| CLAIMS
1. Method for recovering the energy resulting during the operation of lowering the arm, characterized in that, in the step of lowering the excavator arm, the deadweight thereof is in the form of an energy transmitted, by various means, while passing all the way along this path, to a mechanical, hydraulic or pneumatic device which stores the same as a potential energy and in the next step lifting the excavator arm, this energy is automatically released, thereby contributing to the lifting effort made by the excavator.
2. Device for recovering the energy resulting during the operation of lowering the arm, in the first embodiment, characterized in that, it is provided with a pneumatic-hydraulic cylinder (1) anchored at the upper side to the arm (2) of an equipment (A) and with the end of the driving rod (3) to the mobile body of the same equipment (A), a lower chamber (a) being connected with a direction valve (21) and with a distributor (26) in order to eliminate the collected oil, as well as with a position and pressure transducer (16) destined to signal the presence of oil, and an upper chamber (C) above a piston (18) being in connection with a distributor (13) and with a pneumatic accumulator (14) for carrying out the accumulation and with a distributor (24 ) and with a position and pressure transducer (17) for the completion of the layer of oil (e) above the piston (18).
3. Device for recovering the energy resulting during the operation of lowering the arm, in the second embodiment, characterized in that, it is provided with a pulley wheel (27), integral with an arm (28) of an equipment (C) and with the end of a traction cable (29) and a mobile counterweight (30) whereto there is anchored the other end of the cable (29), the traction cable (29) being supported on another pulley wheel (31) and the said counterweight (30) sliding vertically along some guides (32) integral with the mobile side of the equipment ( C).
4. Device of mechanical type for recovering the energy resulting during the operation of lowering the arm, in the third embodiment, in a first carrying out variant, characterized in that, it is provided with a pulley wheel (35) integral with the arm (36) of the excavator (D) and with a traction spring (37) anchored with an end (g) to the mobile side of the equipment (D) and with the other end to a cable (38) integral with the pulley wheel (35).
5. Device of mechanical type for recovering the energy resulting during the operation of lowering the arm, in the third embodiment, in the second carrying out variant, characterized in that, it is provided with a gear wheel (41) integral with an arm (42) of an equipment (E) and with a compression spring (43) resting with one end (h) to the mobile side of the equipment (E) and with the other end in contact with a rack (44) which engages with the gear wheel (41 ).
6. The device of mechanical type for recovering the energy resulting during the operation of lowering the arm, in the third embodiment, in the third carrying out variant, characterized in that it is provided with one or two torsion springs mounted axially with the bolt around which the arm of the equipment rotates, one of the ends of the torsion springs being integral with the arm of the equipment, and the other being rigidly secured with the mobile side of the equipment.
7. The device for recovering the energy resulting from the
Operation of lowering the arm, in the first embodiment, according the claim 1 , characterized in that the driving rod is provided with an axial orifice (f) which also crosses the piston (18). |
METHOD AND DEVICE FOR RECOVERING ENERGY FROM THE ARM LOWERING OPERATION
The present invention refers to a method and a device for recovering the energy from the arm lowering operation, said device being used for excavators and front loaders during the operation of lowering the arm without load.
There is known the fact that at present excavators and front loaders are provided with hydraulic installations by means of which there may be controlled the lifting and lowering of the arm, with or without load. These hydraulic installations are equipped with some hydraulic cylinders located on either side of the arm and are driven by means of some distributors and some pumps.
The disadvantage of these hydraulic installations is that upon lifting the arm by the equipment effort is made and energy is consumed to lift the deadweight of the arm and to lift the load weight.
There is not known a method or a device for recovering the energy while lowering the excavator arm.
The technical problem solved by the present invention is the carrying out of a method and a device for recovering the energy resulting during the operation of lowering the arm, which allow to reduce the fuel consumption by means of an energy accumulator.
According to the invention, the method for recovering the energy during the lowering of the excavator arm, eliminates the above- mentioned disadvantage by that the arm deadweight, in the form of an energy, is transmitted by various means, upon traveling along this path, to a mechanical, hydraulic or pneumatic device which stores the energy as a potential energy and in the step of lifting the excavator arm releases it automatically sharing the lifting effort made by the excavator. The method is applied by means of some devices in various embodiments for recovering the energy resulting during the arm lowering operation.
The device for recovering energy resulting in the operation of lowering the arm, in a first embodiment, is provided with one or several pneumatic cylinder(s) anchored at the upper side to the arm of an
excavator or front loader, and with the end of a driving rod to the mobile body of the same equipment. A lower chamber is connected with a direction valve and a distributor for the elimination of the collected oil, as well as with a position and pressure transducer destined to signal the presence of oil. An upper chamber above a piston is in connection with a distributor and a pneumatic accumulator for carrying out the accumulation, as well as to a distributor and a transducer for the completion of oil level above the piston. In the driving rod of the pneumatic cylinder there is drilled an axial orifice which also crosses the piston that the rod is integral with.
