# US 2010/0166350 A1 · Split-type sliding bearing for crankshaft in internal combustion engine and split-type sliding bearing device > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2010/0166350 A1 - Document ID: US20100166350A1 - Status: Published application - Kind: A1 - Application number: 12/647,151 - Filed: 2009-12-24 - Published: 2010-07-01 - Earliest claimed: 2008-12-26 - Assignees: Daido Metal Company Ltd. - Inventors: Aisuke Kuwabara; Osamu Ishigo; Yasushi Saito - Web page: https://patentgrep.com/patent/US20100166350A1 ## CPC - F16C 9/02: Crankshaft bearings - F16C 17/02: for radial load only - F16C 17/022: {with a pair of essentially semicircular bearing sleeves} - F16C 33/04: Brasses; Bushes; Linings - F16C 33/046: {divided or split, e.g. half-bearings or rolled sleeves} - F16C: SHAFTS; FLEXIBLE SHAFTS; ELEMENTS OR CRANKSHAFT MECHANISMS; ROTARY BODIES OTHER THAN GEARING ELEMENTS; BEARINGS ## Abstract A split-type sliding bearing, for a crankshaft in an internal combustion engine, is comprised of a pair of semi-cylindrical bearings which are fitted between a pair of housing halves having respectively high and low thermal expansion coefficients and constituting a split-type bearing housing, one of the pair of semi-cylindrical bearings being supported on the housing half having a low thermal expansion coefficient, and the other one of the pair of semi-cylindrical bearings being supported on the housing have having a high thermal expansion coefficient. The circumferential end zones of the semi-cylindrical bearing supported on the housing half having a high thermal expansion coefficient have a thickness which is set to be greater than that of the circumferential end zones of the semi-cylindrical supported on the housing half having a low thermal expansion coefficient. The split-type sliding bearing can solve the problem of occurrence of a stepped difference which is caused at the inner surface of the bearing between the abutting end faces of the pair of semi-cylindrical bearings when the temperature of the split-type bearing housing is increased during operation of the internal combustion. ## Claims ### Claim 1 A split-type sliding bearing for a crankshaft in an internal combustion engine, comprised of a pair of semi-cylindrical bearings which are mated with each other into a cylindrical body in use, and adapted to be fitted in a split-type bearing housing having a cylindrical bearing retaining bore which is bi-split so as to be aligned with the pair of semi-cylindrical bearing bore in the mated condition, characterized in that: the split-type bearing housing is composed of a housing half having a relatively high expansion coefficient, and a housing half having a relatively low thermal expansion coefficient in a preinstalled condition, a first semi-cylindrical bearing which is one of the pair of semi-cylindrical bearings, and which is supported on the housing half having a relatively high thermal expansion coefficient, and a second semi-cylindrical bearing which is the other one of the pair of semi-cylindrical bearings, and which is supported on the housing half having a relatively low expansion coefficient, have the following dimensional relationship: (1) the first and second semi-cylindrical bearings have an equal outer diameter, and (2) opposite circumferential end parts of the first semi-cylindrical bearing have a thickness which is larger than that of the opposite circumferential end parts of the second semi-cylindrical bearing; whereby the inner surfaces of the first and second bearings are aligned with each other at the abutting end faces of both semi-cylindrical bearings even though a stepped difference is caused between the abutting end faces of the pair of housing halves due to a difference between degrees of thermal expansion of both housing halves, when the temperature of the housing halves are increased during operation of the internal combustion engine in the condition that the pair of housing halves are mated with each other by fastening bolts after the first and second semi-cylindrical bearings are incorporated between the pair of housing halves. ### Claim 2 (depends on 1) A split-type sliding bearing for a crankshaft in an internal combustion engine as set forth in claim 1, characterized in that the first semi-cylindrical bearing has a thickness which is uniform over the entire circumferential length thereof. ### Claim 3 (depends on 1) A split-type sliding bearing for a crankshaft in an internal combustion engine as set forth in claim 1, characterized in that the first semi-cylindrical bearing has a thickness which is increased from the circumferential center part to the circumferential end faces thereof. ### Claim 4 (depends on 1) A split-type sliding bearing for a crankshaft in an internal combustion engine as set forth in claim 1, characterized in that the second semi-cylindrical bearing has a thickness which is uniform over the entire circumferential length thereof. ### Claim 5 (depends on 1) A split-type sliding bearing for a crankshaft in an internal combustion engine as set forth in claim 1, characterized in that the second semi-cylindrical bearing