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DE-102025146500-A1 - Associated assembly tool and procedure for a sliding bearing unit

DE102025146500A1DE 102025146500 A1DE102025146500 A1DE 102025146500A1DE-102025146500-A1

Abstract

The present invention relates to the assembly of a sliding bearing unit (10) using a special tool. The tool comprises an assembly ring (8) and an assembly shaft (11) with a first frustoconical part (11a) and a second part (11b) for mounting the sleeve (2). To proceed with the assembly of the unit (10), the assembly shaft (11), on which the retaining ring (6) and the sleeve (2) are positioned, is inserted into the bore of the inner ring (4b) on the side opposite the sleeve (2) by axially pushing it in until the retaining ring (6) and the sleeve (2) are inserted into the grooves (22) and (24) provided in the bore of the inner ring (4b) and the outer surface (2a) of the sleeve (2), for example to make the unit integral.

Inventors

  • Alexandre Barthod

Assignees

  • SKF AEROSPACE FRANCE SAS

Dates

Publication Date
20260513
Application Date
20251111
Priority Date
20241113

Claims (10)

  1. Method for assembling a sliding bearing unit (10) using an assembly tool, wherein the sliding bearing unit (10) comprises a swivel joint (1) having an inner ring (4) comprising a spherical outer surface (4a) and an outer ring (5) comprising a spherical inner surface (5a) mounted on the spherical outer surface (4a) of the inner ring, a sleeve (2) having an outer surface (2a) mounted in a bore (4b) of the inner ring (4) of the swivel joint (1), and a radially elastic retaining ring (6) extending into the interior of a groove (44) provided in the bore of the inner ring of the swivel joint (1) and into the interior of a groove (22) provided on the outer surface (2a) of the sleeve (2), wherein the tool comprises: - an assembly ring (8) provided at an axial end with a flange (9); and - a mounting shaft (11) with a first part (11a) having a frustoconical shape and a second mounting part (11b) of the sleeve (2), wherein the mounting shaft (11) is configured to be inserted into the bore (4b) of the inner ring (4) of the swivel joint (1), characterized in that the method comprises the following steps: - a step of positioning the retaining ring (6) on the first part (11a, P1) of the mounting shaft (11); - a step of inserting the sleeve (2) onto the second part (11b) of the mounting shaft (11); - a step of assembling the inner ring (4) of the swivel joint (1) in the bore (5b) of the outer ring (5); - a step of inserting the mounting ring (8) into the bore (4b) of the inner ring (4) of the swivel joint (1) until the flange (9) of the mounting ring (8) abuts the inner ring (4); - a step of inserting the first part (11a) of the mounting shaft (11), which is equipped with the retaining ring (6), into the interior of the bore (4b) of the inner ring axially on the side opposite the sleeve (2); and - a step of axially inserting the mounting shaft (11) into the interior of the bore (4b) of the inner ring (4) of the swivel joint until the following is obtained: - bearing of the retaining ring (6) against the mounting ring (8), and insertion of the retaining ring (6) into the interior of the groove (55) of the inner ring (4) by elastic deformation; then - insertion of the retaining ring (6) into the interior of the groove (22) of the sleeve (2) by elastic return, and axial integration of the sleeve (2) and the inner ring (4) of the swivel joint (1).
  2. Assembly procedure according to Claim 1 , wherein the step of assembling the inner ring (4) into the outer ring (5) is carried out before the step of inserting the mounting ring (8) into the bore (4b) of the inner ring (4).
  3. Assembly method according to the preceding claim, wherein, during the step of axially inserting the assembly shaft (11), the assembly ring (8) is held until the retaining ring (6) abuts the assembly ring (8), which results in the retaining ring (6) sliding along the first part (11a) of the assembly shaft (11) until the retaining ring (6) is inserted into the interior of the groove (44) of the inner ring (4) by elastic return.
  4. Assembly method according to the preceding claim, wherein, during the step of axially inserting the assembly shaft (11), and after inserting the retaining ring (6) into the groove (44) of the inner ring (4), the assembly ring (8) adheres to the first part (11a) of the assembly shaft (11) and is released from the bore (5b) of the outer ring (5).
  5. Assembly procedure according to one of the Claims 1 until 4 , which also includes a step of withdrawing the mounting shaft (11) from the bore (4b) of the inner ring (4) once the sleeve (2) and the inner ring (4) have been made axially integral.
  6. Tool for implementing the assembly method according to one of the preceding claims, wherein the tool comprises: - an assembly ring (8) provided with a flange (9) at an axial end; - an assembly shaft (11) with a first part (11a) having a frustoconical shape and a second assembly part (11b) of the sleeve (2).
  7. Tool according to Claim 6 , wherein the first part (11a) of the mounting shaft (11) has a stepped frustoconical shape comprising several successive contact surfaces (P1, P2, P3) positioned along its axis, and wherein: - the first contact surface (P1) has a first diameter corresponding to the inner diameter of the retaining ring in the free state; - the second contact surface (P2) has a second diameter that is larger than the first diameter and corresponds to the outer diameter of the ring (6) in an elastic deformation configuration, which is smaller than the inner diameter of the bore (4b) of the inner ring (4); - the third contact surface (P3) has a third diameter that is larger than the first and second diameters and smaller than the diameter of the bore (2b) of the sleeve (2).
  8. Tool according to Claim 7 , wherein the third contact surface (P3) of the first part (11a) of the mounting shaft (11) has an axial length that is at least equal to half the axial length of the sleeve (2).
  9. Tool according to one of the Claims 6 until 8 , wherein the mounting part (11b) of the sleeve (20) has a diameter that is less than or equal to the diameter of the bore (4b) of the inner ring (4) of the swivel joint (1).
  10. Tool according to one of the Claims 6 until 9 , wherein the diameter of the inner surface (8a) of the mounting ring (8) is smaller than the diameter of the bore (4b) of the inner ring (4) of the swivel joint (1).

