RU77368U1 - CENTRIFUGAL PUMP - Google Patents

Abstract

The centrifugal pump relates to mechanical engineering and can be used in centrifugal pumps such as NDG, NDM and NDD with crankcase lubricant and contains a housing 1, covers 2 and bearing assemblies connecting the stator part to the rotor one, which includes shaft 3, impellers 4 and the moving part of bearing units including inner rings of bearings 5, 6 and a rotating sleeve 7 located between them, with a freely rotating ring 8, in addition, the movable part of the bearing assemblies is equipped with a freely rotating additional ring 9, located nym on the sleeve 10.

1 p. Fs, 2 figs.

Description

Technical solution centrifugal pump refers to mechanical engineering and can be used in centrifugal pumps such as NDG, NDM and NDD with crankcase lubrication.

Known pump [1], including the stator and rotor parts. The stator part contains a housing, on the sides of which covers are installed. Bearing assemblies are attached to the covers on the brackets, connecting the stator part with the rotor part. The rotor part comprises a shaft with an impeller and a movable part of the bearing assemblies. The bearing is lubricated by a freely rotating ring.

This design of the bearing assembly is very short-lived, since the assembly has one radial bearing that accepts axial loads of alternating signs, caused by an unstable flow of the pumped liquid.

Also known is a pump [2], which also includes stator and rotor parts. In this case, the stator part comprises a housing, covers and bearing units. The latter connect the stator part with the rotor part. The rotor part includes a shaft with an impeller and a movable part of the bearing assembly, which contains two angular contact bearings located at one end of the shaft. Bearings are lubricated and cooled by a freely rotating ring.

This bearing assembly has several advantages in terms of load sensing and rotor retention from axial displacements, but the lubrication of bearings is uneven. A freely rotating ring, which carries oil along with it, drops it onto the bearing, which is located immediately near the ring. The second bearing, which is more distant from the ring, is in the worst position and receives two or more times less lubrication. As a result, the second bearing, due to insufficient lubrication, wears out much faster.

In this pump, bearings are cooled by oil, which, in turn, is cooled by an additional heat exchanger integrated in the housing of the bearing housing. Such cooling is effective, but constructive - the dimensions of the bearing housing increase, the shaft lengthens, naturally increases its deflection, which negatively affects the pump. Also, in this pump, in addition to the indicated bearings, there are sliding bearings on both sides of the shaft, which absorb only axial load and also increase dimensions.

To eliminate these shortcomings, the task was set to create a centrifugal pump with reduced dimensions by improving the bearing assemblies.

To solve this problem, a technical solution is proposed, the centrifugal pump containing the stator and rotor parts, while the stator part contains a solid or stacked housing, covers and bearing assemblies connecting the stator part to the rotor part, the latter includes a shaft with a working impeller / wheel / s / and the movable part of the bearing units with a freely rotating ring.

Unlike the known technical solution, in the inventive centrifugal pump, a freely rotating ring is located in

slots between two bearings mounted on both ends of the shaft, in addition, each bearing assembly is equipped with a freely rotating additional ring located in front of the bearings.

All the distinguishing features are new, interconnected, necessary and sufficient to solve the task, namely:

- a freely rotating ring is located in the gap between the two bearings. The ring, installed between the two bearings, rotates freely during pump operation, carries oil along with it and transfers it from the crankcase oil bath of the bearing housing to the rotating sleeve. Further, the oil under the action of centrifugal force evenly enters the bearings, which are located on both sides of the ring.

Thus, the bearings operate under the same conditions, which means that their wear will be uniform, that is, the bearing service life is increased;

- two bearings are installed on both ends of the shaft. Installation of two radial bearings on both ends of the shaft allows to reduce the dimensions of the pump, reduce the axial load on each of these bearings, remove the sliding bearings from both ends of the shaft (there were two radial bearings and two sliding, four radial bearings became);

- each bearing assembly is equipped with a freely rotating additional ring located in front of the bearings. Such an additional ring, mounted in front of the bearings, cools the shaft, which is heated by the pumped hot liquid. Thus, bearings do not receive heat from the shaft, that is, thermal expansion does not act on bearings. This means that the bearings operate under normal conditions and this positively affects the duration of their work and the pump as a whole.

The inventive centrifugal pump is illustrated by drawings.

Figure 1 - shows a centrifugal pump in the context.

Figure 2 - shows the bearing assembly in section

The centrifugal pump contains a housing 1, covers 2 and bearing units connecting the stator part with the rotor part. The rotor part includes a shaft 3, impellers 4 and a movable part of the bearing assemblies, including the inner rings of the bearings 5, 6 and a rotating sleeve 7 located between them with a freely rotating ring 8. In addition, the movable part of the bearing assemblies 5, 6, is equipped with a freely rotating additional a ring 9 located on the sleeve 10 in front of the bearings 5, 6.

The centrifugal pump operates as follows.

When the rotor rotates, the impeller captures the working fluid and directs it to the discharge pipe under the action of centrifugal force. The resulting axial force acts on the entire rotor, trying to shift it towards the suction cover. Four angular contact bearings, two on each side, compensate for the axial load. For reliable and long-term operation of bearings, they need lubrication, which is provided by a freely rotating ring 8, located between bearings 5, 6.

When pumping liquids with a high temperature, it is necessary to cool the shaft. This is done by a freely rotating additional ring 9. The rings 8, 9 rotating, carry the oil along with them. Ring 8 discharges oil to sleeve 7, then this oil, under the action of centrifugal force, diverges uniformly in both directions, that is, on bearings. At the same time, an additional ring 9 dumps oil onto the sleeve 10. When cooled, the sleeve 10 draws heat from the shaft 3, in other words, cools the shaft.

Thus, the freely rotating ring 8 evenly lubricates the bearings, and the freely rotating additional ring 9 cools the shaft 3.

As a result of uniform lubrication of the bearings and their operation at the nominal temperature, they created optimal conditions that positively affect the operation of the entire pump.

Thus, the improvement of the bearing units and their installation at both ends of the shaft allow us to solve the problem of reducing the size of the pump. In addition, the weight of the pump is reduced, which positively affects its cost.

This technical solution can be used in many types of pumps, it is simple to manufacture and does not require additional material and financial costs.

Claims (1)

A centrifugal pump containing stator and rotor parts, while the stator part contains a one-piece or stacked housing, covers and bearing assemblies connecting the stator part to the rotor part, the latter includes a shaft with impeller (s) and a movable part of the bearing assemblies with freely rotating ring, characterized in that the freely rotating ring is located in the gap between two bearings mounted on both ends of the shaft, in addition, each bearing assembly is equipped with an additional freely rotating ring, located in front of the bearings.