EP1052410B1 - Impeller attached to a rotor - Google Patents

Description

The present invention relates to an electrically operated Pump, in particular a canned pump to promote a Medium in a heating or cooling system with stator and with a rotatably mounted rotor, the rotor being hollow Rotor cylinder with arranged in the cylinder wall Has permanent magnets, in the cavity of a rotor bearing is arranged and which carries an impeller on one end face.

Such pumps are known from e.g. B. GB-A-1 195 747 and DE-A-3 822 897.

Such a structurally simple and sometimes advantageous Block construction pumps with low output up to about 100 watts are known from the prior art. she have a thick-walled rotor cylinder, in the Cavity protrudes a rigid axis, the axis of the Rotor is rotatably mounted. The impeller is directly on the front of the particular made of plastic Rotor cylinder molded so that on a shaft between the Rotor and the impeller can be dispensed with.

The magnetization of the rotor is special Embodiment using a magnetizable material, achieved with a metal powder, for example, with the Plastic is mixed from which the rotor cylinder is made is. In the pumps known from the prior art the rotor cylinder and the impeller in one piece from such "Magnetizable" plastic, especially made of injected into this plastic. The rotor is made after manufacturing magnetized by applying external magnetic fields.

A disadvantage of the known pumps is that the entire rotor-impeller unit from the expensive magnetizable plastic must be manufactured, although the magnetization only in the small areas of the rotor facing the stator coils necessary is. The rotor-impeller unit is therefore expensive. Another disadvantage is that only open in the spraying process Impellers can be made that are known to be a have very low efficiency.

In addition, the user is on the once selected impeller geometry instructed, since in the known pumps an adjustment of the Pump to the special hydraulic conditions a change of the impeller is excluded. In return of an impeller, the rotor-impeller unit should be complete to be replaced. It is also used to manufacture a such a unit requires a special injection tool, which comes with corresponding costs.

The object of the invention is therefore to provide such a pump create that with high reliability and cost-effective Manufacturing great flexibility in terms of customization the pump to meet various requirements.

This task is characterized by a pump with the Features of claim 1 solved. The central idea of the invention is the impeller and the Separate the rotor cylinder and form both parts so that they form-fit with each other at least in the circumferential direction can be connected. The separation of the two parts has when using the magnetized material Plastic has the advantage that only the rotor cylinder the comparatively expensive "magnetizable" plastic must be manufactured. Because of the smaller quantities required can be a higher quality while maintaining the cost Material ("power magnet") can be used. The impeller will then molded from conventional and cheap plastic. This is either a significant cost saving or an increase in performance possible at the same cost.

The pump according to the invention with that on the rotor cylinder mounted impeller is also characterized by a large Insensitivity to structural tolerances. On Another advantage of the pump according to the invention is that Impeller is detachably attached to the rotor cylinder and can be replaced if worn or defective. The expensive rotor cylinder remains in the pump. The interchangeability The impeller offers greater flexibility Pump, because depending on the area of application a corresponding impeller can be placed on the rotor cylinder. It can be used by everyone Type of application ensures optimal efficiency become. The impeller can also be made of metal and on be placed on the rotor cylinder, with metal impellers can also be easily produced in closed form can. Such closed impellers is another Pump efficiency can be increased.

The impeller is advantageously in the axial direction non-positively, in particular by a latch, or positively by a locking mechanism on the front wall of the Mounted rotor cylinder. This makes it easy Ensure assembly and disassembly of the impeller. For the Disassembly of the impeller will simply be the pump housing and the motor part separated and the impeller from the rotor cylinder deducted. This embodiment makes one special easy maintenance.

In a particularly simple embodiment, the pump a rigid axle, which in the case of a canned pump the rear end wall of the can is attached and in this protrudes into it. The rotor cylinder is on the axis mounted by means of a plain bearing, advantageously into the cavity of the rotor cylinder made of plastic a ring of a coal bearing is pressed in on the axle running. This embodiment is characterized by the particularly simple mechanical structure and a large Reliability and can be inexpensive as a mass product manufactured and advantageously in the cooling circuit of Motor vehicles are used.

It is also advantageous to use the impeller and as many as possible to manufacture other components of the pump from plastic. This leads to a significant weight reduction that the use of pumps in motor vehicles especially becomes attractive. Because of the plastic Versatile design options in the design of the Impeller blades can be customized to suit the particular impeller Requirement can be adjusted.

