High temperature pressurized high frequency testing rig and test method

An apparatus for testing a wear resistance of materials and at least one lubricating property of a fluid under conditions where a workpiece is subjected to a reciprocating wear, said testing apparatus comprising;

• a blind bored hollow cylindrical testing chamber having a top end and a bottom end, oriented with its bore axis vertical such that the top end is the cylinder open end and the bottom end is its blind end, said hollow cylinder being fitted near its bottom end with an actuator rod support arm perpendicular to said bore axis, said actuator rod support arm having a bore of sufficient diameter to pass an end of an actuator rod there through and being fitted with a conduit suitable for passing compressed gas into said bore;
• an actuator rod having two ends, a first end being passed through the bore of said actuator rod support arm and residing within said testing chamber, and a second end residing in an ambient environment surrounding said testing chamber, wherein a clearance between said first end of said actuator rod and said bore of said actuator rod support arm is less than 2 millimeters;
• a first workpiece chuck adapted to hold a first workpiece which is rigidly fastened to said first end of said actuator arm;
• a first workpiece rigidly fastened into said first workpiece chuck;
• a workpiece loading device having a lower face and an upper face, said workpiece loading device being inserted into the bore of said testing chamber with said lower face oriented down, wherein said workpiece loading device comprises a solid metal cylinder machined to slide along the bore of said testing chamber under the influence of gravity alone, thereby descending said testing chamber bore until it contacts said first workpiece;
• a second workpiece chuck adapted to hold a second workpiece, wherein said second workpiece chuck is fastened to said lower face of said sample loading device such that a workpiece fastened into said second workpiece chuck will contact a first workpiece fastened into said first workpiece chuck when said sample loading device is passed down the bore of said testing chamber;
• a second workpiece fastened into said second workpiece chuck;
• a pivot clamp fastened to said second end of said actuator rod;
• a crank arm having two ends, a driving end and a driven end, wherein said driven end is fastened to said pivot clamp;
• a cranking assembly fastened to said driving end of said crank arm;
• a drive shaft fastened to said cranking assembly such that rotation of the drive shaft is translated to reciprocating motion of said crank arm by said cranking assembly;
• an electric motor fastened to said drive shaft;
• and
• a cap providing a compression seal fastened to said top end of said testing chamber, said compression seal being able to withstand in excess of 200 psi of pressure without leaking.

A method of testing at least one lubrication property of a fluid that is a liquid at S.T.P. conditions using a sealed testing chamber adapted to simulate an environment encountered in an operating engine, said method comprising the steps of:

• preparing a workface of a first workpiece;
• fastening said first workpiece into a first chuck;
• placing said first chuck containing said first workpiece into a testing chamber;
• fastening said first chuck containing said first workpiece to an end of an actuator rod contained within said testing chamber, said actuator rod being capable of imparting a linear movement to said first chuck and thereby moving said first workpiece;
• preparing a workface of a second workpiece;
• fastening said second workpiece into a second chuck;
• fastening said second chuck containing said second workpiece to a workpiece loading device;
• contacting said first workpiece workface with said second workpiece workface;
• imparting a load to a point of contact between said first and second workpieces with a workpiece loading device;
• immersing said workpiece contact point in a lubricating media;
• sealing said testing chamber;
• pressurizing said testing chamber to a selected pressure;
• heating said lubricating media to a selected temperature;
• imparting a differential linear motion to said workpieces at said workpiece contact point until a measurable scar is imparted to at least one workpiece workface;
• venting said pressure from said testing chamber;
• removing said workpiece having a measurable scar on said workface from said testing chamber;
• and
• evaluating said workface scar;
• wherein said workpiece loading device is a weighted cylinder to which said second chuck is fastened, and wherein a load is applied to said contact area between said first workpiece and said second workpiece contact point by gravity acting on said workpiece loading device which is permitted to slide freely in said testing chamber after contact is established between said first and second workpiece workfaces.

