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
  • F16H—GEARING
  • F16H7/00—Gearings for conveying rotary motion by endless flexible members
  • F16H7/08—Means for varying tension of belts, ropes or chains 
  • F16H7/0829—Means for varying tension of belts, ropes or chains  with vibration damping means
  • F16H7/0831—Means for varying tension of belts, ropes or chains  with vibration damping means of the dry friction type
• • 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
  • F16H—GEARING
  • F16H7/00—Gearings for conveying rotary motion by endless flexible members
  • F16H7/08—Means for varying tension of belts, ropes or chains 
  • F16H2007/0802—Actuators for final output members
  • F16H2007/0806—Compression coil springs
• • 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
  • F16H—GEARING
  • F16H7/00—Gearings for conveying rotary motion by endless flexible members
  • F16H7/08—Means for varying tension of belts, ropes or chains 
  • F16H2007/0889—Path of movement of the finally actuated member
  • F16H2007/0893—Circular path

Definitions

• the invention relates to a tensioning device of a traction mechanism drive of an internal combustion engine, comprising a deflection device, such as a tensioning rail or a tensioning arm with a roller, which is pivotable about a pivot point via a pretensioning device arranged between the deflection device and a support surface separate from the deflection device Biasing means comprises a spring urging a on a track of the deflection movable arranged clamping piece in the direction of the support surface.
• traction drive traction means such as chains or belts are used. These traction means then connect different waves with each other.
• Convention traction means in known traction drives a drive shaft and an output shaft.
• the drive shaft is often the internal combustion engine driven crankshaft and the output shaft is a camshaft and / or a shaft of an accessory.
• clamping devices are used. Such tensioning devices compensate for the changes in length of the traction device.
• so-called hydraulic or mechanical tensioning devices are used, which utilize a medium pressure or a mechanical component cause a retightening of the traction device.
• deflection devices which are pivotable about a pivot point.
• Such deflection devices are often in the form of tensioning rails or tensioning arms which have a roller at one end thereof. Sliding rails have proven to be particularly reliable and cost-efficient.
• the hitherto used hydraulic tensioning devices have the disadvantage that they must use part of the power provided by the internal combustion engine to use the oil pressure in their biasing device for tensioning the deflection device.
• the assembly of such hydraulic tensioning devices is complex.
• a disadvantage in addition to the increase in weight due to numerous lines and the reduction in performance of the internal combustion engine, a forced increase in costs compared to mechanical solutions has been found. It is therefore to be observed that mechanically acting clamping devices are increasingly being used again to avoid the disadvantages described.
• This tensioning device is considered to be the closest prior art.
• the raceway aligned with the clamping piece is designed without rastering and has at least one longitudinally oriented friction elevation section which is in frictional contact with the clamping piece.
• a friction increasing portion is meant such an element that increases the friction between the clamping piece and the raceway in the presence of relative movement between the clamping piece and the raceway relative to the rest of the raceway.
• the spring In order to achieve a sufficiently large tension in the traction means, it is necessary that the spring has a very large spring force. This large spring force is already necessary because the spring and the track occupy an acute angle relative to the support surface. Due to space constraints, however, it is not possible to choose a larger angle in order to make the spring weaker.
• the surface in frictional contact between the clamping piece and the raceway can be increased, so that greater frictional forces occur between these two elements. These larger frictional forces have a damping effect and inhibit the tensioning device from swinging up.
• the clamping piece has at least one friction counterpart section opposite the friction increasing section, which is in contact with the friction increasing section of the running surface.
• the surface in operative contact with each other between the raceway and the clamping piece is increased so that a particularly high friction is achieved.
• the movement of the deflection can be stabilized particularly effective.
• At least one further friction increasing section is formed on the side of the clamping piece facing the support surface. In this way, a good power transmission is ensured by the clamping piece on the support surface.
• the friction-increasing portion and / or the friction-increasing counterpart portion has a roughened surface. It is advantageous if, for example, an oblique side of a V-shaped groove or at least an oblique side of a " ⁇ " -shaped projection is roughened in order to achieve an even better damping.
