Hydraulic machine with oil dams

A hydraulic machine comprising:

• a support structure;
• a rotating group rotatable mounted relative to the support structure and including a shaft and a cylinder barrel with a plurality of circumferentially spaced cylinder bores, reciprocal pistons extending from the shaft with each one of the pistons extending into an associated one of the cylinder bores, a joining assembly joining the shaft and the cylinder barrel so that the shaft and the cylinder barrel rotate together;
• a shaft oil dam associated with the shaft for trapping fluid for providing lubrication for movement of a portion of the joining assembly relative to the shaft;
• a cylinder barrel oil dam associated with the cylinder barrel for trapping fluid for providing lubrication for movement of a portion of the joining assembly relative to the cylinder barrel;
• and
• a lubrication assembly for providing lubrication from a pressure passage within the hydraulic machine to a cavity at least partially closed by the oil dam;
• wherein the lubrication assembly includes a barrel lubrication portion for providing hydraulic fluid to the cylinder barrel cavity, the barrel lubrication portion including passages for providing fluid from the pressure passage to the cylinder barrel cavity that is at least partially closed by the cylinder barrel oil dam;
• wherein the pressure passage is a first pressure passage, the hydraulic machine further including a second pressure passage, the barrel lubrication portion further includes a valve assembly located between the first and second pressure passages and adapted to control the flow of fluid to the cylinder barrel cavity.

A hydraulic machine comprising:

• a support structure;
• a rotating group rotatably mounted relative to the support structure and including a shaft and a cylinder barrel with a plurality of circumferentially spaced cylinder bores, reciprocal pistons extending from the shaft with each one of the pistons extending into an associated one of the cylinder bores, a joining assembly joining the shaft and the cylinder barrel so that the shaft and the cylinder barrel rotate together;
• an oil dam associated with the rotating group and adapted to trap hydraulic fluid used for lubricating portions of the joining assembly, wherein the oil dam is a cylinder barrel oil dam associated with the cylinder barrel for trapping fluid for providing lubrication for movement of a portion of the joining assembly relative to the cylinder barrel;
• and
• a lubrication assembly for providing lubrication from a pressure passage within the hydraulic machine to a cavity at least partially closed by the oil dam;
• wherein the lubrication assembly includes a barrel lubrication portion for providing hydraulic fluid to a location beneath the oil dam and wherein the pressure passage is a first pressure passage, the hydraulic machine further including a second pressure passage, the barrel lubrication portion further includes a valve assembly located between the first and second pressure passages and having a shuttle portion that is movable within a stepped valve bore of the valve assembly in response to a pressure differential between the first and second pressure passages, the shuttle portion adapted to open fluid flow to a lowest pressure one of the first and second pressure passages.