EP3295059A1

EP3295059A1 - Torque transmission device for a rotary machine, assembly of such a device and a turbine, a compressor and/or a pump, and system comprising such an assembly

Info

Publication number: EP3295059A1
Application number: EP16722229.8A
Authority: EP
Inventors: Pierre CONVERT
Original assignee: Aqylon
Current assignee: Aqylon
Priority date: 2015-05-13
Filing date: 2016-05-12
Publication date: 2018-03-21
Also published as: PH12017502004A1; FR3036154A1; WO2016180935A1

Abstract

The invention relates to a torque transmission device (10) for a rotary machine, said device (10) comprising a casing (21, 22), a main shaft (32) and an output shaft (31), said main shaft (32) being confined inside said casing (21, 22), said output shaft (31) emerging outside said casing (21, 22), said casing (21, 22) having a parting surface (23) where two parts of said casing (21, 22) meet, said device (10) further comprising a sealing means (40) arranged in such a way as to provide dynamic sealing at the output shaft (31), said device (10) also comprising a means (33, 34) of mechanical transmission between the main shaft (32) and the output shaft (31). The invention also relates to an assembly of such a device (10) and a turbine, a compressor and/or a pump. The invention also relates to a system implementing the Rankine thermodynamic cycle comprising such an assembly.

Description

Device for transmitting torque for a rotating machine, together such a device and a turbine, a compressor and / or a pump, and system comprising such an assembly The invention relates to a torque transmission device for a rotary machine, especially for a rotating machine intended to be integrated in a thermodynamic system. The invention also relates to an assembly of such a device and a turbine, a compressor and / or a pump. The invention also relates to a system implementing a thermodynamic Rankine cycle comprising such a set.

Outer sealing is a recurring problem for rotary machines of the prior art. This problem arises especially when the machine has a housing that is cut, for example horizontally, to meet manufacturing and / or assembly constraints.

More specifically, the outward sealing must be performed both statically, at the crankcase cutting plane, and dynamically, at the output of the shaft of the machine. Static and dynamic seals are then difficult to ensure, especially when the shaft of the machine is at the level of the cutting plane.

An object of the present invention is to provide effective static sealing and dynamic sealing for a rotating machine which has a cut housing, for example horizontally.

Thus, the invention relates to a torque transmission device for a rotating machine, in particular for a rotating machine intended to be integrated in a thermodynamic system, said device comprising a housing, a main shaft and an output shaft, said main shaft being confined. inside said housing, said output shaft opening outside said housing, said housing having a joint surface between two parts of said housing.

According to the invention said device further comprises a sealing means arranged to ensure a dynamic seal at the output shaft, said device also comprising a mechanical transmission means between the main shaft and the output shaft, said mechanical transmission means being integrated inside said housing and the output shaft being offset relative to the joint surface.

In the case of a casing cut, for example horizontally, the offset of the output shaft relative to the seal surface provides a sealing means, at the output shaft, which is distant from the joint surface.

Thus, the device according to the invention makes it possible to ensure effective static sealing and dynamic sealing for a rotating machine which has such a housing; the seal at the joint plane being the static seal and the sealing at the output shaft being the dynamic seal, said two sealing being performed effectively because independent of one another.

On the other hand, the presence of a mechanical transmission means between the main shaft and the output shaft, integrated inside the housing, has the advantage of limiting the speed of rotation of the output shaft. for example, and thus facilitates the realization of dynamic sealing.

According to various embodiments of the invention, which may be taken together or separately:

said sealing means is a dynamic seal located at the output shaft,

- the joint surface is a joint plane,

the device according to the invention comprises a static seal located at said joint plane,

said main shaft is located at the joint plane,

the main shaft is rotatably mounted on said housing,

said casing has a longitudinal axis of extension along said main shaft,

said output shaft and said main shaft are parallel,

- The device of the invention is configured to occupy two positions, a first position, said operating position, wherein said housing is sealed, and a second position, said rest position, wherein said housing is open and in which the main shaft is adapted to be removed from said housing,

said mechanical transmission means is a gearbox,

said casing comprises different compartments along said main shaft,

said reducer being located inside a first of said compartments,

the housing is configured so that the pressure is not the same in said compartments,

- The housing is configured so that the pressure in the compartment in which the reducer is located is less than that in the or other compartments.