The device in the second embodiment is provided with a pulley wheel integral with an arm of an equipment and with the end of a traction cable, as well as a mobile counterweight whereto there is anchored the other end of the cable. The traction cable is supported on another pulley wheel, and the said counterweight slides vertically along some guides integral with the mobile side of the equipment. In the third embodiment, the mechanical-type device, in a first carrying out variant, is provided with a pulley wheel integral with the equipment arm and with a traction spring anchored with one end to the mobile side of the equipment and with the other end to a traction cable, integral with the pulley wheel. In the third embodiment, the mechanical-type device, in the second carrying out variant, is provided with a gear wheel integral with an arm of an equipment and with a compression spring supported with one end to the mobile side of the equipment and with the other end in contact with a rack which engages a gear wheel.
In the third embodiment, the mechanical-type device, in the third carrying out variant, is provided with one or with two torsion springs, mounted axially with the bolt around which the arm of the equipment rotates, one of the torsion springs ends being integral with the equipment arm, the other being rigid with the mobile side of the equipment.
By the application of the invention the following advantages are obtained:
-reduction of the fuel consumption;
-reduction of the quantity of working fluid used ;
-reduction of the device wear;
-increase of the duration of operation of the hydraulic installation ;
-increase of the quality of the surrounding environment ;
There are given hereinafter embodiments of the device for recovering the energy resulting during the operation of lowering the arm, according to the invention, in connection with the figures from 1 to 5, which represent :
-fig. 1 , side view of an excavator whereon, near the hydraulic cylinder
4 of the main driving circuit of the arm 2 , there is represented the hydro-pneumatic cylinder 1 of the device for recovering the energy resulting during the operation of lowering the arm, in the first embodiment, according to the invention ;
-fig. 1 A, side view of a front loader whereon there is mounted the device of recovering the energy resulting during the operation of lowering the arm, in the same first embodiment according to the invention;
-fig. 2, the hydraulic scheme of the device for recovering the energy resulting during the operation of lowering the arm, in the first embodiment according o the invention;
-fig. 3, the device of a gravitational type for recovering the energy resulting during the operation of lowering the arm, in the second embodiment, according to the invention, mounted on an excavator;
-fog. 3A, the device of a gravitational type for recovering the energy resulting during the operation of lowering the arm, in the second embodiment according to the invention, mounted on a front loader;
-fig. 4, device of a mechanical type for recovering the energy resulting during the operation of lowering the arm, in the third embodiment, in the first carrying out variant according to the invention mounted on an excavator;
-fig. 4A, the device of a mechanical type for recovering the energy resulting during the operation of lowering the arm, in the third embodiment, in the first carrying out variant according to the invention, mounted on a front loader;
-fig. 5 device of a mechanical type for recovering the energy resulting during the operation of lowering the arm, in the third embodiment, in the second carrying out variant according to the invention, mounted on an excavator;
-fig. 5A, device of a mechanical type for recovering the energy resulting during the operation of lowering the arm, in the third embodiment, in the second carrying out variant, mounted on a front loader;
The pneumatic-type device for recovering the energy resulting during the operation of lowering the arm, in the first embodiment, according to the invention, consists of a pneumatic cylinder 1 anchored
at the upper side to an arm 2 of an excavator A, or of a front loader, generically named hereinafter "equipment' and to the end of the driving rod (3)of the body of the equipment A.
The equipment A is provided, from the manufacturing, with some hydraulic cylinders 4, placed on either side of the arm 2 and supported with the working chambers to the body of equipment A and with the ends of some driving rods 5 articulated to the arm (2) of the equipment A. The hydraulic cylinders 4 are connected to a hydraulic circuit B extant from manufacturing on the equipment A and serving to drive the arm 2 both upon lifting and upon lowering the same, the driving being carried out by some pipes 6 and 7.
A lower chamber a of the cylinder 1 is connected through a pipe 8 and a distributor 9 to a chamber b of the hydraulic cylinder 4, and an upper chamber c of the same cylinder 1 is in connection to a chamber c of the hydraulic cylinder 4 by means of another pipe 10 and of another distributor 11.
The chamber c is connected through a pipe 12 and a distributor 13 to a pneumatic accumulator 15, the pressure on this portion of the pneumatic circuit being ensured by an air compressor 15.
The cylinder 1 is also provided with some position and pressure transducers 16 and 17 placed to the extremities of the chambers a and c of the cylinder 1.
Above a piston 18 it is necessary to permanently exist an oil layer e, in order to ensure the lubrication thereof, said oil layer e being completed through an axial orifice f of the rod 3 and brought through the pipe 19 and a distributor 20.
The reduction of the pressure formed and the elimination of the oil accumulated in the chamber a of the piston 1 may be carried out by means of a valve 21 mounted on a pipe 22.
