Ventilation device for transmissions with lubricant comprising water

Abstract

A ventilation device for transmissions with lubricant comprising water, the device being disposed above the transmission (1) and being connected thereto by way of a line (10) and comprising a pressure equalization opening (13) that leads to the surrounding environment, is to operate without loss of evaporating water to the environment. To this end, the device comprises at least one container (17) designed as a condenser for evaporated water rising through the line (10), the container being provided with a cooling element for dissipating heat (15), the condensate passing from said container (17) back to the transmission (1). In one variant, two containers containing a fluid are described which communicate with one another by way of a U-shaped channel.

Description

BACKGROUND OF THE INVENTION[0001]The invention relates to a ventilation device for transmissions with a lubricant containing water, wherein the ventilation device is connected to the transmission housing via a line and has a pressure equalization opening leading to the environment.[0002]In oil-lubricated transmissions there is a ventilation opening, which allows pressure equalization with the environment when the temperature in the transmission rises or falls due to operating conditions and which is usually equipped as a device with installations for retaining oil mist and for keeping away dirt from the environment.[0003]WO 2007 / 098523 A1 discloses a lubricant containing water, which in addition to a high proportion of water contains an agent lowering the freezing point, such as glycol, and further additives and / or suspended matters. Further details as well as the advantages to be obtained with such a lubricant can be gathered from the above-mentioned publication.[0004]DE 22 20 565 ...

AI Technical Summary

Benefits of technology

[0013]The liquid in the siphon and in the two containers can be water, an agent lowering the freezing point, for example, glycol or a mixture of both. Depending on the conditions and requirements, the one or the other is to be preferred. If no temperatures below the freezing point are to be expected, water is preferable because in this way the composition of the lubricating liquid in the transmission remains unchanged. Otherwise the agent lowering the freezing point is more advantageous.

[0014]In a further development of the invention, the space filled with liquid contains a porous material of high thermal conductivity. This improves heat transfer and condensation and prevents fluctuating of the levels of liquid in the two containers. As the porous material, in particular stainless steel wool has proved its worthiness.

Problems solved by technology

This leads to the fact that not only the amount of lubricant in the transmission becomes less and less, which soon results in the destruction of the transmission, but also the composition of the lubricant changes because the proportion of water becomes smaller and smaller.

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