DE10340802B4 - Device with output shaft and shaft sealing ring - Google Patents

Abstract

Device with output shaft, comprising toothed parts and at least one shaft sealing ring for sealing the output shaft against a housing part of the device, characterized in that the shaft sealing ring comprises components made of at least two different materials, at least one first component having at least one sealing lip (4), at least the first Component of the shaft sealing ring is designed from an electrically conductive material, a first toothing part consists of a different material than a further toothing part with which the first is in engagement, the first toothing part is a spur gear or a worm gear and the further toothing part is a spur gear or a Slug.

Description

The invention relates to a device with an output shaft and a shaft sealing ring.

Such devices are known, for example, as drive components such as an electric motor, transmission, clutches or brakes. In the case of gearboxes in particular, an output shaft is mounted in a housing of the gearbox. At least one toothed part, which is in engagement with other toothed parts, is fastened within the housing on the output shaft. When these gear parts move, charge separations take place, which lead to the charging of the rotatable part. But even when using different materials of the toothed parts, electrochemically induced voltages arise between the toothed parts. The resulting currents are partially discharged through the use of lubricants such as mineral lubricants. In some cases, currents are forwarded to connected parts via the rotatable part, especially when using synthetic oils as lubricants. On the one hand, the gear parts are at risk, the lubricant is exposed to electrochemical reactions and the connected parts are energized and thereby endangered.

Shaft seals are used to seal shafts between them and an associated device. In particular, gears are known as such devices.

From the WO 02/086351 A2 A planetary gear is known in which two shaft sealing rings are used on the input and / or output side to increase the tightness.

From the US 6004039 A a shaft seal is known which has components made of different materials.

The invention is therefore based on the object of developing a device with an output shaft and a shaft sealing ring in such a way that hazards caused by electrical currents generated from gear teeth by means of toothed parts can be reduced and lifetimes increased.

According to the invention the object is achieved in the device according to the features specified in claim 1.

Features of the invention in the case of the shaft sealing ring are that the shaft sealing ring comprises components made of at least two different materials,
wherein at least one first component has at least one sealing lip,
wherein at least the first component of the shaft sealing ring is made of an electrically conductive material.

The advantage here is that currents can be easily discharged through the shaft sealing ring, with no additional part being necessary, but rather the existing parts being usable, with only a simple choice of material being necessary. In particular, an electrically conductive plastic can be selected as the material for the first component.

The device is preferably a transmission in which the output shaft is connected to a first toothed part which is made of a different material than a further toothed part with which the first is in engagement.

According to the toothing part is a spur gear or a worm gear which is in engagement with a worm.

In an advantageous embodiment, the worm wheel is made of a different material than a further toothed part with which the first is in engagement.

In an advantageous embodiment, at least one further component is made of metal.

In particular, it is a spring element, a support ring or an outer ring, as a result of which the mechanical stability can be improved and the electrical resistance of the shaft sealing ring can be reduced overall.

In an advantageous embodiment, the material for the first component is more electrically conductive than polyamide, polystyrene or a synthetic oil that can be used as a lubricant.

Essential features of the invention in the device with an output shaft are that it comprises at least one shaft sealing ring for sealing the output shaft against a housing part of the device, the shaft sealing ring comprising components made from at least two different materials, at least one first component having at least one sealing lip, at least the first component of the shaft sealing ring is made of an electrically conductive material.

The advantage here is that the voltages and currents occurring in the device can be derived. Thus, other devices can be driven by the device without any risk for them, in particular also without risk for devices with additionally integrated electronics.

Further advantages result from the subclaims.

