DE102009049904A1 - Separation wall i.e. separating calotte, for ball shaped electric motor, has rotor assembly pivoted to sliding body, and retaining element formed with enclosed surface for sliding body and made of stainless steel deep-drawable material - Google Patents

Abstract

The wall (2) has a rotor assembly (1) rotatably pivoted to a sliding body (4). An enclosed surface of a separation area is placed between the rotor assembly and a stator in a tightly packed manner. A retaining element (20) is formed with an enclosed surface for the sliding body and made of stainless steel deep-drawable material. The retaining element is formed as a hollow body i.e. hollow cone, protruding from the wall. The wall is made of stainless steel such as chromium-nickel-steel i.e. chromium-nickel-molybdenum steel. An independent claim is also included for a method for producing a separation wall.

Description

The invention relates to a separating wall which can be arranged in a sealing manner between a stator and a rotatably mounted rotor unit of an electric motor. The invention further relates to a pump, in particular a circulation pump or a service water pump, with an electric motor comprising a partition wall.

Electric motors with a rotatably mounted rotor unit are also referred to as ball motors. Such ball motors are used as a drive for water pumps, such as circulating pumps, circulation pumps or service water pumps, use. The rotor unit is arranged when using the electric motor in such a pump in a fluid-carrying part of the pump, wherein a rotor core is protected by a sheath and sealing elements. The stator for the electric motor is arranged separately from a conveyed fluid in a dry area. A separation of the fluid-carrying part of the pump from the stator is effected by a partition made of a magnetically permeable, corrosion-resistant material. As a material for the partition, for example, a stainless steel is used. Such a partition is made, for example DE 22 46 418 A1 known.

In order to ensure a reliable seal to the stator, the partition wall preferably has an uninterrupted or closed surface. On the partition a support column is attached, which in turn holds a bearing ball for the rotor unit. The support column has at its free, facing away from the partition end an opening into which the bearing ball is inserted. A connection between the partition and the support column takes place by welding or soldering.

The production of a partition with a welded thereto support column is associated with a lot of work. In addition, after the assembly steps, a check of the height and the concentricity of a rotor unit on the bearing ball is necessary.

It is therefore an object of the invention to provide a simple and inexpensive to produce partition. It is a further object of the invention to provide a pump with a permanently sealing partition.

This object is achieved by a partition wall for an electric motor, comprising a stator and a rotor unit rotatably mounted on a slider, wherein the partition at least in a separation region has a closed surface and sealingly can be arranged between the stator and the rotor unit, and wherein a holding element for the sliding body has a closed surface and is integrally formed with the partition of a non-stainless thermoformable material.

The object is further achieved by a pump, in particular a circulation or a hot water pump, with an electric motor, comprising a stator, a rotatably mounted on a slider rotor unit and a sealing between the rotor unit and the stator sealingly arranged inventive partition with a holding element.

As an integral embodiment of the retaining element with the partition while a one-piece design of the components without additional connection step by welding, soldering or the like is called. Due to the integral or one-piece design of the retaining element with the partition, the mounting steps for attaching a separately prepared support column omitted on the partition.

A closed surface is an uninterrupted wall, by means of which a fluid-tight separation can be realized. The closed surface of the integrally formed holding element ensures that the stator is fluid-tightly separated from a water-carrying part. The partition preferably has a completely closed surface. In other embodiments, the partition wall has interruptions in areas that do not function as a separation area between the stator and the rotor unit.

According to a further aspect of the invention, the dividing wall is produced with the holding element in a deep-drawing process. As a material for the partition, a stainless steel, in particular a chromium-nickel steel, preferably a chromium-nickel-molybdenum steel is used in advantageous embodiments. By deep drawing a hollow body is created. In some embodiments, the dividing wall is at least partially coated with an electrically insulating material.

In an advantageous embodiment, the holding element is designed as a protruding from the partition hollow body, in particular as a hollow cone.

In advantageous embodiments, a bearing surface is formed as a depression or indentation on a free end of the holding element. In a preferred embodiment of the invention, the holding element at its free end on a spherical bearing surface for a ball designed as a sliding body. The storage area is in an advantageous Spherical design. In other embodiments, the bearing surface is cone-shaped.