A method of testing the lubricating properties of a fluid lubricating media which is not a liquid at S.T.P. conditions using a sealed testing chamber adapted to simulate an environment encountered in an operating engine, said method comprising the steps of:

• preparing a workface of a first workpiece;
• fastening said first workpiece into a first chuck;
• placing said first chuck containing said first workpiece into a testing chamber;
• fastening said first chuck containing said first workpiece to an end of an actuator rod contained within said testing chamber, said actuator rod being capable of imparting a linear movement to said first chuck and thereby moving first workpiece;
• preparing a workface of a second workpiece;
• fastening said second workpiece into a second chuck;
• fastening said second chuck containing said second workpiece to a workpiece loading device;
• contacting said first workpiece workface with said second workpiece workface;
• imparting a load to a point of contact between said first and second workpieces with a workpiece loading device;
• sealing said testing chamber;
• charging the test chamber with an S.T.P. gas lubricant media condensate of sufficient volume to immerse said contact point between said workfaces;
• pressurizing said testing chamber to a selected pressure;
• heating said lubricating media to a selected temperature;
• imparting a differential linear motion to said workpieces at said workpiece contact point until a measurable scar is imparted to at least one workpiece workface;
• venting said pressure from said testing chamber;
• removing said workpiece having a measurable scar on said workface from said testing chamber;
• and
• evaluating said workface scar;
• wherein said workpiece loading device is a weighted cylinder to which said second chuck is fastened, and wherein load is applied to said contact area between said flat workpiece and said spherical workpiece by gravity acting on said workpiece loading device which is permitted to slide freely in said testing chamber after contact is established between said flat workpiece and said spherical workpiece.

A wear testing apparatus comprising:

• a test chamber having a workpiece holder holding a first workpiece in contact with a second workpiece;
• a workpiece loading device applying a controlled force to a contact point between the first and second workpiece;
• and
• a motion generator connected to said workpiece holder, said motion generator imparting cyclic differential motion to said first and second workpieces, said motion describing a line at the contact point between the first and second workpiece, thereby forming a measurable scar in at least one workpiece;
• said motion generator comprising an actuator rod support arm comprising an inner end in mechanical communication with said workpiece holder and extending outside of said test chamber to an opposed end, said actuator rod support arm comprising a longitudinal bore therethrough retaining an actuator rod, said longitudinal bore and said opposed end being in fluid communication with a conduit adapted to provide a pressurized gas to said longitudinal bore, said actuator rod being at deviation from linearity through said longitudinal bore and at a clearance through said longitudinal retaining bore wherein a combination of said clearance, said deviation from linearity and said pressurized gas is effective to maintain a seal effective to prevent a fluid placed under pressure within said testing chamber to escape from said testing chamber along an interface between said testing chamber and said actuator rod while permitting said actuator rod to move freely through said actuator rod support arm;
• a sealable conduit affixed to said testing chamber, whereby fluids may be conducted to and from the interior of said testing chamber;
• and
• a heater affixed to said testing chamber, wherein energizing said heater raises a temperature of said workpieces and the fluids;
• wherein said clearance is 50 microns or less and said deviation from linearity is less than 100 microns.

A wear testing apparatus comprising:

• a test chamber having a workpiece holder holding a first workpiece in contact with a second workpiece;
• a workpiece loading device applying a controlled force to a contact point between the first and second workpiece;
• and
• a motion generator connected to said workpiece holder, said motion generator imparting cyclic differential motion to said first and second workpieces, said motion describing a line at the contact point between the first and second workpiece, thereby forming a measurable scar in at least one workpiece;
• said motion generator comprising an actuator rod support arm comprising an inner end in mechanical communication with said workpiece holder and extending outside of said test chamber to an opposed end, said actuator rod support arm comprising a longitudinal bore therethrough retaining an actuator rod, said actuator rod comprising one or more feature selected from the group consisting of a deviation from linearity through said longitudinal retaining bore and a clearance through said longitudinal retaining bore, said one or more feature being effective to maintain a seal effective to prevent a fluid placed under pressure within said testing chamber to escape from said testing chamber along an interface between said testing chamber and said actuator rod while permitting said actuator rod to move freely through said actuator rod support arm;
• further comprising at least one sealable conduit communicating with the testing chamber, whereby fluids and objects may be passed into and out from said testing chamber.

