Vane motor rotor

Abstract

 A rotor for pneumatic engine includes a shaft (3) having a drum (2) with a plurality of sectors (4) divided by a plurality of seats (5) for vanes (13).
The external portion of each sector (4), has a cavity (6) with a wall (7) that is approximately orthogonal to the direction of a compressed air flow (F), in a facing condition (A), in which the cavity (6) faces an outlet (8) of an inlet duct (9).
The wall (7) is fit to increase the engine torque.

Description

[0001] The present invention relates to pneumatic rotary engines. Particularly the invention refers to a rotor for pneumatic rotary engine fit for increasing the delivered torque.

[0002] There are known rotors for turbines or for rotary engines, in which the compressed air is fed to chambers by means of one or more inlet ducts. Each chamber is defined by walls of a cylinder of an engine stator and by a couple of blades or vanes which are slidably housed in radial slots of a rotor drum to slide air-tightly over the walls of the cylinder. In said engines the axis of rotation of the rotor and the geometric axis of the cylinder are usually parallel and misaligned. The compressed air expands causing the rotation of the rotor in a direction in which the chamber volume increases.

[0003] When the chamber has the maximum volume, the air flows out through one or more exhaust ducts.

[0004] The main drawback of these known rotors consists in that because of dirt, dregs produced by lubricating or similar, sometimes the blades or vanes do not flow in the relative drum slots but remain in retracted position so blocking the starting and/or the operation of the engine.

[0005] A further drawback consists in that the known rotors do not increase the power of the engine.

[0006] The main object of the present invention is to propose a rotor fit for supporting and allowing the engine starting when one or more vanes are held in retracted position by dirt or similar and consequently fit for releasing said vanes.

[0007] Further object of the present invention is to propose a rotor fit to increase the engine power.

[0008] The above-mentioned objects are achieved according to the content of the claims.

[0009] The characteristics of the invention are underlined in the following with particular reference to attached drawings, in which:

• figure 1 shows a side view of the rotor object of the present invention;
• figure 2 shows a front view of the rotor of figure 1;
• figure 3 shows a section view along the line III-III of figure 1 in an assembling condition in a stator of an engine.

[0010] With reference to the figures 1-3, numeral 1 indicates the rotor for pneumatic compressed air engine or turbine object of the present invention.

[0011] The rotor 1 includes a drum 2 and a shaft 3. In an assembling condition, the rotor 1 is housed in a cylinder 12 of a stator 10 of the engine, which rotatably supports the shaft 3. The rotor 1 and the cylinder 12 are parallel and misaligned.

[0012] The stator 10 includes an inlet duct 9 ending, in correspondence of one of its outlets 8, into the cylinder 12 and includes an air exhaust duct 20.

[0013] The inlet ducts 9 and the exhaust duct 20 are transversal to the cylinder 12, particularly the inlet duct 9 directs the compressed air flow F approximately in a direction tangent to the drum 2.

[0014] The rotor includes a plurality of sectors 4 divided by a plurality of seats 5 for vanes 13 for instance flat shaped. These latter slide in the respective seats 5 and, under the action of elastic forces exerted by compressed air or springs, match the wall of the cylinder 12, dividing in chambers the volume included between this latter and the rotor. In consequence of the axial rotation of the drum 2 and because of the eccentricity between drum 2 and cylinder 12, the volume of each chamber increases moving from the outlet 8 to the exhaust duct 20 and decrease moving from this latter to the outlet 8.

[0015] The drum 2 is in single body with the shaft 3 or is fixed to this latter which has at least an end extending from the stator 10 for the transmission of the motion.

[0016] The external portion of each sector 4 is shaped as a cylindrical portion and has a cavity 6.

[0017] Said cavity 6, for instance carried out by means of a fluted milling cutter axially translated in direction of the drum 2 axis, has a wall 7, shaped as a cylindrical portion that, in a facing condition A in which the cavity 6 faces the outlet 8, is approximately orthogonal to the direction of the compressed air flow F.

[0018] The shaft 3 can have an axial hole 14. Each sector 4 can have a longitudinal hole 11.

[0019] It is provided that the drum 2 and/or the shaft 3 are made of alloy iron or alloy aluminium or strengthened synthetic material; for instance the shaft 3 can be made of steel and the drum 2 is made of synthetic resin strengthened with carbon fibres.

[0020] The operation of the rotor 1 provides that, in a stop condition of the slide of the vanes 13 held in retracted position inside the respective seats 5 by dregs (derived from lubricating thickened), dirty or similar, the flow F hits the cavity 6 and particularly the wall 7 causing a force, orthogonal to said wall and in the same direction of the rotation. Said force contributes to the rotation of the rotor 1, which causes a centrifugal force applied to the vanes 13 which are therefore subject to a radial force, outwardly directed, contributing to release the vanes. Furthermore the effect of the flow F on the walls 7 contributes to the total torque of the rotor 1 at normal operation conditions.

[0021] It is provided a variant of the rotor 1 in which each cavity 6 extends parallely to the shaft 4 forming a longitudinal groove 21 which is step-shaped and shown by hatch lines in figure 1. The wall 7 is flat and extends along the whole related sector 4. The groove 21, for instance, can be carried out by removing material longitudinally translating a fluted mill cutter.

[0022] The main advantage of the present invention is that to provide a rotor fit to allow the starting of the engine and its consequent release due to the action of the centrifugal force of the vanes held in retracted position by dirt and similar. A further advantage is to provide a rotor fit to increase the total torque of the engine.

Claims

1. Rotor for pneumatic engine including a shaft (3) supported by a stator (10) and having a drum (2) with a plurality of sectors (4) characterized in that the external portion of each sector (4) has at least a cavity (6) fit to engage a feeding flow (F) of the engine.

2. Rotor according to claim 1 characterized in that said cavity (6) has at least a wall (7), which is approximately orthogonal to the direction of the flow (F), in proximity of an outlet (8) of an inlet duct (9) of the stator (10).

3. Rotor according to any of the preceding claims characterized in that the wall (7) is shaped as a cylindrical portion.

4. Rotor according to claim 1 or claim 2 characterized in that each cavity (6) extends parallely to the shaft (3) and the wall (7) is flat.

5. Rotor according to any of the preceding claims characterized in that the shaft (4) is hollow.

6. Rotor according to any of the preceding claims characterized in that each sector (4) has at least a longitudinal hole (11).

7. Rotor according to any of the preceding claims characterized in that the drum (2) and/or the shaft (3) are made of at least one between alloy iron or alloy aluminium and strengthened synthetic material.

Drawing