WO1993014307A1

WO1993014307A1 - Equipment for the boost-feeding of air to an endothermic motor

Info

Publication number: WO1993014307A1
Application number: PCT/IT1992/000131
Authority: WO
Inventors: Mario Brighigna
Original assignee: Mario Brighigna
Priority date: 1992-01-15
Filing date: 1992-10-23
Publication date: 1993-07-22
Also published as: IT1258009B; ITBO920016A0; ITBO920016A1

Abstract

Equipment for the boost-feeding of air to an endothermic motor (19'), comprising a rotary centrifugal compressor exhibiting an outlet tube which is connected to an inlet section of the said endothermic motor (19''), a turbine equipped with a rotor keyed on a shaft supporting a rotor of the said rotary centrifugal compressor and exhibiting an inlet tube connected to an exhaust gas-emission tube of the said endothermic motor (19''), a flow-dynamic activation rotary motor (3) exhibiting a rotor (17) kinematically connected to a rotor of the said rotary centrifugal compressor, and a fluid compressor (22) exhibiting an outlet tube (19) connected to an inlet section of the said rotary motor (3) and activated by the endothermic motor (19'').

Description

Description.

Equipment for the Boost-feeding of Air to an Endothermic Motor.

Technical Field.

The present invention relates to equipment for the boost feeding of air into an endothermic motor.

Background -Art.

The prior art teaches that the performance of endothermic motors has been considerably improved in recent years, by means of the use of forced feeding or boost feeding of the combustion air. This boost feeding, which is usually realised by means of volumetric compressors connected to the motor shaft through more or less complex kinematic chains which gain power from the wheels of the vehicle or by means of turbochargers activated directly by exhaust gases from the motor, has been seen to be particularly advantageous when used in motors functioning with the diesel cycle. The so-called "Diesel" motors, over the last twenty years, have been able to provide direct competition, thanks to boost feeding and with respect to all natures of performance, for the other kinds of endothermic motors with controlled ignition. The boosting has in fact improved, in these motors, the thermodynamic performance , power, torque, specific consumptions, and the weight-power rapport, and has led to a considerable reduction in toxic exhaust emissions, lowering levels of unburned hydrocarbons, nitric oxides, and particles. Other advantages of the turbosupercharger are its small dimensions, its lower weight with respect to volumetric compressors, the absence of a mechanical link with the motor and its easier installation.

In prior art turbosuperchargers the exhaust gases activate a turbine, which sets in rotation a centrifugal compressor, axially keyed to its own shaft, and able to introduce into the combustion chambers a quantity of air which is over and above the volume of the air generated by the pistons.

A negative aspect of the said prior art turbosuperchargers is that the turbine section develops its greatest action (highest performance) in a limited part of the utilisation field of the motor; that is, at high revolutions, penalising the functioning of the motor at lower revolutions. In general, endothermic motors which are boosted with a turbosupercharger, and particularly diesel motors, do not receive a boosting quantity of combustion air during the course of low revolution functioning, that is in the situation wherein a boosting quantity of compression air would be necessary in order to optimise the maximum torque values, making the most of the turbulent conditions and reducing the smoke produced by the motor. This defect is often repeated at very high revolutions since the turbocharging system is designed and dimensioned to provide adequate responses correlated with the medium range of motor revolutions.

This phenomenon is especially present in vehicles equipped with diesel motors, during starting from a stationary position, or at maximum power, and it is the cause of high fume levels during the rapid acceleration of the motor necessary in order to perform the said starting manoeuvre, or during, for example, hill-climbing.

Disclosure of Invention.

