ENGINE
An engine includes: a cylinder; a first bearing that is at least partially integrally formed with the cylinder and configured to rotatably support a first shaft of a crankshaft; a second bearing that is at least partially integrally formed with the cylinder and configured to rotatably support a second shaft of the crankshaft; and a first crankcase member and a second crankcase member that include a resin-based material, and respectively constitute part and remaining part of a crankcase that houses the crankshaft. A connecting portion between the first crankcase member and the second crankcase member is continuously connected along substantially an entire length by at least one of fitting, bonding, and welding.
1 . An engine comprising:
a cylinder;
a first bearing at least partially integrally formed with the cylinder and configured to rotatably support a first shaft of a crankshaft;
a second bearing at least partially integrally formed with the cylinder and configured to rotatably support a second shaft of the crankshaft; and
a first crankcase member and a second crankcase member including a resin-based material, and respectively constituting part and remaining part of a crankcase housing the crankshaft,
wherein a connecting portion between the first crankcase member and the second crankcase member is continuously connected along substantially an entire length by at least one of fitting, bonding, and welding.
2 . The engine according to claim 1 ,
wherein a protrusion is formed in the connecting portion of the first crankcase member to be connected with the second crankcase member, and
a groove is formed in the connecting portion of the second crankcase member to be connected with the first crankcase member, the protrusion being inserted and fitted into the groove.
3 . The engine according to claim 1 ,
wherein the crankshaft is divided into the first crankcase member and the second crankcase member in an axial direction of the crankshaft,
the first crankcase member has a first opening on which the first bearing is mounted,
the second crankcase member has a second opening on which the second bearing is mounted, and
a connecting portion between a circumferential edge of the first opening and the first bearing, and a connecting portion between a circumferential edge of the second opening and the second bearing are each continuously connected along substantially an entire length by at least one of fitting, bonding, and welding.
4 . The engine according to claim 2 ,
wherein the crankshaft is divided into the first crankcase member and the second crankcase member in an axial direction of the crankshaft,
the first crankcase member has a first opening on which the first bearing is mounted,
the second crankcase member has a second opening on which the second bearing is mounted, and
a connecting portion between a circumferential edge of the first opening and the first bearing, and a connecting portion between a circumferential edge of the second opening and the second bearing are each continuously connected along substantially an entire length by at least one of fitting, bonding, and welding.
5 . The engine according to claim 1 ,
wherein at least one of the first crankcase member and the second crankcase member is integrally formed and has a cylinder cover for covering a circumference of the cylinder and guiding cooling air to be introduced to an inside.
6 . The engine according to claim 2 ,
wherein at least one of the first crankcase member and the second crankcase member is integrally formed and has a cylinder cover for covering a circumference of the cylinder and guiding cooling air to be introduced to an inside.
7 . The engine according to claim 3 ,
wherein at least one of the first crankcase member and the second crankcase member is integrally formed and has a cylinder cover for covering a circumference of the cylinder and guiding cooling air to be introduced to an inside.
8 . The engine according to claim 4 ,
wherein at least one of the first crankcase member and the second crankcase member is integrally formed and has a cylinder cover for covering a circumference of the cylinder and guiding cooling air to be introduced to an inside.
9 . The engine according to claim 1 ,
wherein part of a power transmission member housing is integrally formed with at least one of the first crankcase member and the second crankcase member, the power transmission member housing being configured to house a power transmission member which transmits power from the crankshaft to a camshaft.
10 . The engine according to claim 2 ,
wherein part of a power transmission member housing is integrally formed with at least one of the first crankcase member and the second crankcase member, the power transmission member housing being configured to house a power transmission member which transmits power from the crankshaft to a camshaft.
11 . The engine according to claim 3 ,
wherein part of a power transmission member housing is integrally formed with at least one of the first crankcase member and the second crankcase member, the power transmission member housing being configured to house a power transmission member which transmits power from the crankshaft to a camshaft.
12 . The engine according to claim 4 ,
wherein part of a power transmission member housing is integrally formed with at least one of the first crankcase member and the second crankcase member, the power transmission member housing being configured to house a power transmission member which transmits power from the crankshaft to a camshaft.
13 . The engine according to claim 9 ,
wherein a remaining part of the power transmission member housing is integrally formed with part of a blower housing which is fixed to the crankshaft and houses a blower fan for generating cooling air when in rotation.
14 . The engine according to claim 10 ,
wherein a remaining part of the power transmission member housing is integrally formed with part of a blower housing which is fixed to the crankshaft and houses a blower fan for generating cooling air when in rotation.
15 . The engine according to claim 11 ,
wherein a remaining part of the power transmission member housing is integrally formed with part of a blower housing which is fixed to the crankshaft and houses a blower fan for generating cooling air when in rotation.
16 . The engine according to claim 12 ,
wherein a remaining part of the power transmission member housing is integrally formed with part of a blower housing which is fixed to the crankshaft and houses a blower fan for generating cooling air when in rotation.
17 . The engine according to claim 1 ,
wherein the cylinder and a cylinder head are integrally formed, the cylinder head having inlet and exhaust ports and being provided at an end of the cylinder that is opposite to an end of the crankshaft of the cylinder.
18 . The engine according to claim 2 ,
wherein the cylinder and a cylinder head are integrally formed, the cylinder head having inlet and exhaust ports and being provided at an end of the cylinder that is opposite to an end of the crankshaft of the cylinder.
19 . The engine according to claim 3 ,
wherein the cylinder and a cylinder head are integrally formed, the cylinder head having inlet and exhaust ports and being provided at an end of the cylinder that is opposite to an end of the crankshaft of the cylinder.
20 . The engine according to claim 4 ,
wherein the cylinder and a cylinder head are integrally formed, the cylinder head having inlet and exhaust ports and being provided at an end of the cylinder that is opposite to an end of the crankshaft of the cylinder.