WO2022129777A1

WO2022129777A1 - Torque multiplication tool for tightening/loosening capable of being used while immersed in water

Info

Publication number: WO2022129777A1
Application number: PCT/FR2021/052327
Authority: WO
Inventors: André VALLENET; Jérôme SCARCELLA-PORTAVOCE
Original assignee: Onet Technologies Cn
Priority date: 2020-12-17
Filing date: 2021-12-14
Publication date: 2022-06-23
Also published as: FR3117906B1; FR3117906A1

Abstract

The invention relates to a torque multiplication tool (2) for tightening/loosening, capable of being used while immersed in water, comprising a connection pin (4) intended to be immobilised in rotation, a torque transmission input (6) capable of being coupled to a motor, and an interchangeable tightening/loosening sleeve (8) which is sealingly coupled to the torque transmission input by means of a torque-multiplying planetary gearset having two-stage planets (12) and a fixed planet carrier.

Description

Title of the invention: Torque multiplication tool for screwing/unscrewing capable of being used immersed in water

Technical area

The present invention relates to the general field of a tool for screwing and unscrewing. It relates more specifically to a compact tool with torque multiplication for screwing/unscrewing able to be used immersed in water.

Prior technique

The use of a torque multiplication tool for screwing/unscrewing is particularly widespread in the context of inspection and repair operations on screwed assemblies with high torque, for which accessibility and the space available around are low. . This is particularly the case for the fuel assemblies of a pressurized water nuclear reactor. In this application, the fuel assemblies are placed inside a quenching pool filled with water, then dismantled by means of an unscrewing tool mounted at the end of a pole, the latter being handled by operators from outside the pool.

Such dismantling requires the use of a compact unscrewing tool which can on the one hand operate submerged in water, and on the other hand apply high torques to screws or any other device having a screwing.

Torque multiplication tools for screwing/unscrewing screws are known from the prior art. Generally, these tools consist of a screwing/unscrewing socket driven by a motor attached to a speed reducer having the effect of multiplying the torque. The purpose of such a tool is to transmit a high tightening (or loosening) torque to a screw by applying a reduced torque at the input of the movement, the torque multiplication value being defined by the design and sizing of the reducer of speed.

However, the tools known from the prior art have numerous drawbacks. In particular, these tools generally do not include torque multiplier directly in the socket and do not allow a connection of the tool, via an outer crown, to a remote motorization. In addition, these tools are most often bulky and cannot be used submerged in water.

Disclosure of Invention

The object of the present invention is therefore to propose a tool consisting of an epicyclic gear train for multiplying the torque, integrated in a screwing/unscrewing socket, which does not have the aforementioned drawbacks.

According to the invention, this object is achieved thanks to a torque multiplication tool for screwing/unscrewing capable of being used immersed in water, comprising a connecting pin intended to be immobilized in rotation, a transmission input of torque adapted to be coupled to a motor, and an interchangeable screwing/unscrewing sleeve which is coupled in a sealed manner to the torque transmission input by means of a torque-multiplying epicyclic gear train having double satellites stage and a fixed satellite carrier.

The tool according to the invention is remarkable in that it has an interchangeable sleeve (that is to say which can be changed by another according to needs) which is coupled in a sealed manner to the torque transmission input . Furthermore, the use of a planetary gear train with a double stage of satellites makes it possible to obtain a high transmission ratio with minimal bulk. In addition, the presence of a fixed planet carrier makes it possible to guarantee a strong multiplication of the torque while having a simple geometry of the planetary gear train. Because of this design, the tool according to the invention has a small footprint and can thus be used immersed in water.

In practice, the tool according to the invention can be sized to be able to apply a screwing or unscrewing torque of the order of 150 Nm with a reduced size at a diameter of the order of 75 mm for a height of about 120 mm.

According to an advantageous arrangement, the planetary gear train comprises an input sun gear forming the torque transmission input and mounted around a fixed planet carrier forming the connecting axis, and planet wheels each having a first stage pinions which are meshed by one toothing of the input sun gear and a second stage of pinions which mesh with the toothing of an output sun gear forming the sleeve and mounted around the planet carrier.

In this case, the torque multiplication ratio between the input sun gear and the output sun gear of the epicyclic gear train is preferably equal to r, r being a number strictly greater than 1.

In addition, the input sun gear of the planetary gear train is preferably mounted around the planet carrier with the interposition of an O-ring seal.

Similarly, the planetary gear is preferably mounted inside a planetary bell, said planetary bell having one end fixed in a sealed manner to the input sun gear and an opposite end surrounding a free end of the output sun gear with the interposition of an O-ring seal.

These seals contribute to make the tool waterproof to be used in immersion.

In this case, the output sun gear of the planetary gear train can be locked in translation with respect to the planet bell by pins.

In addition, the epicyclic gear train can advantageously comprise a needle bearing interposed radially between the planetary bell and the output sun gear. This needle roller bearing allows radial loads to be taken up.

