CN109301973B

CN109301973B - Motor and ship propulsion device

Info

Publication number: CN109301973B
Application number: CN201710606560.5A
Authority: CN
Inventors: 江宁; 段瑞春; 刘大为; 张利成; 威尔·范·莫尔; 裘富华
Original assignee: Siemens AG
Current assignee: Siemens Energy Global GmbH and Co KG
Priority date: 2017-07-24
Filing date: 2017-07-24
Publication date: 2021-07-30
Anticipated expiration: 2037-07-24
Also published as: CN109301973A; WO2019020358A1

Abstract

The invention provides a motor and a ship propulsion device provided with the same, wherein the motor comprises: a stator; a rotor rotatably disposed on a motor shaft; and a housing structure comprising: a housing extending in an axial direction of the motor and surrounding a stator of the motor; at least one heat sink strip arranged and in contact between an inner side of the housing facing the stator and an outer surface of the stator of the electric machine.

Description

Motor and ship propulsion device

Technical Field

The invention relates to an electric motor, in particular for a ship propulsion device; furthermore, a ship propulsion device, in particular a pod propulsion device for a ship is provided.

Background

A marine propulsion device is a device that provides power to a vessel. Marine propulsors can be divided into two categories, active and reactive, depending on the mode of action. Fibers, sails (see sailing ships) and the like which drive the ship to advance by manpower or wind power are active; the oar, the scull, the paddle wheel, the water jet propeller, the propeller and the like are reaction type. Most modern transport ships adopt reaction type propellers, and the most widely applied mode is a propeller type propeller. Since the motor driving the propeller generates a significant amount of heat during operation, an important way to remove this heat is to transfer it through the stator to the propulsion unit housing, which is exposed to the sea. In an electric motor, the main heat generating components are the rotor, the stator and the terminals of the stator coils. However, the prior fully-covered pod has a large area that cannot be cooled, resulting in locally high temperatures. To solve the heat dissipation problem, a complicated air circulation cooling device needs to be added to the nacelle hanger part. In order to arrange the air passage between the hanger and the motor housing, an extremely complicated connection structure is often required.

Disclosure of Invention

In order to solve one or more of the above problems, the present invention first proposes a motor including: a stator; a rotor rotatably disposed on a motor shaft; and a housing structure comprising: a housing extending in an axial direction of the motor and surrounding a stator of the motor; at least one heat sink strip arranged and in contact between an inner side of the housing facing the stator and an outer surface of the stator of the electric machine. The heat dissipation strips between the housing and the stator help the heat generated by the stator and the rotor to be conducted more smoothly to the surface of the housing and thus be carried away by air or, in the case of the application of the invention, in water.

According to an advantageous embodiment, the at least one heat sink strip extends in the axial direction of the electric machine.

According to a further advantageous embodiment, at least two heat dissipation strips are provided, which are arranged at equal distances from one another in the circumferential direction of the housing, wherein a gap is formed between every two adjacent heat dissipation strips. Through this kind of mode of setting up, can realize evenly dispelling the heat at stator a week, simultaneously, the axial clearance that flows out can be the gaseous flow outflow space inside the casing of casing to the heat dissipation is realized to more favourable mode.

According to an advantageous embodiment, the ratio of the length of the heat sink strip in the circumferential direction of the housing to the length of the gap in the circumferential direction of the housing is between 0.5 and 2. More preferably, the ratio is between 1 and 1.5. The specific numerical value can be reasonably calculated according to the size and the power of the motor.

According to an advantageous embodiment, the length of the heat sink strip is the same as the length of the stator of the electric machine in the axial direction of the electric machine. This enables heat dissipation over the entire axial length of the stator.

According to an advantageous embodiment, the heat sink strip is made of a material that conducts heat well, in particular an alloy of copper or aluminum. The metal material can realize heat conduction better.

According to an advantageous embodiment, heat exchange enhancing structures, in particular fins, are arranged in the gap of the thruster housing. Whereby heat dissipation can be further achieved.

According to an advantageous embodiment, the housing is circular in cross section, wherein the heat sink strip can be clamped in an annular gap between an inner side of the housing and an outer surface of the stator.

According to an advantageous embodiment, an air cooling device is provided inside the housing structure of the electric machine. The air cooling device can realize active heat dissipation, namely, the heat dissipation is further enhanced by utilizing the air flow inside the motor.

According to an advantageous embodiment, the air cooling means is a fan arranged on the motor shaft or a small fan arranged around the motor shaft and powered by an external power source. The number of externally powered small fans may be 1 to 8.