The invention also relates to an assembly of a device as described above and a turbine, a compressor and / or a pump, together in which the main shaft defines a shaft of said turbine, said compressor and / or said pump.

Advantageously, said assembly further comprises a working fluid circulating within said housing.

The invention also relates to a system implementing a thermodynamic Rankine cycle and comprising such an assembly.

The invention will be better understood, and other objects, details, features and advantages thereof will become more clearly apparent in the following detailed explanatory description of at least one embodiment of the invention given to As a purely illustrative and non-limiting example, with reference to the following appended schematic drawings:

FIG. 1 is an isometric representation, slightly inclined, of an exemplary embodiment of a device according to the invention,

- Figure 2 is a longitudinal sectional view of the device shown in Figure 1. As illustrated in Figures 1 and 2, the invention relates to a torque transmission device 10 for a rotary machine, in particular for a rotating machine intended to be integrated in a thermodynamic system. Such a thermodynamic system is not illustrated in detail here. This system may be a system implementing a Rankine thermodynamic cycle, or any other known thermodynamic cycle, without departing from the scope of the invention.

The device according to the invention comprises a housing 21, 22 and an output shaft 31, said output shaft 31 opening out of said housing 21, 22. The housing 21, 22 will be intended to accommodate elements of said thermodynamic system, especially tightly. In other words, said elements of said thermodynamic system will be protected from the outside by said housing 21, 22 and fluids for use by said elements will be held in said housing 21, 22, limiting their leakage to the outside. Considering that said elements of said system are advantageously configured to operate with a working fluid circulating within said system, the external medium will thus be protected from any leakage of said working fluid to the outside.

The output shaft 31 has an axis, marked X in the figures. This X axis will be said, output axis X thereafter.

On the other hand, it is visible in Figures 1 and 2 that the housing 21, 22 has a joint surface 23 between two parts 21, 22 of said housing. By two parts 21, 22 are meant two distinct zones which form an internal cavity when they are joined, or when they are joined to one another. Here, the two parts of the housing 21, 22 are joined via a joint plane P23.

This joint plane P23 is here represented rectilinear, in particular parallel to the output axis X. This representation is not limiting and this joint plane P23, in particular for encapsulation constraints of different elements, for example of control elements, can follow a linear curve, or a curve following broken lines. In other words, said housing will be made in two parts 21, 22 which will be joined at a joint surface 23 and said joint surface 23 will follow the same staged shape of the housing 21, 22. In other words, said surface seal 23 will provide the sealed connection between two parts 21, 22 of a housing 21, 22 cut along a straight or curved line, this using a gasket (not shown here).

Indeed, the device 10 according to the invention will advantageously comprise a static seal located at said joint plane P23.

Said static seal will allow sealing of the casing 21, 22. The sealing of this closure, or said joint surface 23, will be effective because it will include no moving parts. In other words, the output shaft 31, rotatable about its output axis X, will not be included in said joint surface 23. In other words, said joint surface 23 will include no opening to the outside environment.

The static seal along the joint surface 23 can then be obtained, for example by means of a conventional type of static seal, in particular an elastomer seal adequately compressed between said two parts 21, 22 crankcase.

According to the invention said device 10 further comprises a sealing means 40 arranged to provide dynamic sealing at said output shaft 31 - see the figures for the positioning of said sealing means 40, said sealing means 40 not shown in detail.

Said output shaft 31 is off-axis with respect to the joint surface 23.

Said sealing means 40 is thus located at the level of the output shaft 31, around the output axis X, between the internal cavity of a portion of said housing 21 and the external medium, at a distance from said surface of attached 23.

Here the output shaft 31 is at the top of the illustrated example. The term "upper part", one of the two parts of the housing 21 which is above the joint plane P23.

The invention is not limited to this example. The output shaft 31, and the associated dynamic seal, may be provided in the lower part 22 of the casing - part which is below the joint plane P23 - in particular to facilitate the removal of the upper part 21 during a maintenance operation, upper part 21 which would then include fewer items to take away when removed. The dynamic seal at the output shaft 31 can be obtained, for example using a conventional type of dynamic seal, particularly low friction washer type.

