EP1041595B1 - Centrifugal pump unit - Google Patents

Description

The invention relates to a centrifugal pump unit with the in the preamble of Claim 1 specified features.

Centrifugal pump units of this type are used today to increase pressure, as so-called booster pumps. Particularly where the central water supply does not always have a sufficiently high operating pressure, it is customary to install storage containers, for example on the roof, in which case the water is filled from the central water supply to a certain level in the storage container and from there flows to the water tapping point in the households below if necessary. In this way, water can also be drawn off if the delivery pressure drops or the delivery fails in the central supply line. Since the static pressure is usually only very low due to the height difference between the storage container and the tapping point, it is particularly necessary when using electric or gas-operated instantaneous water heaters or comparable devices that require a minimum water flow to use such booster pumps. Booster pumps are typically used for pressure increases of 0.6 to 0.8 bar with a flow rate of 0.5 to 1 m ³ / h.

Since the pressure increase is only necessary when water is removed, if the instantaneous water heater or a similar device is operated, these are Pumps equipped with a flow switch (flow switch) that the electric motor of the centrifugal pump unit controls. Whenever a nozzle on one Tapping point is opened and water due to the low existing static pressure begins to flow, this flow switch is excited then turns on the motor of the centrifugal pump set to this way to generate the desired pressure increase.

Such centrifugal pump units are part of the prior art. A well known Such units are specially designed for this purpose and has a terminal box that the motor housing to reaches over to the pump housing and there an electromagnetic Has switching device with one in this area in the flow path arranged two-armed, pivoted lever is in operative connection. This lever protrudes into the flow path with one arm and carries a magnet on the other arm, which holds the Controls switching device in the form of a reed contact. Because this lever protrudes with one arm into the terminal box, there is a risk that Leaks in the area of the lever feed fluid in reaches the terminal box. In addition, this is known Centrifugal pump unit to adapt the terminal box to to be able to pick up the lever arm and to seal it against it. Furthermore, this construction has the disadvantage that the terminal box can not be easily dismantled, but first remove the lever. Since the aforementioned components are constructive are adapted to the pump type, they are only for this one Pump type can be used, especially with regard to the terminal box is disadvantageous.

Proceeding from this, the object of the invention is to create a generic one Centrifugal pump unit to be designed so that Largely standardized components from large series production can be used are to reduce manufacturing costs.

This object is achieved according to the invention by those specified in claim 1 Features solved.

Advantageous embodiments of the invention are in the subclaims and the description below.

The basic idea of the invention is to spatially and the terminal box physically separate from the flow switch to order on this Way to be able to use a terminal box as it is for others Centrifugal pump units of this size, especially heating circulation pumps Is used. In addition, the centrifugal pump unit through the cartridge-like in the pump housing Guard housing either with or without a flow guard used by fitting an appropriate sealing cap become. The pump unit is not only simplified in terms of design, but also more versatile in terms of purpose.

Inside the guard housing, that towards the outside, i.e. towards the environment hermetically sealed and sealed against the pump housing is, according to the invention, the shift lever, which with one arm protrudes into the flow path and the other arm carries a magnet. So the magnet is inside the guard housing, while the switching device is still in the terminal box remains arranged. Terminal box and guard housing are therefore only magnetically connected to each other, but otherwise completely separated physically and physically. It understands that the terminal box and the guard housing are adjacent to each other are to be arranged to ensure the magnetic operative connection. Otherwise, the terminal box can be connected to the motor housing in a known manner be attached, with only those for electrical safety necessary seals must be provided, but seals compared to the medium completely eliminated. Since that Guard housing to the outside, i.e. to the environment, where it is after installation is accessible from the outside in the pump housing, hermetically sealed a seal against the pump housing is sufficient, to seal off the flow to the outside (for Environment). A simple ring seal is sufficient for this, if the part of the guard housing protruding into the pump housing is essentially cylindrical. Such a cylindrical one Shape with corresponding openings in the area of the flow channel is not only opposite in terms of the aforementioned sealing the pump housing advantageous, but also facilitates the Assembly, as slight twisting when inserting due to slight turning can be canceled. The guard housing is preferably so formed that the housing part lying outside the pump housing is completely closed. To this In this way, no sealing arrangements are required within the guard housing, the tightness of the arrangement is reliably guaranteed.

