A crankshaft is provided. The crankshaft has a first shaft, a second shaft and a first crank arm. A first oil passage is formed in the first shaft along an axis direction of the shaft. A second oil passage is formed in the second shaft along an axis direction of the shaft. The first crank arm is configured to be connected between the first shaft and the second shaft. The first crank arm is provided with a third oil passage. The third oil passage is configured to communicate the first oil passage and the second oil passage. The second shaft is eccentrically provided relative to the axis of the first shaft. A compressor having the crankshaft and a refrigeration device having the compressor are also provided.

Provided is a half bearing constituting a sliding bearing that is unlikely to cause damage during an operation of an internal combustion engine. The half bearing includes at least one protrusion, and the protrusion projects outward in a radial direction from an outer circumferential surface. A recessed portion that is recessed inward in the radial direction from the outer circumferential surface is formed over the entire inner-circumferential length between the protrusion and a circumferential-direction end surface of the half bearing. Two radial-direction grooves are formed in the circumferential-direction end surface of the half bearing relative to the protrusion, and each of the radial-direction grooves is adjacent to each of recessed portion side surfaces. The radial-direction grooves extend in the radial direction along the recessed portion side surfaces and are separated from the recessed portion at a midpoint of the extension. An inner circumferential surface-side end portion in an extending direction of the radial-direction grooves is located between a recessed portion bottom surface and an inner circumferential surface of the half bearing. A groove width and a groove depth of the radial-direction grooves decrease from the position separated from the recessed portion toward the inner circumferential surface-side end portion and reach zero at the inner circumferential surface-side end portion.

Provided is a half bearing constituting a sliding bearing that is unlikely to cause damage during an operation of an internal combustion engine. The half bearing includes at least one protrusion, and the protrusion projects outward in a radial direction from an outer circumferential surface. A recessed portion that is recessed inward in the radial direction from the outer circumferential surface is formed over the entire inner-circumferential length between the protrusion and a circumferential-direction end surface of the half bearing. Two radial-direction grooves are formed in the circumferential-direction end surface of the half bearing relative to the protrusion, and each of the radial-direction grooves is adjacent to each of recessed portion side surfaces. The radial-direction grooves extend in the radial direction along the recessed portion side surfaces and are separated from the recessed portion at a midpoint of the extension. An inner circumferential surface-side end portion in an extending direction of the radial-direction grooves is located between a recessed portion bottom surface and an inner circumferential surface of the half bearing. A groove width and a groove depth of the radial-direction grooves decrease from the position separated from the recessed portion toward the inner circumferential surface-side end portion and reach zero at the inner circumferential surface-side end portion.

A crankshaft includes a first oil hole, a second oil hole, and a through hole. The second oil hole extends in a direction in which the second oil hole intersects the first oil hole. A first extension is an imaginary line extending from an inner wall surface of the first oil hole on a second oil hole side. A second extension is an imaginary line extending from an inner wall surface of the second oil hole on a first oil hole side. The through hole passes through an intersection between the first extension and the second extension. At least one end of the through hole opens on an outer peripheral surface.

A crankshaft includes a first oil hole, a second oil hole, and a through hole. The second oil hole extends in a direction in which the second oil hole intersects the first oil hole. A first extension is an imaginary line extending from an inner wall surface of the first oil hole on a second oil hole side. A second extension is an imaginary line extending from an inner wall surface of the second oil hole on a first oil hole side. The through hole passes through an intersection between the first extension and the second extension. At least one end of the through hole opens on an outer peripheral surface.

A crankshaft has a main journal surrounded by a main bearing defining a groove provided with oil from an oil gallery and at least one oil inlet formed in the main journal providing oil from the groove into the main journal. A first crankpin journal is connected to a first side of the main journal by way of a first web. A second crankpin journal is connected to a second side of the main journal by way of a second web. Pairs of crankpin bearings are provided around each of the first and second crankpin journals. Each crankpin bearing supports a piston rod thereon. Each of the first and second crankpin journals has a pair of oil outlets providing oil to a respective crankpin bearing. Oil passageways in the crankshaft provide the pairs of oil outlets in both the first and second crankpin journals with oil from the main journal.

A crankshaft has a main journal surrounded by a main bearing defining a groove provided with oil from an oil gallery and at least one oil inlet formed in the main journal providing oil from the groove into the main journal. A first crankpin journal is connected to a first side of the main journal by way of a first web. A second crankpin journal is connected to a second side of the main journal by way of a second web. Pairs of crankpin bearings are provided around each of the first and second crankpin journals. Each crankpin bearing supports a piston rod thereon. Each of the first and second crankpin journals has a pair of oil outlets providing oil to a respective crankpin bearing. Oil passageways in the crankshaft provide the pairs of oil outlets in both the first and second crankpin journals with oil from the main journal.

An automobile vehicle crankshaft including a crankshaft casting of a nodular iron. The crankshaft casting includes multiple main journals coaxially aligned on a common crankshaft casting axis. Multiple crankpin journals are fixedly connected to the main journals by individual webs. Multiple lightening holes have individual ones of the multiple lightening holes integrally formed within individual ones of the crankpin journals during casting. A bubble space is located proximate to a mid-portion of selected ones of the multiple lightening holes of the crankpin journals. The bubble space locally increases a passage size of the selected ones of the multiple lightening holes and reduces a mass of the individual ones of the crankpin journals.

An automobile vehicle crankshaft including a crankshaft casting of a nodular iron. The crankshaft casting includes multiple main journals coaxially aligned on a common crankshaft casting axis. Multiple crankpin journals are fixedly connected to the main journals by individual webs. Multiple lightening holes have individual ones of the multiple lightening holes integrally formed within individual ones of the crankpin journals during casting. A bubble space is located proximate to a mid-portion of selected ones of the multiple lightening holes of the crankpin journals. The bubble space locally increases a passage size of the selected ones of the multiple lightening holes and reduces a mass of the individual ones of the crankpin journals.

Provided is a half bearing constituting a sliding bearing for a shaft member of an internal combustion engine that is unlikely to cause seizure in a sliding surface even if deflection or whirling of the shaft member occurs during an operation of the internal combustion engine. In a half bearing that constitutes a sliding bearing, a plurality of circumferential-direction grooves are formed to be adjacent to each other in a sliding surface including first and second curved surfaces with different curvatures, the sliding surface includes a plane portion that is parallel to an axial line direction and an inclined surface portion that is adjacent to the plane portion, the inclined surface portion is displaced from the plane portion toward an end portion of the sliding surface in the axial line direction such that the sliding surface successively comes close to a back surface, positions of maximum groove depths of the circumferential-direction grooves are located on groove center lines, the groove center lines in the inclined surface portion of the sliding surface are inclined relative to a vertical line toward the end portion of the sliding surface in the axial line direction, a groove inclination angle of the circumferential-direction grooves that are closest to the plane portion is a minimum angle, and the groove inclination angle successively increases toward the end portion of the sliding surface in the axial line direction.