Rubber compound with fiber reinforcement

A rubber compound for use in a stator, the rubber compound comprising:

• a fiber reinforcement, the fiber reinforcement including a plurality of fibers, wherein fibers in the fiber reinforcement create a grain direction in which “with the grain” is generally orthogonal to “across the grain”, wherein the rubber compound has a first value for 25% tensile Modulus “across the grain” and a second value for 25% tensile Modulus “with the grain”, wherein the first value is at least 10% lower than the second value;
• wherein the fiber reinforcement includes a fiber loading of greater than 1.0 phr of fibers;
• wherein the rubber compound has a 25% tensile Modulus of greater than 400 psi “across the grain” and a 50% tensile Modulus of greater than 700 psi “across the grain”;
• and
• wherein the fiber reinforcement includes short chop fibers.

A rubber compound for use in a stator, the rubber compound comprising:

• a fiber reinforcement, the fiber reinforcement including a plurality of fibers, wherein fibers in the fiber reinforcement create a grain direction in which “with the grain” is generally orthogonal to “across the grain”, wherein the rubber compound has a first value for 25% tensile Modulus “across the grain” and a second value for 25% tensile Modulus “with the grain”, wherein the first value is at least 10% lower than the second value;
• wherein the fiber reinforcement includes a fiber loading of greater than 1.0 phr of fibers;
• wherein the rubber compound has a 25% tensile Modulus of greater than 400 psi “across the grain” and a 50% tensile Modulus of greater than 700 psi “across the grain”;
• and
• wherein at least some of the fibers have a Modulus greater than 2.0 GPa.