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Entry type: FAQ Entry ID: 109755298, Entry date: 01/29/2018

SIMOGEAR, 2KJ1/2KJ3: Installing the oil expansion unit

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How is the expansion unit installed?

An oil expansion unit can be used depending on the power, drive speed, type of construction and transmission ratio. It is used to equalize changes in the oil volume caused by temperature fluctuations during operation.

The oil expansion unit is supplied as mounting set, and can either be mounted vertically on the geared motor or at an angle.

The oil expansion unit for sizes 39 to 89 is mounted using a screw connection at the highest hole on the gearbox housing or motor bearing shield.

Before commissioning the gearbox, replace the pressure vent valve that is already installed with the provided oil expansion unit.


  1. Completely unscrew the pressure vent valve with transport fixture.
  2. Screw in the completely preassembled oil equalization unit.
  3. Align the oil expansion unit so that it is vertical.

The vent valve must be replaced every year to ensure correct functioning. When replacing, prevent dirt and damaging atmospheres from entering the gearbox.

Note: Please refer also to

Operating instructions BA 2030: SIMOGEAR gearbox 60666158

Catalog MD 50.1: SIMOGEAR Geared Motors 109746934

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