Pump rod and driving link with side-load reducing configuration

A driving system for a displacement pump comprising:

• a pump rod comprising:
• a shaft having a first end and a second end;
• a head extending from the first end, the head having a bottom side and a top side;
• and
• a load concentrating feature attached to and projecting from the top side of the head, wherein the load concentrating feature is aligned with a centerline of the shaft;
• wherein the load concentrating feature is recessed from an edge of the top side such that a cross-sectional area of the load concentrating feature is smaller than a cross-sectional area of the head;
• wherein a portion of the top side extending between the edge of the top side and the load concentrating feature comprises a first flat surface extending fully around the load concentrating feature;
• and
• wherein the load concentrating feature includes a second flat surface disposed parallel to the first flat surface and offset from the first flat surface along the centerline;
• and
• a driving link comprising:
• a cylinder having a first end and a second end;
• a cavity extending into the first end, the cavity including a first sidewall, a second sidewall spaced from the first sidewall, a lower opening extending between the first sidewall and the second sidewall, and a driving surface disposed between the first sidewall and the second sidewall opposite the lower opening;
• and
• a U-shaped flange extending into the cavity, wherein the cavity is configured to receive the head of the pump rod and the U-shaped flange is configured to secure the head within the cavity;
• wherein the second flat surface is configured to contact the driving surface, align a load from the driving link with the centerline of the shaft, and prevent the edge of the top side of the head from contacting the driving surface.

A driving link for powering a double displacement pump of a fluid sprayer, the driving link comprising:

• a body having a first end and a second end;
• a cavity extending laterally into the first end, the cavity comprising:
• a forward-facing opening;
• a first wall extending into the cavity from the forward-facing opening;
• a second wall extending into the cavity from the forward-facing opening;
• a side wall extending between and connecting the first wall and the second wall;
• a lower opening;
• and
• a contact surface disposed opposite the lower opening;
• and
• a load concentrating feature projecting from the contact surface and into the cavity, wherein the load concentrating feature is spaced from each of the first wall, the second wall, the side wall, and the forward-facing opening, and wherein the load concentrating feature includes a circular flat surface spaced from the contact surface and disposed parallel to the contact surface;
• and
• wherein the flat surface is configured to directly contact a top side of a head of a pump rod, align a load from the driving link with a centerline of the pump rod, and prevent a top edge of the top side of the head from contacting the contact surface, and wherein an area of the flat surface is smaller than an area of the top side of the head of the pump rod.

A pump rod comprising:

• a shaft having a first end, a second end, a hollow portion extending into the second end, and a fluid passage extending through the shaft to the hollow portion, wherein the hollow portion and fluid passage form a flowpath through the shaft;
• a head attached to the first end, the head having bottom side and a top side;
• and
• a load concentrating feature attached to and projecting from the top side of the head, wherein the load concentrating feature is aligned with a centerline of the shaft;
• wherein the load concentrating feature is recessed from an edge of the top side such that a cross-sectional area of the load concentrating feature is smaller than a cross-sectional area of the head;
• wherein a portion of the top surface extending between the edge of the top side and the load concentrating feature comprises a first flat surface extending fully around the load concentrating feature;
• wherein the load concentrating feature includes a second flat surface disposed parallel to the first flat surface and axially offset from the first flat surface along the centerline;
• and
• wherein the second flat surface is configured to contact a driving surface, align a load from the driving surface with the centerline, and prevent the edge of the top side of the head from contacting the driving surface.