The aim of the present invention is thus to provide equipment for combustion air boost charging in an endothermic motor which does not exhibit the above- described prior-art drawbacks, and which is able to boost charge an endothermic motor at low revolutions and also guarantee a rapid motor response when there is an unexpected need for energy, also at low revolutions. The invention, as it is described in the claims which follow, solves the above-mentioned problem by providing equipment for the boost air-feeding of an endothermic motor, comprising a rotary compressor exhibiting an outlet tube which is connected to the inlet section of the said endothermic motor, characterised by the fact of comprising a flow-dynamic activation rotary motor exhibiting a rotor kinematically connected to the rotor of the said rotary compressor, and a further fluid compressor exhibiting an outlet tube connected to an inlet section of the said rotary motor. According to a preferred embodiment of the present invention the said apparatus for boost air-feeding to an endothermic motor also comprises a turbine equipped with a rotor keyed on a shaft supporting the rotor of the said rotary compressor and exhibiting an inlet tube connected to an exhaust gas-emission tube of the said endothermic motor.

The characteristics of the present invention will better emerge from the detailed description that follows, made with reference to the accompanying drawings, which represent a preferred embodiment here illustrated in the form of a non-limiting example, and in which: - Figure 1 shows a view in section of a first embodiment of the supercharger according to the present invention; - Figure 2 shows a schematic view, partially in section, of a portion of the supercharger of figure 1 and of a system incorporating the said supercharger;

Figure 3 shows a view in section of a second embodiment of the supercharger according to the invention. With reference to figure 1, 1' denotes, in its entirety, equipment for the boost air-feeding of an endothermic motor, of which a turbosupercharger forms a part, indicated in its entirety by 1, comprising a compression section 2 and a flow-dynamic rotary motor constituting a turbine section 3.

The compressor 1 comprises a box structure 4 internally defining a chamber 5 having a cylindrical shape and developing along and about a horizontal axis 6. The said chamber 5 is respectively defined on two sides, left and right in figure 1, by two vertical walls 7 and 8, parallel to each other, the second of which is crossed by a through-hole 9 coaxial to the horizontal axis 6. The through-hole 9 is coaxially crossed, without contact and with a fluid-sealed coupling, by a shaft 10, which is rotatably supported by means of a bearing pair 11 and a bracket 12 solid to the wall 8 externally to the box structure 4. A rotor 13 of known type is keyed on a portion of the shaft 10 internal to the box structure 4: the said rotor 13 is part of a centrifugal compressor 14 which constitutes part of the compression section 2, while a portion of the shaft 10 external to the box structure 4 arranged, in figure 1, on the right of the bracket 12, coaxially crosses, with fluid-sealed coupling, an internal chamber 15 of a box structure 16 solid to the right portion of the bracket 12 itself.

The internal chamber 15 of the box structure 16 exhibits substantially a cylinder-shape and internally contains a rotor 17 which is part of the turbine section 3 and which is keyed on a portion of the shaft 10 contained in the internal chamber 15 itself.

The turbine section 3, of known type, can be activated, for reasons that will become clear hereinafter, by any kind of fluid, and is therefore able to operate, according to different forms of actuation of the present invention,, using for example oil or air as propelling fluids. In the description that follows, however, the fluid used is oil, and the modifications to be made to the supercharger 1 to render it operative with fluids constituted by different liquids or with gaseous substances will not be considered, their being absolutely obvious to technicians in the field. The turbine can be of the Pelton type.

The chamber 5 of the box structure 4 communicates, through a passage 18 of variable section, of known type to specialised technicians in the field, with an air inlet tube 19 ending in the chamber 5 through an upper portion of the box structure 4. An axial end of the box structure 4 opposite to the wall 8 is open, and communicates through a tube 19' with an air inlet tube (not illustrated) to the feeding section of an endothermic motor.

According to figure 2, the internal chamber 15 of the box structure 16 superiorly communicates, through a fluid inlet tube 19 terminating in a nozzle 20 of known type, with an outlet mouth 21 of a compressor or pumping element 22, which pumping element 22 is preferably but not compulsorily, according to what is shown schematically in figure 2, of the rotary type (for example the screw-type) and is motorised, through a shaft 22a schematically represented in figure 2, and kinematically connected to the motor. The internal chamber 15 also communicates, inferiorly and through a distancing tube 23 of the said fluid (constituted, as has already been explained, by oil), with a tank 24 to contain the fluid itself and in communication with an inlet mouth 25 of the said pumping element or compressor 22. The said tank 24 might advantageously be constituted by a housing, not illustrated (the so-called oil sump) containing the lubricating oil of the motor 19' ' .

