EP3543528B1

EP3543528B1 - Alternative twin cylinder air compressor

Info

Publication number: EP3543528B1
Application number: EP19162590.4A
Authority: EP
Inventors: Lorenzo Boccato
Original assignee: FIAC SRL
Current assignee: Abac Aria Compressa SRL
Priority date: 2018-03-19
Filing date: 2019-03-13
Publication date: 2021-03-03
Anticipated expiration: 2039-03-13
Also published as: IT201800003733A1; EP3543528A1; US20190285062A1; CN110285034A; ES2866549T3

Description

This invention relates to an alternative twin cylinder air compressor.
Air compressors are used in many different fields of application, both in professional and household contexts.
Whilst, in fact, the professional use of compressed air is well known, it is increasingly being used also in the home, for example with respect to hobby applications or even for more common activities such as washing/suction.
There is a very wide range of constructional architectures for volumetric air compressors but, excluding, for the sake of this invention, those more strictly used in professional contexts (screw, lobe, vane compressors), the most widespread are without doubt alternative compressors.
Alternative air compressors compress the air by means of a piston movable in alternating motion inside a cylinder.
Alternative compressors are both single cylinder and multi-cylinder and the multi-cylinder ones can be both single stage (the cylinders operate in parallel) and multi-stage (the cylinders operate in series).
In particular, in the case of alternative twin cylinder compressors, amongst the possible architectures there is one, which is very widespread, comprising two cylinders arranged in line, spaced from each other and with the electric motor axially interposed between the two cylinders, at the base of them.
More in detail, the two cylinders are located at the opposite ends of an electric motor equipped with a through transmission shaft which engages at its two opposite longitudinal ends with the respective crank of each of the two piston-cylinder pumping units.
Moreover, each cylinder has a respective valve plate positioned at the head.
Although this architecture is functional from the different points of view, it has been shown that it can be improved both in operational and construction terms.
Examples of alterative twin cylinders compressors are disclosed in documents US2010178185 and US5584675 .
The aim of this invention is to provide a volumetric air compressor which is simple and practical to make.
A further aim of this invention is to provide a volumetric air compressor which is effective and practical to use.
The technical features of the invention according to the above-mentioned objects may be easily inferred from the contents of the appended claims, especially claim 1, and, preferably, any of the claims that depend on this claim.
The advantages of the present invention are more apparent from the detailed description which follows, with reference to the accompanying drawings which illustrate a preferred embodiment of the invention provided merely by way of example without restricting the scope of the inventive concept, and in which:

Figure 1 is a schematic perspective view from above of a preferred embodiment of the alternative twin cylinder air compressor according to the invention;
Figure 2 is a schematic perspective view from a different angle of the air compressor of Figure 1;
Figure 3 is a schematic side elevation view of the air compressor of the above-mentioned drawings;
Figure 4 is a schematic top plan view, with some parts cut away to better illustrate others, of the compressor of the above-mentioned drawings;
Figure 5 illustrates a detail, with some parts cut away to better illustrate others, of the compressor of Figure 1;
Figure 6 illustrates the compressor of Figure 2, with some parts cut away to better illustrate others.