Description

Technical field of the invention The present invention relates generally to sliding bearing units of the rotary joint type, which can be used, among other things, in the aerospace industry. More precisely, the invention relates to the assembly of a unit of this type. State of the art Typically, a plain bearing unit comprises an outer ring with a spherical inner surface and an inner ring with a spherical outer surface. In the aviation industry, these units are often installed on rotary joints to adapt to deformations of the structures that may be caused by expansion. During maintenance, these joints must be disassembled to detach the unit. To facilitate assembly and disassembly, the inner ring is known to be designed as a split ring, and is therefore manufactured in several parts. However, during maintenance work, the design of the inner ring in several parts can lead to indentations on the shaft of the joint at the slot(s) of the inner ring, which therefore makes it necessary to carry out an often expensive replacement of the joints every time a disassembly takes place. To eliminate this disadvantage, it is known to mount an annular sleeve in the bore of the inner ring to obtain continuous cylindrical contact without interruption with the shaft of the joint. To form a single unit that is easy to assemble and disassemble, the sleeve must be made firmly integral with the inner ring. Several methods for mounting the sleeve on the inner ring are known in the prior art, including a method consisting of equipping the sleeve at one end with an annular support which is axially supported against one of the end faces of the inner ring, and at the other end with a thread onto which a nut is screwed which is supported against the other end face of the inner ring. However, these methods have certain disadvantages, particularly a lack of practicality, since the sleeve, which must act as a wear part, must be easy to replace during maintenance work and to be mounted in the inner ring. Until now, no special tool has made it possible to efficiently assemble a sliding bearing unit of this type. Summary of the invention The aim of the invention is therefore to eliminate this disadvantage by proposing a method for assembling a sliding bearing unit using an assembly tool. The sliding bearing unit comprises a swivel joint provided with an inner ring having a spherical outer surface and an outer ring having a spherical inner surface mounted on the spherical outer surface of the inner ring, a sleeve having an outer surface mounted in the bore of the inner ring of the swivel joint, and a radially elastic retaining ring extending into the interior of a groove provided in the bore of the inner ring of the swivel joint and into the interior of a groove provided on the outer surface of the sleeve. The assembly tool set includes: - a cylindrical mounting ring provided with a flange at one axial end; and - a mounting shaft with a first part having a frustoconical shape and a second mounting part of the sleeve, wherein the mounting shaft is designed to be inserted into the bore of the inner ring of the swivel joint. Additionally, the frustoconical shape of the first part of the mounting shaft can correspond to a stepped frustoconical shape, comprising several successive contact surfaces along the axis of the first part of the shaft. Each contact surface can have its own diameter. - wherein the first contact surface has a first diameter that corresponds to the inner diameter of the retaining ring in the free state; - wherein the second contact surface has a second diameter that is larger than the first diameter and corresponds to the outer diameter of the retaining ring in a design of elastic deformation that is smaller than the inner diameter of the bore of the inner ring; - wherein the third contact surface has a third diameter that is larger than the first and second diameters and smaller than the diameter of the sleeve bore. Additionally, the third contact surface of the part of the mounting shaft can have a length that is at least equal to half the length of the sleeve. Once the sleeve is inserted onto the second part of the mounting shaft, the diameter of the outer surface of the mounting part of the sleeve is smaller than, or the same as, the diameter of the bore of the inner ring of the swivel joint. The diameter of the outer surface of the mounting ring is designed to be smaller than, or the same as, the diameter of the bore of the inner ring of the swivel joint. The invention also relates to a method for assembling the sliding bearing unit, as defined above, using an assembly tool. The method comprises the following steps: - one step of positioning the retaining ring on the first part of the mounting shaft (11); - one step of inserting the sleeve onto the second part of the mounting shaft; - a step in the assembly of the inner ring of the swivel joint in the bore of the outer ring; - one step of inserting the mounting ring into th