9 lies flat on the transverse wall 4 of the heat spreader 2.

The first component 8 has connections 1 directed towards the stator 1, which are bent away from the plane of the semiconductor component 9 by 90 ° and are also enclosed by the potting body 10 in this bent region. These connections 12 with the surrounding part of the potting 10 are guided over the longitudinal groove 5 to the stator 1, so connect the power unit directly to the stator 1 of the motor.

Curved at 90 ° from the plane of the semiconductor device 9 in the direction facing away from the stator 1 are lines whose upwardly directed ends form terminals 13, which comprises the power unit comprising the first component 8 with a second, the input and intermediate circuit of the frequency-forming component 14 connect. The second component 14 is constructed on a circuit board 15, whose components are arranged in the illustration according to the figure on the underside. The terminals 13 may be formed either as plug-in connections or as solder terminals for electrical connection to this board 15.

As is apparent from the figure, the terminals 7 of the coil 6 are designed so that they are in the assembled state in the region of the terminals 14, whereby this coil 6 with the circuit board 15 and thus with the second component 14 is conductively connected. The board 15 extends, as can also be seen from the figure, substantially in the longitudinal direction of the motor assembly.

Parallel to the board 15, but arranged below it, a third, the control and regulating circuit of the frequency converter exhibiting component 16 is provided, which also has a circuit board 17. The board 17 also carries the electronic components on the bottom side in FIG. The electrical connection of this third component 16 via terminals 18, which are formed in the same manner as the terminals 13, but on the underside of the first component 8. About the first component 8, therefore, the second component 14 and the third component 16 are line connected.

The electrical supply takes place via the second component 14, which has at the side facing away from the first heat spreader 2 side corresponding (not shown) line connections. On this side, a coil 19 is electrically connected to the circuit board 17. However, the coil itself is not disposed on the board 17, but next to it and is seated in a recess 20 of a second heat spreader 21, which is also pressed into the housing shell and rests with its entire outer periphery of this for the purpose of heat conduction. The coil 19 is incorporated into the heat-conducting recess 20 in order to deliver the heat generated there via the heat spreader 21 to the housing shell and thus the surrounding fluid. The coil 19 is an EMC coil.

The boards 15 and 17 are each incorporated and supported in half-shells 22 and 23, which are made of plastic and form a substantially cylindrical inner housing, incorporating the aforementioned boards, but whose diameter is slightly smaller than that of the housing shell, so that this section to friction can be inserted into the housing shell. The visible in the figure bracket 24 are used for grounding, since the inner housing is not conductive. The half-shells 22 and 23 form an inner housing, which forms with the heat spreader 2 on the side facing the stator 1 and with the heat spreader 21 on the side facing away from the stator 1, a plug-in unit which is pressed as a whole into the housing jacket. Because this unit only at the ends, namely in the region of the heat spreader 2 and 21 rests thermally conductive on the housing shell, the press-in operation with relatively little effort is possible because any misalignment of the housing shell are compensated by the intervening game of the inner housing. The connection line to the mains connection is passed through the heat spreader 21 and that to the motor through the heat spreader 2. The above-described plug-in unit is constructed with a minimum of components and in particular suitable for the production and automatic assembly in medium and large series production.

LIST OF REFERENCE NUMBERS

1 -

stator

2 -

first heat spreader

3 -

recess

4 -

partition

5 -

longitudinal groove

6 -

Kitchen sink

7 -

Connections for coil

8th -

first component

9 -

Semiconductor device

10 -

potting

11 -

drilling

12 -

Connections to the engine

13 -

Connections to the second component

14 -

second component

15 -

Board of the second component

16 -

third component

17 -

Board of the third component

18 -

Connections to the third component

19 -

Kitchen sink

20 -

recess

21 -

second heat spreader

22 -

upper half shell

23 -

lower half shell

24 -

hanger

Claims (13)

1. A motor construction unit for a submersible pump assembly, with an electric motor (1) and a frequency converter connected in series, which are arranged in a common housing casing round in cross section, wherein the frequency converter as an insert is arranged axially flush to the motor (1) and consists at least of a first component (8) containing the power part, of a second component (14) containing at least the intermediate circuit and of a third component (16) comprising the control electronics, and wherein at least the first component (8) via a heat distributor (2) is connected to the housing casing in a heat-conducting manner, characterised in that at least one heat distributor (2, 21) is provided, which essentially over its whole periphery bears on the housing casing, and whose outer contour essentially corresponds to the inner contour of the housing casing.
2. A motor construction unit according to claim 1, characterised in that the heat distributor (2) which is connected to the first component (8) in a heat conducting manner, is arranged on the motor-side end of the frequency converter.
3. A motor construction unit according to claim 1, characterised in that the second component also comprises the input circuit.
4. A motor construction unit according to one of the preceding claims, characterised in that a further heat distributor (21) is provided, which essentially over its whole periphery bears on the housing casing and whose outer contour essentially corresponds to the inner contour of the housing casing.
5. A motor construction unit according to one of the preceding claims, characterised in that the heat distributors (2, 21) are arranged at ends, distant to one another, of the insert forming the frequency converter.
6. A motor construction unit according to one of the preceding claims, characterised in that the heat distributors (2, 21) are pressed into the housing casing.
7. A motor construction unit according to one of the preceding claims, characterised in that the first heat distributor (2) comprises a transverse wall (4) on which the first component (8) bears in a heat-conducting manner.
8. A motor construction unit according to one of the preceding claims, characterised in that at least one heat distributor (2, 21) comprises an axial recess (3, 20) for receiving a coil (6, 19).
9. A motor construction unit according to one of the preceding claims, characterised in that the second component (14) comprises a circuit board (15) which extends in the longitudinal direction of the motor construction unit.
10. A motor construction unit according to one of the preceding claims, characterised in that the third component (16) comprises a circuit board. (17) which extends in the longitudinal direction of the motor construction unit:
11. A motor construction unit according to one of the preceding claims, characterised in that the circuit boards (15, 17) of the control electronics and of the intermediate circuit board are arranged: between the heat distributors (2, 21), preferably lying over one another.
12. A motor construction unit according to one of the preceding claims, characterised in that the electrical connections (12, 13, 18) of the component (8) comprising the power electronics are formed by sheet metal sections which are held by a plastic body (10) cast with the component (8), wherein the component (8) is fastened on the heat distributor (2) by way of the plastic body (10).
13. A motor construction unit according to one of the preceding claims, characterised in that the component (8) comprising the power electronics comprises electrical connections (13, 18) to the component (14) containing the intermediate circuit and to the component (16) comprising the control electronics, as well as lead connections (12) to the motor (1).

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