WO1997046762A1

WO1997046762A1 - Rotating device

Info

Publication number: WO1997046762A1
Application number: PCT/FI1997/000342
Authority: WO
Inventors: Kalle Eero Moilanen
Original assignee: Metallikoneistamo E. Moilanen Ky
Priority date: 1996-06-03
Filing date: 1997-06-02
Publication date: 1997-12-11
Also published as: EP0907804B1; AU2965397A; DE69721769T2; FI962313A; FI100902B; DE69721769D1; EP0907804A1; FI962313A0

Abstract

The object of the invention is a rotating device for rotating the extension arm of an excavator or a similar machine, the device comprising fastening plates (1 and 2) for the extension arm and bucket with fastening elements, a body (3), clutch shoes (4), friction material (5), a fastening plate (6) for the body, slide bearing plates (7, 8) with lubrication channels, a locking cylinder (14), a rotary cylinder (12), a hydraulic accumulator, a lock valve, direction valves, limit switches, and a control arrangement, and the necessary electric and hydraulic conductors. The rotating device is attached between two extension arms or similar elements, such as a bucket and extension arm of an excavator, thus making it possible to continuously change the position of the bucket in a desired way and as is advantageous for the working phase in question. With the present invention, it is possible to fast rotate the extension arms of an excavator, rock drilling machine, forest tractor, passenger hoist, truck crane, etc. to an advantageous working position. For example, when working with an excavator in close places, near walls, or on roadwork sites in busy street areas, the invention makes it possible to rotate the bucket to an arbitrary angular position, thus substantially improving the range and the driver's eye contact to the machine. The invention also provides a circular or arcuate working movement. The rotation of the bucket and the working movements may also be carried out semi-automatically or fully automatically by controlling the hydraulic system with a suitable control arrangement. The excavation costs will be reduced, as the amount of earth masses to be moved will be smaller, and as the location of the excavator need not be changed so often.

Description

Rotating device

The object of the present invention is a rotating device for rotating the extension arm of an excavator or a similar machine, the device comprising fastening plates for the exten¬ sion arm and bucket with connecting elements, a body, a clutch shoe, friction material, a fastening plate for the body, a slide bearing arrangement with lubrication channels, a lock cylinder, a rotary cylinder, a hydraulic accumulator, a lock valve, direction valves, limit switches, and a control arrange¬ ment, and the necessary electric and hydraulic conductors. The rotating device is attached between two extension arms or similar parts, for example between an excavator bucket and extension arm, thus making it possible to continuously change the position of the bucket as desired and as is advantageous for each particular work stage.

The present invention enables fast rotation of the extension arms of an excavator, rock drill machine, forest tractor, passenger hoist, truck crane, etc., into an advantageous work¬ ing position. For example, when using an excavator in close places, near walls or on roadwork sites in busy street areas, by using the present invention, it is possible to rotate the bucket to an arbitrary angular position, and to substantially improve the range and the driver's eye contact to the target. The present invention also provides a circular or arcuate work movement. The rotation and work movements of the bucket can also be carried out semi-automatically or fully automatically by controlling the hydraulic arrangement with a suitable control arrangement. Excavation costs will be reduced, as the amount of earth masses to be moved will be smaller, and as the location of the excavator will not have to be changed so often. A good example of this is a situation in which a tractor excavator equipped with the rotating device may be used to dig a pole hole without having to move the machine during work and without having to dig an oversized hole. The excavation method may be changed by rotating the bucket 180° from a more generally used position required by the so-called back hoe excavation method, whereafter it is possible to use the machine for the so-called offset excavation method. Changing the excavation method provides the work with extra range, and it is thus possible to dig excavations with deep edges and with rectangular bottom shape. The device of the present invention is simple and reliable, and in expensive, so that it is also financially possible to purchase it, for example, as an acces¬ sory for an excavator.

Digging by a conventional excavator is conducted so that the excavator is positioned as advantageously as possible with regard to the work to be carried out; it is then supported in place by stabilizers, whereafter digging may be started. The excavation movement is conducted vertically to the machine (back hoe) or away from it (offset) , which entails that the location of the machine has to be changed relatively often so that digging would be possible everywhere. The change of location reduces considerably the effective working time, because, especially in close places and in difficult terrain, it takes a lot of time to search for a steady "foothold". When building in densely populated areas, it is often downright impossible to finish the excavation work with an excavator, because it is not possible to position the machine correctly. A known problem is also that, for a relatively minor excavation work, large quantities of masses have to transferred in vain, due to the inadvantageous position of the excavator or tractor excavator.