Advantageously, the one that is pivotally mounted within the guard housing Lever formed by a one-piece injection molded part, which not only the two Lever arms, i.e. the arm protruding into the flow path and the magnet supporting arm, but also has a pivot axis with which the lever is mounted inside the housing.

To ensure that the lever arm protruding into the flow path is already at very low flow is deflected, it is appropriate to paddle this to train, so that when it is transverse to the flow, it has a large flow resistance forms and as small as possible in the direction of the flow. The outer contour of the paddle-like lever arm should be essentially that Flow channel cross-section correspond to a response as sensitive as possible to enable.

Although the solution according to the invention allows the lever with both lever arms in Arrange fluid - it is not necessary to place it inside the guard housing to provide a seal between the two lever arms - but it is it expedient, the lever arm that carries the magnet, and the pivot axis to protect against the guard housing by an elastic sleeve. On this prevents contamination or deposits in it Area of the guard housing or that there are currents inside train this housing part.

The lever arrangement is preferably designed such that the one acting on the lever Flow force with increasing deflection of the paddle-like lever out of the Flow path decreases. On the one hand, this can be achieved by appropriate shaping the paddle-like lever arm and on the other hand by a corresponding Interpretation of the lever return arrangement are supported. The lever provision is also preferably carried out by means of magnetic force, for this purpose within or Another magnet (auxiliary magnet) is provided outside the guard housing can be, depending on the arrangement, either repulsive or attractive. The auxiliary magnet is expediently arranged with respect to that arranged on the lever arm Magnets so polarized that it repels them. This arrangement is particularly favorable because it allows the pump housing to be selected to manufacture from plastic or from a ferromagnetic material without that there is a risk that the lever due to the magnetic force near the pump housing wall holds.

As explained at the beginning, in the configuration according to the invention of Terminal box and guard housing terminal boxes are used as they are for heating circulation pumps already built inexpensively in large quantities , with only the circuit board located inside the terminal box Modify accordingly to accommodate the reed relay at a suitable location. Such terminal boxes known from heating circulation pumps have usually a three-stage switch on, which for heating circulation pumps Speed setting is used. It is therefore particularly advantageous to do this anyway to use existing switches for the pump unit according to the invention, what in that this tap changer with the switching functions ON, OFF and flow switch control is applied. It can be more Series parts can be used for the special purpose.

Fig. 1:

einen Längsschnitt durch ein erfindungsgemäßes Kreiselpumpenaggregat,

Fig. 2:

in vergrößerter perspektivischer Darstellung das Wächtergehäuse,

Fig. 3:

einen Längsschnitt durch das Wächtergehäuse,

Fig. 4:

das Wächtergehäuse in Darstellung nach Fig. 2 mit hälftig geschnittenem Außengehäuse sowie hälftigem Einschubteil,

Fig. 5:

einen Längsschnitt durch das Wächtergehäuse in einer zu Fig. 3 um 90° versetzten Schnittebene,

Fig. 6:

in vergrößerter Darstellung die Einzelheit VI in Fig. 1,

Fig. 7:

die Einzelheit gemäß Fig. 6 in Ausgangsstellung mit Darstellung des vom Hauptmagneten ausgehenden Magnetfeldes und

Fig. 8:

die Darstellung gemäß Fig. 7 in ausgelenkter Stellung des paddelartigen Hebelarmes.

The invention is explained below with reference to an embodiment shown in the drawing. Show it:

Fig. 1:

2 shows a longitudinal section through a centrifugal pump unit according to the invention,

Fig. 2:

in an enlarged perspective view the guard housing,

Fig. 3:

a longitudinal section through the guard housing,

Fig. 4:

2 with half-cut outer housing and half insert part,

Fig. 5:

3 shows a longitudinal section through the guard housing in a sectional plane offset by 90 ° from FIG. 3,

Fig. 6:

the detail VI in Fig. 1 in an enlarged view,

Fig. 7:

the detail according to FIG. 6 in the starting position with representation of the magnetic field emanating from the main magnet and

Fig. 8:

7 in the deflected position of the paddle-like lever arm.

The centrifugal pump unit shown in FIG. 1 has a motor housing 1, which receives an electric motor, with a stator 2 and one Rotor 3, which is separated from the stator space in a manner known per se via a can is. The rotor 3 has a shaft 4 which carries a gyroscope 5 which is arranged within a pump housing 6.

