SU1446355A1 - Pump shaft unit - Google Patents

Abstract

The invention improves the sealing of the pump shaft. In the bore 2 of the housing 1, high and low pressure contact sealing elements 3 and 4 are installed. Elements 3 and 4 form between the case 1 and the shaft 5 an airtight cavity 6, in which the screw 7 is installed. In the bore 2 there is an anvil ring 8. Element 4 is axially displaceable and spring-loaded to the ring 8 by means of a spring 9. The cavity area 10 6 between element 3 and screw 7 communicates with high pressure area 11 via check valve 12. This design reduces pressure drops on elements 3 and 4 and accumulates leaks in cavity 6, which are forced out of it by means of spring 9. 1 silt (/) with ii; 4 ate SP

Description

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The invention relates to pump construction, namely to contact seals of rotating shafts of hydraulic pumps.

The purpose of the invention is to increase the tightness by reducing the pressure drop across the sealing elements and accumulating leakage in the hermetic cavity.

The drawing shows schematically a shaft sealing assembly, a longitudinal section.

The pump shaft seal assembly includes a housing 1, in the bore 2 of which high and low pressure contact sealing elements 3 and 4 are installed, forming between the casing 1 and the shaft 5 an airtight cavity 65 in which the auger 7 is mounted. 8, the low-pressure sealing element is axially displaced and spring-loaded to the thrust ring 8 by means of a spring 9, while the area 10 of the sealed cavity 6 between the high-pressure sealing element 3 and the screw 7 communicates and with the region 11 of high pressure pump 12 through a check valve.

The seal unit {enu works as follows.

When the shaft 5 rotates, the screw 7 creates a greater pressure on the sealing element 3 and reduces the pressure in front of the element 4, as a result of which the assembly can absorb higher pressure drops. In the event of a short-term increase in the pressure of the pump injection and the leakage of the pumped liquid through the warning element 4, the pumped liquid enters the hermetic cavity 6 and moves

the sealing element 4 in the direction of the low pressure side, which eliminates significant pressure build-up on this cleaning element. After the pump head decreases, the screw 7 pumps the liquid through the non-return valve 12 into the pump. If the pressure generated by the screw 7 is insufficient, then after the pump stops, the leakage accumulated in cavity 6 will be forced out of the pump by spring 9.

The proposed design of the seal assembly eliminates the leakage of the pumped medium from the pump and uses low-pressure sealing elements, for example, of a lip-type type, to seal the pump shaft, which develops high heads in a short period of time.

Claims (1)

Invention Formula five 0 five 0 A pump shaft seal assembly, comprising a housing, in the bore of which a contact sealing element is installed: - high and low pressure, a sealed cavity between the housing and the shaft, which is in order to increase tightness by reducing the pressure drop on the sealing element} and accumulating leakage in an airtight cavity, in the latter a screw is mounted on the shaft, a stop ring is placed in the bore of the housing, a low pressure sealing element is installed with the possibility of axial overload The spacer is spring-loaded to the stop ring, while the area of the sealed cavity between the high-pressure sealing element and the auger communicates with the high-pressure area of the pump through a check valve.