Classifications

• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
  • F16D—COUPLINGS FOR TRANSMITTING ROTATION; CLUTCHES; BRAKES
  • F16D1/00—Couplings for rigidly connecting two coaxial shafts or other movable machine elements
  • F16D1/06—Couplings for rigidly connecting two coaxial shafts or other movable machine elements for attachment of a member on a shaft or on a shaft-end
  • F16D1/08—Couplings for rigidly connecting two coaxial shafts or other movable machine elements for attachment of a member on a shaft or on a shaft-end with clamping hub; with hub and longitudinal key
  • F16D1/09—Couplings for rigidly connecting two coaxial shafts or other movable machine elements for attachment of a member on a shaft or on a shaft-end with clamping hub; with hub and longitudinal key with radial clamping due to axial loading of at least one pair of conical surfaces
  • F16D1/091—Couplings for rigidly connecting two coaxial shafts or other movable machine elements for attachment of a member on a shaft or on a shaft-end with clamping hub; with hub and longitudinal key with radial clamping due to axial loading of at least one pair of conical surfaces and comprising a chamber including a tapered piston moved axially by fluid pressure to effect clamping
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
  • F16D—COUPLINGS FOR TRANSMITTING ROTATION; CLUTCHES; BRAKES
  • F16D1/00—Couplings for rigidly connecting two coaxial shafts or other movable machine elements
  • F16D1/06—Couplings for rigidly connecting two coaxial shafts or other movable machine elements for attachment of a member on a shaft or on a shaft-end
  • F16D1/08—Couplings for rigidly connecting two coaxial shafts or other movable machine elements for attachment of a member on a shaft or on a shaft-end with clamping hub; with hub and longitudinal key
  • F16D1/09—Couplings for rigidly connecting two coaxial shafts or other movable machine elements for attachment of a member on a shaft or on a shaft-end with clamping hub; with hub and longitudinal key with radial clamping due to axial loading of at least one pair of conical surfaces
  • F16D1/093—Couplings for rigidly connecting two coaxial shafts or other movable machine elements for attachment of a member on a shaft or on a shaft-end with clamping hub; with hub and longitudinal key with radial clamping due to axial loading of at least one pair of conical surfaces using one or more elastic segmented conical rings forming at least one of the conical surfaces, the rings being expanded or contracted to effect clamping
  • F16D1/095—Couplings for rigidly connecting two coaxial shafts or other movable machine elements for attachment of a member on a shaft or on a shaft-end with clamping hub; with hub and longitudinal key with radial clamping due to axial loading of at least one pair of conical surfaces using one or more elastic segmented conical rings forming at least one of the conical surfaces, the rings being expanded or contracted to effect clamping with clamping effected by ring contraction only
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
  • F16B—DEVICES FOR FASTENING OR SECURING CONSTRUCTIONAL ELEMENTS OR MACHINE PARTS TOGETHER, e.g. NAILS, BOLTS, CIRCLIPS, CLAMPS, CLIPS OR WEDGES; JOINTS OR JOINTING
  • F16B2/00—Friction-grip releasable fastenings
  • F16B2/005—Means to increase the friction-coefficient

