Clutch assembly including wet friction material with calcined kaolin clay and tung modified phenolic resin
A clutch assembly for a motor vehicle drivetrain includes a rigid support and a wet friction material fixed to a surface of the rigid support. The wet friction material includes a base material including a matrix of fibers and filler particles embedded in the matrix of fibers. The filler particles include calcined kaolin clay, and the base material includes, by percent weight, 5 to 60% of calcined kaolin clay. The wet friction material also includes a binder embedded in the base material. The binder is tung modified phenolic resin.
1. A clutch assembly for a motor vehicle drivetrain comprising:
a rigid support; and
a wet friction material fixed to a surface of the rigid support, the wet friction material comprising:
a base material including a matrix of fibers and filler particles embedded in the matrix of fibers, the filler particles including calcined kaolin clay, the base material including, by percent weight, 5 to 60% of calcined kaolin clay; and
a binder embedded in the base material, the binder being tung modified phenolic resin,
wherein the wet friction material includes, by percent weight, 31 to 35%, of tung modified phenolic resin,
wherein the wet friction material has a dynamic friction coefficient of 0.17 to 0.24 in automatic transmission fluid having a temperature of 120° C. in a rotational speed range of 5 RPM to 50 RPM and in an applied pressure of 1.0 to 2.5 MPa.
2. The clutch assembly as recited in claim 1 wherein the base material includes, by percent weight, 10 to 40% of calcined kaolin clay.
3. The clutch assembly as recited in claim 1 wherein the base material includes, by percent weight, 15 to 25% of calcined kaolin clay.
4. The clutch assembly as recited in claim 1 wherein the base material includes, by percent weight, 5 to 60% fibers, 1 to 20% graphite by percent weight and 5 to 40% of a further filler material.
5. The clutch assembly as recited in claim 1 wherein the base material includes, by percentage weight, 20-60% fibers, 5-60% calcined kaolin clay, and 5-40% diatomaceous earth.
6. The clutch assembly as recited in claim 1 wherein the base material includes, by percentage weight, 30-60% fibers, 10-40% calcined kaolin clay and 10-40% diatomaceous earth.
7. The clutch assembly as recited in claim 1 wherein the base material includes, by percentage weight, 45-55% fibers, 15-25% calcined kaolin clay and 25-35% diatomaceous earth.
8. The clutch assembly as recited in claim 1 wherein the wet friction material has a dynamic friction coefficient in automatic transmission fluid of at least one of the following:
0.21 to 0.24 at a fluid temperature of 120° C. in a rotational speed range of 5 RPM to 50 RPM at an applied pressure of 1.0 MPa;
0.20 to 0.23 at a fluid temperature of 120° C. in a rotational speed range of 5 RPM to 50 RPM at an applied pressure of 1.5 MPa;
0.19 to 0.21 at a fluid temperature of 120° C. in a rotational speed range of 5 RPM to 50 RPM at an applied pressure of 2.0 MPa; or
0.17 to 0.19 at a fluid temperature of 120° C. in a rotational speed range between 5 RPM to 50 RPM at an applied pressure of 2.5 MPa.
9. The clutch assembly as recited in claim 1 wherein the wet friction material has a dynamic friction coefficient in automatic transmission fluid of at least one of the following:
0.17 to 0.21 at a fluid temperature of 120° C. in an applied pressure range of 1.0 MPa to 2.5 MPa at a rotational speed of 5 RPM;
0.19 to 0.23 at a fluid temperature of 120° C. in an applied pressure range of 1.0 MPa to 2.5 MPa at a rotational speed of 10 RPM;
0.19 to 0.24 at a fluid temperature of 120° C. in an applied pressure range of 1.0 MPa to 2.5 MPa at a rotational speed of 30 RPM;
0.19 to 0.24 at a fluid temperature of 120° C. in an applied pressure range of 1.0 MPa to 2.5 MPa at a rotational speed of 40 RPM; or
0.18 to 0.24 at a fluid temperature of 120° C. in an applied pressure range of 1.0 MPa to 2.5 MPa at a rotational speed of 50 RPM.
10. The clutch assembly as recited in claim 1 wherein the wet friction material has a dynamic friction coefficient of 0.20 to 0.24 in automatic transmission fluid having a temperature of 120° C. in a rotational speed range of 5 RPM to 50 RPM and in an applied pressure of 1.0 to 1.5 MPa.
11. The clutch assembly as recited in claim 1 wherein the wet friction material reaches a static friction coefficient of 0.23 during a 5 second breakaway cycle ramping up to 5 RPMs at a pressure of 1.0 MPa and in automatic transmission fluid having a temperature of 120° C.
12. A method of making the clutch assembly as recited in claim 1 , the method comprising:
fixing the wet friction material to the surface of the rigid support,
the wet friction material being made by:
providing the base material including the matrix of fibers and filler particles embedded in the matrix of fibers, the filler particles including calcined kaolin clay;
saturating the base material with tung modified phenolic resin; and
curing the tung modified phenolic resin.
13. A wet friction material comprising:
a base material including a matrix of fibers and filler particles embedded in the matrix of fibers, the filler particles including calcined kaolin clay, the based material including, by percent weight, 5 to 60% of calcined kaolin clay; and
a binder embedded in the base material, the binder being tung modified phenolic resin,
wherein the wet friction material includes, by percent weight, 31 to 35%, of tung modified phenolic resin,
wherein the wet friction material has a dynamic friction coefficient of 0.17 to 0.24 in automatic transmission fluid having a temperature of 120° C. in a rotational speed range of 5 RPM to 50 RPM and in an applied pressure of 1.0 to 2.5 MPa.