RU199030U1 - Oil-injected single rotor screw compressor - Google Patents

Abstract

This utility model relates to the field of compressor equipment and, in particular, to screw compressors that are used to compress air, as well as a circulating compressor in industrial refrigeration plants of food industry enterprises. A screw single-rotor oil-filled compressor containing a housing with suction and discharge cavities, two disc toothed cutters and a rotor installed in the housing with the possibility of engaging with the cutters teeth, the helical groove of which has a section bounded by an arc of a circle, in the plane, the end surface of the cutters tooth, in which the lateral surface of each cutter tooth has a profile that provides a minimum clearance when turning at any angle with the surface of the corresponding helical groove of the rotor in the area of engagement.

Description

This utility model relates to the field of compressor equipment and, in particular, to screw compressors, which are used to compress air, as well as as a circulation compressor in industrial refrigeration plants of food industry enterprises.

The utility model can be used as a source of low pressure compressed air.

The main factors that determine the price / quality ratio of screw compressors for obtaining the required parameters of compressed air are:

- availability of manufacturing technology;

- low manufacturing cost;

- structural reliability;

- energy efficiency of compressed air.

A single-rotor screw compressor is known, comprising a housing with suction and discharge cavities, a central screw installed in the housing, and at least one disc toothed cutter mounted with the possibility of engagement with the central screw, while the cutter teeth are made with the possibility of deflection in the plane of the disc relative to the axis fasteners and are equipped with return springs and initial position clamps mounted on the disk so that at the initial moment of engagement the longitudinal axis of the tooth is perpendicular to the axis of rotation of the screw (USSR AS No. 1359485, IPC F04C18 / 16, publication 1987).

The disadvantage of the known device is the increased complexity of manufacturing and low reliability of the compressor containing a large number of moving elements.

Known single-rotor positive displacement screw compressor, oil-filled type, which contains a housing with nozzles for supply and removal of the compressed medium, a rotor installed in it, having a globoid profile with working channels covered by a housing, and two cut-off devices with a rectangular tooth profile, mounted on the shafts perpendicular to the axis of rotation rotor. The compressor working bodies are made of antifriction material. The shutters are installed symmetrically, thereby compensating for the radial forces (US patent No. 3133695, IPC F04C 18/16, published 1965).

The disadvantage of the known single-rotor screw compressor is:

- complex geometry of tightly installed, mutually contacting working bodies, which requires high precision and quality of manufacture;

- low productivity due to the small volume of the working channels in contact with the rectangular profiles of the razor teeth.

A single-rotor screw compressor is known, comprising a housing with suction and discharge cavities, at least one disc toothed cutter, and a screw installed in the housing with the ability to engage with the cutter, the screw groove of which has a section in the plane of rotation of the cutter, limited by an arc of a circle, while the cutter teeth made in the form of screw pillars bounded on the side of the suction and discharge cavities by circles parallel to the plane of rotation of the shutter, and the axis of the screw pillars coincides with the axis of rotation of the shutter (USSR AS No. 1813924, IPC F04C 18/16, publication 1993).

The disadvantage of the known device is that due to the loose abutment of the contacting surfaces of the working bodies, due to the use of cutter teeth in the form of a helical column, which do not contact tightly enough with the helical groove, there is an overflow of the compressed medium from cavities with high pressure in the suction cavity. As a result of mixing a fresh portion of the compressed medium and the overflowing medium entering through the slots, the temperature of the medium in the suction cavities increases, which leads to a decrease in the compressor performance.

The purpose of this utility model is to provide an easy-to-manufacture, cheap, reliable and energy-efficient compressor.

This goal is achieved by creating an oil-filled compressor design with a tighter abutment of the working bodies along the entire thickness of the cutter teeth and increasing the efficiency of the compression process by improving the circumferential profile of the teeth.

The essence of the proposed utility model is as follows.

The screw single-rotor oil-filled compressor contains a housing with suction and discharge cavities, two disc toothed cutters and a rotor installed in the housing with the possibility of engagement with the teeth of the cut-off devices, and the helical groove of the rotor and the teeth of the cut-off devices have a profile that provides a minimum clearance in the engagement area when turning at any angle between the lateral surface of each cutter tooth and the surface of the corresponding helical groove of the rotor, limited by a circular arc in the plane of the end surface of the cutter tooth. In this case, oil is supplied to the engagement area at an angle to the rotor axis of rotation.