Definitions

• the present invention refers to a sleeve for increasing the torque transferring ability between a first elongated machine member and a second machine member.
• a common method for connecting a first, elongated machine member to a second machine member having an opening surrounding the elongated machine member is to position the opening of the second machine member over an end portion of the first elongated machine member and create a grip between the first and second machine members by means of a shrink coupling mounted on the second machine member for creating a high pressure between the two machine members.
• Such a coupling can for example be used between a gearbox shaft and a main shaft in a wind turbine.
• the tubular gearbox shaft can be positioned over the end of the main shaft and a shrink coupling can be applied for causing the required grip.
• the length available for the coupling is rather short and for this reason it is required a coupling with a big diameter for permitting the high pressure required for transfer of high torques.
• the coupling will be bulky and heavy, particularly for the wind turbines of the future which will be designed for generating higher effects. This means that the components in the wind turbines will become heavier and the shaft and particularly the shaft coupling will have to transfer more torque, without slipping. This will also cause higher stresses in the involved components in the system.
• the purpose of the invention is to propose a sleeve for increasing a torque transferring ability between a first elongated machine member and a second machine member having an opening surrounding the first elongated machine member, and intended to be subjected to a pressure directed toward the first elongated machine member, with which the weight and the stresses are reduced and the torque which can be transmitted is increased, and this has been achieved by providing the sleeve, at least at one of its inner and outer envelope surfaces, with a friction increasing layer.
• Fig.l is a section along line A - A in Fig. 2 of a coupling between a first and a second machine member in accordance with the present invention
• Fig. 2 is an end view of the coupling and machine members shown in Fig. 1, and
• Fig. 3 is a perspective view of the coupling as shown in Figs . 1 and 2.
• Fig. 4 is a view of an embodiment of the sleeve 4.
• Fig. 1 shows a cross-section along line A- A in Fig, 2 of a first machine member 1, in the embodiment illustrated, a tubular, cylindrical shaft journal.
• a second machine member 2 which is a tubular cylindrical member, such as a hollow shaft, is positioned to enclose the first machine member 1.
• a shrink coupling such as for instance an oil injection shaft coupling 3 as illustrated.
• a new component has been added to the system, in form of a high friction sleeve 4.
• This sleeve 4 has a higher friction coefficient than the two machine members 1, 2, and it is preferably - but not necessarily - in an embodiment a plasma coated sleeve, positioned between the first and the second machine members.
• the coating on the sleeve is in an embodiment preferably based on carbides.
• the coating is very robust allowing the sleeve to be remounted several times without any significant reduction of the friction coefficient.
• the plasma sprayed coating does not wear down significantly during operation of the coupling system.
• the coating layer has preferably a thickness of 0.02 to 0.04 mm.
• the sleeve 4 is illustrated as a cylindrical bushing positioned in a corresponding recess 5 in the second or outer machine member 2, and in this case both the inner and outer envelope surfaces of the sleeve have been subjected to a friction increasing treatment.
• the shape of the sleeve 4 is not necessarily cylindrical but it might be tapering and it can even be stepped if the first machine member 1 and/or the second machine member 2 have such an outer or inner shape, respectively.
• the drawing shows an outer or second machine member 2 with a recess 5 for accommodating the high friction sleeve 4, it is of course also possible that the inner or first machine member 1 has an outer recess in which the sleeve 4 can be positioned, and it is even possible that the sleeve 4 is made integral with the material in the outer envelope surface of the first machine member 1 or with the material in the inner surface of the second or outer machine member 2.
• Fig. 2 is an end view of the coupling and machine members shown in smaller scale as compared to Fig. 1, and the coupling and machine members are shown in perspective in Fig. 3, whereby a 45° section has been cut out for clarifying the mutual relation between the different components of the arrangement .
• the shaft coupling 3 illustrated in the drawing is an oil injection shaft coupling, although any other appropriate shrink coupling can be used for effecting the clamping effect giving a sufficient pressure for causing a grip between the first and the second machine members 1, 2.
• shrink couplings or shrink discs.
• the oil injection shaft coupling 3 incorporates an outer ring 3a having a tapering inner envelope surface, which cooperates with a correspondingly tapering outer envelope surface on an inner ring 3b. At one end of the outer ring 3a there is provided a concentric cylindrical recess.
• a nut 3c is screwed up and tightened on an external thread on the inner ring 3b thus that a closed chamber 3d is formed by the recess between the outer ring 3a, the inner ring 3b and the nut 3c.
• Oil injection nipples 6, 7 are provided through the outer ring 3a for supply of pressurized oil to the chamber 3d and to the cooperating surfaces between the outer ring 3a and the inner ring 3b.
• the proposed high friction sleeve can be used in all types of applications, where torque is to be transferred, having a first machine member and a second machine member according to the described embodiments.
• the proposed high friction sleeve 4 it can in an embodiment be calculated with a friction coefficient of ⁇ 0.50.
• the approved coefficient of friction for a coupling without use of a high friction sleeve is ⁇ 0.18.
• the torque which can be transmitted will be more than 2.5 times higher when a high friction sleeve is used as compared to a coupling having no such high friction sleeve.
• the result will be a reduced pressure on the first machine member and/or a reduced coupling size.
• sleeve 4 In fig. 4, an embodiment of the sleeve 4 according to the invention is shown, wherein the sleeve 4 presents at least one slit 8 extending axially from one axial end of the sleeve 4. In the embodiment shown, there are four axially extending slits 8.
• the slits 8 facilitate mounting and dismounting of the sleeve onto the first machine member 1. Furthermore, the slits 8 make it possible to mount the sleeve with zero play between the sleeve 4 and the first machine member 1 in cold condition, i.e. there is no need to warm up the sleeve 4 to achieve zero play.
• plugs 9 can be inserted into the slits 8 to radially expand the sleeve 4.
• the invention is not limited to the embodiment illustrated in the accompanying drawings and described with reference thereto.
• the high friction sleeve is positioned in a recess in the second or outer machine member, which recess does not extend along the entire length of the second machine member, thus that the high friction sleeve 4 will abut a shoulder in the recess 5, but the high friction sleeve can also extend along the entire length of the second - or first - machine member thus that there is no specific recess made in anyone of the two machine members.

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• Engineering & Computer Science (AREA)
• General Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Physics & Mathematics (AREA)
• Fluid Mechanics (AREA)
• Mutual Connection Of Rods And Tubes (AREA)

Applications Claiming Priority (2)

Publications (2)

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Citations (3)

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• 2010
  • 2010-03-08 EP EP10751078A patent/EP2406503A4/de not_active Withdrawn
  • 2010-03-08 WO PCT/SE2010/000049 patent/WO2010104442A1/en active Application Filing

Patent Citations (3)

Non-Patent Citations (1)

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