In order to ensure a good functioning of the hydro-pneumatic cylinder 1 the chamber c is in connection, through a pipe 23 and a distributor 24, with the main working circuit, in order to complete the oil layer e necessary for the lubrication, and the oil accumulated in the chamber a, of the same cylinder 1, may be removed through a pipe 25 and a distributor 26.
The manner of operation of this pneumatic-hydraulic type device embodiment, according to the invention, is as follows: there is permitted the lowering of the arm 2 without driving, by means of any control, the main hydraulic circuit of the excavator A. Only the oil in chamber d of the piston 4 is permitted to come out through the pipe 6
towards a reservoir, not represented in the figure, and through the pipe 7 the access to oil is permitted from the reservoir into the chamber b.
Before carrying out these controls, distributors 9, 11 and 13 shall be closed.
Due to its deadweight, the arm 2 may be lowered now, this movement leading to the lowering of the cylinder of the piston 1 and to decreasing the volume of the chamber c. The air pressure in chamber c is transmitted through the first portion of the pipe 10, through the pipe 12 and distributor 13, normally open, towards the pneumatic accumulator 14 thereby carrying out an energy accumulation as an overpressure.
Upon lifting the arm 2 of the equipment A simultaneously with the control of supplying oil into the chamber d of the cylinder 4 through pipe 6, the overpressure in accumulator 14, working as a spring in the elasticity domain, will help to lifting the arm 2 by the extension of its volume into chamber c of the piston 1.
In other words, the hydro-pneumatic cylinder 1 supports an important part of the deadweight of the arm 2 without load, following that the main hydraulic cylinder of the equipment A should take over the difference of weight of the arm 2 and of the load to thereby ensure the normal controls of the arm 2 of the equipment A.
The gravitational-type device for recovering the energy resulting during the operation of lowering the arm, in the second embodiment according to the invention, consists of a pulley wheel 27 integral with an arm 28 of an equipment C and with the end of a traction cable 29, and of a mobile counterweight 30 to which the other end of the cable 29 is anchored.
Above the counterweight 30 the traction cable 29 is supported on another pulley wheel, and said counterweight 30 may slide vertically along some guides 32 integral with the mobile side of the equipment C.
Upon lowering the arm 28, simultaneously with rotating the same around a bolt 33, there is also rotated the wheel 27 which drives the cable 29 lifting the counterweight 30 and thereby accumulating a potential energy which it yields upon lifting the arm 28, carried out by the known method by means of a hydraulic cylinder 34. Constructively, the pulley wheel 27 may be carried out, depending on the maximum arc described by the arm 28 during the operation, only as a sector of a circle.
The mechanical-type device for recovering the energy resulting during the operation of lowering the arm, in the third embodiment, in a first carrying out variant according to the invention, is provided with a pulley wheel 35 integral with an arm 36 of the equipment D and with a
traction spring 37 anchored with an end g to the mobile side of the excavator D, and with the other end of a cable 38 integral with the pulley wheel 35.
Upon lowering the arm 36 together with it there rotates, around a bolt 39, the wheel 35 which, by means of the cable 38 stretches the traction spring 37, tensioning it.
Upon lifting, operation which is carried out by means of a hydraulic piston 40, by the tension release of the spring 37 there is compensated a part of the energy necessary to lift the arm 36.
The mechanical-type device for recovering the energy resulting during the operation of lowering the arm, in the third embodiment, in the second carrying out variant, according to the invention, is provided with a gear wheel 41 integral with an arm 42 of an excavator E and with a compression spring 43 supported with one end h to the mobile side of the excavator E and with the other end in contact with a rack 44 which engages the gear wheel 41.
Upon lowering the arm 42 together with it there rotates, around the bolt 45, the gear wheel 41 which, by means of the rack 44 produces the compression of spring 43 tensioning it.
Upon lifting, operation performed in the known manner, by the stress-relieving spring 43, a part of the energy necessary to lift arm 42 is compensated.
The mechanical-type device for recovering energy resulting during the operation of lowering the arm, in the third embodiment, in the third carrying out variant according to the invention, is provided with one of more torsion springs, not represented in the figures, mounted axially with the bolt around which the arm of the equipment rotates, one of the ends of the torsion springs being integral with the arm of the excavator, and the other being rigidly secured with the movable side of the excavator.
Upon lowering the arm of the equipment together therewith there rotates the end of the torsion spring it is integral with, in this way the spring reaching a state of tension.
Upon lifting, operation performed in the known manner, by the stress-relieving of the torsion spring there is compensated a part of the energy necessary to lift the arm of the equipment.
The hydraulic-type device for recovering the energy resulting during the operation of lowering the arm, in another carrying out variant of the first embodiment, is provided with a usual hydraulic cylinder, not represented in the figures, which may replace the pneumatic-hydraulic cylinder 1, by using the same hydraulic scheme.
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