With reference to the accompanying drawings, the numeral 1 denotes in its entirety an alternative twin cylinder air compressor made in accordance with the invention.
As illustrated in the accompanying drawings, the alternative twin cylinder air compressor 1 comprises a base 2 and a central body 3 supported by the base 2.
The central body 3 extends longitudinally along a first predetermined direction D1 and houses, centrally, an electric motor EM, shown in the partially disassembled configuration of Figures 5 and 6.
The above-mentioned electric motor EM has an axis of rotation A which is parallel to the above-mentioned first predetermined direction D1.
The architecture of the air compressor 1 comprises a first 4 and a second 5 pumping unit positioned on opposite sides of the electric motor EM which, therefore, is interposed between the two pumping units 4, 5.
As is known, the electric motor EM has the relative through drive shaft, in such a way as to activate both the first and second pumping units 4, 5, even though positioned on opposite sides of the same electric motor EM. The first and second pumping units 4, 5 are arranged in line.
The central body 3 and the base 2 are advantageously made in a single piece, in a single casting, which is divided into two portions 3a, 3b, one for each pumping unit 4, 5.
The two portions 3a, 3b are side by side in the predetermined direction D1 and are rigidly assembled together.
Each first and second pumping unit 4, 5 has a respective cylinder 40, 50 inside of which moves, with reciprocating motion, a respective piston is not visible in the accompanying drawings.
As clearly illustrated in Figure 3, the two cylinders 40, 50 extend transversally to the above-mentioned axis of rotation A of the electric motor EM.
Respective heads 41, 51, equipped with fins for the purposes of their effective cooling, are positioned on the top of the cylinders 40, 50.
Below the heads 41, 51 each cylinder 40, 50 comprises a respective valve plate, not illustrated in detail, of known type and not described further.
At its opposite longitudinal ends, also defining the longitudinal ends of the air compressor 1, the first and second pumping units 4, 5 have respective cooling fans, not shown in the accompanying drawings, keyed on opposite longitudinal ends of the above-mentioned and not illustrated shaft of the electric motor EM.
With reference in particular to Figures 1 and 2, the air compressor 1 comprises, partly covering the above-mentioned fans, two respective covers 6.
The covers 6 have a respective octagonal-shaped zone 6c with slits defining an aeration grille designed for the passage of air moved by the fans.
The covers 6 extend in the direction of above-mentioned cylinders 40, 50 and are configured to convey at least a part of the flow of air generated by the fans to the top of said cylinders 40, 50, at the respective heads 41, 51.
As illustrated in Figures 1 to 3, the air compressor 1 according to the invention comprises a containment body 7 interposed between the above-mentioned cylinders 40, 50 of the respective first and second pumping units 4, 5.
As illustrated in detail in Figure 5, the containment member 7 comprises a tray 70 positioned between the two cylinders 40, 50, at the respective heads 41, 51.
The tray 70 comprises a first chamber 71, a second chamber 72 and a third chamber 73.
The first chamber 71 defines a housing for a filter 8 for the air entering towards the cylinders 40, 50.
An opening facing the above-mentioned filter 8 is formed on a side wall of the first chamber 71.
The filter 8 is also in pneumatic connection with both the heads 41, 51 by means of the respective conduit 74 designed to feed air to both the cylinders 40, 50.
The air entering which passes through the filter 8 is fed to the conduit 74 by means of a curved pipe, not visible in the accompanying drawings, passing beneath the second chamber 72.
A pipe 75 for pneumatic connection between the heads 41, 51 is positioned inside the second chamber 72 of the tray 70.
As illustrated in Figures 1 and 2, the tray 70 comprises a cap 76 covering both the first and second chambers 71, 72.
The cap 76 is designed to provide a hermetic seal at least for the first chamber 71.
As illustrated in Figures 1 and 2, the containment member 7 comprises two lateral guards 77a, 77b, positioned on opposite faces of the air compressor 1, symmetrically with respect to a vertical plane passing through the axis of rotation A of the electric motor EM.
An air intake conduit 9 is formed on the guard 77a located in the proximity of the first chamber 71.
The air intake conduit 9 is in common for both the cylinders 40, 50 and leads inside the first chamber 71, for feeding air from the outside to the filter 8.
The intake conduit 9 extends transversally relative to the above-mentioned axis of rotation A of the electric motor EM.
The intake conduit 9 is positioned at a mid-point zone M between the cylinders 40, 50 so as to be suitably spaced from them. An inlet opening 78 of the above-mentioned intake conduit 9 is defined on the lateral guards 77a on which said air intake conduit is made.
Advantageously, the inlet opening 78 protrudes in a cantilever fashion relative to the cylinders 40, 50.
This circumstance, together with said above-mentioned positioning at the mid-point of the intake conduit 9 and therefore also of the relative inlet opening 78, means that the air drawn in to convey it to the filter 8 is picked up far as possible from the cylinders 40, 50 and from their heads 41, 51 and therefore not heated by them.
Moreover, another advantageous aspect is the fact that the intake conduit 9 is made as a single conduit, thus minimising its overall size and allowing an optimum positioning in terms of distance from the sources of heat constituted by the cylinders 40, 50.
As illustrated in Figure 6, the above-mentioned containment body 7 defines a housing for an electric capacitor 10, necessary for operation of the air compressor 1.
The capacitor 10 is advantageously supported by one of the lateral guards 77a, 77b.
The two lateral guards 77a, 77b are advantageously made the same, for the purposes of optimising costs, even though the intake conduit 9 and its respective opening 78 are only operational inside the lateral guard 77a facing the first chamber 71, whilst in the lateral guard 77b, even though they are present physically they are not connected to any and, therefore, are not operational.
Respective slots 11 configured to define a zone for circulation of air from the outside to the inside of the containment body 7, designed for cooling the above-mentioned electric motor EM are made in the lower part of each lateral guard 77a, 77b.
With reference to Figures 2 and 4, an outlet connector 12 of the compressed air in both cylinders 40, 50 is positioned on the cylinder 40, on the relative head 41.
The above-mentioned connecting pipe 75 and first chamber 71 define, for the air compressor 1 according to the invention, pneumatic connection means 13 designed to allow the flow of air towards and away from the cylinders 40, 50.
In use, as illustrated in Figure 4, the air sucked using the intake conduit 9 at its opening 78 is directed to the filter 8 housed inside the first chamber 71 of the tray 70.
From the filter 8 the sir sucked is conveyed towards both the cylinders which, in known manner, compress it by the pumping action of the respective pistons moving with alternating movement.
According to the single-stage configuration illustrated, the compressed air in the cylinder 50 is transferred to the head 41 of the cylinder 40 using the pneumatic connection pipe 73; from the head 41 of the cylinder 40, the compressed air in both cylinders 40, 50 is discharged outside through the above-mentioned outlet connector 12.
The air compressor unit 1 according to the invention achieves the preset aims and brings important advantages.
A first advantage linked to the invention is due to the fact that by adopting the containment body 7, the space interposed between the cylinders 40, 50 is used to house components of the compressor 1, thereby optimising the overall dimensions.
A further advantage is due to the fact that by means of the containment body 7 and its lateral guards 77a, 77b a protection is actuated regarding the accidental contact with electrical elements contained inside.
Another advantage is due to the arrangement and shape of the intake conduit 9 which, by optimising the relative distance from the cylinders of the compressor, makes it possible to draw in cool air, not heated by contact with the heads of the cylinders.