When manufacturing the rotor cylinder from "magnetizable" Plastic, it is advantageous in the cavity of the rotor the inner wall covering the inner sleeve made of metal press or let in for greater stability of the To ensure rotors. It is also advantageous this sleeve towards the impeller over the front of the Let the rotor cylinder protrude, and the protruding one Ring in one in the rear end of the impeller introduced and extending in the axial direction insert cylindrical groove. Through this inserted ring the impeller is centered.

In an advantageous embodiment, the plastic manufactured rotor cylinder from an outer sleeve made of metal surround, it being particularly advantageous to form a shape to form the inner and outer sleeve into which the Plastic for the rotor cylinder can be cast. On this is on the one hand great stability of the rotor given, while on the other hand the metallic sleeves ensure closed magnetic flux.

To ensure the axial hold of the rotor cylinder on the axis it is advantageous to secure between the rotor cylinder and to arrange a thrust bearing in the axis, which in a special simple embodiment only of a circlip is formed, which is introduced into a rigid axis Ring groove is used. Against this ring runs in the Bearing bush pressed into the rotor cylinder. Even if the rotor in the axial direction by the force of the stator and rotor magnets is held, the thrust bearing secures the position of the rotor cylinder.

In another particularly preferred embodiment the axial bearing is formed from the rotor and impeller Unit accomplished by a plain bearing that between the Impeller and the inner wall of the impeller chamber is arranged. This has the great advantage that the bypass flow around the impeller around is almost impossible, especially with centrifugal pumps small size and low power for the increase efficiency plays a crucial role. The on The bypass flow bypass contains only that for Lubrication of the slide bearing required medium.

It is particularly simple and advantageous to use the plain bearing form axial plain bearing, which between one around the Suction opening arranged ring surface and an end face the impeller is arranged. This is due to this plain bearing Impeller held in the axial direction against the pump housing. The plain bearing is particularly advantageous if the impeller and shaft or rotor are decoupled in the axial direction. In this case the impeller is "floating" in axial Direction held in the impeller chamber, resulting in a large one Tolerance towards structural inaccuracies and thus too contributes to simplification of production. The bigger one Insensitivity also affects different Thermal expansion of the individual components. Favorable Way the impeller remains in the axial direction against that Axial bearing movable. The rotor cylinder is thereby magnetic forces between the stator and the rotor in stabilized in the axial direction.

With such a floating bearing, it is advantageous the impeller rotates on a separate impeller axis store that protrudes into the impeller chamber. The impeller has a central hub in this embodiment, in which can be pressed into the bearing bush of a coal warehouse and in which the impeller shaft is inserted. In this Embodiment can completely the hydraulic part from electrical part to be separated, resulting in a large Maintenance friendliness of the centrifugal pump leads.

Figur 1

eine Kreiselpumpe mit einem auf den Rotor aufgesteckten Laufrad und

Figur 2

eine Kreiselpumpe mit Axaillager im Pumpengehäuse

Particularly advantageous forms of the pump according to the invention are shown in drawings 1 and 2 and are described in more detail below. Show it:

Figure 1

a centrifugal pump with an impeller attached to the rotor and

Figure 2

a centrifugal pump with axial bearing in the pump housing

In Figure 1 is a section through an electrically operated Canned tube pump shown how to promote the cooling medium can be used in a motor vehicle. The one Motor housing 1 made of plastic surrounded electric drive the pump has a stator with stator windings 2 which can be applied to a supply voltage via lines 3. The control electronics 4 of the pump is on the rear Front of the pump arranged. The stator is through one Can 5 rotatable from within the stator mounted rotor 6 hydraulically separated. The motor housing 1 is attached to a pump housing 7 via a flange and sealed with an O-ring seal 8.

In an impeller chamber located in the pump housing 7 in this case an open impeller 9 with blades 10 arranged, the medium via an inlet port 11th is supplied and which the medium to an outlet port 12 promotes. The impeller with the molded blades 10 is in in this case molded from plastic.

The rotor 6 has a fetching rotor cylinder 13 which is in this case is molded from plastic, being in the Plastic is a magnetizable material embedded. After the material has been magnetized, the outer wall bears of the rotor cylinder 13 permanent magnets with the Interact stator windings 2. In the interior of the Rotor cylinder 13 is a metal sleeve 14 is introduced serves to stabilize the rotor cylinder 13. In these Metal sleeve 14 is a bushing 15 of a coal store pressed in, which is rotatably mounted on a rigid shaft 16 is. It is against a displacement in the axial direction Rotor cylinder 13 through an axial bearing with a slide ring 17 secured in the manner of a circlip that fits into a groove is inserted at the head of the axis 16. The rigid axis 16 is into a cylindrical holder 20 formed on the containment shell 5 plugged in.

