RU2331771C2 - Compensator of axial forces acting on screw machine rotor - Google Patents

Abstract

FIELD: engines and pumps.

SUBSTANCE: invention relates to machine building, particularly, to screw machines. The compensator of axial forces acting on the rotor contains a housing accommodating a piston, a balancing chamber formed by the piston and the housing and communicating with the pressure source to counteract against axial forces. The piston is arranged in the housing with a clearance and coupled with the latter by seals. The compensator is provided with a pressure element transmitting the force to the shaft and a bearing with one racer fastened at the piston and the other one linked with the shaft end of the unloaded rotor. The seal can be made as a membrane, or a bellows, or O-rings or a combination thereof. The housing is coupled with the compensator by fasteners. The housing outer racer is fastened at the piston and the inner one linked with the shaft end of the unloaded rotor, or the inner racer is fastened at the piston and the outer one linked with the shaft end of the unloaded rotor. The proposed invention increases service life and reliability, rules out working medium leaks through seals, widens the application range thanks to chance of using various working media.

EFFECT: longer life, higher reliability and performances.

4 cl, 6 dwg

Description

The invention relates to the field of engineering, in particular to screw machines.

Known steam screw machine (RU 2168023 C1, 05.27.2001, F01C 1/16) having devices for compensating axial and radial forces acting on the rotor, in which the device for compensating axial forces acting on the driving rotor is made in the form of a piston connected with this shaft through the movable element of the unit and installed in the housing of this device. The annular gap between the cylindrical surfaces of the piston and the housing is sealed with rings. It uses water vapor as a working fluid.

The disadvantage of this design is that in the axial force compensation device there is a rapid wear of the sealing rings, due to which steam and its condensate leak into the unit, which reduces the reliability of the steam engine, as well as the low maintainability of the structure.

A device for compensating the axial force acting on the rotor, comprising a housing with a piston installed inside it, an unloading chamber formed by the piston and the housing, connected to a pressure source to provide resistance to axial forces, while the piston is installed in the housing with a clearance and connected with it through the seals, the device is equipped with a bearing, the outer ring of which is fixed to the piston, and the inner ring at the end of the shaft of the unloaded rotor, the seal is made in the form of sealing rings, em bearing outer ring fixed to the piston and the internal - unload the shaft end of the rotor (US 5,281,115 A, 25.01.1994, F01C 1/16).

The disadvantage of this design is that in the axial force compensation device there is a rapid wear of the sealing rings and friction power loss, this design has a low maintainability.

The problem to which the present invention is directed is to increase the service life and reliability by compensating axial forces acting on the rotor of the unit, eliminating leakages of the working fluid through seals, reducing friction losses, and expanding the scope of application by making it possible to use as the working fluid of various environments and increasing the maintainability of the axial force compensation device, and therefore the unit in which it is installed.

The technical result consists: firstly, in the exclusion of the transmission of rotational motion from the discharged rotor to the piston by using a thrust or angular contact bearing associated with the piston, which, in turn, allowed to reduce friction losses in the device itself; secondly, in isolating the discharge chamber of the device using seals used in couples that perform reciprocating movements, for example, bellows, membranes, o-rings, etc., which made it possible to use various media in different aggregate states as a working fluid ( steam, gas, liquid); thirdly, in the use of the pressure element, which made it possible to provide misaligned axial unloading elements due to the use of spherical surfaces in the area of power contact of the pressure element (thrust bearing) and the end of the rotor shaft of the unit.

The specified technical result is achieved in that the device for compensating the axial force acting on the rotor comprises a housing with a piston installed inside it, an unloading chamber formed by the piston and the housing, in communication with a pressure source to provide resistance to axial forces, while the piston is installed in the housing with a gap and connected with it through seals, the device is equipped with a pressure element that transfers force to the shaft, and a bearing, one of the rings of which is fixed to the piston, and the other is connected the end of the shaft of the discharged rotor, the seal is made in the form of a membrane or bellows, or o-rings, or combinations thereof, and the housing is connected to the unit by means of connecting elements, with the outer ring of the bearing mounted on the piston and the inner ring at the end of the shaft of the discharged rotor, or the inner ring the bearing is mounted on the piston, and the outer one is at the end of the shaft of the unloaded rotor.

In addition, embodiments are possible in which:

in the gap between the piston and the housing or unit mounted bodies of revolution;

guides are made on the housing and / or piston to allow for the longitudinal movement of the piston;

rotation bodies are located in guides.

Figure 1 shows a section of the first embodiment of the device, in which the outer ring of the bearing is mounted on the piston;

figure 2 is a section of the second embodiment of the device, in which the inner ring of the bearing is mounted on the piston, and on the outer mounted pressure element, with which the axial force is transmitted to the shaft of the unloaded rotor;

figure 3 is a section of a second embodiment of a device in which the piston is installed in the housing of the unit;

figure 4 is a section of a second embodiment of the device with the location of the pressure element on the shaft;

figure 5 is a section of a second embodiment of a device operating according to the "pulling principle";

figure 6 shows the skew of the shaft.

The present invention is illustrated by a specific implementation example, which, however, is not the only possible, but clearly demonstrates the possibility of achieving the above set of features of a technical result.

