SUCTION VALVES"

Field of the invention

The present invention refers to a reciprocating compressor provided with an arrangement of suction valves and, more particularly, a reciprocating compressor, which is capable of operating with at least two suction lines having different working pressures, is made up of an arrangement of valves comprising at least two "orifice valve" sets.

Generally speaking, the core of the invention in question refers to the physical location of the "orifice valve" sets in the reciprocating compressor, and each of said "orifice valve" sets is disposed in a specific region of the compression mechanism of said reciprocating compressor, so as to streamline assembly and maintenance of the arrangement of suction valve as a whole.

Background of the invention

As it is known to persons skilled in the art, compressors comprise devices capable of compressing a working fluid by volumetric shrinkage of one or more compression chambers where said working fluid is temporarily stored.

Reciprocating compressors, for example, comprise a compression mechanism where a piston slides inside a cylinder, increasing and decreasing the volume of the latter. As it is also known to persons skilled in the art, volumetric shrinkage of a compression chamber is cooperative to the switching of valves which are also part of the compression mechanism of a compressor.

Thus, it is normal that a compression mechanism of a reciprocating compressor, preferably used in a cooling system, should include at least a discharge valve and at least a suction valve. Said valves enable a certain quantity of working fluid to enter inside the compression chamber and, subsequently, enable this quantity of working fluid - under high pressure - to be expelled from the compression chamber.

Normally, the entry of cooling fluid, or suction, is carried out when a suction valve is "open" and a discharge valve is "closed". In contrast, the expulsion of the cooling fluid, or discharge, is carried out when a suction valve is "closed" and a discharge valve is "open".

According to the current state of the art, reciprocating compressors applied in cooling system normally use bypass-type valves, which are shaped by metal blades that are able to change the operating state (from open to closed and from closed to open) based on the difference in pressure inside the compression chamber. Bearing in mind this type of operation, it is possible to define that current bypass-type valves (either for suction, or for discharge) are automatic valves, after all, the change of their operating states occurs without interference from an external operator.

The use of this type of valve is extremely beneficial; after all there is no need for electronic systems or drives responsible for switching its operating states.

According to the most conventional state of the art, it can be noted that a compression mechanism of a reciprocating compressor used in a cooling system is fundamentally made up of a compression cylinder, a valve plate and a mobile piston, and the space defined between the top of the mobile piston, the inner face of the wail of the compression cylinder and the valve plate makes up the compression chamber, the volume of which is altered according to the movement of said mobile piston. In these basic known embodiments, there is provided only one suction set comprised by a suction valve having cooperative actuation with its respective suction orifice, and only one discharge set comprised by a discharge valve having cooperative actuation with its respective discharge orifice. Conventionally, both the suction set and the discharge set are disposed on the valve plate of the reciprocating compressor. As it is known to persons skilled in the art, a suction valve is geared inwardly of the compression chamber and a discharge valve is geared outwardly of the compression chamber.

Therefore, when a suction valve is subject to a suction pressure, it tends to move towards the mobile piston. In contrast, when a discharge valve is subject to a discharge pressure, it tends to move outwardly of the discharge chamber. Accordingly, it is known that the assembly, sizing and actuation of said suction valve is more complex than the assembly, sizing and actuation of the discharge valve. The current state of the art, for example, provides for the shaping of recesses on top of the mobile piston to avoid contact of same with a suction valve.

Besides the basic embodiment cited above, the current state of the art further provides embodiments of reciprocating compressors that are able to actuate with multiple different suction lines among themselves, that is, with multiple suction pressures having different values. These compressors are known as multiple suction reciprocating compressors.

An example of a multiple suction reciprocating compressor is described in document BRP11001359.

In general terms, and as described in said document BRPI1001359, a single compression mechanism is able to operate exclusively with one of at least two suction lines.

Accordingly, said reciprocating compressor is provided with an arrangement of suction valves comprising at least two suction sets and each comprised by a suction valve having cooperative actuation with its respective suction orifice. Evidently, there is further provided a discharge set.

As described in document BRPI1001359, both suction sets, besides the discharge set, are disposed on a single valve plate belonging to the compression mechanism of said reciprocating compressor. Thus, both suction orifices, as well as the fastening means of the suction valves are fastened to or disposed on said valve plate.

It is further noted that one of the suction sets also comprises an electromagnetic field generating element hat is capable of assisting and/or preventing the switching of the operating state (from open to closed and from closed to open) of the suction valve. Consequently, it is ascertained that said suction valve can be driven electronically (by the electromagnetic field generating element) and/or driven automatically (by the difference in pressure of the compression chamber). Bearing in mind this type of operation, it is possible to define that a suction valve is a semi-automatic or semi-commanded valve.

It is therefore possible to assert that the reciprocating compressor of cited document BRPI1001359 comprises an arrangement of suction valves comprising a semi-commanded suction set and an automatic suction set, and that said sets operate exclusively, that is, they do not operate simultaneously.