The impeller 9 is on the front wall of the Mounted rotor cylinder 13 and is in by a bracket Circumferential direction held positively. These are at the Rear of the impeller 9 arranged pins 18 in corresponding recesses in the front of the Rotor cylinder inserted. In the axial direction it is Impeller 9 held non-positively. To center the Impeller has this axially in its rear extending annular groove 19 into which the metal sleeve 14th is plugged in.

In Figure 2 a similar pump is shown, in which the Rotor cylinder 13 against displacement in the axial direction by the magnetic force between the stator and the rotor held. The rigid axis 16 is in turn in a Can 5 molded cylindrical holder 15 inserted.

Between the impeller 9 and the inner wall of the An axial sliding bearing is provided in the impeller chamber the gap between the inner wall surrounding the suction opening the impeller chamber and the end face of the impeller 9 is arranged. The impeller 9 is thus over the slide bearing against the inner wall, with a sliding ring in the inner wall 21 is embedded. The impeller points to separate storage a hub 25 with which it is on one on the pump housing attached and protruding into the impeller chamber Impeller axis 21 slides. The impeller axis 21 is in a Pump housing molded socket 22 inserted, the Bushing 22 via radial webs 23 with the Inner wall of the suction opening is connected. The webs 23 have a hydrodynamically particularly favorable profile and offer only a small flow to the medium Resistance. In the hub of the impeller 9 is a bearing bush 24 of a coal bearing pressed in with the impeller axis Plain bearing forms.

Claims (14)

1. Electrically driven pump, particularly a slotted tube pump, for conveying a medium in a heating or cooling system, with a stator and with a rotor that is supported such that it can rotate, whereby the rotor has a hollow rotor cylinder, with permanently magnetic areas, in the walling of the cylinder, the said hollow rotor cylinder carries a impeller on an end face and a rotor bearing is disposed in its cavity,
   characterized in that
   the impeller (9) can, in the peripheral direction, be placed, form-locking, on the end face walling of the rotor cylinder (13).
2. Pump in accordance with claim 1,
   characterized in that the impeller (9) can, in an axial direction, be attached tensionally, or form-locking, to the end face of the rotor cylinder (13).
3. Pump in accordance with claim 1 or 2,
   characterized in that the impeller (9) is held on the end face of the rotor cylinder (13) by a catch connection.
4. Pump in accordance with one of the preceding claims,
   characterized in that, the impeller (9) is formed from plastic.
5. Pump in accordance with one of the preceding claims,
   characterized in that the rotor cylinder (13) is made of material that can be magnetized, particularly from plastic with added material that can be magnetized.
6. Pump in accordance with claim 5,
   characterized in that the plastic which takes up the material that can be magnetized is cast in a form that is formed by an inner (14) and an outer casing.
7. Pump in accordance with one of the preceding claims,
   characterized in that a thrust bearing is disposed between the rotor cylinder (13) and the shafting (16).
8. Pump in accordance with claim 7,
   characterized in that the thrust bearing is formed from a guard ring (17) that is inserted into an annular groove applied into the rigid shafting (16).
9. Pump in accordance with one of the preceding claims,
   characterized in that a sleeve bearing is disposed between the impeller (9) and the inner wall of the impeller chamber.
10. Pump in accordance with claim 9,
    characterized in that the sleeve bearing is an axial sleeve bearing that is disposed in a gap between the inner surface of the impeller chamber, surrounding the intake (11), and the end face of the impeller (9), whereby the impeller (9) lies against the inner surface, above the sleeve bearing.
11. Pump in accordance with one of the preceding claims,
    characterized in that the sleeve bearing has a slide ring (21), introduced into the inner walling, on which the impeller (9) lies with a front side of its central intake (11).
12. Pump in accordance with claim 11,
    characterized in that the rotor cylinder (13) is held, in the axial direction, such that it can move (floating) on the rotor shafting (16).
13. Pump in accordance with claim 11,
    characterized in that the impeller (9) has a boss (25) with which it slides on the impeller shafting (21) that is applied to the pump housing and extends into the impeller chamber.
14. Use of the pump in accordance with one of the preceding claims for conveying coolant in the in coolant circuit of a vehicle.

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