WENTZEL HENRIK (SE)
| US6145182A | 2000-11-14 | |||
| US4908245A | 1990-03-13 | |||
| JPH09158359A | 1997-06-17 | |||
| EP1515005A2 | 2005-03-16 |
CLAIMS
1. A method for vibration damping in a threaded connection joining together at least two components which are connected by the threaded connection and each have their respective contact surface facing that of the other, characterised by the step of modifying the topology of the contact pressure by adapting the configuration of the contact surfaces in order to increase the energy loss caused by microsliding at the surfaces of the connection which are subject to contact pressure.
2. A method according to claim 1, characterised by the step of altering the contact surface configuration and the contact pressure topology by means of at least one recess (11, 17, 24) in the contact surface of a component (10) which is subject to contact pressure.
3. A method according to claim 1 or 2, characterised by the step of adapting the configuration of the contact surfaces by applying between the contact surfaces an insert (1) which is subject to contact pressure.
4. A method according to claim 3, characterised by the step of applying the connecting element of the connection (1 '), e.g. a screw or bolt, through an aperture (4) in the insert.
5. A method according to claim 4, characterised by the step of shaping the insert's aperture (4) and outer contour (5) to the contact surface configuration of the insert.
6. A method according to any one of claims 1-5, characterised by the step of orienting the surfaces which are subject to contact pressure (8, 9, 12, 13, 15, 16) with the direction of their main extent transverse to the direction of the shear load to which the contact surfaces are subject.
7. A method according to claim 6, characterised by the step of arranging an insert (1) comprising a substantially rectangular aperture (4) in such a way that the longest sides of the aperture run perpendicular to the direction of the shear force to which the contact surfaces (8, 9) are subject.
8. A device for vibration damping in a threaded connection joining together at least two components which are connected by the threaded connection and each have their respective contact surface facing that of the other, characterised in that the surfaces of the connection which are subject to contact pressure (8, 9, 12, 13, 15, 16, 20, 22) are adapted to increasing the energy loss caused by microsliding, whereby the configuration of the contact surfaces is adapted to modifying the topology of the contact pressure.
9. A device according to claim 8, characterised by at least one recess (11) in a contact surface of a component (10) which is subject to contact pressure, which recess (11) alters the configuration of the contact surface and hence the contact pressure topology.
10. A device according to claim 8, characterised by an insert (1) arranged between the contact surfaces in order to adapt the configuration of the contact surfaces, which insert is adapted to being subject to contact pressure.
11. A device according to claim 10, characterised in that connecting element of the connection (1 '), e.g. a screw or bolt, is applied to run through an aperture (4) in the insert.
12. A device according to claim 10 or 11, characterised in that the main contact surface configuration of the insert is formed by the insert's aperture (4) and outer contour (5).
13. A device according to claim 10, 11 or 12, characterised by an insert (1) with a substantially rectangular outer contour (5) and a substantially rectangular aperture (4) which extends in principle between two mutually opposite sides (6, 7) of the insert in order to form two substantially rectangular mutually opposite contact surface portions (8, 9).
14. A device according to claim 8, characterised by a contact surface configuration comprising mutually opposite contact surface portions (15, 16) separated by a void
(18) constituted by a recess (17) in which a screwhole (19) is situated.
15. A device according to claim 14, characterised in that the mutually opposite contact portions (15, 16) form parts of a circular surface or parts of a quadrilateral surface.
16. A device according to claim 8 or 9, characterised by a contact surface configuration comprising a central circular portion (20) in which a screwhole (21) is situated, and a peripheral circular portion (22), whereby a void (23) running circumferentially is formed by a recess (24) running circumferentially between the central and peripheral portions.
17. A device according to claim 14, 15 or 16, characterised in that said contact surface configuration is encompassed by an insert. |
METHOD AND ARRANGEMENT FOR VIBRATION ABSORPTION
1. Background
1.1 Technical field
The present invention relates to a method according to the introductory part of the attached claim 1.
The invention also relates to a device according to the introductory part of the attached claim 8.
1.2 State of the art
In, for example, a threaded connection, the topology of the contact pressure results in energy loss caused by microsliding in the connection. The energy loss caused by microsliding in threaded connections is the most important vibration-damping mechanism for certain components.
The object of the present invention is to provide a connection which affords high energy losses for the purpose of vibration damping.
2. Summary of the invention
The object as above is achieved with a method and a device according to the attached independent claims 1 and 8 respectively.
Further advantages are achieved by what is specified in the respective dependent claims.