The sliding body can be connected to the holding element in a suitable manner, for example by soldering, welding and / or gluing. A radius of the spherical bearing surface is in advantageous embodiments less than a radius of the bearing ball. Due to the smaller radius, there is a line contact between the bearing ball and the spherical bearing surface. A ratio between the radius of the bearing ball and the radius of the spherical bearing surface is, for example, 1.1 to 1.2.

In one embodiment of the invention, the dividing wall is designed as a separating calotte, which is flattened in a bottom region, wherein the dividing region defines a spherical segment region which is essentially concentric with the sliding body. The shape of the partition wall allows wobbling motion of the rotor unit in the ball section area.

In a further development of the invention, a distance of the bottom region of the flattened separating calotte from a midpoint of the spherical segment region is minimized so that a ratio of the distance to the radius of the spherical segment region is less than approximately 0.8, in particular less than approximately 0.7, preferably less than approximately 0.6. Due to the flattening and minimizing the height of the height of the partition is lower than in a dome-shaped configuration. A lower height of the partition allows good manufacturability by deep drawing. An associated rotor or an associated rotor unit is also formed flatter. As a result, an overall mass center of gravity of the rotor unit shifts in the direction of a movement center on the bearing ball. By this shift, the running properties of the rotor unit are improved. By a permanent magnet magnetic stabilization forces are generated. The magnetic stabilization forces of the rotor unit can be made smaller by the shift of the total mass center of gravity. As a result, the axial component (bearing load) can be minimized. In addition, can be dispensed with support elements.

When using the partition wall in an electric motor for a pump, the cavity behind the holding element can be used for other applications. It is provided in one embodiment of the invention that in the cavity, a sensor is arranged. In a development of the invention, a sensor for measuring a temperature of the delivered fluid is arranged in the cavity. By the sensor, a measurement of the temperature of the fluid is possible without disturbing influences by the electric motor. Alternatively or additionally, a sensor for measuring a magnetic field of the rotor core of the rotor unit is provided in the cavity, for example a Hall sensor. By such a sensor, a rotor core is monitored. A lack of rotation of the rotor unit, for example, due to contamination and / or limescale is recognizable so early and optically and / or acoustically displayable by appropriate signals. In a further embodiment, a sensor for detecting incoming water is provided, for example an ultrasonic sensor.

Further advantages of the invention will become apparent from the subclaims and from the following description of an embodiment of the invention, which is shown schematically in the drawings. For identical or similar components, the same reference numbers are used in the drawings.

In the drawings show:

1 FIG. 2 is a sectional side view of a rotor unit for an electric motor; FIG.

2 a perspective view of a partition wall;

3 a sectioned side view of the partition according to 2 ;

4 : a detail IV according to 3 and

5 : a detail V according to 3 ,

1 shows schematically in a sectional side view of a rotor unit 1 for an electric motor used for example in a pump. The water-bearing rotor unit 1 is through a partition 2 separated by a stator, not shown for the electric motor sealing. The partition 2 is on a schematically illustrated housing 3 attached. The runner unit 1 includes a support body 10 on which a rotor core 11 is fixed. In the illustrated embodiment, the rotor core 11 a permanent magnet. Due to the permanent magnetic stabilization forces can be dispensed with support elements. Next comprises the rotor unit 1 an impeller 12 with blades 13 , The rotor core 11 is through a sheath 14 sealed against the pumped liquid. At the edge of the casing 14 are preferably not shown sealing elements provided. The runner unit 1 is with a storage pan 15 on a designed as a bearing ball slider 4 rotatably mounted so that the rotor unit 1 can perform a staggering movement.

Between the jacket 14 and the partition 2 is formed a gap, which the tumbling movement of the rotor unit 1 allows.

A holding element 20 for the slider 4 is according to the invention in one piece or integral with the partition wall 2 educated. The partition 2 points including the holding element 20 in a separation area between the stator and the rotor unit 1 a closed surface, so that a fluid-tight separation of the stator is ensured by the water-carrying area.

The holding element 20 is as one of the partition 2 protruding hollow cone formed. In a cavity 200 of the holding element 20 are not shown in an embodiment sensors or other elements arranged.

