The present invention relates to the field of mechanical coupling devices.

In particular, the invention relates to a rotating joint, of the type used for coupling pipes used for transferring fluids under pressure.

In particular, the present invention relates to a rotating joint according to the preamble of claim 1.

The rotating joint according to the present invention finds an advantageous and preferred application as a component of transfer lines for liquids with articulated arms in the oil industry and in the food industry.

STATE OF THE ART

In piping systems, and in mechanical constructions in general, in order to transfer fluids under pressure from a conduit to another, coupling sections of pipes by the use of flanges are known per se, i.e. through the mutual fastening of two facing plates having the shape of a ring, each of which is integral with one of the two ends of the pipes that need to be connected one to the other.

It is also known in the art to use a particular type of flange which allows a relative rotation between the two sections of a pipe.

In general, such rotating couplings, or rotating joints, are made by providing a male ring element that fits into a female ring element, on each of which a plate of a flange is screwed. Between the male element and the female element there is a seat of the sealing element of the coupling, in general an O-ring, and in an assembled condition, the respective openings of the two ring elements are coaxial.

Inside the joint, between the male element and the female element, a rolling track with balls is also formed that, by actually providing a bearing, allows a relative rotation of the two elements.

Although this solution gives good sealing qualities of the coupling, it presents the drawback of providing complicated and laborious tasks for the maintenance of the rotating joint due to the presence of the ring of ball bearings.

Moreover, the rotating joints of this type have the disadvantage of being quite weak, especially regarding mechanical stresses of twisting type, as those exerted in use or during the installation operations, due to the small contact surface between the balls and the ring elements.

OBJECTS AND SUMMARY OF THE INVENTION

The object of the present invention is to overcome the drawbacks of the known art. In particular, it is an object of the present invention to provide a rotating joint with high characteristics of mechanical strength, in particular to twisting type stresses. It is also an object of the present invention to provide a rotating joint which is easy to assemble.

It is also an object of the present invention to provide a rotating joint which requires a simple and not frequent maintenance.

It is also an object of the present invention to provide a rotating joint which has a lower manufacturing cost and an increased durability.

These and other objects of the present invention are achieved by a rotating joint incorporating the features of the appended claims, which form an integral part of the present description.

The basic idea of the present invention provides for the manufacture of a rotating joint without the traditional ring of ball bearings, and in particular replacing this latter with a disk-shaped rotating element.

Such solution allows the rotation between the parts, reducing the cost of the coupling element and increasing its performances, especially the resistance to twisting moments.

Such solution, thanks to the absence of rolling bearings, allows at the same time to simplify the assembly operations as well as the maintenance operations.

Further advantageous features of the present invention will become more apparent from the description that follows and from the appended claims, which form an integral part of the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will be described hereinbelow with reference to non-limiting examples, provided for the purposes of explanation, and not limitation in the accompanying drawings. These drawings illustrate different aspects and embodiments of the present invention, and where appropriate, reference numbers showing illustrating structure, components, materials and/ or similar elements in different figures are denoted by similar reference numerals.

Figure 1 shows an overall side view of a rotating joint in accordance with the invention.

Figure 2 shows a top view of the joint of figure 1.

Figure 3 shows a section along a side view of the joint shown in figure 1.

Figures 3a and 3b show respectively a first and a second enlarged detail of figure 3.

Figures 4a and 4b respectively show a top view and a side view of a first constructive detail - disk-shaped element - of the joint according to the invention.

Figures 5a and 5b respectively show a top view and a side view of a second constructive detail - first ring element - of the joint according to the invention.

Figures 6a and 6b respectively show a top view and a side view of a third constructive detail - sealing element - of the joint according to the invention.

Figures 7a and 7b respectively show a top view and a side view of a fourth constructive detail - second ring element - of the joint according to the invention.

DETAILED DESCRIPTION OF THE INVENTION

While the invention is susceptible to various modifications and alternative constructions, some non-limiting embodiments, provided for explanatory purposes, are described in detail hereinbelow.

It should be understood, however, that there is no intention to limit the invention to the specific embodiments illustrated, but, on the contrary, the invention is intended to cover all modifications, alternative constructions, and equivalents which fall within the scope of the invention as defined in the claims.

In the following description, therefore, the use of "for example", "etc.", "or/either" indicates not exclusive alternatives without any limitation, unless otherwise indicated; the use of "also" means "including, but not limited to" unless otherwise indicated; the use of "includes/ comprises" means "includes/comprises but not limited to" unless otherwise indicated. As mentioned above, the present invention relates to a rotating joint or coupling, for transfer lines for liquids without ball bearings.

The movement between the contact surfaces, that in this type of mechanical components occurs in a discontinuous way in time and at low speed, is ensured by an anti-friction surface treatment.

The increased contact surface with respect to the use of ball bearings ensures a greater resistance to twisting forces.

The joint, or coupling, advantageously shows ease of assembly and lack of maintenance.

Figures 1, 2 and 3 show a rotating joint according to the invention.