has a thickness which is decreased from the circumferential center part to the circumferential end faces thereof. ### Claim 6 (depends on 1) A split-type sliding bearing for a crankshaft in an internal combustion engine as set forth in claim 1, characterized in that at least the second semi-cylindrical bearing have multi circumferential grooves formed in the inner surface thereof and extended circumferentially thereof, and the circumferential grooves formed in circumferential end zones of the second semi-cylindrical bearing, which respectively include two circumferential end faces of the second semi-cylindrical have a depth from 5 to 20 μm. ### Claim 7 (depends on 6) A split-type sliding bearing for a crankshaft in an internal combustion engine as set forth in claim 6, characterized in that the circumferential end zones of the inner surface has a range defined by a circumferential length corresponding to a circumferential angle of at least 10 deg. but 50 deg. at maximum, measured from the circumferential end faces as a starting point. ### Claim 8 (depends on 7) A split-type sliding bearing for a crankshaft in an internal combustion as set forth in claim 7, characterized in that the inner surface has a degree of surface roughness which is not greater than 3.2 μmRz, except the circumferential end zones. ### Claim 9 (depends on 6) A split-type sliding bearing for a crankshaft in an internal combustion engine as set forth in claim 6, characterized in that the circumferential grooves have pitches from 0.3 to 1.5 mm. ### Claim 10 (depends on 6) A split-type sliding bearing for a crankshaft in an internal combustion engine as set forth in claim 6, characterized in that the depth H of the circumferential grooves formed in the inner surface of the second semi-cylindrical bearing is equal to or greater than the degree of the stepped difference caused between the abutting end surfaces of the first and second semi-cylindrical bearings. ### Claim 11 (depends on 6) A split-type sliding bearing for a crankshaft in an internal combustion engine as set forth in claim 6, characterized in that the first semi-cylindrical bearing has multi circumferential grooves formed in the inner surface thereof and extended circumferentially thereof, and the circumferential grooves which are formed in circumferential end zones which respectively include two circumferential end faces of the first semi-cylindrical bearing have a depth from 5 to 20 μm. ### Claim 12 (depends on 11) A split-type sliding bearing for a crankshaft in an internal combustion engine as set forth in claim 11, characterized in that the circumferential end zones of the first semi-cylindrical bearing have a range which is defined by a circumferential length corresponding to a circumferential angle which is at least 10 deg. but 50 deg. at maximum, measured from the circumferential end surfaces as a stating point. ### Claim 13 (depends on 12) A split-type sliding bearing for a crankshaft in an internal combustion engine as set forth in claim 12, characterized in that the inner surface of the first semi-cylindrical bearing has a degree of surface roughness which is not higher than 3.2 μmRz, except the circumferential end zones. ### Claim 14 (depends on 11) A split-type sliding bearing for a crankshaft in an internal combustion engine as set forth in claim 11, characterized in that the circumferential grooves formed in the first semi-cylindrical bearing have pitches which is 0.3 to 1.5 mm. ### Claim 15 A split-type sliding bearing device for a crankshaft in an internal combustion engine, comprising: a split-type sliding bearing for a crankshaft in an internal combustion engine, comprised of a pair of semi-cylindrical bearings which are mated with each other into a cylindrical body in use, and a split-type bearing housing having a cylindrical bearing retaining bore which is bi-split so as to be aligned with the pair of semi-cylindrical bearings in the mated condition, for accommodating and retaining the pair of semi-cylindrical bearings in the bearing retaining bore, characterized in that the split-type bearing housing is comprised of a housing half having a relatively high thermal expansion coefficient, and a housing half having a relatively low thermal expansion coefficient, a first semi-cylindrical bearing which is one of the pair of semi-cylindrical bearings, and which is supported on the housing half having a relatively high thermal expansion coefficient, and a second semi-cylindrical bearing which is the other one of the pair of semi-cylindrical bearings, and which is supported on the housing half having a relatively low expansion coefficient, have the following dimensional relationship in a preinstalled condition: (1) the first and second semi-cylindrical bearings have an equal outer diameter, and (2) opposite circumferential end parts of the first semi-cylindrical bearing have a thickness which is larger than that of the opposite circumferential end parts of the second semi-cylindrical bearing; whereby the inner surfaces of the first and second bearings are aligned with each other at the abutting end faces of both semi-cylindrical bearings even