Composite apex seal

Claim 2

AN APEX SEAL FOR A ROTARY INTERNAL COMBUSTION AND HAVING SURFACES TO BE SEALED COMPRISING: A. A SUPPORTING PORTION DEFINED TO ESTEND BETWEEN SAID SURFACES AND IS COMPRISED OF A METAL CONSISTING ESSENTIALLY OF ALUMINUM AND HAVING A SPECIFIC GRAVITY NO GREATER THAN 3.0 AND A MODULUS OF ELASTICITY NO LESS THAN 12 MILLION P.S.I., B. A WEAR-RESISTANT COATING SUBSTANTIALLY ENVELOPING SAID SUPPORTING PORTION AND HAVING A THICKNESS BETWEEN 0.015 INCHES AND 0.025 INCHES, SAID COATING BEING COMPRISED OF AND ADMIXTURE OF TWO DIFFERENT TYPES OF ABRASION RESISTANT PARTICLES HAVING A PARTICLE SIZE NO GREATER THAN 74 MICRONS, SAID PARTICLES BEING SELF-FUSED TO EACH OTHER PROVIDING LIMITED POROSITY OF 2-5%, SAID COATING BEING MECHANICALLY LOCKED TO SAID SUPPORTING PORTION WITH A UNIFORM ADHESIVE FORCE NO LESS THAN 8,500 P.S.I. AS DETERMINED BY AN EPOXY TEST PROCEDURE, SAID ADHESIVE FORCE RESULTING FROM THE IMPACTION OF SAID ABRASION RESISTANT PARTICLES AGAINST SAID SUPPORTING PORTION BY A PLASMA JET HAVING A FLOW VELOCITY IN EXCESS OF MACH 1.

Claim 3

An apex seal as in claim 1, in which the hardness of said as-deposited coating is at least 40 Rc and has a hardness value at an operating temperature of about 350*F of at least Rc 40.

Claim 4

An apex seal as in claim 1, in which the as-deposited surface roughness of said coating is no greater than 300 r.m.s.

Claim 5

In a rotary piston engine having a rotor mounted for planetary movement within an enclosure of said engine, the rotor carrying at least one seal element within a slot at an apex thereof, said seal being adapted to be urged by gas pressure within said enclosure to seal against the side of said slot and also against said enclosure, the combination system comprising: a. a coating system for said enclosure consisting of a metal bonded refractory having a hardness of at least 40 Rc, b. an apex seal construction having a supporting portion adapted to extend between said slot and the coating system of said enclosure, said supporting portion consisting essentially of aluminum and having a curved crown adapted to facilitate sliding engagement with said enclosure coating system, and a continuous wear-resistant coating having a thickness less than 0.025 inch, said coating substantially enveloping said supporting portion and being mechanically bonded to and enveloping at least the full crown of said supporting portion with an adhesive force of at least 8,500 p.s.i. as determined by an epoxy test procedure, said wear-resistant coating consisting essentially of an admixture of a metal and a refractory powder with the particle size of said powders not exceeding 74 microns, said powders being self-fused to each other and impacted with each other and to said supporting portion to possess an improved matallurgical union, the coating being the result of self-fusion of the particles after having been subjected to a temperature in the range of 2,800*F and impelled by a plasma jet stream having a velocity of at least Mach I.

Claim 6

In a rotary piston engine having a rotor mounted for planetary movement within an enclosure of said engine, the rotor carrying at least one seal element within a slot at an apex thereof, said seal being adapted to be urged by gas pressure within said enclosure to seal against the side of said slot and also against said enclosure, the combination system comprising: a. a coating system for said enclosure consisting of a metal bonded refractory having a hardness of at least 40 Rc, b. an apex seal construction having a supporting portion adapted to extend between said slot and the coating system of said enclosure, said supporting portion consisting essentially of aluminum and having a curved crown adapted to facilitate sliding engagement with said enclosure coating system, and a continuous wear-resistant coating having a thickness less than 0.025 inch, said coating substantially enveloping said supporting portion and being mechanically bonded to and enveloping at least the full crown of said supporting portion with an adhesive force of at least 8,500 p.s.i. as determined by an epoxy test procedure, said wear-resistant coating consisting essentially of an admixture of a metal and a refractory powder with the particle size of said powders not exceeding 74 microns, said powders being self-fused to each other and impacted with each other and to said supporting portion to possess an improved matallurgical union, the coating being the result of self-fusion of the particles after having been subjected to a temperature in the range of 2,800*F and impelled by a plasma jet stream having a velocity of at least Mach I.