As it can be seen, in particular with reference to figure 3, the rotating joint 1 comprises

- a first ring element 2 provided with a first opening 3 intended to receive an end of a first pipe 20 (not shown),

- a second ring element 4 provided with a second opening 15 and integral with the first ring element 2,

- a frusto-conical element 5 provided with a fifth opening 16 intended to receive an end of a second pipe 40 (not shown),

- a sealing element 6 provided with a third opening 7 and interposed between said first 2 and second 4 ring elements,

- a plurality of blocking means 8 for joining said first 2 and second 4 ring elements and the frusto-conical element 5,

- decoupling means in contact with the first 2 and second 4 ring elements and also with said sealing element 6, in which the decoupling means are suitable for limiting the mutual friction.

The rotating joint 1 is characterized in that the decoupling means comprise a disk- shaped element 10 provided with a fourth opening 11, and whose surface is provided with a plurality of grooves 12 adapted to receive a fluid lubricant.

As can be seen in figure 3 and in the detailed representation in figure 3a, the disk- shaped element 10 is coupled to the other elements so to keep the first 3, second 15, third 7, the fourth 11 and fifth 16 openings in fluid communication and coaxial with each other.

The disk-shaped element 10 is integral with the frusto-conical element 5 and with the corresponding second pipe 40 so as to allow the relative rotation of the group formed by the disk-shaped element 10, by the frusto-conical element 5 and the second pipe 40 with respect to the group formed by the ring elements 2 and 4 and by the first pipe 20.

With reference to figures 4a and 4b, it can be observed that the grooves 12 of the disk-shaped element 10 are circular; such circular configuration has the advantage of a greatly simpler construction.

In alternative embodiments, which are not shown here, the grooves 12 may be radial or helical or may have any other geometry according to the specific application requirements; in particular, the radial and helical configurations have the advantage of facilitating the lubrication of the rotating joint.

The disk-shaped element 10 also has notches 14 regularly arranged on the periphery; such notches 14 serve to reduce the contact surface among the rotating parts and also work as containers for the fluid lubricant.

In the shown embodiment, the disk-shaped element 10 of the rotating joint 1 is tapered at its distal end with respect to the fourth opening 11, i.e. it has a tapered shape with the thinned ends; the tapered shape of the disk-shaped element 10 is more efficient and is less prone to friction, and therefore is the preferred one.

In alternative embodiments which are not shown here, the disk-shaped element is not tapered at the periphery, and may have any profile depending on specific requirements.

It may also be provided that the disk-shaped element 10 of the rotating joint 1 be thermally treated, for example by nitriding; the heat treatment, in fact, reduces the friction and consequently gives better wear resistance properties against rubbing during the rotation.

In addition, or as an alternative to the heat treatment, it may be provided that the grooves 12 of the rotating joint 1 be superficially treated by carry-overs of various materials, specifically of anti-wear materials; the surface treatment contributes to the reduction of friction, and if carried out in addition to the heat treatment described above, contributes to increase the improvement of wear resistance properties.

The blocking means 8 used to join the first 2 and second 4 ring element are preferably screws and/ or bolts, but any other means suitable for the purpose of joining the two ring elements in a removable manner can be used.

With reference to figures 5a and 5b, it can be observed that the first ring element 2 of the joint 1 has a first opening 3; it is provided with holes for the blocking, which enable its connection to the second ring element 4. The first 2 and second 4 ring elements are connected to one of the two pipes, for example to the first pipe 20, connected by the rotating joint 1, the other pipe, for example the second pipe 40, being connected to the frusto-conical element 5, capable of rotating with respect to the ring elements 2 and 4.

With reference to figures 6a and 6b, it can be observed that the sealing element 6 of the joint 1 has a third opening 7; it is also shown in detail in figure 3b, in which it can be observed the housing of the sealing elements 6 made of rubber.

With reference to figures 7a and 7b, it is observed that the second ring element 4 of the joint 1 has a second opening 15; it is integral with the first ring element 2.

The first ring element 2, the second ring member 4 and the disk-shaped element 10 of the rotating joint 1 according to the invention are preferably made of metallic material, for example steel, but they may be made of any other material depending on the fluid passing through the rotating joint V, in particular, for use in the oil industry, the aforesaid components of the rotating joint will be made of steel, whereas for use in the food industry the aforesaid components of the rotating joint will be made in nickel-chrome steel, such as for example AISI 310 or AISI 304.

The sealing element 6 of the rotating joint 1 according to the invention is preferably made of polymeric material, for example of Viton, but it can also be made of other materials.

As will be apparent to the person skilled in the art, the rotating joint 1 according to the invention may have different nominal diameters in order to be connected to pipes of various dimensions; for example, the rotating joint 1 can have a diameter equal to 51 mm or 76 mm or 100 mm, and so forth. The rotating joint 1 according to the invention is capable of withstanding pressures and temperatures in a wide range of values depending on the materials and the dimensions of its components, and as it will be apparent to the person skilled in the art, joints resistant at different pressures and temperatures may be made according to specific needs and by known techniques.

The rotating joint 1 according to the invention may also be provided with control devices for the sealing element.

From the description above it is apparent how the described rotating joint allows to achieve the intended objects.

Therefore, it is apparent to a person skilled in the art that it is possible to make modifications and variants to the solution described with reference to the figures indicated above, without departing from the scope of protection of the present patent, as defined by the appended claims.

For example, not shown embodiments provide that the disk-shaped element is not tapered at the periphery and has any profile depending on the specific requirements and/ or that its grooves are radial or helical or have any other geometry according to specific application requirements.