Hydrodynamic Bearing: Features of Application and Principle of Operation

The hydrodynamic bearing is a machine-building unit in which the main load is accounted for by a thin layer of insulating washing liquid pumped by means of a lubricated shaft into the structure. Often, the article is called hydraulic.

Modern hydrodynamic bearings are used in various precision mechanisms, especially when conventional roller or ball varieties do not meet the requirements that are imposed on them to ensure the operation of individual units or structures. For example, the use of hydraulic elements allows for a minimum vibration, low noise level, while the devices have a long service life. Such types of bearings in the process of further improvements and developments are becoming increasingly competitive, since the cost of their production is constantly decreasing.

Unlike hydrostatic products, the hydrodynamic bearing has a slightly different operating principle. If in the first case the working pressure of the liquid is produced by means of a special pump, then in the latter case, self-smearing is performed when the working shaft rotates. It should be noted that the self-smearing effect itself occurs only when certain speeds of the shaft rotation are reached, which are indicated in the product passport.

Otherwise, the thickness of the lubricant under the shaft will be insufficient, which will lead to an increase in frictional forces, and eventually cause premature wear of the mechanism. Thus, to exclude these situations that often occur, for example, when starting and stopping the device, it makes sense to use a special start-up pump that will be used in the described transient modes.

The hydrodynamic bearing has a number of advantages. First, products are reliable and simple in design. Usually in their device they consist of an inner and outer ring with a toroidal shape, at the junctions the products have hermetic seals. Due to the improved design, the hydrodynamic bearing has practically no operating costs (or they are minimal). The mechanism is characterized by a long period of service.

In the production of products, the requirements for the level of accuracy are much lower than for the production of ball or roller types. The noise level from the hydraulic devices is much lower than the sound coming from the rolling bearings. Products produce minimal vibrations. Due to the design features, they have a high damping ability.

The disadvantages of the products include their high sensitivity to the inaccuracies arising in the manufacture of shafts. In addition, they have a significant loss of energy.

Hydrodynamic bearings have found application in computer devices. With their help, the hard drive works, as well as the cooling fans of the system unit. In addition, they are used in nuclear reactors, they operate elements of metalworking machines.