A displacement pump with a barrier against the fluid leakage

Abstract

A displacement pump driven by a motor, wherein a barrier (4.1; 8; 2.2) suitable for preventing or reducing the fluid leakage is inserted in at least one of the pump regions which are subjected to a leakage between the inner space of the pump and the outside. In one embodiment, in one of two component parts (2,4) subjected to relative movement is formed at least one step (4.1 ) which determines a limited region of mutual contact between the two component parts (2,4) subjected to relative movement, thus forming a sort of labyrinth which favores the seal against the fluid leakage. As an alternative, on one of the two component parts (2,4) subjected to relative movement is provided an annular inclined area (4.2) located facing a seat (2.1 ) for an annular sealing element (8) whereby, due to the pressure difference between the inner fluid and the outer fluid, the annular sealing element (8) is biased to contact against the annular inclined area (4.2). Moreover, the sealing barrier (2.2) can be provided in the region wherein there is a coupling joint (5) driving the rotor (4), by forming on the support member (2) a step (2.2) which acts as a closure for the rotor (4) and keeps in position the driving coupling joint (5), the coupling clearance being annulled by the oil penetrating between the parts.

Description

technical field [0001] The subject of the invention is a displacement pump equipped with a barrier against fluid leakage, the purpose of which is to prevent or reduce the exchange of fluid between the interior space of the pump and the outside. Background technique [0002] According to the applicant's research, it was found that in displacement pumps, and mainly in vacuum pumps used in automobiles, one of the key factors that negatively affects the good performance of the pumps is fluid leakage, including leakage from the inner space of the pump to the outside and from the The outside leaks into the pump interior space. The subject matter developed below finds application in pumps which are provided with one or more sliding areas communicating with the outside, or in which significant leakage occurs through the guide area of ​​the shaft or rotor. [0003] Fluid leakage between the pump interior and the outside adversely affects pump performance in a direct manner, mainly b...

AI Technical Summary

Problems solved by technology

[0003] Fluid leakage between the pump interior and the outside adversely affects pump performance in a direct manner, mainly because, for vacuum pumps, it involves air or fluid re-entering the pump interior from the outside, thus compromising the achieved low pressure level and the time it takes to achieve low pressure levels

However, fluid leakage also adversely affects performance in an indirect manner, as fluid leakage results in the removal of oil lubricating mutually displaced components and in this way leads to an increase in the amount of oil required to lubricate the pump, thus supplying lubrication Increased energy consumption of oil-based equipment and increased strain on component parts

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