Shaft support and method for assembling the shaft support in a tube
AssigneeHusqvarna AB
InventorGöte Karlsson
Life of this patent
Estimating the term…
Abstract
Arrangement in a tube for an engine powered tool for support of a drive shaft extending inside the tube. A tube shaped section (15) acts as a shaft support (14) for the drive shaft and the tube shaped section (15) is constituted by a number of sections (19) provided with ribs (16) for support of the tube shaped section (15) inside the tube. The sections (19) are connected by flexible parts (17) placed between the sections (19) to absorb movements between the sections (19).
Claims15
Arrangement in a tube (11) for an engine powered tool for support of a drive shaft extending inside the tube (11), characterised in that the drive shaft is surrounded by a tube shaped section (15) acting as a shaft support (14) for the drive shaft,
- said tube shaped section (15) is constituted by a number of generally symmetrical discontinuous sections (19) moveable relative to each other and each being provided with at least one rib (16) each having a tip end (30) for support of the tube shaped section (15) inside the tube (11), the at least one rib (16) being generally symmetrical and extending in a radial direction outwards from the tube shaped section (15) towards contact with the tube (11), and
- flexible parts (17) placed between the discontinuous sections (19) to absorb movements between the discontinuous sections (19), each of said discontinuous sections (19) being attached to an adjacent discontinuous section (19) by way of a flexible part (17), the discontinuous sections being biased away from each other by the flexible parts (17) such that the tip end (30) of the at least one rib (16) abuts the tube (11).
Shaft support (14) for an engine powered tool, characterised in that the shaft support (14) comprises a tube shaped section (15) adapted to be supported within a tube (11) having a generally fixed inner radius (r1) the tube shaped section (15) having a center and being made of a number of discontinuous sections (19) and provided with at least one rib (16) to support the tube shaped section (15) within the tube (11), the at least one rib (16) extending in a radial direction outwards from the tube shaped section (15) towards contact with the tube (11), the at least one rib (16) having a nominal dimension (r2) defined as the radial distance measured from the center of the tube shaped section (15) to a tip end (30) of the at least one rib (16),
- said discontinuous sections (19) are connected by a number of flexible parts (17) arranged to absorb movements between the discontinuous sections (19) to permit deformation of the tube shaped section (15) to thereby permit adjustment of the nominal dimension (r2) such that when the shaft support (14) is located outside of the tube (11) the nominal dimension (r2) of the at least one rib (16) is greater than the inner radius (r1) of the tube (11), and when the shaft support (14) is located inside of the tube (11) the nominal dimension (r2′) of the at least one rib (16) is substantially equal to the inner radius (r1) of the tube (11).
Method for assembling a shaft support in a tube (11), comprising the steps of:
- providing a shaft support (14) that includes a tube shaped section (15) formed of a plurality of generally symmetrical discontinuous sections (19) and having at least one rib (16) with a nominal dimension (r2) defined as the radial distance measured from a center of the tube shaped section (15) to a tip end (30) of the at least one rib (16);
- sealing one end of the shaft support (14) so that no air can enter the tube shaped section (15);
- connecting the other end of the shaft support (14) to a vacuum device;
- sucking the air out of the tube shaped section (15) with the vacuum device so that the nominal dimension (r2) of the at least one rib (16) is reduced;
- putting the shaft support inside the tube (11);
- and
- returning the pressure inside the tube shaped section (15) to the atmospherical pressure by disconnecting the vacuum device so that the shaft support (14) expands and is stabilized in the tube (11) by abutment of the tip end (30) of the at least one rib (16) against the tube (11).
Dependencies are inferred from the claim text.