RU154860U1 - AXIAL PISTON PUMP DIAGNOSTIC DEVICE - Google Patents

Abstract

A device for diagnosing an axial piston pump, comprising a drain line connected to the pump rotor cavity, the latter having a calibrated orifice installed therein and a differential pressure sensor on the orifice to determine the amount of fuel flow bypassed along the drain line, characterized in that the drain line is provided with a bypass line with an overhead crane installed on it, and the input and output sections of the bypass line are connected to the drain line along the fuel in it before and follows the place of connection to her differential pressure sensor.

Description

The utility model relates to the field of diagnosing automatic control systems for aircraft gas turbine engines (GTE), in particular to the diagnostic systems for axial piston fuel supply pumps.

A device for diagnosing volumetric hydraulic machines is known, comprising a main pump, a hydraulic motor, a make-up pump, an overflow hydraulic valve and a hydraulic tank, the pump being configured to supply working fluid to a low pressure line (see patent RU 2027907, class F04B 51/00, publ. 27.01. 1995.

This device allows you to determine the amount of leakage in the hydraulic machine by replenishing these leaks with an additional circuit with a feed pump, which is installed during diagnosis.

However, in this device it is not possible to use in the diagnosis of axial piston pumps of aircraft gas turbine engines, since this requires an additional bench system with a feed pump, which cannot be installed on the gas turbine engine.

The closest technical solution to the claimed one is a device for diagnosing an axial piston pump, containing a drain line connected to the pump rotor cavity, the drain line is equipped with a calibrated throttle and a differential pressure sensor on the throttle that determines the amount of fuel flow bypassed (see RU patent 2269029, class F04B 51/00, publ. 01/27/2006).

However, this device does not provide the required accuracy for determining leaks, which is due to the fact that it is necessary to drain from the rotor cavity with minimal hydraulic resistance and at the same time provide a pressure drop across the throttle, which, in turn, leads to an increase in pressure in the rotor cavity and as a result, to a violation of the estimated balance of forces on the rotor, an increase in the load on the bearings with a corresponding decrease in the service life of the axial piston pump.

The objective of the utility model is to eliminate the above disadvantages.

The technical result consists in the possibility of reducing the pressure in the rotor cavity at the operating modes of the axial piston pump with a device for diagnosing the axial piston pump.

This problem is solved, and the technical result is achieved due to the fact that the device for diagnosing an axial piston pump contains a drain line connected to the pump rotor cavity, the latter is equipped with a calibrated orifice and a differential pressure sensor on the orifice to determine the amount of discharge flow fuel, while the drain line is equipped with a bypass line with a stopcock installed on it, and the input and output sections of the bypass mag Strahl connected to the drain line downstream of fuel therein before and after connection point to the differential pressure sensor therein.

The drawing schematically shows a device for diagnosing an axial piston pump.

A device for diagnosing an axial piston pump comprises a drain line 3 connected to the rotor cavity 1 of the pump 2.

The drain line 3 is equipped with a calibrated throttle 4 installed therein and a differential pressure sensor 5 on the throttle 4 to determine the amount of fuel flow bypassed along the drain line 3.

Drain line 3 is equipped with a bypass line 6 with a stopcock 7 installed on it, and the input and output sections of the bypass line 6 are connected to the drain line 3 along the fuel line in it before and after the point of connection of the differential pressure sensor 5. The device can be structurally configured in a single unit, joined at the end of the pump.

A device for diagnosing an axial piston pump operates as follows.

Hydraulic losses in the pumping unit of the axial piston pump 2 are determined by fuel leaks into the rotor cavity 1 by the gaps in the distribution valve and plungers, which allows us to evaluate the perfection of the axial piston pump 2 and its volumetric efficiency.

To diagnose the axial piston pump 2, the bypass line 6 is closed with a shut-off valve 7 and the control mode of the gas turbine engine is set according to the rotational speed and fuel consumption GT.

In this mode, the flow meter 8 measures the fuel consumption in the engine, and the sensor 5 - the differential pressure on the calibrated throttle 4, which determines the amount of fuel flow through the drain line 3.

, где F - площадь проходного сечения калиброванного дросселя 4,

- перепад на калиброванном дросселе 4, µ - коэффициент истечения, который определяется экспериментально.Knowing the cross-sectional area of the calibrated throttle 4, determine the fuel consumption from the rotor cavity 2

where F is the flow area of the calibrated throttle 4,

- the differential on the calibrated throttle 4, µ is the expiration coefficient, which is determined experimentally.

When evaluating Gy at different periods of time, the fuel temperature is maintained at the same temperature in the control operation mode of the gas turbine engine. If it is impossible to fulfill this requirement, a correction is made for Gy by the fuel temperature, which is determined experimentally.

After carrying out the measurements described above, the shut-off valve 7 is opened, which allows almost the entire fuel drain to be directed along the bypass line 6.

As a result, a decrease in hydraulic pressure in the discharge line 3 allows one to reduce the pressure in the rotor cavity 1 and, accordingly, restore the optimal design balance of forces on the rotor, reduce the load on the bearings with a corresponding increase in the service life of the axial piston pump. In addition, bypassing fuel along the bypass line 6 allows you to use a calibrated throttle 4 with a smaller bore, which, in turn, can improve the accuracy of measurements of fuel consumption on the drain line 3.

Thus, this device allows you to assess the technical condition of the pump running hours associated with the wear of the main rubbing parts: plungers and distribution spool directly on the turbine engine without significant alterations of the fuel supply system and at the same time ensure the optimal operation of the axial piston pump.

Claims (1)

A device for diagnosing an axial piston pump containing a drain line connected to the pump rotor cavity, the latter having a calibrated orifice installed therein and a differential pressure sensor on the orifice to determine the amount of fuel flow bypassed along the drain line, characterized in that the drain line is provided with a bypass line with a stopcock installed on it, and the input and output sections of the bypass line are connected to the drain line along the fuel in it before and follows the place of connection to her differential pressure sensor.

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