This dynamic seal will be more effective than it will be the only seal at said output shaft 31. Indeed, the output shaft 31 is offset with respect to said joint surface 23. This means that the dynamic seal to be provided at the output shaft 31 does not interfere with the static seal at provided at the joint surface 23. On the other hand, the device 10 according to the invention further comprises a main shaft 32 confined inside said housing 21, 22. This shaft 32 is in particular mounted in rotation on said housing 21, 22, in particular at said joint plane P23 but without interfering with said gasket. It has an axis, said main axis, which is marked Y in the figures. The joint plane P23 comprises said main axis Y.

By "confined" is meant understood integrally inside said housing 21,

22. In other words, the main shaft 32 does not extend towards the outside of the housing 21, 22.

Said housing 21, 22 will advantageously comprise hinge bearings 35-37 of said main shaft 32. These bearings, of conventional type will allow said main shaft 32 to be driven in a rotational movement about said main axis Y, especially when it is rotated for example by a turbine provided at its level. As non-limiting examples, said 35-37 hinge bearings may be hydrodynamic or even magnetic.

Here, said housing 21, 22 has a longitudinal extension axis along said main shaft 32. In other words, the housing 21, 22 has, here, a shape that extends along a longitudinal extension axis which, itself, is confused with the main axis Y. In particular, the housing 21, 22 has, here, a cylindrical shape.

Said cylindrical shape comprises two half-cylindrical parts 21, 22 which join along the joint plane P23, said joint plane P23 separating them into two substantially symmetrical parts. However, this representation is not limiting and the casing 21, 22 can be made from two parts 21, 22 of non-symmetrical shape. Thus the housing 21, 22 can be obtained from any other given forms to the two parts which join along the joint surface 23. The device according to the invention further comprises a mechanical transmission means 33, 34, or gearbox 33, 34, between the main shaft 32 and the output shaft 31. Said gearbox 33, 34 is integrated inside said housing 21, 22. Said gear 33, 34 will be formed by at least two toothed wheels 33, 34. In the example illustrated here, said gear comprises a first gear 34 linked at the main shaft 32 and a second 33 linked to the output shaft 31. Said two toothed wheels 33, 34 are engaged with each other and can make it possible to reduce the speed of rotation of the output shaft 31 relative to that of the main shaft 32.

The presence of this gear 33, 34 then has the advantage of providing a dynamic seal which is all the easier to achieve that the rotational speed of the output shaft 31 is low.

In an alternative embodiment, and without departing from the scope of the invention, said mechanical transmission means 33, 34 may be used to increase the rotational speed of said output shaft 31.

On the other hand, it should be noted that the main axis Y and the output axis X are parallel to each other, in particular to ensure optimum operation of said gearbox 33, 34. Moreover, like the main shaft 32, said output shaft 31 is hinged inside the casing 21, 22, in particular on a partition wall 26 of the casing 21, 22, in particular with the aid of a bearing 38 referenced in the figures.

Indeed, said housing 21, 22 may comprise different compartments 24, 25 along said main shaft 32, that is to say along said main axis Y.

The gearbox 33, 34 will advantageously be located inside a first of said compartments 25. This will have the advantage of isolating it from the rest of the casing 21, 22, in particular from that part of the main shaft 32 which is intended to defining a shaft of elements such as a turbine, a compressor and / or a pump.

These latter elements will advantageously belong to the thermodynamic system, or even constitute this thermodynamic system.

Advantageously, the housing 21, 22 will be configured so that the pressure is not the same in the different compartments 24, 25. For example, the pressure in the compartment 25 in which the gearbox 33 is situated, 34 could be provided less than that in the other compartments, in particular to that in the compartment 24 intended to include said turbine, said compressor and / or said pump. This has the advantage of providing a dynamic seal, at the output shaft 31, between the compartment 25 which contains it and the outside, which will be all the easier to realize that the pressure that prevails there will be close the pressure of the external environment, the pressure of the external medium being often the atmospheric pressure.

Indeed, a low pressure gradient between the compartment 25 of the gearbox 33, 34 and the outside decreases the mechanical stress on the dynamic seal and promotes its sealing.

In an alternative embodiment, and without departing from the scope of the invention, the pressure in the compartment 25 in which the reducer 33, 34 is located could be greater than that in the other compartments, in particular to that in the compartment. 24 intended to include said turbine, said compressor and / or said pump.

