1. A switchable tappet for a direct transmission of a cam lift to a tappet push rod in a valve train of an internal combustion engine, said tappet comprising a housing in whose axially extending cavity a longitudinally displaceable inner element is arranged that can be connected to the housing, in a relative position to the housing, by a coupling means, said housing comprising on an end facing away from the cavity, a contact surface for a cam, and the inner element comprising on a side of the cavity, a support for the tappet push rod, which inner element extends beyond the cavity by an extension and is biased away from the housing by at least one coiled compression spring, characterized in that
the coiled compression spring is arranged at least substantially around the extension of the inner element and acts at one end on a support of the inner element facing away from the cavity and at another end against an edge of the cavity or on a section of the cavity near the edge.
2. A tappet of claim 1, wherein
the housing is thin-walled and has a continuously open, tube-like geometry.
3. A tappet of claim 1, wherein
the contact surface for the cam is made as a rotatable roller that is mounted on the housing on a pin.
4. A tappet of claim 3, wherein
an end of the inner element facing the contact surface comprises a cylindrical depression extending in a direction of the contact surface.
5. A tappet of claim 1, wherein
starting from the edge, the cavity of the housing comprises a radially inwards stepped configuration so that the section near the edge is an annular shoulder situated within the cavity.
6. A tappet of claim 1, wherein
the extension of the inner element is made as a separate component out of thin-walled light-weight material.
7. A tappet of claim 6, wherein
the light-weight material is sheet metal.
8. A tappet of claim 6, wherein
the extension is connected to one of an outer peripheral surface and an inner peripheral surface of the inner element by a clip or snap connection.
9. A tappet of claim 1, wherein
the support for one end of the coiled compression spring on the inner element is made as an annular collar formed integrally on the extension.
10. A tappet of claim 1, wherein
the support for one end of the coiled compression spring on the inner element is made as a separate stop member.
11. A tappet of claim 10, wherein the separate member is a locking ring.
12. A tappet of claim 1, wherein
a hydraulic clearance compensation element is installed in the inner element.
13. A tappet of claim 12, wherein
a pressure piston of the clearance compensation element, which pressure piston encloses a reservoir for hydraulic medium, is lengthened axially beyond the edge of the housing so as to protrude into the extension of the inner element, and the support for the tappet push, rod extends directly on the pressure piston in an immediate axial vicinity of the support on the inner element.
14. A switchable tappet for a direct transmission of a cam lift to a tappet push rod in a valve train of an internal combustion engine, said tappet comprising a housing in whose axially extending cavity a longitudinally displaceable inner element is arranged that can be connected to the housing, in a relative position to the housing, by a coupling means, said housing comprising on an end facing away from the cavity, a contact surface for a cam, and the inner element comprising on a side of the cavity, a support for the tappet push rod, which inner element extends beyond the cavity by an extension and is biased away from the housing by at least one coiled compression spring, characterized in that
the housing is thin-walled and has a continuously open, tube-like geometry.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. A nickel-base superalloy comprising, in percentages by weight, from about 4.7% to 4.9% chromium, (Cr), from about 9.0% to about 10.0% cobalt (Co), from about 0.6% to about 0.8% molybdenum (Mo), from about 8.4% to about 8.8% tungsten (W), from about 4.3% to about 4.8% tantalum (Ta), from about 0.6% to about 0.8% titanium (Ti), from about 5.6% to about 5.8% aluminum (Al), from about 2.8% to about 3.1% rhenium (Re), from about 1.1% to about 1.5% hafnium (Hf), from about 0.06% to about 0.08% carbon (C), from about 0.012% to about 0.020% boron (B), from about 0.004% to about 0.010% zirconium (Zr), the balance being nickel and incidental impurities.
2. The nickel-base superalloy of claim 1, wherein the tantalum is present in an amount of from about 4.4% to about 4.7% by weight.
3. The nickel-base superalloy of claim 1, wherein the total content of tungsten, rhenium, tantalum and molybdenum is from about 16.4% to about 17.0% by weight.
4. The nickel-base superalloy of claim 1 comprising, in percentages by weight, about 4.8% chromium, about 9.2\u20139.3% cobalt, about 0.7% molybdenum, about 8.5\u20138.6% tungsten, about 4.5% tantalum, about 0.7% titanium, about 5.6\u20135.7% aluminum, about 2.9% rhenium, about 1.2\u20131.3% hafnium, about 0.07\u20130.08% carbon, about 0.015\u20130.016% boron, about 0.005% zirconium, the balance being nickel and incidental impurities.
5. A single crystal casting prepared from a nickel-base superalloy comprising, in percentage by weight, from about 4.7% to 4.9% chromium, (Cr), from about 9.0% to about 10.0% cobalt (Co), from about 0.6% to about 0.8% molybdenum (Mo), from about 8.4% to about 8.8% tungsten (W), from about 4.3% to about 4.8% tantalum (Ta), from about 0.6% to about 0.8% titanium (Ti), from about 5.6% to about 5.8% aluminum (Al), from about 2.8% to about 3.1% rhenium (Re), from about 1.1% to about 1.5% hafnium (Hf), from about 0.06% to about 0.08% carbon (C), from about 0.012% to about 0.020% boron (B), from about 0.004% to about 0.010% zirconium (Zr), the balance being nickel and incidental impurities.
6. The single crystal casting of claim 5, wherein the tantalum is present in an amount of from about 4.4% to about 4.7% by weight.
7. The single crystal casting of claim 5, wherein the total content of tungsten, rhenium, tantalum and molybdenum is from about 16.4% to about 17.0% by weight.
8. The single crystal casting of claim 5, where 10\u201350 ppm La, Y, Ce individually or in combination is present to improve bare oxidation resistance and coating performance.
9. A nickel-base turbine vane, turbine blade, or multiple turbine vane segment cast from a nickel-base superalloy comprising, in percentage by weight, from about 4.7% to 4.9% chromium, (Cr), from about 9.0% to about 10.0% cobalt (Co), from about 0.6% to about 0.8% molybdenum (Mo), from about 8.4% to about 8.8% tungsten (W), from about 4.3% to about 4.8% tantalum (Ta), from about 0.6% to about 0.8% titanium (Ti), from about 5.6% to about 5.8% aluminum (Al), from about 2.8% to about 3.1% rhenium (Re), from about 1.1% to about 1.5% hafnium (Hf), from about 0.06% to about 0.08% carbon (C), from about 0.012% to about 0.020% boron (B), from about 0.004% to about 0.010% zirconium (Zr), the balance being nickel and incidental impurities.
10. The turbine vane, turbine blade, or multiple turbine vane segment of claim 9, wherein the tantalum is present in an amount of from about 4.4% to about 4.7% by weight.