WO2007029058A1

WO2007029058A1 - Combined machine with friction couplings

Info

Publication number: WO2007029058A1
Application number: PCT/IB2006/001503
Authority: WO
Inventors: Marino Pedrazzini Bertolazzi
Original assignee: Marino Pedrazzini Bertolazzi
Priority date: 2005-09-08
Filing date: 2006-06-08
Publication date: 2007-03-15
Also published as: ITCR20050012A1

Abstract

A multi-purpose combined machine, for example a pump-compressor unit, comprising motor means (M) and a plurality of utility devices such as pump (H), compressor (C), vacuum pump (V) and so on, wherein friction couplings (FH, FC, FV) are provided between the motor means (M) and said utilities, so that each utility can be powered in a selective and independent manner.

Description

"Combined machine with friction couplings". DESCRIPTION

The invention relates to a combined machine for do-it-yourself or professional purposes: the term "combined machine" is used with reference to a machine comprising at least a motor and a plurality of utilities like a high-pressure pump, an air compressor, a vacuum pump, etc.

The technical problem faced by the invention is to allow a selective use of said utilities, with a single motor. It is a need which is felt particularly in DIY or professional fields: as an example, the advantages in term of flexibility of use of a multi-purpose machine comprising a high-pressure cleaner and an air compressor are evident.

A known solution (see WO 2004/107534) is to make use of freewheel bearings also known as one-way clutches, which are able to transmit torque in one sense, running idle in the other. The machine is powered by a motor adapted to run in both directions, typically an electric motor equipped with a manual switch to reverse the sense of rotation; two utilities, for example a pump and a compressor, are connected to the motor shaft via respective freewheels, which engage in opposite directions. By reversing the rotation of the motor, one or the other machine is run in an independent and selective manner.

Other solutions proposed by the same applicant consist in the mounting of the freewheel bearings directly into the motor, or in an external gearbox between the motor and the utilities (see WO

i 2005/101617).

All these proposed solutions, however, require a reversible motor, i.e. a motor adapted to run in both directions of rotation. As a consequence, an electric motor without the aforesaid manual switch or, even more, a 4-stroke internal combustion engine (which can be started in one sense of rotation only) cannot be used.

Moreover, some modification of the machines or the motor is required to mount the freewheel bearings. In a piston pump, for example, the bearings can be housed directly in the oscillating wobble plate (if present), or between the pin of the motor and the shaft of the pump, instead of the commonly used rigid tab. Such operations are not generally difficult, but there is still the need to dismantle and/or modify a commercial item.

The purpose of the invention is to overcome the above disadvantages: more in detail, one aim of the invention is to realize a combined machine as defined above, wherein the utilities can be operated in a selective and independent manner, without reversing the sense of rotation of the motor as required by freewheel-based systems. A further aim of the invention, then, is to allow the use of any kind of motor, including all known electric motors and all known internal combustion motors, two-strokes, four-strokes, Otto, Diesel, etc...

The aims are reached with a combined machine, such as pump- compressor or the like, comprising motor means and a plurality of utilities operable by said motor means, characterized by a plurality of friction couplings and wherein each one of said friction couplings is provided between said motor means and one respective of said utilities.

The invention can make use of any known friction coupling, but magnetic clutches are preferred.

The friction couplings may drive the utilities through known driving means such as gears, pulleys or equivalent means.

The motor means comprise at least one motor unit, adapted to power the utilities of the combined machine. According to one embodiment, the motor means comprise an electric motor. According to another embodiment, the motor means comprise an internal combustion engine. According to a further embodiment, the motor means comprise an internal combustion engine coupled to an electric generator, to provide a further power source for an electric item, e.g. a drill or a welding machine.

According to still further embodiments, the motor means can be realized with a pre-assembled motor-generator unit, a motor-pump unit or similar.

According to another embodiment, the motor means comprise a hydraulic motor, powered e.g. by oil at a high pressure. This can be useful in some circumstances, for example the powering of the multi purpose machine of the invention by means of a farm tractor.

Thanks to the friction couplings, the operating utilities are powered in a selective and independent manner. It is no longer required to reverse the direction of rotation of the motor, thus all motors can be used, with no restriction. As the freewheel bearings are not necessary, difficulties and/or additional costs due to their mounting are avoided.

The features and advantages of the invention will become clearer with the help of the following description and of the attached drawings, wherein:

Fig. 1 is a block diagram exemplifying one embodiment of the invention;

Fig. 2 is a block diagram exemplifying another embodiment, wherein the motor means comprise an electric generator;

Fig. 3 is a block diagram of a further embodiment, wherein there is a secondary shaft to drive the friction couplings.

Block diagram of Fig. 1 show a combined machine comprising motor means M and a plurality of utilities which, in the given example, are a high pressure pump H, a compressor C and a fan V.

Said utilities H, C and V are operable by said motor means M which, in the given example, comprise an electric motor M1. It should be noted, however, that any kind of motor can be used, including both electric and internal combustion, because as stated above there is no particular specification of the motor and, more in detail, it is not required that the sense of rotation is reversible. Among others, two or four-stroke i.e. engines will also be suitable, both Otto or Diesel cycle.