FIG. 1 shows a screw single-rotor oil-filled compressor - general view (side view); in fig. 2 is a longitudinal section a-a in FIG. 1; in fig. 3 - cross section b-b in Fig. 1; in fig. 4 is an enlarged view of the engagement of the cutter tooth and the corresponding rotor groove with a minimum clearance a _min in the O-O plane formed by the end surface of the cutter tooth; in fig. 5 - engagement of the cutter tooth profile and the corresponding rotor groove in the O-O plane at zero rotation of the cutter, with a minimum clearance a _min ; in fig. 6 - engagement of the profiles of the teeth of the cutter and the profiles of the corresponding grooves of the rotor in the plane O-O when the cutter is turned through an angle of approximately 30 °, with a minimum clearance a _min .

The screw single-rotor oil-filled compressor (see Fig. 1) contains a housing that includes a lower part 1 and an upper part 2, fastened by a detachable bolted connection. Inside the body (see Fig. 2), a central rotor 3 is installed, which has four grooves and cutoffs 4 and 5 with teeth 6 (five teeth, respectively). The rotor 3 is mounted on a shaft 7, which in turn is placed in angular contact ball bearings 8 and in a deep groove ball bearing 9. The bearing 9 has a sliding fit on the shaft 7 to compensate for thermal expansion of the housing and shaft. The output end of the shaft 7 has a keyway with a key 10 (see Fig. 1) and serves to drive the compressor. Cut-off devices 4 and 5 (see Fig. 3) with teeth 6 are installed in the compressor casing on shafts 11 and 12 in tapered roller bearings 13. To seal the casing (see Fig. 2), a front cover 14 with an oil seal 15 and a collar 16 is provided, as well as the rear cover 17 and the cover 18 of the cut-off devices (see Fig. 3). In parts of the compressor housing 1 and 2 (see Fig. 1), holes are provided (in Fig. 3, covered with covers 18) for installing cut-off devices 4 and 5 in the working part of the compressor, suction windows 19 and discharge 20. End clearances between the lower and upper parts housings 1 and 2 and cutters 4 and 5 are adjusted by changing the thickness of the rings "K", the axial run of the bearings of the cutters 13 - by changing the thickness of the rings "L". Rings are pressed by covers of 18 cut-off devices. The helical groove of the rotor (see Fig. 4, 5, 6), in the plane O-O formed by the end surface of the cutter tooth, has a profile bounded by an arc of a circle with a diameter d. The teeth of the cutters are made in such a way that each point of the lateral surface of the tooth, when rotated at any angle, provides a minimum clearance a _min with the surface of the corresponding helical groove in the engagement area.

Profile minimum clearances a _min (see Fig. 4, 5, 6) in the engagement of the rotor and cut-off devices are regulated by the thickness of the adjusting ring 21.

To the bearings of the rotor and cut-off devices, as well as to the working cavities of the working bodies, oil is supplied through the fittings 22 with chokes 23 (see Figs. 1 and 3).

Screw single-rotor oil-filled compressor works as follows.

When the central rotor screw 3 rotates, the compressed medium through the suction window 19 enters the working cavities of the rotor 3, which, when the rotor 3 rotates, are alternately isolated from the suction chamber 19 by the teeth 6 of the cutters 4 and 5, driven by the rotor 3 and rotating around their axis.

With further rotation of the rotor 3, the process of volumetric compression begins. Compression occurs in parallel in two opposite helical cavities, which allows the rotor 3 to be unloaded from the action of radial forces. By the end of the compression, the medium to be compressed enters the pressure port 20 and leaves the screw compressor.

The utility model expands the arsenal of technical means used to obtain compressed air and provides an easy-to-manufacture, cheap, reliable and energy-efficient compressor.

Claims (2)

1. Screw single-rotor oil-filled compressor containing a housing with suction and discharge cavities, two disc toothed cutters and a rotor installed in the housing with the possibility of engaging with the teeth of the cutters, characterized in that the helical groove of the rotor and the teeth of the cutoffs have a profile that provides when turning at any angle the minimum clearance in the area of engagement between the lateral surface of each cutter tooth and the surface of the corresponding helical groove of the rotor, limited by a circular arc in the plane of the end surface of the cutter tooth. 2. Compressor according to claim 1, characterized in that oil is supplied to the area of engagement of the rotor and cut-off devices obliquely to the axis of rotation of the rotor.

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