Therefore, when desirable to select (work with) said suction pressure, it is suffice not to activate the electromagnetic field generating element. Under this circumstance, the very suction pressure keeps the suction valve open and, additionally, the suction valve closed. When desirable to select (work with) a suction pressure, it is suffice to activate the electromagnetic field generating element. Under this circumstance, the magnetic field generated by this element makes the suction valve become attracted so as to obstruct its suction orifice, blocking the suction pressure and enabling the suction pressure to keep the suction valve open in relation to its suction orifice.

The concept of multiple suction compressors described in document BRPI1001359 is extremely interesting and enables improvement of cooling systems comprised by multiple evaporators, after all, each evaporator may have its own suction line and be driven independently from the other evaporators, and this drive selection made on the compressor itself by the simple drive of an electric coil. However, even considering that the general concept described above is beneficial and revolutionary, the embodiments provided for in cited document BRPI1001359 have various aspects that can be streamlined and improved.

One such aspect concerns the current location of the suction sets, which are closely disposed on the valve plate of the compressor. Since they are close, the assembly of this arrangement of suction valves is extremely problematic and, especially in cases where the compressor is a miniaturized compressor, after all, there is less physical space for said assembly.

As is known to persons skilled in the art, one of the main sources of inefficiency of the reciprocating compressors is due to the loss of energy caused by the runoff of cooling fluid through the suction valves. Thus, efforts are made in the development of said compressors to maximize the passage area of the runoff between the suction valve and its respective orifice. This is normally limited by matters of reliability of the bypass and/or geometric restrictions, since the space on the valve plate is restricted.

Moreover, and still relating to the proximity between the suction sets, it is further noted that the introduction of an electromagnetic field generator to the valve plate is extremely problematical, after all, the space for said assembly is highly restricted.

Based on this context, and with a view to remedying this specific aspect, the present invention arises.

Objectives of the invention

Therefore, one of the objectives of the invention in question is to describe a reciprocating compressor provided with arrangement of suction valves capable of resolving the sizing problems related to the embodiment of the arrangement of suction valves detailed in document BRPI1001359.

Thus, it is an objective of the invention in question that the arrangement of suction valves now addressed be capable of facilitating the assembly, maintenance and operation of the multiple suction valves of a multiple suction compressor.

It is another objective of the invention in question that the arrangement of suction valves now addressed be capable of facilitating the addition of an electric coil directly on the valve plate of a multiple suction compressor.

Lastly, it is an objective of the invention in question to streamline the use of space of the valve plate of miniaturized multiple suction compressors.

Summary of the invention

The objectives of the invention in question are fully achieved by way of the reciprocating compressor provided with arrangement of suction valves, where the compressor comprises at least a compression cylinder, at least a valve plate disposed on one of the ends of the compression cylinder, and at least a mobile piston disposed inside the compression cylinder.

Furthermore, said compressor, according to the invention in question, also comprises at least a first "orifice valve" set comprised of at least a suction orifice, at least a suction valve having cooperative actuation with its respective suction orifice), and at least an electromagnetic field generating element capable of selectively interacting with the suction valve and at least a second "orifice valve" set comprised of at least a suction orifice, at least a suction valve having cooperative actuation with its respective suction orifice.

In general terms, the invention in question gains prominence by the fact that said "orifice valve" sets are disposed on different components of the reciprocating compressor.

Description of the drawings

The invention in question will be described in greater detail based on the figures listed below, wherein:

Figure 1 illustrates a double suction compression mechanism comprising a first embodiment of the arrangement of suction valves, according to the invention in question;

Figure 2 illustrates a double suction compression mechanism comprising a second embodiment of the arrangement of suction valves, according to the invention in question; and

Figure 3 illustrates a double suction compression mechanism comprising a third embodiment of the arrangement of suction valves, according to the invention in question.

Detailed description of the invention

As previously explained, the invention in question comprises a complement to the invention detailed in document BRPI1001359, seeking to present certain purely optional improvements, of a technical constructive nature. Particularly, the main objective of the invention in question is to solve the sizing problems related to the embodiment of the arrangement of valves detailed in document BRP11001359.

Therefore, three possibilities of general embodiments are presented, all especially suited to a reciprocating compressor comprising a compression cylinder 1 , a valve plate 2 disposed at one of the ends of the compression cylinder 1 , a mobile piston 3 disposed inside the compression cylinder 1 , a first "orifice valve" set 41 comprised by a suction orifice 51 , a suction valve 61 having cooperative actuation to its respective suction orifice 51 , and an electromagnetic field generating element 71 capable of selectively interacting with a suction valve 61 , and a second "orifice valve" set 42 comprised by at least a suction orifice 52, at least a suction valve 62 having cooperative actuation with its respective suction orifice 52.

In this context, it is worth mentioning that the "orifice valve" set 41 comprises a suction semi-commanded valve, and the "orifice valve" set 42 comprises an automatic suction valve, and that both valves specifically comprise bypass-type valves.