though a stepped difference is caused between the abutting end faces of the pair of housing halves due to a difference between degrees of thermal expansion of both housing halves, when the temperature of the housing halves are increased during operation of the internal combustion engine in the condition that the pair of housing halves are mated with each other by fastening bolts after the first and second semi-cylindrical bearings are incorporated between the pair of housing halves. ### Claim 16 (depends on 15) A split-type sliding bearing device for a crankshaft in an internal combustion engine as set forth in claim 15, characterized in that the first semi-cylindrical bearing has a thickness which is uniform over the entire circumferential length thereof. ### Claim 17 (depends on 15) A split-type sliding bearing device for a crankshaft in an internal combustion engine as set forth in claim 15, characterized in that the first semi-cylindrical bearing has a thickness which is increased from the circumferential center part to the circumferential end faces thereof. ### Claim 18 (depends on 15) A split-type sliding bearing device for a crankshaft in an internal combustion engine as set forth in claim 15, characterized in that the second semi-cylindrical bearing has a thickness which is uniform over the entire circumferential length thereof. ### Claim 19 (depends on 15) A split-type sliding bearing device for a crankshaft in an internal combustion engine as set forth in claim 15, characterized in that the second semi-cylindrical bearing has a thickness which is decreased from the circumferential center part to the circumferential end faces thereof. ### Claim 20 (depends on 15) A split-type sliding bearing device for a crankshaft in an internal combustion engine as set forth in claim 15, characterized in that at least the second semi-cylindrical bearing have multi circumferential grooves formed in the inner surface thereof and extended circumferentially thereof, and the circumferential grooves formed in circumferential end zones of the second semi-cylindrical bearing, which respectively include two circumferential end faces of the second semi-cylindrical have a depth from 5 to 20 μm. ### Claim 21 (depends on 20) A split-type sliding bearing device for a crankshaft in an internal combustion engine as set forth in claim 20, characterized in that the circumferential end zones of the inner surface has a range defined by a circumferential length corresponding to a circumferential angle of at least 10 deg. but 50 deg. at maximum, measured from the circumferential end faces as a starting point. ### Claim 22 (depends on 21) A split-type sliding bearing device for a crankshaft in an internal combustion as set forth in claim 21, characterized in that the inner surface has a degree of surface roughness which is not greater than 3.2 μmRz, except the circumferential end zones. ### Claim 23 (depends on 20) A split-type sliding bearing device for a crankshaft in an internal combustion engine as set forth in claim 20, characterized in that the circumferential grooves have pitches from 0.3 to 1.5 mm. ### Claim 24 (depends on 20) A split-type sliding bearing device for a crankshaft in an internal combustion engine as set forth in claim 20, characterized in that the depth of the circumferential grooves formed in the inner surface of the second semi-cylindrical bearing is equal to or greater than the degree of the stepped difference caused between the abutting end surfaces of the first and second semi-cylindrical bearing. ### Claim 25 (depends on 20) A split-type sliding bearing device for a crankshaft in an internal combustion engine as set forth in claim 20, characterized in that the first semi-cylindrical bearing has multi circumferential grooves formed in the inner surface thereof and extended circumferentially thereof, and the circumferential grooves which are formed in circumferential end zones of the inner surface of the first semi-cylindrical bearing, which respectively include two circumferential end faces of the first semi-cylindrical bearing have a depth from 5 to 20 μm. ### Claim 26 (depends on 25) A split-type sliding bearing device for a crankshaft in an internal combustion engine as set forth in claim 25, characterized in that the circumferential end zones of the first semi-cylindrical bearing have a range which is defined by a circumferential length corresponding to a circumferential angle which is at least 10 deg. but 50 deg. at maximum, measured from the circumferential end surfaces as a stating point. ### Claim 27 (depends on 26) A split-type sliding bearing device for a crankshaft in an internal combustion engine as set forth in claim 26, characterized in that the inner surface of the first semi-cylindrical bearing has a degree of surface roughness which is not higher than 3.2 μmRz, except the circumferential end zones. ### Claim 28 (depends on 25) A split-type sliding bearing device for a crankshaft in an internal combustion engine as set forth in claim 25, characterized in that the circumferential grooves formed in the first semi-cylindrical bearing have pitches which is 0.3 to 1.5 mM.