A compressor and a refrigeration system having the same are provided. The compressor includes a crankcase, a thrust bearing and a crankshaft. The crankcase is formed with a crankshaft hole therein and provided with a mounting protrusion at an upper end thereof. The crankshaft hole runs upward through the mounting protrusion. The thrust bearing is fitted over the mounting protrusion. The crankshaft is rotatably disposed within the crankshaft hole, has a thrust part, and is formed with an oil supply passage therein. A lower end face of the thrust part is abutted against an upper end face of the thrust bearing. A cavity is defined by the mounting protrusion, the thrust bearing and the thrust part. A through hole is formed in a peripheral wall of the crankshaft for communicating the oil supply passage with the cavity.

A main bearing includes first and second half bearings, each having a main cylinder portion and crush relief portions in both circumferential end portions. An oil groove circumferentially extends on an inner circumferential surface only of the first half bearing, one circumferential end portion of the oil groove opens on a circumferential end surface on a front side in a rotation direction, and the other circumferential end portion of the oil groove is positioned in the crush relief portion on a rear side in the rotation direction. The first half bearing includes a transition region between the crush relief portion on the front side in the rotation direction and the main cylinder portion, and the second half bearing includes a transition region between the crush relief portion on the rear side in the rotation direction and the main cylinder portion.

A main bearing includes first and second half bearings, each having a main cylinder portion and crush relief portions in both circumferential end portions. An oil groove circumferentially extends on an inner circumferential surface only of the first half bearing, one circumferential end portion of the oil groove opens on a circumferential end surface on a front side in a rotation direction, and the other circumferential end portion of the oil groove is positioned in the crush relief portion on a rear side in the rotation direction. The first half bearing includes a transition region between the crush relief portion on the front side in the rotation direction and the main cylinder portion, and the second half bearing includes a transition region between the crush relief portion on the rear side in the rotation direction and the main cylinder portion.

It is common for crankshafts of internal combustion engines to have main bearing journals provided between each of the conrod bearing journals. However, to reduce engine friction, the fewest main bearing journals that can be used while still meeting the design targets is preferred. A crankshaft for an in-line, four-cylinder engine, according to an embodiment of the disclosure, has three main bearing journals. Bridges, one each located between first and second conrod bearing journals and between third and fourth conrod bearing journals. The bridges have a cross-section with at least two concavities to improve the strength of the bridge compared to, for example, a cylindrical bridge, without greatly increasing the mass of material used in the bridge. Furthermore, a locus of a centroid of cross sections through the bridge are not coincident with an axis of rotation of the crankshaft, but instead is displaced toward the nearer conrod bearing journal.

A half thrust bearing for a crankshaft of an internal combustion engine is formed of a back metal layer and a bearing alloy layer to have a slide surface and two thrust reliefs. Each thrust relieve includes a first region, where the back metal layer is exposed, on a circumferential end surface side, and a second region and a third region, where the bearing alloy layer is exposed while the slide surface includes a fourth region. A circumferential end region consists of the first and second regions. The bearing alloy layer includes a uniform thickness portion, and a decreased thickness portion adjacent to an inner-diameter-side end surface in a cross-section of the second region and includes a uniform thickness portion and an increased thickness portion adjacent to the inner-diameter-side surface in cross-sections of the third and fourth regions.

A half thrust bearing for a crankshaft of an internal combustion engine is formed of a back metal layer and a bearing alloy layer to have a slide surface and two thrust reliefs. Each thrust relieve includes a first region, where the back metal layer is exposed, on a circumferential end surface side, and a second region and a third region, where the bearing alloy layer is exposed while the slide surface includes a fourth region. A circumferential end region consists of the first and second regions. The bearing alloy layer includes a uniform thickness portion, and a decreased thickness portion adjacent to an inner-diameter-side end surface in a cross-section of the second region and includes a uniform thickness portion and an increased thickness portion adjacent to the inner-diameter-side surface in cross-sections of the third and fourth regions.

A half thrust bearing for a crankshaft of an internal combustion engine is formed of a back metal layer and a bearing alloy layer to have a slide surface and two thrust reliefs. Each thrust relieve includes a first region, where the back metal layer is exposed, on a circumferential end surface side, and a second region, where the bearing alloy layer is exposed, on the slide surface side while the slide surface includes two third regions adjacent to the second region, and a fourth region between the two third regions. A circumferential end region consists of the first, second and third regions. In the second region and the third regions, the bearing alloy layer includes a uniform thickness portion at a radial center, and a decreased thickness portion adjacent to an inner-diameter-side end surface.

A half thrust bearing for a crankshaft of an internal combustion engine is formed of a back metal layer and a bearing alloy layer to have a slide surface and two thrust reliefs. Each thrust relieve includes a first region, where the back metal layer is exposed, on a circumferential end surface side, and a second region, where the bearing alloy layer is exposed, on the slide surface side while the slide surface includes two third regions adjacent to the second region, and a fourth region between the two third regions. A circumferential end region consists of the first, second and third regions. In the second region and the third regions, the bearing alloy layer includes a uniform thickness portion at a radial center, and a decreased thickness portion adjacent to an inner-diameter-side end surface.

A thrust washer for a flange half-bearing may include a semi-annular panel having an inner edge and an outer edge. A plurality of hooking lugs may project inwardly from the inner edge of the panel. The hooking lugs may have at least one latching edge configured to engage with a corresponding opening in a bearing shell received by the thrust washer and prevent disconnection of the thrust washer and the bearing shell without deformation of the bearing shell. The hooking lugs may have a hooking lug inner portion proximate to a central part of the thrust washer around the inner edge of the panel for engaging against an edge of the corresponding opening of the bearing shell, and a hooking lug outer portion remote from the central part around the inner edge of the panel. The hooking lug inner portion may be thinner than the hooking lug outer portion.

A thrust washer for a flange half-bearing may include a semi-annular panel having an inner edge and an outer edge. A plurality of hooking lugs may project inwardly from the inner edge of the panel. The hooking lugs may have at least one latching edge configured to engage with a corresponding opening in a bearing shell received by the thrust washer and prevent disconnection of the thrust washer and the bearing shell without deformation of the bearing shell. The hooking lugs may have a hooking lug inner portion proximate to a central part of the thrust washer around the inner edge of the panel for engaging against an edge of the corresponding opening of the bearing shell, and a hooking lug outer portion remote from the central part around the inner edge of the panel. The hooking lug inner portion may be thinner than the hooking lug outer portion.