A device for compensating axial force (Figs. 1, 2, 3, 4, and 5) acting on the rotor comprises a housing 1 with a piston 2 installed inside it, to which an angular contact bearing 3 is connected. One of the bearing rings is mounted on the piston 2 and the other is connected to the end of the shaft, for example, the driving rotor of a screw machine. The piston 2 is connected to the housing 1 through seals 5 to prevent the ingress of the working fluid inside the unit; this solution made it possible to use various media, gas, steam, and liquid as the working fluid. Seals 5 can be made in the form of a membrane, bellows, o-rings, or combinations thereof. In all the presented embodiments, the piston 2 is installed in the housing 1 of the axial force compensation device, or in the unit housing with a gap to ensure movement along the axis of the shaft 8. In order to set the desired direction of movement of the piston 2, the device has guides 6, and the installation of the piston 2 in the housing 1 and / or the housing 12 of the unit is implemented using bodies of rotation 7. In this case, the guides 6 can be made on the piston 2 and / or the housing 1, and the bodies of rotation 7 are located inside the guides 6.

In the device of FIG. 1, the piston 2 is mounted on the outer ring of the angular contact bearing 3, and the pressure element 4, by which the axial force is transmitted to the shaft 8, is installed in the inner ring 3 *. The discharge chamber 9 of the device is communicated through a fitting 10 with a pressure source (not shown in the drawings).

The housing 1 of the device can be integral with the housing 12 of the unit (not shown) or connected to it by means of connecting elements 11. The presence of spherical surfaces 13 in the area of the power contact of the pressure element 4 of the axial unloading and the end of the shaft 8 makes it possible to compensate for skew axes 14 of the shaft 8 and the power contact of the pressure element 4 of the misaligned arrangement of the axial unloading elements (Fig.6).

In the devices of FIGS. 2, 3, 4 and 5, the inner ring 3 * of the angular contact bearing is mounted on the piston 2, and on the outer 3 there is a pressure element 4, with which the axial force is transmitted to the shaft 8. The discharge chamber 9 of the device through the fitting 10 is also connected to a pressure source.

A feature of the implementation of the device shown in figures 4 and 5, while the outer ring of the bearing 3 is connected with the shaft 8, and the inner ring is with the piston 2, is the location of the pressure element 4 on the shaft 8.

Another design feature of the device depicted in FIG. 5 is that it works according to the “pulling” principle, i.e. creates a "pulling" force applied to the shaft 8 to ensure favorable working conditions of the bearings installed on this shaft.

The device operates as follows.

According to the invention, the movements of the piston 2 are limited by the wall of the housing 1 (Fig. 1, 3) or the wall of the housing 12 (2, 4, 5) and the guides 6 so that the piston 2 can only perform the necessary movement, for example longitudinal along the axis of the rotor, and if necessary, angular relative displacement. In the unloading chamber 9, formed by the walls of the housing 1 and the wall of the piston 2, the working fluid is supplied under pressure, due to which the unloading axial force is created. Moreover, the pressure of the working fluid is, for example, a function of the pressure of the working fluid at the inlet to the unit.

In order to prevent leakage of the working fluid from the unloading chamber 9 into the unit through the gap between the housing 1 and the piston 2, a seal 5 is located, which can be made in the form of a membrane, bellows or in the form of ring seals, etc., which does not prevent the piston 2 from making necessary for the operation of the device of longitudinal displacements relative to the housing 12 of the unit and completely eliminating leakage of the working fluid from the unloading chamber 9 due to the tight installation of the edges of the seals 5 on the piston 2 and the housing 1.

Moreover, in the design of the axial force compensation device, there is no transmission of rotation from the shaft 8 to the piston 2, and therefore, when using the sealing rings as seals 5, they do not wear and fail.

The design of the axial force compensation device, as can be seen from FIGS. 1-5, is easily removable, which makes it maintainable, that is, it allows you to remove and install the axial force compensation device without disassembling the unit itself. To do this, it is enough to remove the elements 11 connecting the housing 12 of the unit and the housing 1 of the device.

The invention meets the condition of patentability "industrial applicability", since it is feasible using known means of production.

Claims (4)

1. A device for compensating the axial force acting on the rotor, comprising a housing with a piston installed inside it, an unloading chamber formed by the piston and the housing, connected to a pressure source to provide resistance to axial forces, while the piston is installed in the housing with a clearance and is connected with through the seals, the device is equipped with a pressure element that transmits the force to the shaft and a bearing, one of the rings of which is mounted on the piston, and the other is connected with the end of the shaft of the unloaded rotor, filled in the form of a membrane or bellows, or o-rings, or combinations thereof, and the housing is connected to the unit by means of connecting elements, with the outer bearing ring mounted on the piston and the inner ring at the end of the shaft of the unloaded rotor, or the inner bearing ring mounted on the piston, and outer - at the end of the shaft of the unloaded rotor. 2. The device according to claim 1, characterized in that in the gap between the piston and the housing or unit mounted bodies of revolution. 3. The device according to claim 1, characterized in that the guides are made on the housing and / or piston to ensure the movement of the piston in the longitudinal direction. 4. The device according to claim 1, characterized in that the bodies of revolution are located in the guides.

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