There have previously been known various rotating devices for eliminating the above-mentioned problems. For example, in connection of the publication U 940322 disclosing a fast coupling device there is provided a solution according to which the bucket rotates in a sort of guideway, and it can be locked in place by an extendable locking device. In the patent application FI 843454, the rotation of an excavator bucket is solved by internally placed hollow bars, idlers and rotary cylinders. The publication print SE 464644 discloses a device in which a bucket is rotated to various angular positions by a gear assembly and locked in place by friction. However, devices available on the market have a relatively complicated structure; for this reason, considerable defects have been noticed in their operation, i.a. because of malfunctions caused by dirt, and defects in durability. With the latter arrange¬ ment, for example, it is not possible to generate sufficient frictional forces, and too high stresses are applied to the gear assembly due to excavation forces. Because of the complicated structure, the manufacturing costs of the said solutions are high, thus increasing the purchase prices too high and making it impossible to purchase the devices, for example, as accessories for excavators.

The above mentioned problems are solved by the present inven¬ tion, and also deficiencies in the known technology are elimi¬ nated. It is also possible to use the excavator in close places so that the good range of the device makes it possible to carry out digging without having to move the machine, thus simultaneously lessening the quantity of earth masses to be transferred.

The said advantages are achieved by the rotating device of the present invention, the special features of which are defined in the characterizing part of the appended claims.

The invention is next described in more detail referring to some advantageous exemplary embodiments and the enclosed draw¬ ings, in which F Fiigg.. 1 1 is a section of the device along the line A-A;

Fig . 2 shows the device seen from the direction of the tractor extension arm;

Fig . 3 is a side projection of the device;

Fig . 4 is a section of the device along the line C-C; F Fiigg.. 5 5 presents the hydraulic system of the device with the help of standard drawing indications; Fig. 6 shows a rotating device similar to that in Fig. 7, but the bucket has been rotated to an angular position from the vertical level, and it is seen from the direction of the extension arm in section along the line B-B; and

Fig. 7 shows a side projection of a rotating device fixed between the bucket and extension arm of an excavator.

In Figures 1, 2, 3 and 4 there are shown a fastening plate 1 for the extension arm and a fastening plate 2 for the bucket; they are attached to the body 3 most suitably by screw and nut joints 9 and 10. The massive body 3 receiving the flexural moments and cutting forces consists of a tubular web, both ends of which comprise doughnut flanges for fastening and pivoting. The tubular structure of the body makes it possible to advantageously lead the electric, hydraulic and other connectors 35 through apertures 34, thus protecting the con¬ nectors well against damage. In this connection, it is not necessary to describe the structure of the body or the manu¬ facturing method in detail. The body 3 is attached to the fastening plate 1 of the extension arm by the said joint 9 and the flange-like fastening plate 6 of the body, and by a slide bearing arrangement. Bearing plates 8 of suitable bearing material are arranged on the periphery of, and above and below the flange-like fastening plate 6 of the body. The correspond¬ ing bearing surfaces of the fastening plate 6 are constructed so that upon tightening of the part 9, a suitable bearing clearance is provided between the surfaces. The clearance may be adjusted in ways well-known in the bearing technology, e.g. by thin adjustment plates installed between the fastening plate 1 of the extension arm and the fastening plate 6 of the body; however, these adjusting plates are not shown in the figures. The bearing arrangement also includes one or more lubrication channels 11 and sealing elements 7. The bearing allows the joint to have only one degree of freedom, i.e. it is only possible to rotate the parties in relation to each other. Brackets 29 of the bucket and brackets 27 of the extension arm are attached to the fastening plate 1 of the extension arm by welding. The body 3 and the fastening plate 1 may be locked rigidly in relation to each other, or they may be rotated in relation to each other by a rotary cylinder 12 and a friction clutch arrangement comprising two stable clutch shoes 4, a fastening element 16, a single-action locking cylinder 14, a tightening element 15, and frictional material 5. The torque transmitted by the friction clutch arrangement is directly proportional to the tightening force provided by the locking cylinder and to the friction coefficient between the frictional surfaces. A double-action rotary cylinder 12 is attached to the clutch shoe 4 and to the fastening plate of the extension arm by closed bearings and pins 18 of the cylinder, brackets 11 are attached to the clutch shoe advantageously by welding, and brackets 13 are attached to the fastening plate of the extension arm also by welding.