Claims

An alternative twin cylinder air compressor comprising:
- a first (4) and a second (5) pumping unit, said two pumping units (4, 5) being arranged in line and having respective cylinders (40, 50),

- an electric motor (EM) interposed between said first (4) and second (5) pumping unit, comprising a respective axis of rotation (A), said cylinders (40, 50) extending transversely to said axis (A) of rotation,

- pneumatic connection means (13) designed to allow the flow of air towards and away from said cylinders (40, 50), characterised in that it comprises, interposed between the cylinders (40, 50), a containment body (7) for containing the pneumatic connection means (13), the containment body (7) comprising a chamber (71) for housing a filter (8) for the air and defining at least one intake conduit (9) for air intake, in common for the cylinders (40, 50), the intake conduit (9) extending transversely relative to the axis (A) of rotation of the electric motor (EM) and leading to the inside of said chamber (71).
The compressor according to claim 1, characterised in that the intake conduit (9) is positioned at a centre line zone (M) between said cylinders (40, 50) to be spaced from them.
The compressor according to any one of the preceding claims, characterised in that the containment body (7) comprises lateral guards (77a, 77b) on one of which is made said air intake conduit (9).
The compressor according to claim 3, wherein on the lateral guard (77a) on which is made the air intake conduit (9) is defined an inlet opening (78) of the intake conduit (9), characterised in that the inlet opening (78) protrudes in a cantilever fashion relative to said cylinders (40, 50).
The compressor according to claim 3 or 4, comprising an electric capacitor (10), characterised in that the containment body (7) defines a housing for said electric capacitor (10), the electric capacitor (10) being supported by at least one of said lateral guards (77a, 77b).
The compressor according to any one of claims 3 to 5, characterised in that on said lateral guards (77a, 77b) are made respective slots (11) configured to define a zone of circulation of air from the outside to the inside of the containment body (7), designed for cooling the electric motor (EM).
The compressor according to any one of the preceding claims wherein said electric motor (EM) comprises a through drive shaft and on opposite longitudinal ends of the drive shaft are keyed two respective cooling fans, characterised in that it comprises, at said fans, two respective covers (6) extending in the direction of the cylinders (40, 50) and configured to convey at least a part of the flow of air generated by the fans up to the top of the cylinders (40, 50).