2 schematically shows the partition 2 in a perspective view. 3 shows a sectional side view of the partition 2 , The 4 and 5 show details IV and V of the partition 2 ,

The illustrated partition 2 with the integrally formed holding element 20 is made of a stainless steel as a deep-drawn part. How best in the 3 and 4 can be seen, the holding element has 20 at his in detail 4 end shown a spherical bearing surface 201 on. Through the storage area 201 is designed as a bearing ball slider 4 according to 1 received. In the illustrated embodiment, a radius of the spherical bearing surface 201 while slightly smaller than a radius of the bearing ball, so that between the bearing ball and the bearing surface 201 there is a line contact. The bearing ball is without finishing on the spherical bearing surface 201 positionable with sufficient accuracy.

The holding element 20 is designed as a stepless hollow cone, so that a simple production of the partition 2 with the holding element 20 as a deep-drawn part is possible. A maximum diameter of the retaining element 20 is dimensioned so that the holding element 20 a wobbling motion of the rotor unit 1 according to 1 not impaired in use.

How best in 3 is recognizable, is the dividing wall 2 in the form of a in a floor area 21 flattened calotte trained. The separation area between the rotor unit 1 and the stator according to 1 defines one to a center M of the storage area 201 essentially concentric sphere section area 22 with a radius R. A height H of the partition 2 ie a distance of a floor surface 21 from the midpoint M is minimized in the illustrated embodiment. This will create a flat partition 2 for a flat rotor unit 1 created.

In an in 5 shown in detail edge area 23 the partition 2 is a recording room 230 formed for a stator, not shown. As in 1 is recognizable, is preferably an outer edge of the partition 2 for attachment to the housing 3 crimped. The shape of the partition 2 is optimized in terms of flow in advantageous embodiments. Like also in 5 can be seen, closes for this purpose in the illustrated embodiment of the ball portion area 22 with a radius R an area 24 with a sloped surface.

To ensure good manufacturability and stresses in the part of the partition 2 To avoid, have transitions between the ball section area 22 and the floor area 21 , between the ball section area 22 and the area 24 as well as between the floor area 21 and the holding element 20 Radii on.

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• DE 2246418 A1 [0002]

Claims (10)

Partition for an electric motor, comprising a stator and a slider ( 4 ) rotatably mounted rotor unit ( 1 ), wherein the partition ( 2 ) has a closed surface at least in a separation area and sealingly between the stator and the rotor unit ( 1 ) can be arranged, characterized in that a holding element ( 20 ) with a closed surface for the sliding body ( 4 ) integral with the partition wall ( 2 ) is formed of a stainless thermoformable material. Partition wall according to claim 1, characterized in that the retaining element ( 20 ) as one of the partition ( 2 ) protruding hollow body, in particular as a hollow cone, is formed. Partition wall according to claim 1 or 2, characterized in that the partition wall ( 2 ) made of stainless steel, in particular of chromium-nickel steel, preferably made of chromium-nickel-molybdenum steel. Partition wall according to claim 1, 2 or 3, characterized in that the retaining element ( 20 ) at its free end a bearing surface, in particular a spherical bearing surface ( 201 ) for a bearing ball designed as a sliding body ( 4 ), wherein preferably a radius of the spherical bearing surface ( 201 ) is less than a radius of the bearing ball. Partition according to one of claims 1 to 4, characterized in that the partition ( 2 is formed as a flattened in a bottom region Trennkalotte, wherein the separation area a to the sliding body ( 4 ) substantially concentric spherical section area ( 22 ) Are defined. Partition wall according to claim 5, characterized in that a distance (H) of the floor area ( 21 ) from a midpoint (M) of the sphere portion region (FIG. 22 ) is minimized such that a ratio (H / R) of the distance (H) to a radius (R) of the ball portion region ( 22 ) is less than about 0.8, in particular less than about 0.7, preferably less than about 0.6. Method for producing a dividing wall according to one of claims 1 to 6, characterized in that the dividing wall ( 2 ) with the retaining element ( 20 ) is produced in a deep-drawing process. Pump with an electric motor, comprising a stator, one on a sliding body ( 4 ) rotatably mounted rotor unit ( 1 ) and one between the rotor unit ( 1 ) and the stator sealingly arranged partition wall ( 2 ) according to one of claims 1 to 6. Pump according to claim 8, characterized in that the retaining element ( 20 ) than from the partition ( 2 ) projecting hollow body, in particular as a hollow cone is formed, wherein in a cavity of the holding element ( 20 ) at least one sensor is arranged. Pump according to claim 9, characterized in that the sensor is designed as a temperature sensor and / or as a sensor for measuring magnetic fields, in particular as a Hall sensor.

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