CN211924399U

CN211924399U - Reciprocating compressor

Info

Publication number: CN211924399U
Application number: CN202020127457.XU
Authority: CN
Inventors: R·克雷默; R·普夫; D·E·B·利耶; A·A·德艾斯宾窦拉; A·B·费尔德曼
Original assignee: Embraco Industria de Compressores e Solucoes em Refrigeracao Ltda
Current assignee: Nidec Global Appliance Compressores e Solucoes em Refrigeracao Ltda
Priority date: 2019-12-11
Filing date: 2020-01-20
Publication date: 2020-11-13
Anticipated expiration: 2030-01-20
Also published as: BR102019026312A2

Abstract

The utility model discloses a reciprocating compressor, it is particularly suitable for including axial-flow type electric motor as the driving source, this axial-flow type electric motor's stator axially arranges on the rotor. An axial bearing disposed between a lower surface of the axial channel of the mounting block and an upper surface of the rotor region physically coupled to the rotating shaft is also provided.

Description

Reciprocating compressor

Technical Field

The present invention relates to a reciprocating compressor, preferably for use in refrigeration systems, and particularly suitable for including an axial-flow electric motor as a drive source.

In general, the present invention focuses on the arrangement of bearings required to realize an axial flow electric motor in a reciprocating compressor.

Background

As is well known to those skilled in the art, the prior art is integrated by radial flow electric motors. Although radial electric motors can be constructed of different technologies, it is important to note that the stator-rotor topology is always the same.

Fig. 1 shows a complete schematic representation of the stator-rotor topology of a radial motor. As shown in this figure, it can be observed that the rotor 100 is annularly surrounded by the stator 102. The arrangement of radial motors in which the stator is surrounded annularly by the rotor is also known. In any case, a radial electric motor with respect to a stator-rotor topology can be characterized by the fact that: the rotating magnetic field between rotor 100 and stator 102 (see illustrative arrows in fig. 1) is generated between the radial physical separation between the rotor and the stator.

As is well known to those skilled in the art, a radial electric motor can be associated with the rotating shaft of a reciprocating compressor without complications; after all, no axial movement is foreseen between the relative positioning between the stator and the rotor.

As is well known to those skilled in the art, the prior art is integrated by an axial flow electric motor. While axial flow electric motors can be constructed of different technologies, it is important to note that the stator-rotor topology is always the same.

Fig. 2 shows the stator-rotor topology of an axial flow motor in a complete schematic representation. As shown in this figure, it can be observed that the rotor 200 is arranged on the stator 202 in the same radial plane. The arrangement of axial flow motors whose stators are arranged on the rotor in the same radial plane is also known. In any case, an axial flow electric motor with respect to a stator-rotor topology can be characterized by the fact that: the rotating magnetic field between the rotor and the stator (see the illustrative arrows in fig. 1) is generated between the axial physical spacing between the rotor and the stator.

Unlike a radial electric motor in which electromagnetic integration between a stator and a rotor generates only a rotational force in the rotor, an axial electric motor is subjected to an attractive force between the rotor and the stator in the axial direction in addition to the rotational force in the rotor. This means that the rotating shaft attached to the rotor of an axial flow electric motor tends to undergo axial displacement in addition to rotational movement. Therefore, by including such other displacement force vectors between the rotor and the stator, the axial-flow type electric motor can hardly be applied to the reciprocating compressor; after all, conventional reciprocating compressor embodiments do not include mechanical elements capable of handling axial movement of the rotating shaft.

The present invention has been made based on this background.

SUMMERY OF THE UTILITY MODEL

The main object of the present invention is to disclose a reciprocating compressor particularly adapted to comprise an axial flow electric motor as driving source.

In this sense, another object of the present invention is that the reciprocating compressor comprises means able to mitigate the transmission of the axial movement between the rotor and the stator of the axial-flow electric motor to a movable element, coupled to the rotating shaft, integrated with the compression mechanism.

All the above objects are achieved by the reciprocating compressor disclosed herein, comprising at least one mounting block (provided with at least one axial channel, at least one vertical protrusion and at least one compression cylinder), at least one rotating shaft (provided with at least one platform and at least one internal lubrication channel) and at least one electric motor integrated by at least one rotor and at least one stator, the rotor of the electric motor being physically coupled to the rotating shaft and the stator of the electric motor being physically coupled to the mounting block, the rotor being fastened to the rotating shaft by a fastening arrangement. According to the present invention, the electric motor comprises an axial flow motor, the stator being arranged axially between the centre of the mounting block and the rotor. Also in accordance with the present invention, the reciprocating compressor further comprises at least one axial bearing disposed between a face of the axial passage and the rotor physically coupled to the rotating shaft, the face of the axial passage being distal from a face near the platform of the rotating shaft.

Drawings

Fig. 1 schematically shows a top view of a radial motor;

fig. 2 schematically shows a side view of an axial flow motor;

figure 3 schematically shows the coupling between an electric axial motor and the reciprocating mechanism of a reciprocating compressor, particularly suitable for such coupling, the reciprocating compressor object of the present invention being described in detail on the basis of figure 3.

Detailed Description

Thus, according to the present invention, as schematically illustrated in fig. 3, a reciprocating compressor is provided, which comprises, in addition to other traditional systems and components known to those skilled in the art, a mounting block 1, a rotating shaft 2 and an axial-flow electric motor constituted by a rotor 3 and a stator 4.

Said mounting block 1, preferably made of a metal alloy, comprises an axial channel 11 configured for receiving the rotating shaft 2, at least two vertical projections 12 configured for fastening the mounting block 1 to a compressor housing (not shown), and a compression cylinder 13 configured for receiving a movable piston integrated with a compression mechanism. It is important to underline that, in general, the basic construction of the mounting block 1 as described and illustrated in fig. 3 is conventional and therefore belongs to the prior art.