The pump housing 6 is screwed to the motor housing 1 and has one Suction nozzle 7, whose channel opens into the suction mouth of the impeller 5. As in Spiral casing of this type is customary, closes radially to the impeller 5 a pressure port 8 leading channel 9. In the area of this channel 9 is a Flow monitor 10 arranged.

A terminal box 11 is arranged on the side of the motor housing 1, in which the electrical wiring between the stationary network and the motor takes place and in addition, all the other electronics of the unit is arranged. 1 of these components can be seen a capacitor 12, a circuit board 13 and between the circuit board 13 and the housing wall arranged reed relay 14. The terminal box 11 is by a removable cover 15 completed.

The flow monitor 10 has a lever 16 which is designed as an injection molded part a pivot axis 17, a lever arm 18 projecting into the channel 9 and has a lever arm 19 projecting to the other side. The lever arm 18 is paddle-like, as can be clearly seen in FIG. 3. Its outer contour is adapted to the channel cross section in this area, so that it Channel 9 almost completely closed in the rest position. The other side of the The pivot axis 17 arranged lever arm 19 is used as a holder for it attached magnet 20 formed. The magnet 20 has a cylindrical shape and a north-south polarization along the cylinder axis, so that one end the North Pole and the other end forms the South Pole, like that in the FIGS. 7 and 8 illustrate the magnetic field lines.

The magnet 20 acts with the reed relay 14 arranged in the terminal box 11 together, so that depending on the position of the lever 16 or the magnet 20 that Reed relay 14 is in one or the other switching position. The two Switch positions are shown in Figures 7 and 8. The circuit takes place such that in the rest position (Fig. 7), so when there is no flow inside of channel 9 takes place, the engine is switched off and deflected in the other Position (Fig. 8) the engine is switched on.

The lever 16 is mounted within a guard housing 21, which is in three parts is trained. It has a cartridge-like insertion part 22 which is in the has a substantially cylindrical outer contour and two plastic injection molded parts 22a and 22b is formed. The insertion part has a channel 9 that continues Opening across to the direction of insertion. The insert halves 22a and 22b are assembled by means of dowel pins 23 with the inclusion of the lever 16. In the installed position, the halves become correspondingly cylindrical designed cross hole to the channel 9 in the pump housing 6. About that an outer housing 24 made of plastic injection molding also overlaps a cylindrical shoulder of the insert part 22. Since the guard housing 21 is not only in the area of the paddle-like lever arm 18 has fluid contact, but the interior of the outer housing 24 can also be fluid-filled, all that is required an annular seal 25 with which the outer housing 24 opposite the transverse bore is sealed in the pump housing 6.

To prevent 24 dirt deposits in the interior of the outer housing or the like, an elastic protective sleeve 26 is provided, which on the one hand sits on the lever 16 and on the other hand within the insertion part 22 is held. For assembly, the protective sleeve is initially so far above the Lever 16 pushed until it is in its intended position approximately in the middle (see Fig. 3) takes. From this position it can due to a head start 27 do not slip off the lever. The edge of the cuff is then in the insert 22 fixed, then the entire insertion part with the lever located thereon is inserted into the outer housing 24, and then in the transverse bore of the pump housing 6 recorded and by means of the provided on the outer housing 24 Bores 28 to be screw fastened.

Inside the outer housing 24 there is a recess 29 open to the outside formed, which is accessible before assembly and another at the bottom Magnet 30 (auxiliary magnet) is fixed. The auxiliary magnet also has a cylindrical one Shape and a north-south polarization along its cylinder axis. Here is the The arrangement of the magnet 20 is selected such that the same poles face each other on the end face, so that the magnet 20 is repelled by the magnet 30.

The outer housing 24 has a cavity which is open towards the channel 9 and which the lever arm 19 receives and adjacent the externally accessible recess 29 for the magnet and is otherwise in its shape to the outer contour adapted to the terminal box. The recess 29 is only accessible when the terminal box 12 is removed or the pump housing 6 with the Guard housing 21 is removed from the motor housing 1. The distance between Terminal box 11 and guard housing 21, in particular outer housing 24, is so chosen that on the one hand a free space is formed, on the other hand the magnet 20 switches the reed relay 14 reliably.