3. Brief description of the drawings
The invention is described below in more detail with respect to embodiment examples and the attached drawings, in which:
- Fig. 1 depicts schematically a first embodiment of a device according to the invention,
- Fig. 2 depicts schematically a second embodiment of a device according to the invention,
- Fig. 3 depicts schematically a third embodiment of a device according to the invention,
- Fig. 4 depicts schematically a fourth embodiment of a device according to the invention,
- Fig. 5 depicts schematically a typical pressure distribution at the contact surface round a screwhole in the respective cases of planar surfaces and surfaces of a contact surface configuration according to the invention.
In Fig. 1, ref. 1 denotes an insert intended and arranged to be applied in a threaded connection joining together at least two components (not depicted) which are connected by the threaded connection and each have their respective contact surface facing that of the other. The insert applied between the contact surfaces of the components is thus adapted to encompassing the contact surfaces of the connection which are subject to contact pressure, whereby the configuration of the contact surfaces matches the configuration of the two main surfaces 2, 3 of the insert. It should be noted that the insert is not depicted to scale as regards thickness but should be thinner relative to its extent in other respects. A suitable thickness is usually < 0.5 mm.
According to the embodiment depicted in Fig. 1, the connecting element of the connection, represented by a chain-dotted centreline 1' in Fig. 1, is adapted to running
through an aperture 4 in the insert, the main contact surface configuration of the insert being formed by the aperture in the insert and the outer contour 5 of the insert. According to the embodiment depicted, the insert is provided with a substantially quadrilateral, e.g. rectangular, outer contour and a substantially quadrilateral, e.g. rectangular, aperture extending in principle between two mutually opposite sides 6, 7 of the insert in order to form two substantially rectangular mutually opposite contact surface portions 8, 9 of the insert.
The object of the embodiment depicted in Fig. 2 is to provide a contact surface configuration situated directly at the surface of a component 10 which is intended to be subject to contact pressure. The originally continuous surface (not depicted) is here provided with a recess 11 whereby a contact surface configuration comprising two mutually opposite contact surface portions 12, 13 separated by a void 11' constituted by the recess is formed, with a hole 14 for the connecting element of the connection, a screwhole, situated in the groove, where the connecting element is represented by a chain-dotted centreline 1 ' .
According to the embodiment depicted in Fig. 3, the contact surface configuration comprises two mutually opposite contact surface portions 15, 16 which form part of an originally circular surface (not depicted) in which a diametral groove 17 is arranged, resulting in a void 18 between the mutually opposite contact surface portions, with a hole 19 for the connecting element of the connection, a screwhole, situated in the groove, preferably at the centrepoint of the originally circular surface, where the connecting element is represented by a chain-dotted centreline 1 '.
According to the embodiment depicted in Fig. 4, the contact surface configuration comprises a central circular portion 20 in which a hole 21 for the connecting element of the connection, represented by a chain-dotted centreline 1 ', is situated centrally, and a portion 22 running peripherally in a circular path, resulting in a void 23 running circumferentially in the form of a recess 24 situated between the central and peripheral portions.
In the pressure distribution diagram depicted in Fig. 5 by way of example in relation to a 10 mm diameter screwhole, the continuous curves 25 represent the pressure distribution of the state of the art, i.e. two mutually opposite planar working surfaces in the threaded connection, and the broken curves 26 represent a pressure distribution with a contact surface configuration according to the invention, i.e. with, for example, an insert which keeps the contact surface away from the screwhole. The result is increased energy losses in the connection, since a shear force acting at the contact surface of the connection will act across a larger proportion of the surface which is subject to contact pressure.
The method and the function of the device according to the invention are probably substantially indicated by the foregoing description.
With the object of increasing the energy losses caused by microsliding at the surfaces of a threaded connection which are subject to contact pressure, the topology of the contact pressure is modified by adapting the configuration of the contact surfaces. Increasing the energy loss improves the vibration damping in the connection.
The extent of the microsliding depends inter alia on the shear loads acting at the surfaces which are subject to contact pressure and it is desirable that the respective contact surface configuration should provide a certain orientation with respect to the direction of the shear loads concerned.
With regard to the configurations according to Figs. 1-3, it is therefore in many cases desirable for there to be orientation such that shear loads act perpendicular to the hole/groove in the surface configuration which is subject to contact pressure. The embodiment according to Fig. 4 is primarily intended for rotary loads and is therefore axially symmetrical.
The invention is described above in relation to various embodiment examples and embodiments. Further embodiments and minor additions and modifications are of course conceivable without departing from the basic concept of the invention. Thus
the embodiments according to Figs. 3 and 4 may take the form of inserts as depicted in the drawing. Corresponding contact surface configurations may also be arranged directly on a component in order to constitute the surface of the component which is subject to contact pressure.
Said recess may be created by, for example, milling or plastic machining.
According to preferred embodiments the insert is preferably made of suitable steel.