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US5101554A Expired / Lapsed US ⏱️ 0.0 years remaining

Process for producing an assembled camshaft as well as assembled camshaft consisting of a shaft tube and slid-on elements

Assignee: Vitesco Technologies Lohmar Verwaltungs GmbH
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Filing: 1991-01-14
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Granted: 1992-04-07
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Expires: 2011-01-14
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Abstract

Abstract In the production of an assembled camshaft slid-on elements, such as control cams, bearing rings, gear wheels or bevel gears, are placed on an axially extending shaft tube. The slid-on elements are secured in place by expanding the shaft tube in the region of the elements by applying internal pressure. In producing the camshaft, a high strength material is used for the slid-on elements and an inferior strength material for the shaft. In the expanding step, an axially extending portion of the shaft tube is plastically deformed and the slid-on element is predominately elastically deformed. After expansion, the outer zone of the slid-on elements are elongated in the tangential direction in the range of 1%.

Inventors

  • 👤 Hans-Jurgen Breuer
  • 👤 Wolfgang Maus
  • 👤 Rudolf Schulze
  • 👤 Helmut Swars
  • 👤 Hans Hanswillemenke
  • 👤 Helmut Riemscheid
  • 👤 Karl Weiss
  • 👤 Herbert Frielingsdorf
  • 👤 Engelbert Schwarz
  • 👤 Heribert Grewe
  • 👤 Klaus Greulich

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-05 16:47
CPC Classifications
B; B21; B21D; B21D39/00; B21D39/04; B21D53/00; B21D53/84; B21D53/845; Y; Y10; Y10T; Y10T29/00; Y10T29/49; Y10T29/49229; Y10T29/49293; Y10T29/49805; Y10T29/49826; Y10T29/49908; Y10T29/49938; Y10T29/4994; Y10T74/00; Y10T74/21; Y10T74/2101

Claims Analysis

Total Claims: 15
Claim 1
Independent Claim 154 words
A process for producing an assembled camshaft formed of an axially extending hollow shaft tube and elements slid-on the shaft tube, such as control cams, bearing rings, gear wheels or bevel gears, by expanding the shaft tube in the region of the elements by applying internal pressure, the slid-on elements having a circumferentially extending outer zone, comprising the steps of using a high strength material for the slid-on elements and an inferior strength material for the shaft tube, in the expanding step plastically deforming an axially extending portion of the shaft tube and predominantly elastically deforming the slid-on element zone of the slid-on element and expanding the tube on an axial portion L ax R which, at each end, exceeds the length L ax E of the slid-on element by a projection U ax of a minimum of 50% and a maximum of 150% of the wall thickness L rad R of the tube.
Claim 2
Dependent Claim 154 words
A process for producing an assembled camshaft formed of an axially extending hollow shaft tube and elements slid-on the shaft tube, such as control cams, bearing rings, gear wheels or bevel gears, by expanding the shaft tube in the region of the elements by applying internal pressure, the slid-on elements having a circumferentially extending outer zone, comprising the steps of using a high strength material for the slid-on elements and an inferior strength material for the shaft tube, in the expanding step plastically deforming an axially extending portion of the shaft tube and predominantly elastically deforming the slid-on element zone of the slid-on element and expanding the tube on an axial portion L ax R which, at each end, exceeds the length L ax E of the slid-on element by a projection U ax of a minimum of 50% and a maximum of 150% of the wall thickness L rad R of the tube.
Claim 3
Dependent Claim 74 words
A process according to claim 1, characterized in that prior to expansion, the difference U min between the outer tube diameter d a and the inner element diameter D i is at least 0.9 times the value of the outer tube diamerter d a multiplied by the quotient of 0.2% yield point (R p ) and the modulus of elasticity E of the tube material, in accordance with the equation U.sub.min ≧0.9d.sub.a ×(R.sub.P /E)
Claim 4
Dependent Claim 52 words
A process according to claim 1 or 2, characterized in that the expansion of the tube takes place uniformly on an axial portion covering two adjoining slid-on elements if the free distance A ax between the two elements is less than 40% of the wall thickness L rad R of the tube.
Claim 5
Dependent Claim 33 words
A process according to claim 1, characterized in that in the expanding step , in addition to an adhesion locking effect, forming a form-fitting effect between the shaft tube and the slid-on element.
Claim 6
Dependent Claim 26 words
A process according to claim 4, characterized by flowing the material of the tube into circumferentially spaced indentations in the element for forming a macro-form-fitting connection.
Claim 7
Dependent Claim 37 words
A process according to claim 5, characterized by flowing the material of the tube radially outwardly into a central portion of the element aperture with an increased diameter relative to the outside for forming a macro-form-fitting connection.
Claim 8
Dependent Claim 28 words
A process according to claim 4, characterized by pressing a hard particle coating within an aperture of the element into the tube material for forming a micro-form-fitting connection.
Claim 9
Dependent Claim 38 words
A process according to claim 4, characterized by machining grooves extending axially within an aperture in the slid-on element and pressing tube material outwardly into the grooves for forming a micro-form-fitting connection between the tube and the element.
Claim 10
Dependent Claim 34 words
A process according to claim 4, characterized by pressing tube material into indentations within an aperture in the element and producing the indentations by sand blasting or shot opening for forming a micro-form-fitting connection.
Claim 11
Dependent Claim 54 words
A process according to claim 1, characterized in that in the expanding step providing plastic radial surface deformation occurs in an aperture of the element comprising steel and extends for a material depth Δ L rad in the range of 10 to 15% of the smallest wall thickness L rad E of the element.
Claim 12
Dependent Claim 35 words
A process according to claim 1, characterized when using a ductile material such as steel for the element with elongation in the outer zone after the expanding step in the range of 0.1 to 0.4%.
Claim 13
Dependent Claim 37 words
A process according to claim 1, characterized when using material such as cast or sintered material for the element with elongation in the outer zone after the expanding step being in the range of 0.01 to 0.2%.
Claim 14
Dependent Claim 37 words
A process according to one of claims 1, 2 and 4 to 10, characterized in that elongating the outer zone of the slide-on element in the tangential direction after expansion in the range of 0.01% to 1%.
Claim 15
Dependent Claim 43 words
A process according to claim 1, characterized in that when using one of aluminum or titanium for the element the elongation occurring in the outer zone of the element in the tangential direction after expansion is of a magnitude of up to 1%.

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1995-04-07 1995-10-07 1996-04-07 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1999-04-07 1999-10-07 2000-04-07 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 2003-04-07 2003-10-07 2004-04-07 $7700.00 Window Closed / Lapsed

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