In Fig. 5 there is shown a hydraulic arrangement included in the device. It comprises a locking cylinder 14, a rotary cylinder 12, a hydraulic accumulator 19, a lock valve 20, e.g. a pressure-controlled counter valve, direction valves 22, 23, 30, limit switches 32, which are most suitably electrically operated, a control system 33 and the necessary hydraulic and electric conductors 17, 21, 31 with appropriate components, connectors and equipment; the latter are not shown in the picture.

Fig. 7 shows the connection principle of the bucket 24, exten¬ sion arm 26, bucket cylinder 25 and rotating device 28. In this embodiment, the rotating device is attached between the extension arm and bucket so that it is rotated 180° compared with Fig. 3. The fastening plate of the extension arm and that of the bucket are connected to the rotating device in a con¬ ventional way by pin and bracket connection and by welding.

In Fig. 6 the rotating device is shown in rotated position in vertical plane. The rotating device of the invention may be rotated to any arbitrary angular position. The manually conducted operation of the rotating devices is in principle the following. In its initial position, the rotating device is locked by a locking cylinder 14, which receives the necessary pressure energy from the hydraulic accumulator 19. When the direction valve 23 controlling the rotary cylinder 12 is in its center position, the rotating device and the bucket are rigidly connected to each other, thus making normal excavation movements possible. By controlling the rotary cylinder by a direction valve it is also possible to provide the bucket with an arcuate working movement within limits allowed by the cylinder stroke. When wishing to change the position of the bucket, the driver drives the rotary cylinder + movement to the extreme position and uses the lock valve 20 to release the pressure from the hydraulic accumulator to the container and rotates the clutch shoes to a new position by using the rotary cylinder. After this he leads the pressure to the locking cylinder and hydraulic accumulator, the locking procedure is again possible, and the bucket/extension arm can be rotated to a new position.

When desired, the system may be controlled by control system 33, which may advantageously be a programmable logic, or a similar arrangement. It is then possible to link the messages conveyed by the limit switches 32 and other possible means observing the state of the system, e.g. sensors, as input signals of the programmable logic, and the necessary control commands, e.g. control voltages of the direction valves, as output signals. In Fig. 5 there is shown an advantageous solution for realizing the control, according to which the limit switches 32, cylinders 12 and 14, and direction valves 22 and 30 are connected to each other by using a sequential principle in which the control system 33 controls only the direction valve 23. However, the connection of the direction valve 23 to the control system is not shown in Fig. 5.

The figures and the related description are meant only to illustrate the present invention. The details of the rotating device may vary within the scope of the appended claims and the inventory idea included in the description. It is apparent to those skilled in the art that, for example, the device may include one or more rotary cylinders, locking cylinders or clutch shoes, and that the components may also be arranged unsymmetrically. It is also obvious that the way the rotating device is attached to the extension arm of an excavator or a similar device, or to the bucket, is dependent on the shapes and dimensions of the structure. Further, it is obvious to those skilled in the art that the applications may vary within the scope of structural solutions introduced in connection of working conditions, customer's demands, inexpensive serial working methods, and mass production. For example, the body and fastening plates may be constructed as integrated units of two or a few physical pieces, and the hydraulic and electric systems may be integrated in a fixed way to the device, or they may be realized by using generally available components. Further, the mutual operation and the order of operation of the control system and hydraulic system may be different from the advantageous embodiment in the description.

Claims

1. A rotating device for rotating the extension arm of an excavator or a similar machine, the device comprising a body (3) , a fastening plate (1) and a fastening plate (2) , charac¬ terized in that the bucket or extension arm is rotated by frictional force using a rotary cylinder (12) and a friction clutch arrangement comprising one or more clutch shoes (4) , a fastening element (16) , a single-action locking cylinder (14) , a tightening element (15) , and friction material (5) .

2. The rotating device of claim 1, characterized in that it includes a hydraulic system comprising a locking cylinder (14) , a rotary cylinder (12) , a hydraulic accumulator (19) , a lock valve (20), direction valves (22, 30 and 33) , and the necessary hydraulic and electric conductors (17, 31, 21) with appropriate connectors.

3. The rotating device of claim 1, characterized in that the operation of the device is controlled by a control arrangement comprising electrically driven limit switches (32) , electrically controlled hydraulic direction valves (22, 23, 30), and a programmable logic (33), or a similar system, and the necessary hydraulic and electric conductors (17, 21, 31) with appropriate circuit components, connectors and equipment.

4. The rotating device of claim 1, characterized in that the body (3) is tubular so that conductors in the system may be arranged to pass through the body to various working devices.