Similarly, the planetary gear may advantageously further comprise a ball bearing interposed radially between the input sun gear and a planet carrier ring on which the satellites are mounted. This ball bearing allows radial and axial loads to be taken up.

The interior of the socket may comprise a hexagonal or square recess intended to receive a screw to be screwed in or unscrewed.

Preferably, the interior of the sleeve comprises an O-ring seal in order to hold a screw to be screwed in or unscrewed by wedging.

The torque transmission input can be coupled to a motor via a belt or a sprocket. Also preferably, the tool further comprises an axial needle stop mounted against a face of the input sun gear of the epicyclic gear train which is intended to come into abutment against a frame for immobilizing the connecting axis in rotation.

The connecting pin may comprise a square section endpiece adapted to be housed in a recess of the frame for immobilizing the connecting pin in rotation.

Brief description of the drawings

[Fig. 1] Figure 1 is a perspective view of a torque multiplication tool according to the invention.

[Fig. 2] Figure 2 is a top view of the tool of Figure 1.

[Fig. 3] Figure 3 is a sectional view along III-III of Figure 2.

[Fig. 4] Figure 4 is a sectional view along IV-IV of Figure 2.

Description of embodiments

FIG. 1 represents in perspective an embodiment according to the invention of a torque multiplication tool 2 which is used for screwing and unscrewing screws or any other device having a screwing interface and which is suitable to be used submerged in water.

In known manner, at one end of the connection, this tool 2 comprises a connection pin 4 intended to be mounted on a frame (not shown in the figures) and immobilized in rotation, and a torque transmission input 6 which is adapted to be coupled to a motor.

At a screwing end opposite the connecting end, the tool 2 also comprises a screwing/unscrewing sleeve 8 which is coupled to the torque transmission input 6. All of these parts are centered on an X-X axis of revolution of the tool.

According to the invention, the screwing/unscrewing sleeve 8 is an interchangeable sleeve (that is to say it can be easily replaced by another sleeve) which is coupled in a sealed manner to the torque transmission input 6 by means of a planetary gear train with torque multiplication, the latter being of the double-stage satellite type and with a fixed planet carrier. As more precisely shown in FIG. 3, the torque transmission input 6 is formed by an input sun gear of the epicyclic gear train, and the connecting axis 4 is formed by a fixed planet carrier, the input sun gear 6 being mounted around the fixed planet carrier 4.

Similarly, the screwing/unscrewing sleeve 8 is formed by an output sun gear which is also mounted around the planet carrier 4.

It will be noted that the input sun gear 6 is mounted around the planet carrier 4 with the interposition of an O-ring 10 making it possible to contribute to obtaining a tightness of the tool.

The planetary gear train also comprises double-stage planet wheels 12 each having a first stage of pinions 12a which are meshed by a toothing 6a of the input sun gear 6 and a second stage of pinions 12b which mesh with the toothing 8a of the output sun gear 8.

This epicyclic gear train thus has a torque multiplication ratio between the input sun gear 6 and the output sun gear 8 which is equal to r, r being a number strictly greater than 1 (for example equal to 4).

Even more precisely, each double-stage satellite 12 comprises an axis 12c carrying the pinions 12a, 12b which is parallel to the axis X-X of the tool. This axis 12c is mounted on the side of the tool's connecting end in a planet carrier hoop 14, and on the side of the opposite end on the planet carrier 4, while being held on the latter by a nut 16.

A ball bearing 18 is interposed radially between the input sun gear 6 and the planet carrier ring 14 in order to take up the axial and radial loads.

Furthermore, the planetary gear is mounted inside a planetary bell 20 centered on the axis XX of the tool. This planetary bell has at the connecting end of the tool one end which is fixed in a sealed manner to the input sun gear 6, and an opposite end which surrounds a free end of the output sun gear 8. A sealing O-ring 22 is interposed between the planetary bell 20 and the free end of the output sun gear 8 in order to contribute to obtaining a tightness of the tool.

At the screwing end of the tool, the output sun gear 8 is locked in translation with respect to the planet bell 20 by means of a plurality of pins 24 which are housed in corresponding notches 26 of the output planetary.

As shown in Figure 4, at its opposite end, the planetary bell 20 is fixed to the input sun gear 6 via a plurality of pins 28 regularly distributed around the X-X axis of the tool.

Preferably, as shown in Figure 3, the epicyclic gear train further comprises a needle bearing 30 which is interposed radially between the planetary bell 20 and the output sun gear 8. This needle bearing 30 allows the radial loads to be taken up.

Furthermore, the interior of the output sun gear 8 comprises, at the screwing end of the tool, an indentation 32 which is of hexagonal or square section. This recess 32 is intended to receive a screw to be screwed in or unscrewed (or any other member having a screwing interface).

It will be noted that the dimensions of the recess 32 of the output sun gear can be modified according to the use by directly changing the sleeve.

In order to facilitate the maintenance of the screw inside the cavity 32, the interior of the output sun gear 8 comprises an O-ring seal 34 which ensures a maintenance by wedging of the screw. The screw can thus be removed and replaced without the risk of being dropped.