Now the functioning of the supercharger 1 will be described.

The rotor 13 of the centrifugal compressor 14 is made to rotate, through the shaft 10, by the rotor 17 of the turbine section 3, which latter rotor 17 is in its turn caused to rotate by the introduction through the nozzle 20 of an adequate flow of pressurised oil fed by the compressor 22. Consequently, supercharging air is drawn by the centrifugal compressor 14, through the tube 19' , towards the inlet tube of the motor 19' ' which motor 19' ' , according to a preferred activation form of the supercharger 1, constitutes the origin of the compressor 22 movement.

It should be noted that the degree of supercharging desired for every functioning condition of the motor 19' ' can be previously decided and memorised, in known ways, in a command board 27 (which can be electronic) of known type, using appropriate known-type sensor means, schematised in the figure as a block 28 and able to read determined functioning parmeters of the motor 19' ' such as the revolution rate and/or the boost-charge pressure. The said command board 27 constantly regulates, once again in known ways (for example by means of activation and deactivation of an electromechanical joint not illustrated and interpositioned between the motor 19' ' and the compressor 22 or through the regulation of an electro- rheological joint (having the ability to change viscosity according to the current passing through it) also interplaced between the compressor 22 and the motor 19' ' ), the activation and deactivation, or, in the case of use of an electro-rheological joint, the rotation velocity of the compressor 22, in such a way as to guarantee a correct boost-charging pressure to the motor for whatever rotation velocity. The command board 27 regulates the oil supply to the compressor 22, and this regulation can occur in the above-described manners, or, according to a further embodiment not illustrated of the apparatus 1' , could also be effected by preventing a part of the compressed oil from reaching the turbine section 3.

According to a further embodiment of the apparatus 1' represented in figure 3 and denoted by 29' and wherein the details already described with reference to figures 1 and 2 retain their original reference numbers, a left wall 31 of a box structure 32 is connected to a lateral wall 30 (on the right in figure 3) of the box structure 16: the said left wall 31 is part of a turbine section 33 and substantially exhibits a cylindrical shape. The said shaft 10 extends inside the internal chamber 34 of the box structure 32 through respective through-holes 35 and 36 of the walls 30 and 31, and bears a blade rotor 37 of the type commonly used in gas turbines. _ g _

An axial end of the box structure 32 opposite to the left wall 31 is open, and communicates through an conduit 38 with an exhaust tube (not illustrated) of the motor 19' ' . The internal chamber 34 of the box structure 32 communicates, through a various-section passage 39, with an emission tube 40 which sends into the outside atmosphere, through an upper portion of box structure 32, exhaust gases from the motor 19'' which have internally travelled through the turbine section 33. The functioning of the supercharger 29 will now be describe .

When the revolutions of the motor 19' ' reach above a predetermined level, read by the command board 27, the rotor 13 of the centrifugal compressor 14 is set in rotation, through the shaft 10, by the blade rotor 37 of the turbine section 33, which blade rotor 37 is in its turn set in rotation thanks to the introduction through the conduit 38 of exhaust gases from the motor 19^ft. Consequently, air for boost-feeding is drawn from the centrifugal compressor 14 towards the injection tube of the motor 19'', exactly as in known supercharging units.

When the command board 27, through its sensors 28, reads that the revolution level of the motor 19' ' has fallen below (or risen above) the said predetermined revolution level, with a consequent reduction in the velocity of the shaft 10 and the rotor 13, and a notable loss of effectiveness of the centrifugal compressor 14, it activates in the above-described way the compressor 22, determining the sending of a volume of oil to the turbine section 3, that is, a volume of oil sufficient to cause the rotor 17 to rotate, and thus also the shaft 10, with a higher speed and sufficient newly to bring about, through the work of the rotor 13, the sending to the injection tube of the motor 19' ' of a volume of air which is sufficient to boost the motor 19' ' in the correct manner.

