An oil injection apparatus includes: a storage unit extruding lubricating oil through an ejection hole formed at a lower end thereof; a discharge unit communicating with the storage through the ejection hole and discharging the lubricating oil outside according to a pumping operation; a plurality of discharge pumps arranged at regular intervals in a circumferential direction of the discharge unit and having respective first ends disposed in the discharge unit; and a driving unit rotating in a direction to sequentially press the first ends of the discharge pumps, which are disposed in the discharge unit, thereby causing the discharge pumps to perform the pumping operation in turn.

A lubrication pump includes a housing defining a bore, an adjustable cylinder sleeve within the bore, and a piston slidably movable within the bore along a longitudinal axis of the bore. A connector may be drivingly interposed between a cam and the piston for driving the piston in reciprocating axial motion. The connector may have a coupling for engaging the piston, which may enable rotational engagement between the connector and the piston. The connector may have a roller for bearing engagement with the cam, which may enable the connector to rotate about the longitudinal axis relative to the housing as the connector moves axially within the bore. The cam may be laterally displaceable relative to the connector. The cylinder sleeve may be adjustable relative to the piston for varying lubricant fluid output flow. The cylinder sleeve and corresponding piston may be interchangeably disposed in the housing.

A box lubricator that includes a pump with a piston housing and piston. The piston housing extends from a first end to a second end, and includes a bore extending through the piston housing from the first end of the piston housing to the second end of the piston housing. The piston housing also includes a recess disposed at the second end of the piston housing, the recess being concentric with the bore and comprising a diameter larger than a diameter of the bore. The piston is disposed inside the bore of the piston housing. At least one elastomeric seal is disposed inside the recess of the piston housing and around the piston. In some embodiments, a ball and socket joint connects the piston to the rocker arm assembly. In some embodiments, a fluid passage and a check valve are disposed inside the piston.

A box lubricator that includes a pump with a piston housing and piston. The piston housing extends from a first end to a second end, and includes a bore extending through the piston housing from the first end of the piston housing to the second end of the piston housing. The piston housing also includes a recess disposed at the second end of the piston housing, the recess being concentric with the bore and comprising a diameter larger than a diameter of the bore. The piston is disposed inside the bore of the piston housing. At least one elastomeric seal is disposed inside the recess of the piston housing and around the piston. In some embodiments, a ball and socket joint connects the piston to the rocker arm assembly. In some embodiments, a fluid passage and a check valve are disposed inside the piston.

A box lubricator that includes a pump with a piston housing and piston. The piston housing extends from a first end to a second end, and includes a bore extending through the piston housing from the first end of the piston housing to the second end of the piston housing. The piston housing also includes a recess disposed at the second end of the piston housing, the recess being concentric with the bore and comprising a diameter larger than a diameter of the bore. The piston is disposed inside the bore of the piston housing. At least one elastomeric seal is disposed inside the recess of the piston housing and around the piston. In some embodiments, a ball and socket joint connects the piston to the rocker arm assembly. In some embodiments, a fluid passage and a check valve are disposed inside the piston.

A box lubricator that includes a pump with a piston housing and piston. The piston housing extends from a first end to a second end, and includes a bore extending through the piston housing from the first end of the piston housing to the second end of the piston housing. The piston housing also includes a recess disposed at the second end of the piston housing, the recess being concentric with the bore and comprising a diameter larger than a diameter of the bore. The piston is disposed inside the bore of the piston housing. At least one elastomeric seal is disposed inside the recess of the piston housing and around the piston. In some embodiments, a ball and socket joint connects the piston to the rocker arm assembly. In some embodiments, a fluid passage and a check valve are disposed inside the piston.