In addition, at the link end of the tool, the input sun gear 6 is capable of being coupled to a motor (not shown in the figures) via pinions 36 (or a belt ) arranged on the outer periphery of the input sun gear. The motor thus makes it possible to apply an input torque to the tool.

According to an advantageous arrangement, the tool 2 further comprises an axial needle stop 38 which is mounted on the side of its connecting end against a face of the input sun gear 6. This needle thrust bearing 38 is intended to come into abutment against a frame for immobilizing the connecting shaft in rotation (not shown in the figures) to support the axial forces.

Furthermore, the planet carrier 4 forming the connecting axis comprises an end piece 40 of square section which is housed in a recess of this frame for immobilizing it in rotation.

The operation of the tool thus described follows from the foregoing.

The tool 2 is fixed to the frame for immobilizing it in rotation by means of its end piece 40 which is housed in the imprint of complementary shape of the frame. A screw (not shown in the figures) is screwed into a thread 42 of this end piece 40 in order to secure the tool to the frame. In this position, the needle bearing 38 supports the axial forces.

The motor is then coupled to the input sun gear 6 via pinions 36 made on its outside diameter in order to apply the desired input torque to the tool.

The double-stage epicydoidal train of satellites as described above makes it possible to multiply the torque applied at the input by the factor r.

The recovery of the torque multiplied by the factor r is possible at the level of the screwing end of the tool thanks to the imprint 30 made inside the output sun gear 8.

Given the choice of operation of the epicydoidal train with an immobilization in rotation of the planet carrier 4, the direction of rotation of the screwing/unscrewing sleeve 8 is opposite to that of the pinions 36 of the input sun gear 6.

The O-rings 10, 22 positioned at the level of the connecting end and the screwing end of the tool between the various rotating parts make it possible to ensure confinement of the interior of the tool, which makes its use in immersion in water possible.

Claims

8 Claims

[Claim 1] Torque multiplication tool (2) for screwing/unscrewing capable of being used immersed in water, comprising a connecting pin (4) intended to be immobilized in rotation, a torque transmission input ( 6) adapted to be coupled to a motor, and an interchangeable screwing/unscrewing bushing (8) which is coupled in a sealed manner to the torque transmission input by means of a torque-multiplying epicyclic gear train having double stage satellites (12) and a fixed satellite carrier.

[Claim 2] Tool according to claim 1, in which the planetary gearset comprises an input sun gear (6) forming the torque transmission input and mounted around a fixed planet carrier (4) forming the axis of link, and satellites (12) each having a first stage of pinions (12a) which are meshed by a toothing (6a) of the input sun gear and a second stage of pinions (12b) which mesh with the toothing (8a) of an output sun gear (8) forming the sleeve and mounted around the planet carrier.

[Claim 3] Tool according to claim 2, in which the torque multiplication ratio between the input sun gear (6) and the output sun gear (8) of the planetary gear set is equal to r, r being a number strictly greater than 1.

[Claim 4] Tool according to one of Claims 2 and 3, in which the input sun gear (6) of the epicyclic gear train is mounted around the planet carrier (4) with the interposition of a sealing O-ring (10 ).

[Claim 5] A tool according to any one of claims 2 to 4, wherein the planetary gear set is mounted within a sun gear (20), said sun gear having one end sealed to the sun gear. input (6) and an opposite end surrounding a free end of the output sun gear (8) with the interposition of an O-ring seal (22). 9

[Claim 6] Tool according to claim 6, in which the planetary gear output sun gear (8) is locked in translation with respect to the sun gear bell (20) by pins (24).

[Claim 7] Tool according to one of Claims 5 and 6, in which the planetary gear train further comprises a needle roller bearing (30) interposed radially between the planetary bell (20) and the output sun gear (8).

[Claim 8] Tool according to any one of Claims 2 to 7, in which the planetary gear train further comprises a ball bearing (18) interposed radially between the input sun gear (6) and a planet carrier ring (14 ) on which the satellites (12) are mounted.

[Claim 9] Tool according to any one of claims 2 to 8, further comprising an axial needle thrust bearing (38) mounted against a face of the input sun gear (6) of the planetary gear set which is intended to abut against a frame for immobilizing the connecting shaft in rotation.

[Claim 10] Tool according to claim 9, wherein the connecting pin (4) comprises an end piece (40) of square cross-section adapted to be housed in a recess of the frame for immobilizing the connecting pin in rotation.

[Claim 11] Tool according to any one of claims 1 to 10, wherein the interior of the sleeve (8) comprises a recess (32) hexagonal or square intended to receive a screw to be screwed or unscrewed.

[Claim 12] Tool according to any one of claims 1 to 11, in which the interior of the sleeve (8) comprises an O-ring seal (34) in order to hold by wedging a screw to be screwed in or unscrewed.

[Claim 13] A tool according to any of claims 1 to 12, wherein the torque transmission input (6) is coupled to a motor via a belt or sprocket (36).