Self-lubricating pump throat seal

A lubrication system comprising:

• a pump comprising:
• a housing having a fluid inlet and a fluid outlet;
• a reservoir mounted on the housing and configured to store a lubricant;
• a piston having a first end and a second end, the piston extending through the housing and configured to draw the lubricant through the fluid inlet and drive the lubricant through the fluid outlet, wherein the piston axially overlaps each of the fluid inlet and the fluid outlet both with the piston at an end of a first stroke in the downstream direction and with the piston at an end of a second stroke in the upstream direction;
• a motor attached to and configured to drive the piston;
• a throat seal disposed about the second end of the piston, the throat seal having an upstream face and a downstream face, wherein the throat seal fluidly separates a high-pressure region and a low-pressure region within the housing;
• and
• a vent path extending through the housing and configured to provide a flow path for the lubricant between the reservoir and the downstream face of the throat seal, wherein the vent path is fluidly connected to the low-pressure region;
• a lubrication line extending from the fluid outlet;
• a lubricant injector disposed on the lubrication line and configured to receive the lubricant from the lubrication line;
• and
• a controller configured to alternatingly activate the motor to initiate a pressure cycle and to deactivate the motor to initiate a vent cycle.

A lubricant pump comprising:

• a housing having a fluid inlet and a fluid outlet;
• a reservoir mounted on the housing and configured to store a lubricant;
• a piston having a first end and a second end, the piston extending through the housing and configured to draw the lubricant through the fluid inlet and drive the lubricant through the fluid outlet;
• a throat seal disposed about the second end of the piston, the throat seal having an upstream face and a downstream face;
• a vent path extending through the housing and configured to provide a flow path for the lubricant between the reservoir and the downstream face of the throat seal;
• a cylinder mounted on the housing, an upstream end of the cylinder disposed in an upstream cylinder bore of the housing proximate the fluid inlet and a downstream end of the cylinder disposed in a downstream cylinder bore of the housing proximate the fluid outlet, wherein the downstream cylinder bore is divided into a high-pressure region and a low-pressure region;
• and
• a compression nut extending into the low-pressure region of the downstream cylinder bore and connected to the housing, the compression nut abutting the downstream end of the cylinder;
• wherein the vent path is fluidly connected to an interface between the compression nut and the cylinder.

A lubrication system comprising:

• a pump comprising:
• a housing having a fluid inlet and a fluid outlet;
• a reservoir mounted on the housing and configured to store a lubricant;
• a piston having a first end and a second end, the piston extending through the housing and configured to draw the lubricant through the fluid inlet and drive the lubricant through the fluid outlet;
• a motor attached to and configured to drive the piston;
• a throat seal disposed about the second end of the piston, the throat seal having an upstream face and a downstream face;
• and
• a vent path extending through the housing and configured to provide a flow path for the lubricant between the reservoir and the downstream face of the throat seal;
• a cylinder mounted on the housing, the cylinder comprising:
• an upstream end disposed in an upstream cylinder bore of the housing proximate the fluid inlet;
• a downstream end disposed in a downstream cylinder bore of the housing proximate the fluid outlet and the pressure path;
• a cylinder orifice extending through the downstream end of the cylinder;
• a cylinder seal is disposed about the downstream end of the cylinder, the cylinder seal and the throat seal dividing the downstream cylinder bore into a high-pressure region and a low-pressure region;
• a compression nut extending into the low-pressure region of the downstream cylinder bore and connected to the housing, wherein the compression nut comprises:
• a central bore;
• a neck extending upstream and disposed within the downstream end of the cylinder;
• a nut orifice extending through the neck
• a shoulder extending radially from the neck, the shoulder abutting the downstream end of the cylinder;
• and
• a cap receiving end disposed opposite the shoulder;
• and
• an end cap mounted on the cap receiving end of the compression nut, the end cap enclosing the bore;
• wherein the cylinder orifice and the nut orifice are disposed in the low-pressure region and in fluid communication with the vent path a lubrication line extending from the fluid outlet;
• a lubricant injector disposed on the lubrication line and configured to receive the lubricant from the lubrication line;
• and
• a controller configured to alternatingly activate the motor to initiate a pressure cycle and to deactivate the motor to initiate a vent cycle.