Pod propulsion unit of a ship

Patent metadata

Field	Value
Publication number	US-2017081007-A1
Application number	US-201615363973-A
Country	US
Kind code	A1
Filing date	Nov 29, 2016
Priority date	May 30, 2014
Publication date	Mar 23, 2017
Grant date	—

Abstract

The invention relates to a pod propulsion unit of a ship. The pod propulsion unit comprises a pod housing arranged at least partly below a hull of the ship, an electric propeller motor within a motor gondola of the pod housing, an annular gap between a rotor and a stator of the electric propeller motor, and gas channels extending through the rotor, a closed cooling gas circuit, and a fan for circulating gas in the closed cooling gas circuit. The closed cooling gas circuit comprising a feeding duct extending between the return duct and the first motor end face of the electrical propeller motor, and a return duct extending between the feeding duct and the opposite second motor end face of the electrical propeller motor.

First claim

1 . A pod propulsion unit of a ship, wherein the pod propulsion unit comprises
a pod housing arranged at least partly below a hull of the ship, an electric propeller motor within a motor gondola of the pod housing for rotating at least one propeller, wherein the electric propeller motor having a rotor, a stator, an annular gap between the rotor and the stator, and gas channels extending through the rotor, a closed cooling gas circuit, wherein the annular gap between the rotor and the stator and the gas channels extending through the rotor forms a part of the closed cooling gas circuit, and a fan for circulating gas in the closed cooling gas circuit, wherein the pod housing comprises a strut section between the hull of the ship and the motor gondola, and wherein the stator of the electric propeller motor being fitted such as snug-fitted, form-fitted, or shrink-fitted in a tubular section of the motor gondola of the pod housing of the pod propulsion unit,
wherein:
the closed cooling gas circuit comprising a feeding duct and a return duct for conducting gas between the pod housing and the hull of the ship,
the electrical propeller motor having a first motor end face and an opposite second motor end face,
the feeding duct extending between the return duct and the first motor end face of the electrical propeller motor, and
the return duct extending between the feeding duct and the opposite second motor end face of the electrical propeller motor,
the tubular section of the motor gondola having a circumferential outer surface that forms a part of the outer surface of the pod housing, and
the stator of the electric propeller motor being cooled to water surrounding at least a circumferential section of the circumferential outer surface of the tubular section of the motor gondola through the wall of the tubular section of the motor gondola.

2 . The pod propulsion unit according to claim 1 , which further includes an gas-liquid heat exchanger arranged in the closed cooling gas circuit between the feeding duct and the return duct for exchanging thermal energy between gas flowing in the closed cooling gas circuit and liquid circulating in at least one cooling liquid circuit.

3 . The pod propulsion unit according to claim 2 , wherein the cooling liquid circuit being a closed cooling liquid circuit.

4 . The pod propulsion unit according to claim 2 , wherein the closed cooling liquid circuit being a part of a closed cooling liquid system of the ship.

5 . The pod propulsion unit according to claim 2 wherein the fan and the gas-liquid heat exchanger being parts of an independent cooling unit.

6 . The pod propulsion unit according to claim 5 , wherein the independent cooling unit being provided outside the pod housing and within the hull of the ship

7 . The pod propulsion unit according to claim 2 which further comprises by a first temperature sensor for measuring temperature of the gas flowing in the closed cooling gas circuit downstream of the electric propeller motor and upstream of the gas-liquid heat exchanger, and
which further comprises a second temperature sensor for measuring temperature of the gas flowing in the closed cooling gas circuit upstream of the electric propeller motor and downstream of the gas-liquid heat exchanger.

8 . The pod propulsion unit according to claim 2 which further comprises a leakage sensor providing information about leakage of cooling liquid in gas-liquid heat exchanger connected to cooling liquid circuit.

9 . The pod propulsion unit according to claim 2 which further comprises a humidity sensor for measuring humidity of the gas flowing in the closed cooling gas circuit upstream of the electric propeller motor and downstream of the gas-liquid heat exchanger.

10 . The pod propulsion unit according to claim 2 which further comprises a third temperature sensor for measuring the temperature of the liquid circulating in said at least one cooling circuit.

11 . The pod propulsion unit according to claim 1 which further comprises cooling fins in the closed cooling gas circuit and attached to the pod housing of the pod propulsion unit for exchanging thermal energy between gas flowing in the closed cooling gas circuit and water surrounding the pod housing.

12 . The pod propulsion unit according to claim 1 wherein the motor gondola being connected to the strut section by means of a first connection section and a second connection section of the strut section,
wherein the connection section and the second connection section of the strut section being spaced apart from each other so that an opening is formed between said the connection section and the second connection section of the strut section and the circumferential outer surface of the tubular section of the motor gondola, and by at least a part of said circumferential section of the circumferential outer surface of the tubular section of the motor gondola being located in said opening.

13 . The pod propulsion unit according to claim 12 , wherein the opening extending at least for 50%, of a length of the stator of the electric propeller motor.

14 . The pod propulsion unit according to claim 12 , wherein
a part of the feeding duct of the closed cooling gas circuit is in the first connection section, and a part of the return duct of the closed cooling gas circuit is in the second connection section.

15 . The pod propulsion unit according to claim 1 wherein
the strut section of the pod housing being attached to the ship by means of slewing bearing for allowing turning of the pod housing with respect to the hull of the ship, and
the pod propulsion unit comprising a slip ring between a power plant within the hull of the ship and electrical propeller motor within the pod housing for supplying electrical power from the power plant to the electrical propeller motor.

16 . The pod propulsion unit according to claim 15 , wherein the feeding duct and the return duct of the closed cooling gas circuit being configured to conduct gas past the slip-ring.

17 . The pod propulsion unit according to claim 15 , wherein the slip-ring being arranged outside the closed cooling gas circuit.

18 . The pod propulsion unit according to claim 15 wherein the feeding duct is arranged inside the return duct at the level of the slewing bearing.

19 . The pod propulsion unit according to claim 18 , wherein
the feeding duct comprising a tubular rotating feeding duct section, which is coaxial with the slewing bearing, and which is configured to turn with the pod housing with respect to the ship, the return duct comprising an annular return duct section ( 33 a ), which is coaxial with the slewing bearing and coaxial with the tubular rotating feeding duct section of the feeding duct, and which is stationarily arranged with respect to the ship, and the tubular rotating feeding duct section of the feeding duct and the annular return duct section of the return duct being provided in a region between the slip ring and the motor gondola of the pod housing.

20 . The pod propulsion unit according to claim 15 wherein the return duct is arranged inside the feeding duct at the level of the slewing bearing.

21 . The pod propulsion unit according to claim 20 , wherein
the feeding duct comprising an annular feeding duct section, which is coaxial with the slewing bearing and which is stationarily arranged with respect to the ship, by the return duct comprising a tubular rotating return duct section, which is coaxial with

Assignees

• Abb Schweiz Ag

Inventors

• Kosso Antto
• Lahtinen Lasse
• Säkkinen Petri

Classifications

• B63H2005/1258

  with electric power transmission to propellers, i.e. with integrated electric propeller motors · CPC title

• H02K21/00

  Synchronous motors having permanent magnets; Synchronous generators having permanent magnets · CPC title

• B63H23/24

  electric {(dynamo-electric machines H02K)} · CPC title

• H02K9/10

  by gaseous cooling medium flowing in closed circuit, a part of which is external to the machine casing · CPC title

• H02K9/12

  wherein the cooling medium circulates freely within the casing · CPC title