• In der 1 ist ein Schnitt durch einen Radialwellendichtring mit metallischem Außenring 1 und einem Mantel 3 gezeigt, wobei im Mantel 3 eine als Zugfeder 2 ausgebildete Ringfeder vorgesehen ist. Der Mantel 3 weist eine Dichtlippe 4 auf, die über den Ölschmierfilm mit der äußeren Oberfläche einer nicht gezeigten Welle als Dichtung zusammenwirkt. Der Anpressdruck wird durch die Zugfeder 2 wesentlich bestimmt. Allerdings ist auch durch die genaue Ausformung und Geometrie des Mantels 3 und der Welle der Anpressdruck beeinflussbar.
• In der 2 ist ein anderer Wellendichtring gezeigt. Dabei weist der Mantel 21 als weitere Lippe eine Staublippe 22 und einen metallischen Stützring 23 auf. Dieser Stützring 23 beeinflusst ebenfalls durch seine geometrische Form den Anpressdruck der Dichtlippe 4 an die Welle.
• In den 3, 4 und 5 sind räumliche Ansichten von erfindungsgemäßen Wellendichtringen mit jeweils verschiedenen Mänteln 3, 41 und 51 gezeigt.

The invention will now be explained in more detail with the aid of figures:

• In the 1 is a section through a radial shaft seal with a metallic outer ring 1 and a coat 3rd shown, being in the coat 3rd one as a tension spring 2nd trained ring spring is provided. The coat 3rd has a sealing lip 4th on the oil lubricating film cooperates with the outer surface of a shaft, not shown, as a seal. The contact pressure is generated by the tension spring 2nd essentially determined. However, it is also due to the precise shape and geometry of the jacket 3rd and the shaft of the contact pressure can be influenced.
• In the 2nd another shaft seal is shown. The coat shows 21 as a further lip a dust lip 22 and a metallic support ring 23 on. This support ring 23 also influences the contact pressure of the sealing lip due to its geometric shape 4th to the wave.
• In the 3rd , 4th and 5 are spatial views of shaft seals according to the invention, each with different shells 3rd , 41 and 51 shown.

In other exemplary embodiments according to the invention, the jacket has further sealing lips and / or is made in two or more parts.

The shaft sealing ring is provided in particular for a gearbox or another device with a closed interior that is at least partially filled with lubricant.

By way of example, the shaft is an output shaft of a transmission, the shaft being connected to a toothing part which is in engagement with at least one further toothing part. Not only mineral oil but also synthetic oil is permitted as a lubricant, although it has an extremely low electrical conductivity.

However, the choice of the material of the components is an essential and further aspect of the invention. In the shaft sealing ring according to the invention, a material is used which has a higher electrical conductivity than polyamide or synthetic oil, which can be used as a lubricant in the transmission.

Instead of a transmission, a motor, in particular an electric motor fed by a converter, can be used as a device with an interior. The rotatable part is a rotor shaft of the motor.

Reference list

1

metallic outer ring

2nd

Tension spring

3rd

coat

4th

Sealing lip

21

coat

22

Dust lip

23

Support ring

41

coat

51

coat

Claims (9)

Device with output shaft, comprising toothed parts and at least one shaft sealing ring for sealing the output shaft against a housing part of the device, characterized in that the shaft sealing ring comprises components made of at least two different materials, at least one first component having at least one sealing lip (4), at least the first component of the shaft sealing ring is made of an electrically conductive material, a first toothing part consists of a different material than another toothing part with which the first is in engagement, the first toothing part is a spur gear or is a worm gear and the further toothing part is a spur gear or a snail. Device after Claim 1 , characterized in that the material for the first component is an electrically conductive plastic. Device according to at least one of the preceding claims, characterized in that at least one of the further components is made of metal. Device according to at least one of the preceding claims, characterized in that one of the further components or the further component is a spring element. Device according to at least one of the Claims 1 to 3rd , characterized in that one of the further components or the further component is a support ring. Device according to at least one of the Claims 1 to 3rd and 5 , characterized in that one of the further components or the further component is an outer ring (1). Device according to at least one of the preceding claims, characterized in that the material for the first component is more electrically conductive than polyamide, polystyrene or a synthetic oil that can be used as a lubricant. Device according to at least one of the preceding claims, characterized in that the device is a transmission. Device according to at least one of the preceding claims, characterized in that the output shaft is connected to the first toothed part.

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