Said rotating shaft 2, preferably made of a metal alloy, comprises a platform 21, the platform 21 being provided with an eccentric upper end and an internal axial channel 22 for circulating lubricating oil, which channel extends from the lower end of said rotating shaft 2 to an internal radial channel for lubricating oil outlet, the internal axial channel 22 and the internal radial channel being fluidly connected to each other such that lubricating oil entering the internal axial channel 22 is sprayed by the internal radial channel. It is also worth emphasizing that the basic construction of the rotating shaft 2 as described and illustrated in fig. 3 is conventional in general and therefore belongs to the prior art.

The electric motor (integrated by the rotor 3 and the stator 4) is an electric motor of the axial flow type, as shown in fig. 2 and widely described in the technical literature.

As shown in fig. 3, the rotor 3 is spatially arranged below the stator 4. However, from a more conceptual point of view, it can also be said that the stator 4 is arranged axially between the centre 15 of the mounting block 1 and the rotor 3.

According to the present invention, the rotor 3, which essentially consists of magnets 31 mounted on a support structure, is fastened to the rotating shaft 2 by means of a fastening arrangement 32, which fastening arrangement 32 may comprise any known fastening arrangement (welding, adhesive, screws, etc.). The support structure and the fastening arrangement 32 are intended to transmit the rotational movement of the rotor 3 to the rotating shaft 2.

According to the present invention, the stator 4, which is substantially constituted by an electric coil 41 mounted on a supporting structure (preferably metallic), is fastened to the mounting block 1 by a fastening arrangement 42, which fastening arrangement 42 may comprise any known fastening arrangement (welding, adhesive, screws, etc.). The support structure and fastening arrangement 42 are intended to maintain the positioning of the stator 4 relative to the mounting block 1. As shown in fig. 3, the stator 4 is preferably arranged in an empty space 14 in the lower region of the mounting block 1 between the axial channel 11 and the vertical projection 12.

Considering that the rotor 3 tends to have an axial displacement with respect to the stator 4 when the electric motor is started, it is important to provide a means such that the tendency of such axial displacement does not affect the positioning of the rotating shaft 2, the rotating shaft 2 not being able to undergo axial variations with respect to the mounting block 1. And this is a great technical advantage of the present invention.

In this sense, an axial bearing 5 is provided, arranged between the lower surface of the axial channel 11 of the mounting block 1 and the upper surface of the rotor 3 region physically coupled to the rotating shaft 2. Also from a more conceptual point of view, it can be said that the axial bearing 5 is arranged between the face of the axial channel 11, which face of the axial channel 11 is distant from the face near the platform 21 of the rotating shaft 2, and the rotor 3 physically coupled to the rotating shaft 2.

Preferably, but not limited to, said axial bearing 5 is a rolling bearing or equivalent technical solution. In addition to contributing to the rotation of the rotor 3, such an axial bearing 5 also prevents the rotating shaft 2 from undergoing axial displacement due to the magnetic attraction between the rotor 3 and the stator 4 at the start-up of the electric motor.

The most important advantage of the present invention relates to the fact that by simply realizing the axial bearing 5 in a suitable arrangement, it is possible to use an axial electric motor as the driving source of any reciprocating compressor.

In addition, at least one hydrodynamic radial bearing 6 is provided between the inner surface of the axial passage 11 of the mounting block 1 and the outer surface of the rotating shaft 2. To this end, it should be noted that the space formed between the inner surface of the axial channel 11 of the mounting block 1 and the outer surface of the rotating shaft 2 is particularly suitable for retaining a lubricating oil film (preferably an inner radial channel from the lubricating oil outlet) capable of forming a hydrodynamic radial bearing of said rotating shaft 2.

In this regard, it is very important to note that the radial bearing 6 may comprise any known bearing type, and it is clear that embodiments of such a bearing may be a rolling bearing, a hydrodynamic bearing (a bearing that supplies some type of lubricant between minimal clearances of parallel (and in this case axially aligned) surfaces), or further a hydrostatic bearing (a bearing that forcibly supplies some type of pressure-injected lubricant between two parallel (and in this case axially aligned) surfaces).

Importantly, the foregoing descriptions are intended only to illustrate specific embodiments of the present invention. It is therefore evident that modifications, variations and constructive combinations of elements which perform the same function in substantially the same way to achieve the same results are still within the scope of protection defined by the appended claims.

Claims

1. A reciprocating compressor comprising:

at least one mounting block (1) provided with at least one axial channel (11), at least one vertical protrusion (12) and at least one compression cylinder (13);

at least one rotating shaft (2) provided with at least one platform (21) and at least one internal lubrication channel (22);

at least one electric motor integrated by at least one rotor (3) and at least one stator (4), the rotor (3) of the electric motor being physically coupled to the rotating shaft (2) and the stator (4) of the electric motor being coupled to the mounting block (1);

the rotor (3) is fastened to the rotating shaft (2) by a fastening arrangement (32);

the method is characterized in that:

the electric motor comprises an axial flow motor, the stator (4) being arranged axially between the centre (15) of the mounting block (1) and the rotor (3); and is

The reciprocating compressor further comprises at least one axial bearing (5), the at least one axial bearing (5) being arranged between a face of an axial channel (11) and the rotor (3) or a support member of the rotor physically coupled to the rotating shaft (2), the face of the axial channel being remote from a face near the platform (21) of the rotating shaft (2).

2. The reciprocating compressor according to claim 1, comprising at least one radial bearing (6) between the inner surface of the axial channel (11) of the mounting block (1) and the outer surface of the rotating shaft (2).