• the invention also relates to a traction drive with a traction means, such as a chain or a belt, and with a mechanical tensioning device as explained, wherein the tensioning device is installed so that it pushes away a tensioning rail of a combustion engine fixed support surface for tensioning the traction means.
• FIG. 1 shows a first embodiment of a clamping device according to the invention with a nearly maximally extended biasing device in a perspective view
• FIG. 2 shows a cross section through the clamping device according to the embodiment of FIG. 1
• Fig. 3 shows a second embodiment with two "V-shaped recesses in a supporting body of a deflection and to the same" ⁇ "- shaped projections of a clamping piece, wherein between the projections and the recesses and adjacent to these, the track is designed smooth .
• FIG. 4 shows a third embodiment in which, in the region of the raceway, there is a roughening on both sides of the clamping piece, as well as on the sides of the supporting body,
• FIG. 5 shows a fourth embodiment of a tensioning device according to the invention, in which the oblique surfaces of the projections and recesses are roughened
• FIG. 6 shows a fifth embodiment in which only one side of the protrusion present in the raceway and only the side adjacent thereto are the counterpart Groove is roughened.
• a first embodiment of a clamping device 1 is shown.
• the tensioning device 1 is part of a traction mechanism that is used in an internal combustion engine.
• the tensioning device 1 has a deflection device 2.
• the deflection device 2 has a support body 3 and a slip-on cover 4 clipped onto the support body 3.
• the sliding lining 4 is clipped on the side of the supporting body 3, on which a traction means, not shown, such as a chain or a belt, is arranged.
• a raceway 5 is formed on the support body 3.
• This raceway 5 is arranged on the zugstofffernen side of the support body 3.
• This raceway 5 runs obliquely to zugstoffnahen side of the support body 3 and forms an acute angle with a support surface, not shown.
• the supporting surface is immovably positioned relative to the internal combustion engine, which is also not shown.
• a clamping piece 6 is applied to the track 5 and surrounds this with a plurality of symmetrically to each other and to the longitudinal axis of the deflection device 2 arranged guide pieces 7 at least in sections.
• the clamping piece 6 is movable on the raceway 5 in two directions. The directions are aligned opposite.
• a guide pin 8 for a spring 9 of a biasing device 10 is present.
• the spring 9 is supported on the support body 3 and is arranged by the guide pin 8, which is an integral part of the support body 3, or as a separate component with her, compressible and expandable.
• the spring abuts with one end on the clamping piece 6.
• the spring engages on the side of the clamping piece 6 in a not shown recess of the clamping piece 6 a.
• the clamping piece 6 is urged by the spring along the raceway 5 in the direction of a pivot point 1 1 of the support body 3.
• a contact surface 12 is present on the side facing the support surface of the clamping piece 6.
• the raceway 5 is formed smooth and planar on the side facing the spring 9, but has a friction increasing portion 13 which in longitudinal direction. direction of the raceway 5 and the spring 9 is aligned.
• the friction increasing portion 13 has a "V-shaped cross section.
• a further friction enhancement section 13 is also formed on the contact surface 12 of the clamping piece 6. Also, this, on the contact surface 12 located Reibungserhöhungsabites 13, has a "V-shaped surface and extends on a convex outer side of the clamping piece. 6
• the clamping piece 6 also has friction-increasing counterpart portions aligned in the direction of the pulling means.
• Such a friction increase counterpart section 14 is shown in FIG. In the embodiment of FIG. 2, the sliding surfaces of the friction increasing portion 13 are smooth, as are the friction increasing counter portions 14 on the inclined surfaces thereof.
• FIG. 1 Such a variant is shown in FIG.
• " ⁇ " -shaped projections as friction-increasing counterpart portions 14 are in positive and non-positive contact with "V-shaped friction increasing portions 13 of the support body 3.
• two elongated friction increasing portions 13 are on the side of the clamping piece facing away from the support body 3 6. In these recesses then engage projections of the support surface.
• projections and recesses were dispensed with and a roughened surface was used only in the region of the friction heightening sections 13 and the friction-increasing counterpart sections 14. In the embodiment of FIG.

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• Engineering & Computer Science (AREA)
• General Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Devices For Conveying Motion By Means Of Endless Flexible Members (AREA)

Priority Applications (2)

Applications Claiming Priority (1)

Publications (1)

Family

ID=46208556

Family Applications (1)

Country Status (2)

Cited By (4)

Citations (7)

• 2012
  • 2012-06-06 BR BR112014024564A patent/BR112014024564A8/pt not_active IP Right Cessation
  • 2012-06-06 WO PCT/EP2012/060632 patent/WO2013182233A1/fr not_active Ceased

Patent Citations (7)

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