Marine reduction gear
A marine reduction gear makes it possible to reduce the installation space of an electrical rotating machine. A marine reduction gear includes: an input shaft coupled to an output shaft of an engine; an output shaft coupled to a propeller shaft that rotates a screw propeller; a gearbox accommodating an input gear provided on the input shaft and an output gear provided on the output shaft, the gearbox supporting a first bearing that supports the output shaft in a rotatable manner; and an electrical rotating machine including: a central shaft that rotates together with the output shaft; a rotor fixed to the central shaft; and a stator surrounding the rotor. The gearbox supports the stator and a second bearing that supports the central shaft of the electrical rotating machine in a rotatable manner.
1. A marine reduction gear comprising:
an input shaft coupled to a first output shaft that is an output shaft of an engine;
a second output shaft coupled to a propeller shaft that rotates a screw propeller;
a gearbox accommodating an input gear provided on the input shaft and an output gear provided on the second output shaft, the gearbox supporting a first bearing that supports the second output shaft in a rotatable manner; and
an electrical rotating machine including:
a central shaft that rotates together with the second output shaft;
a rotor fixed to the central shaft; and
a stator surrounding the rotor, wherein
the gearbox supports the stator and a pair of second bearings that supports the central shaft of the electrical rotating machine at both sides of the rotor in a rotatable manner.
2. The marine reduction gear according to claim 1 , further comprising a lubricating oil pump mounted to the gearbox and driven by the input shaft, wherein
the lubricating oil pump circulates lubricating oil such that the lubricating oil flows downward in the gearbox, and supplies the lubricating oil to the pair of second bearings, and
the lubricating oil supplied to the pair of second bearings is ejected from the pair of second bearings into the gearbox.
3. The marine reduction gear according to claim 1 , further comprising a coolant pump mounted to the gearbox and driven by the input shaft, wherein
the coolant pump supplies a coolant to the electrical rotating machine, such that the coolant flows in contact with the stator of the electrical rotating machine.
4. The marine reduction gear according to claim 3 , wherein
the coolant pump supplies the coolant to the electrical rotating machine through a first coolant supply line, and supplies the coolant to a heat exchanger through a second coolant supply line, and
the heat exchanger cools a lubricating oil by exchanging heat between the lubricating oil and the coolant, the lubricating oil being the lubricating oil that is to be sucked into a lubricating oil pump or the lubricating oil that has been discharged from the lubricating oil pump.
5. The marine reduction gear according to claim 2 , further comprising a coolant pump mounted to the gearbox and driven by the input shaft, wherein
the coolant pump supplies a coolant to the electrical rotating machine, such that the coolant flows in contact with the stator of the electrical rotating machine.
6. The marine reduction gear according to claim 5 , wherein
the coolant pump supplies the coolant to the electrical rotating machine through a first coolant supply line, and supplies the coolant to a heat exchanger through a second coolant supply line, and
the heat exchanger cools the lubricating oil by exchanging heat between the lubricating oil and the coolant, the lubricating oil being the lubricating oil that is to be sucked into the lubricating oil pump or the lubricating oil that has been discharged from the lubricating oil pump.
7. A marine reduction gear comprising:
an input shaft coupled to a first output shaft that is an output shaft of an engine;
a second output shaft coupled to a propeller shaft that rotates a screw propeller;
a gearbox accommodating an input gear provided on the input shaft and an output gear provided on the second output shaft, the gearbox supporting a first bearing that supports the second output shaft in a rotatable manner;
an electrical rotating machine including:
a central shaft that rotates together with the second output shaft;
a rotor fixed to the central shaft; and
a stator surrounding the rotor; and
a lubricating oil pump mounted to the gearbox and driven by the input shaft; and
a coolant pump mounted to the gearbox and driven by the input shaft, wherein
the gearbox supports the stator and a second bearing that supports the central shaft of the electrical rotating machine in a rotatable manner, the lubricating oil pump circulates lubricating oil such that the lubricating oil flows downward in the gearbox, and supplies the lubricating oil to the second bearing,
the lubricating oil supplied to the second bearing is ejected from the second bearing into the gearbox,
the coolant pump supplies a coolant to the electrical rotating machine, such that the coolant flows in contact with the stator of the electrical rotating machine,
the coolant pump supplies the coolant to the electrical rotating machine through a first coolant supply line, and supplies the coolant to a heat exchanger through a second coolant supply line, and
the heat exchanger cools the lubricating oil by exchanging heat between the lubricating oil and the coolant, the lubricating oil being the lubricating oil that is to be sucked into the lubricating oil pump or the lubricating oil that has been discharged from the lubricating oil pump.