BACKGROUND

Field

The present disclosure is generally related to a pump assembly having a pressure relief valve mounted to the pivot pin.

Description of Related Art

It is known to use electrical valves (e.g., pulse width modulation valves) in vane pumps and/or control valves to assist in controlling feed to/from control chambers of pumps. In some instances, panic or fail-safe valves have been provided to relieve pressure in such pumps. Typically, the pump housing includes a machined area to accommodate panic valves. In some cases, the panic valves are provided on top of or outside the pump housing, but in fluid communication with the pump. U.S. Pat. Nos. 8,496,445, 9,534,519, 9,347,344, and 10,030,656, and U.S. Patent Publication No. 20120199411 provide examples of placing panic valves outside or on a pump housing.

Some pump designs include an end-to-end path through the pivot pin body that direct fluid to an outlet from their chamber(s). For example, see U.S. Pat. Nos. 8,439,650, 2,952,215 and 2,142,275.

SUMMARY

It is an aspect of this disclosure to provide a pump for dispensing lubricant to a system. The pump includes: a housing; an inlet for inputting lubricant from a source into the housing; an outlet for delivering the lubricant to the system from the housing; a control slide pivotable about a pivot pin within the housing in a displacement increasing direction and a displacement decreasing direction to adjust displacement of the pump through the outlet; a resilient structure biasing the control slide in the displacement increasing direction; a rotor with at least one vane mounted in the housing for rotation within the control slide to pressurize the lubricant; at least one control chamber between the housing and the control slide for receiving pressurized lubricant to move the control slide in the displacement decreasing direction; and a pressure relief valve mounted to the pivot pin and positioned along an outflow path leading the pressurized lubricant from the control slide to the outlet. The pressure relief valve has a pressure receiving surface receiving pressure from the pressurized lubricant in the outflow path to urge the pressure relief valve in an opening direction. The pressure relief valve is biased in a closing direction to a closed position closing a pressure relief opening. Pressure on the pressure receiving surface moves the pressure relief valve in the opening direction to open the relief opening for outflow of the pressurized lubricant to relieve pressure in the outflow path.

Other aspects, features, and advantages of the present disclosure will become apparent from the following detailed description, the accompanying drawings, and the appended claims.