A wear testing apparatus comprising:

• a test chamber having a workpiece holder holding a first workpiece in contact with a second workpiece;
• a workpiece loading device applying a controlled force to a contact point between the first and second workpiece;
• and
• a motion generator connected to said workpiece holder, said motion generator imparting cyclic differential motion to said first and second workpieces, said motion describing a line at the contact point between the first and second workpiece, thereby forming a measurable scar in at least one workpiece;
• said motion generator comprising an actuator rod support arm comprising an inner end in mechanical communication with said workpiece holder and extending outside of said test chamber to an opposed end, said actuator rod support arm comprising a longitudinal bore therethrough retaining an actuator rod, said longitudinal bore and said opposed end being in fluid communication with a conduit adapted to provide a pressurized gas to said longitudinal bore, said actuator rod comprising one or more feature selected from the group consisting of a deviation from linearity through said longitudinal bore and a clearance through said longitudinal retaining bore wherein a combination of said one or more features and said pressurized gas is effective to maintain a seal effective to prevent a fluid placed under pressure within said testing chamber to escape from said testing chamber along an interface between said testing chamber and said actuator rod while permitting said actuator rod to move freely through said actuator rod support arm;
• further comprising at least one sealable conduit communicating with the testing chamber, whereby fluids and objects may be passed into and out from said testing chamber.

A wear testing apparatus comprising:

• a test chamber having a workpiece holder holding a first workpiece in contact with a second workpiece;
• a workpiece loading device applying a controlled force to a contact point between the first and second workpiece;
• and
• a motion generator connected to said workpiece holder, said motion generator imparting cyclic differential motion to said first and second workpieces, said motion describing a line at the contact point between the first and second workpiece, thereby forming a measurable scar in at least one workpiece;
• said motion generator comprising an actuator rod support arm comprising an inner end in mechanical communication with said workpiece holder and extending outside of said test chamber to an opposed end, said actuator rod support arm comprising a longitudinal bore therethrough retaining an actuator rod, said actuator rod comprising one or more feature selected from the group consisting of a deviation from linearity through said longitudinal retaining bore and a clearance through said longitudinal retaining bore, said one or more feature being effective to maintain a seal effective to prevent a fluid placed under pressure within said testing chamber to escape from said testing chamber along an interface between said testing chamber and said actuator rod while permitting said actuator rod to move freely through said actuator rod support arm;
• wherein said testing chamber is a hollow cylinder, said workpiece loading device further comprises a solid metal cylinder having an outer diameter and surface finish to permit it to slide freely within said testing chamber inner bore, and wherein contact pressure between said first and second workpieces held in said first and second workpiece holders is generated by the weight of said work piece loading device impinging upon a horizontal array of said workpiece holders containing workpieces, said horizontal array of workpiece holders being arranged such that a surface of said first workpiece resides in contact with a surface of said second workpiece.

A wear testing apparatus comprising:

• a test chamber having a workpiece holder holding a first workpiece in contact with a second workpiece;
• a workpiece loading device applying a controlled force to a contact point between the first and second workpiece;
• and
• a motion generator connected to said workpiece holder, said motion generator imparting cyclic differential motion to said first and second workpieces, said motion describing a line at the contact point between the first and second workpiece, thereby forming a measurable scar in at least one workpiece;
• said motion generator comprising an actuator rod support arm comprising an inner end in mechanical communication with said workpiece holder and extending outside of said test chamber to an opposed end, said actuator rod support arm comprising a longitudinal bore therethrough retaining an actuator rod, said longitudinal bore and said opposed end being in fluid communication with a conduit adapted to provide a pressurized gas to said longitudinal bore, said actuator rod comprising one or more feature selected from the group consisting of a deviation from linearity through said longitudinal bore and a clearance through said longitudinal retaining bore wherein a combination of said one or more features and said pressurized gas is effective to maintain a seal effective to prevent a fluid placed under pressure within said testing chamber to escape from said testing chamber along an interface between said testing chamber and said actuator rod while permitting said actuator rod to move freely through said actuator rod support arm;
• wherein said testing chamber is a hollow cylinder, said workpiece loading device further comprises a solid metal cylinder having an outer diameter and surface finish to permit it to slide freely within said testing chamber inner bore, and wherein contact pressure between said first and second workpieces held in said first and second workpiece holders is generated by the weight of said work piece loading device impinging upon a horizontal array of said workpiece holders containing workpieces, said horizontal array of workpiece holders being arranged such that a surface of said first workpiece resides in contact with a surface of said second workpiece.