Motor M1 has a motor shaft A, wherein clutches FH, FC and FV are provided for the engagement with, respectively, said pump H, compressor C and fan V.

Said clutches FH, FC, FV are known per se; preferably the invention is realized with magnetic clutches like, for example, those commonly used in the automotive field to drive the compressor of the air conditioning system.

Substantially, these devices comprise mechanical parts which can be engaged simply by supplying the device itself with a certain voltage. In a typical case there are two friction wheels distanced by few tenth of a millimeter, that can be coupled by the force of a magnetic field generated by a suitable electric coil.

This friction coupling is preferred because of low cost, quick engage and disengage, no need of expensive hydraulic or pneumatic systems. As an alternative, however, the invention can equally be realized with a manually operated mechanical clutch, or an automatic clutch, such as a centrifugal clutch adapted to engage above a certain speed. More in general, any known friction coupling can be used.

Referring with more detail to Fig. 1 , clutches FH, FC and FV drive the respective utilities H, C and V by driving pulleys. Each clutch is essentially formed by an internal ring, fixed to the shaft A, and an external ring provided with a race to drive a pulley B. The internal ring and external ring are made integral when the clutch is engaged, so that a driving torque can be transmitted from motor means M to the respective utility.

Other equivalent forms are possible, wherein different driving means are provided between each clutch FH, FC, FV and the respective utility: for example a geared coupling, chain, and so on. For each one of the utilities, a different velocity ratio can be provided, according to needs.

Turning to Fig. 2, another embodiment is shown, wherein the motor means M comprise a motor-generator unit with an internal combustion engine M2 and an electric generator G. Said generator G provides at least a power source E for a further utility like a drill, a welding unit, etc... Engine M2, as above, can be of any type, including two- or four- stroke internal combustion engines.

Fig. 3 relates to an embodiment wherein the generator G is driven by a first secondary shaft connected to the motor shaft, and the friction couplings are connected to a further secondary shaft driven by said first secondary shaft.

More in detail, there is a geared coupling 100, 101 on the motor shaft A, driving the generator G through a secondary shaft 102, and said shaft 102 drives a further secondary shaft 105 via geared coupling 103, 104. Friction couplings FH, FC and FV are then connected to said further secondary shaft 105. In the shown embodiment, the shaft 102 is passing through the generator G.

It can be appreciated that this arrangement avoids the need of mounting the friction couplings directly on the motor shaft A; moreover, a degree of freedom as regards the velocity ratio is introduced, because secondary shafts 102 and 105 may have a rotational speed equal, less or greater than shaft A.

Equivalent means (e.g. pulleys) can be used instead of geared couplings 100, 101 and 103, 104.

In a further embodiment (not shown) the machine is powered by a motor-pump unit or similar. A market available motor-pump assembly, for example, can be used.

The invention is clearly open to many further embodiments, falling into the functional schemes of Figs. 1 and 2.

For example, the clutches FH, FC and FV may be mounted directly on the utilities H, C, V, instead of being fitted on the motor shaft A.

Where the motor means M have a mechanical output on both sides, the clutches may also be provided on both sides of the same, mainly to reduce length of the motor shaft and, thus, the risk of vibrations.

The invention is useful for realizing multi-purpose combined machines, leaving a free choice of the power source. Applications are obviously not limited to the above examples, but, as the case may be, can be extended to any machine or utility adapted to be powered by the available motor.

Claims

1. A combined machine, such as pump-compressor or the like, comprising motor means (M) and a plurality of utilities (H, C, V), operable by said motor means (M), characterized by a plurality of friction couplings (FH, FC, FV) and wherein each one of said friction couplings is provided between said motor means (M) and one respective of said utilities (H, C, V).

2. A machine according to claim 1 , characterized in that said friction couplings (FH, FC, FV) are realized with magnetic clutches.

3. A machine according to claim 1 , characterized in that said friction couplings (FH, FC, FV) are realized with mechanical clutches.

4. A machine according to any one of preceding claims, characterized in that said friction couplings (FH, FC, FV) are mechanically connected to said utilities (H, C, V) through driving pulleys (B).

5. A machine according to claim 4, characterized in that each friction coupling (FH, FC, FV) comprises a clutch with an internal ring, fixed to a shaft (A) of said motor means (M), and an external ring provided with a race to drive a pulley (B), wherein the internal ring and external ring are made integral when the clutch is engaged.

6. A machine according to any one of preceding claims, characterized in that said motor means comprise an electric motor (M1).

7. A machine according to any one of preceding claims, characterized in that said motor means comprise a hydraulic motor.

8. A machine according to any one of preceding claims, characterized in that said motor means (M) comprise a two stroke or four stroke internal combustion engine (M2).

9. A machine according to claim 7 or 8, characterized in that said motor means (M) further comprise an electric generator (G).

10. A machine according to claim 9, characterized in that said generator (G) is driven by a first secondary shaft (102) connected to the motor shaft (A), and said friction couplings (FH, FC and FV) are connected to a further secondary shaft (105) driven by said first secondary shaft (102).