The correct boosting obtained in this way permits of increasing the introduction of fuel in the motor 19' * with a consequent generation of a larger quantity of combustion gases which more greatly activate the turbine section 33.

It should be noted that, in the case in which it is envisaged that the command board 27 should control the functioning of the compressor 22 causing, according to necessity, its activation or deactivation, on the deactivation of the compressor 22 the pressurised oil flow to the turbine section 3 is arrested, and the rotor 17 of the said turbine section 3 simply rotates together with the shaft 10 and does not influence in any way the functioning of the supercharger 29.

From the preceding it is clear how the supercharger 1, and even more how the supercharger 29 plainly satisfy the aims defined in the premise to the present description, and how the supercharger 29 described permits of enormously reducing inertia phenomena in the response of the motor 19' ' to urgent energy requests.

Claims

Claims ,

1). Equipment (1', 29') for the boost-feeding of air to an endothermic motor (19'), comprising a rotary centrifugal compressor (14) exhibiting an outlet tube (19') which is connected to an inlet section of the said endothermic motor (19''), characterised by the fact of comprising a flow-dynamic activation rotary motor (3) exhibiting a rotor (17) kinematically connected to a rotor (13) of the said rotary centrifugal compressor (14), and a fluid compressor (22) exhibiting an outlet tube (19) connected to an inlet section of the said rotary motor (3) .

2) . Equipment according to claim 1, characterised by the fact of comprising a turbine (33) equipped with a rotor (37) keyed on a shaft supporting the rotor (13) of the said rotary centrifugal compressor (14) and exhibiting an inlet tube (19) connected to an exhaust gas-emission tube of the said endothermic motor (19' ' ) .

3). Equipment as in claims 1 or 2, characterised by the fact of comprising command means for the control of fluid flow on the part of the said compressor (22), equipped with sensors (28) for the reading of determined functioning parameters of the said endothermic motor (19''), the said command board (27) comprising a command board (27) for the processing of signals received from the said sensors (28) .

4). Equipment as in claim 1 or 2, characterised by the fact that the said rotary motor (3) is consitituted by a further turbine.

5). Equipment as in claim 1, characterised by the fact that the rotor (17) of the said rotary motor (3) and the rotor (13) of the said rotary centrifugal compressor (14) are keyed on to a same shaft (10).

6) . Equipment for the boost feeding of air to an endothermic motor (19' ' ), comprising a rotary centrif gal compressor (14) equipped with a rotor (13) exhibiting an exhaust tube (19') connected to an inlet section of supercharging air of the said endothermic motor (19' ' ) and a turbine (33) equipped with a blade rotor (37) keyed on a shaft (10) supporting the said rotor (13) and exhibiting an inlet tube (19) connected to an exhaust tube of exhaust gases of the said endothermic motor (19''), in such a way as to define a turbosupercharging system, characterised by the fact of comprising a flow-dynamic rotary motor (3) exhibiting a rotor (17) kinematically connected to the rotor (13) of the said rotary centrifugal compressor (14) and a fluid compressor (22) exhibiting an inlet tube (19) which is connected to an inlet section of the said rotary motor (3). 7). Equipment as in claim 6, characterised by the fact that the rotor (17) of the said rotary motor (3) is directly keyed on the said shaft (10) .

8). Equipment as in claims 1 or 6, characterised by the fact that the activating fluid of the said rotary motor (3) is constituted by oil.

9) . Equipment as in claim 8, comprising a tank (24) for containing the said oil, characterised by the fact that the said tank is constituted by the endothermic motor oil sump.

10). Equipment as in claims 1 or 6, characterised by the fact that the activating fluid of the said rotary motor (3) is constituted by a gaseous substance.

11). Equipment as in claim 10, characterised by the fact that the activating fluid of the said rotary motor (19'') is constituted by air.

12). Equipment as in claim 1 or 6, characterised by the fact that the said fluid compressor (22) is activated by the said endothermic motor (19' ').