All the technical aspects cited thus far belong to the current state of the art, and are broadly illustrated and described in document BRP11001359.

The core of the invention in question, however, consists of presenting constructions where the "orifice valve" sets are disposed on different components of the reciprocating compressor, so as to enable size streamlining of the components of which said compressor is made.

A first embodiment is illustrated in Fig. 1.

As illustrated in Fig. 1 , the "orifice valve" set 41 (duly comprised by a suction orifice 51 , a suction valve 61 having cooperative actuation with its respective suction orifice 51 , and an electromagnetic field generating element 71 capable of selectively interacting with a suction valve 61 ) is disposed on the compression cylinder 1 of the reciprocating compressor.

More particularly, said suction valve 61 is fastened on a kind of antechamber fluidly connected to the inside of the compression cylinder 1 by means of said suction orifice 51 (the valve fastening means on their respective orifices, according to the present invention, may occur in different forms belonging to the current state of the art). Additionally, it is also noted that cited electromagnetic field generating element 71 , preferably the electric coil, is preferably disposed inside the aforementioned antechamber.

Further in connection with figure 1 , it is noted that the "orifice valve" set 42 (duly comprised by a suction orifice 52 and a suction valve 62 having cooperative actuation with its respective suction orifice 52), is disposed on the valve plate 2 of the reciprocating compressor.

Optionally, and further according to this first embodiment, the "orifice valve" set 42 may also be disposed on the mobile piston 3 of the reciprocating compressor.

Further within this context, it is worth disclosing that the aforementioned antechamber may comprise a doubly-functional environment, that is, an environment suitable for the assembly of the "orifice valve" set 41 and, at the same time, an environment having acoustic optimization functions (suction muffler).

A second embodiment is illustrated in Fig. 2.

As illustrated in Fig. 2, the "orifice valve" set 41 (duly comprised by a suction orifice 51 , a suction valve 61 having cooperative actuation with its respective suction orifice 51 , and an electromagnetic field generating element 71 capable of selectively interacting with a suction valve 61 ) is disposed on the valve plate 2 of the reciprocating compressor.

More particularly, the electromagnetic field generating element 71 is fastened on the valve plate 2 so as to be outside the compression cylinder 1 , whereas said suction valve 61 is disposed inside the compression cylinder 1 . The suction orifice 51 itself comprises a hollowed orifice shaped on the valve plate 2. The valve fastening means on their respective orifices, according to the present invention, may occur in different forms belonging to the current state of the art.

Further in connection with figure 2, it is noted that the "orifice valve" set 42

(duly comprised by a suction orifice 52 and a suction valve 62 having cooperative actuation with its respective suction orifice 52), is disposed on the compression cylinder 3 of the reciprocating compressor, this type of disposition being already known by persons skilled in the art.

Optionally, and further according to this second embodiment, the "orifice valve" set 42 may also be disposed on the compression cylinder 1 of the reciprocating compressor.

A third embodiment is illustrated in Fig. 3.

As illustrated in Fig. 3, the "orifice valve" set 41 (duly comprised by a suction orifice 51 , a suction valve 61 having cooperative actuation with its respective suction orifice 51 , and an electromagnetic field generating element 71 capable of selectively interacting with suction valve 61 ) is disposed on the compression cylinder 3 of the reciprocating compressor.

More particularly, the electromagnetic field generating element 71 is fastened on the rear face of the compression cylinder 3 so as to be outside the compression cylinder 1 , whereas said suction valve 61 is disposed inside the compression cylinder 1. The suction orifice 51 itself comprises a hollowed orifice shaped on the very compression cylinder 3, and the valve fastening means on their respective orifices, according to the present invention, may occur in different forms belonging to the current state of the art.

Further in connection with figure 3, it is noted that the "orifice valve" set 42 (duly comprised by a suction orifice 52 and a suction valve 62 having cooperative actuation with its respective suction orifice 52), is disposed on the valve plate 2, this type of disposition being already known by persons skilled in the art.

Optionally, and further according to this third embodiment, the "orifice valve" set 42 may also be disposed on the compression cylinder 1 of the reciprocating compressor.

The big advantage of these embodiments in relation to the state of the art (especially the state of the art described in document BRPI1001359) refers to the fact that the semi-commanded valve (suction valve 61 and its electromagnetic field generating element 71 ) is disposed "distant" from the automatic valve (suction valve 62), on different components of the reciprocating compressor. This enables the use of a space entirely dedicated to the assembly of the "orifice valve" set 41 and, more particularly, a space entirely dedicated to the assembly of the electromagnetic field generating element 71 belonging to said "orifice valve" set 41 , whereby enabling a feasible and implementable embodiment in small-sized compressors.

Examples of the preferred embodiments of the invention in question having been described, it must be understood that the scope of the present patent may encompass other potential variations, which are limited solely by the content of the claims, possible equivalent means being included therein.