The function of the arrangement described above is as follows: In the starting position (Fig. 7) no fluid flows within the channel 9. The repulsive power of the magnet 30 to the magnet 20 causes the lever 16 in that shown in Fig. 7 Rest position is pivoted, in which the paddle-like lever arm 18 the flow channel 9 almost completely closes. As soon as a valve for the purpose water is opened, one flows due to the static pressure small amount of water through the pump, which leads to the lever arm 18th a flow force is exerted, which is shown in FIG swung out position moved. As a result, the magnet 20 moves opposite the reed relay 14, which thereby changes its switching position, switches on the motor and thus further increases the flow through channel 9. Only when the removal is completed and the valve is closed again, the lever 16 falls back to the starting position shown in Fig. 7, in which the pump is switched off.

LIST OF REFERENCE NUMBERS

1 -

motor housing

2 -

stator

3 -

rotor

4 -

wave

5 -

impeller

6 -

pump housing

7 -

suction

8th -

pressure port

9 -

channel

10 -

flow Switch

11 -

terminal box

12 -

capacitor

13 -

circuit board

14 -

Reed Relays

15 -

cover

16 -

lever

17 -

swivel axis

18 -

Lever arm (paddle)

19 -

Lever arm (magnet)

20 -

Magnet (main magnet)

21 -

Guardian housing

22 -

insertion part

22a, 22b -

Half of the insert

23 -

dowels

24 -

outer casing

25 -

ring seal

26 -

booted

27 -

head Start

28 -

drilling

29 -

recess

30 -

Magnet (auxiliary magnet)

Claims (10)

1. A centrifugal pump unit with a flow switch (10) arranged within the pump housing (6) in the flow path (9) of the delivery flow, with an electromagnetic switch device (14) and with a two-armed, pivotally mounted lever (16) whose one arm (18) projects into the flow path (9) and whose other arm (19) carries a magnet (20) which is actively connected to the switch device (14) in a contact-free manner, wherein the switch device (14) is arranged within a terminal box (11) and at least the part of the lever (16) carrying the magnet (20) is surrounded by a switch housing (21) which is hermetically sealed with respect to the surroundings, is separated from the terminal box (11) and is arranged adjacent to this.
2. A centrifugal pump unit according to claim 1, characterised in that the switch housing (21) comprises a part (22) which projects into the pump housing (6) and which has an essentially cylindrical shape, and which is open[ed] in the region of the flow channel (9) and is incorporated into the pump housing (6) in the manner of a cartridge.
3. A centrifugal pump unit according to one of the preceding claims, characterised in that the switch housing (21) comprises a housing part (24) lying outside the pump housing (6) as well as a housing part (22) lying within pump housing, and that only the housing part (24) lying outside the pump housing (6) is sealed with respect to the pump housing (6).
4. A centrifugal pump unit according to one of the preceding claims, characterised in that the lever arms (18, 19) are formed by a one-piece injection moulded part (16) which also comprises an arbor (17) arranged between the lever arms, with which the lever (16) is pivotally mounted within the switch housing (21).
5. A centrifugal pump unit according to one of the preceding claims, characterised in that the lever arm (18) projecting into the flow path (9) is designed in a paddle-like manner and in its outer contour is adapted to the flow channel cross section in this region.
6. A centrifugal pump unit according to one of the preceding claims, characterised in that a lever arm (19) is protected with respect to the flow housing (9) by way of an elastic sleeve (26) arranged near to the arbor (17).
7. A centrifugal pump unit according to one of the preceding claims, characterised in that the flow force acting on the lever (16) reduces with an increasing deflection of the paddle-like lever arm (18) out of the flow path.
8. A centrifugal pump unit according to one of the preceding claims, characterised in that a multi-step switch is provided, wherein in one switch step the unit is constantly switched on, in another switch step is constantly switched off and in a third switch step is switched in dependence on the lever position of the flow switch.
9. A centrifugal pump unit according to one of the preceding claims, characterised in that a further magnet (30) for setting back the lever (16) is arranged in the switch housing (21).
10. A centrifugal pump unit according to one of the preceding claims, characterised in that the further magnet (30) is aligned such that it repels the magnet (20) arranged on the lever arm (18).

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