Thus, the device 10 of the invention is configured to occupy two positions, a first position, called operating position, in which said housing 21, 22 is sealed (see FIGS. 1 and 2), and a second position, said rest position, wherein said housing 21, 22 is open and wherein the main shaft 32 is adapted to be removed from said housing 21, 22 (not shown here).

The invention also relates to an assembly of a device 10 as described above and the turbine, compressor and / or pump introduced above; assembly in which the main shaft 32 is intended to define a shaft of said turbine, said compressor and / or said pump.

The set is easily removable. By this is meant that the assembly can be easily removed, without dismantling a large number of mechanical parts. In other words, the opening of the housing 21, 22 allows the extraction, in a single block, the main shaft 32 and the elements that are connected thereto, for example said turbine, said compressor and / or said pump.

This has the advantage of saving the number of bearings to be mounted / disassembled during maintenance operations for example. The whole of the invention therefore has the additional advantage of limiting the losses due to the bearings, in particular by reducing their number.

The invention which has just been described finds particular application for rotating machines which have a cut housing, for example horizontally, in order to meet manufacturing and / or assembly constraints of said turbine, said compressor and / or of said pump inside said housing 21, 22. In fact, the invention, by providing a static seal which circulates around the flat surface 23 of contact of the two halves of the housing 21, 22, and a dynamic seal to the location of the output of the shaft of the machine 31, solves the sealing problem that arises when the axis of the machine shaft is on the contact surface.

The device of the invention solves this problem by deporting the output axis through the gearbox 33, 34.

It should be noted, moreover, that the gearbox will be configured to bathe in the working fluid of the thermodynamic system.

It should also be noted that the real geometry of the casing 21, 22 may be more complex than the simple representation that is made in Figures 1 and 2. It should also be noted that the device 10 described above will find a particular application for turbomachines comprising a step of expansion of a gas flow.

It should also be noted that variant embodiments are of course possible. In particular, it is also conceivable, in an embodiment not shown here, that the casing is made in more than two parts, all joined by joint surfaces provided with static seals, said joint surfaces having, at their level, no output for the shaft of the rotating machine.

Claims

claims

1. Torque transmission device (10) for a rotating machine, in particular for a rotary machine intended to be integrated in a thermodynamic system, said device (10) comprising a housing (21, 22), a main shaft (32) and a shaft outlet (31), said main shaft (32) being confined within said housing (21, 22), said output shaft (31) opening out of said housing (21, 22), said housing (21). , 22) having a joint surface (23) between two parts of said housing (21, 22), said device (10) further comprising sealing means (40) arranged to provide a dynamic seal at the shaft outlet (31), said device (10) also comprising a mechanical transmission means (33, 34) between the main shaft (32) and the output shaft (31), said mechanical transmission means (33, 34 ) being integrated inside said housing (21, 22) and, the output shaft (31) being misaligned by port at the joint surface (23).

2. Device (10) according to the preceding claim, wherein the joint surface (23) is a joint plane (P23).

3. Device (10) according to the preceding claim, wherein said main shaft (32) is located at the joint plane (P23).

4. Device (10) according to any one of the preceding claims, wherein the main shaft (32) is rotatably mounted on said housing (21, 22).

5. Device (10) according to any preceding claim, configured to occupy two positions, a first position, said operating position, wherein said housing (21, 22) is sealed, and a second position, said rest position, wherein said housing (21, 22) is open and wherein the main shaft (32) is adapted to be removed from said housing (21, 22).

6. Device (10) according to any one of the preceding claims, wherein said mechanical transmission means (33, 34) is a gear (33, 34).

7. Device (10) according to the preceding claim, wherein said housing (21, 22) comprises different compartments (24, 25) along said main shaft (32), said gear (33, 34) being located inside. a first (25) of said compartments (24, 25).

An assembly of a device (10) according to any one of the preceding claims and a turbine, a compressor and / or a pump, together in which the main shaft (32) defines a said turbine, said compressor and / or said pump.

9. Assembly according to the preceding claim, further comprising a working fluid circulating within said housing (21, 22).

10. System implementing a thermodynamic Rankine cycle comprising the assembly according to any one of claims 8 or 9.