The invention also correspondingly provides a ship propulsion device, and an electric unit of the ship propulsion device comprises the motor in any one of the above embodiments.

Drawings

The drawings are only for purposes of illustrating and explaining the present invention and are not to be construed as limiting the scope of the present invention. Wherein,

figure 1 schematically shows a pod propulsion device according to the prior art;

figure 2 schematically shows a pod propulsion device according to an embodiment of the invention;

figure 3 schematically shows a schematic view of a III-III cross section of an electric unit of a pod propulsion device according to an embodiment of the invention;

figure 4 schematically shows a schematic view of the interior of a pod propulsion device according to an embodiment of the invention;

figure 5 schematically shows a schematic view of the interior of another pod propulsion device according to an embodiment of the invention;

fig. 6 schematically shows a schematic view of the interior of a further pod propulsion device according to an embodiment of the invention.

List of reference numerals:

1 Motor Unit

3 hanger

4 joint ring

5 Propeller

6 lower part

8 mounting hole

30-rotation bearing disc

40 electric unit

41 distal end

42 proximal end

44 casing

45 first connection region

46 second connection region

47 electric machine

48 bearing

49 a cooling device; fan with cooling device

49' cooling means; small fan

50 hanger structure

51 first leg

51 second leg

53 air gap

54 hanger shell

55 hanger structure body

56 hanger structural bearing end

60 a propeller; propeller

62 blade

70 circulating air path

100 ship propulsion device

441 heat dissipation strip

442 gap

445 inner side surface

446 outer surface of stator

448 first annular space portion

449 second annular void portion

470 electric motor shaft

471 rotor

473 stators

Detailed Description

In order to more clearly understand the technical features, objects, and effects of the present invention, embodiments of the present invention will now be described with reference to the accompanying drawings.

Fig. 1 schematically shows a pod propulsion device according to the prior art. The propulsion device mounted in the lower part of the hull comprises a motor unit 1 with a housing structure. The motor unit 1 is mounted on a cradle 3 which is rotatably connected to the bottom of the hull by an engagement ring 4. A propeller 5 or propeller 5 is mounted at the upstream end 2 of the motor unit 1. At the downstream end corresponding to the upstream end 2, is connected to the spreader 3 by a so-called lower part 6. The lower part 6 is provided with mounting holes 8 for fastening bolts. The water flow flowing into the lower portion 6 cools the motor unit in the direction of the motor unit 1.

In the embodiment shown in the prior art, the hanger 3 and the motor unit 1 form an L-shaped structure, so that the outer wall of the motor unit 1 can be exposed to water in a wide range, which is beneficial to heat dissipation. The L-shaped configuration, however, makes the connection between the motor unit 1 and the arm 3 less rigid than a fully covered boom. The large cantilever structure can also cause large moment at the bending part, and needs thickening design.

Although not shown, in another pod propulsion device according to the prior art, the lower end of the boom of the propulsion device extends in the longitudinal direction of the motor unit 1 and is connected thereto, thereby providing a robust connection between the boom and the motor unit. The problems of stress and water flow regulation can be solved by the connection mode. However, due to this "full-coverage" type of connection, the outer wall of the motor unit cannot be fully exposed to the water to obtain sufficient cooling, and this prior art has designed a special water cooling system in the pylon. This necessarily further increases manufacturing difficulty and cost.

In order to ensure that the motor unit has good heat dissipation effect, the invention provides a specific scheme.

Fig. 2 schematically shows an embodiment of a marine propulsion device 100 according to the invention.

The vessel propulsion device 100 is in particular a pod-type vessel propulsion device which can be connected to the vessel, in particular to the bottom of the vessel, typically by means of a slewing ring 30 or coupling ring known in the art, such that the pod-type vessel propulsion device 100 can be rotated in order to adjust the direction of travel of the vessel. The boat propulsion device 100 shown in fig. 2 includes an electric unit 40, and the electric unit 40 mainly includes an electric motor 47 (not shown in fig. 2, see fig. 4). The motor comprises a housing 44, and the stator, rotor and motor shaft of the motor are enclosed by the housing 44. The construction of the motor is known in the art and will not be described in detail here. On one end 42 of the electrical unit 40 is provided a propeller 60, which is typically a screw propeller or propeller 60. In the embodiment shown in fig. 2, the propeller 60 includes four specially designed blades 62. It is conceivable that the number of blades may also be 3, 5, the shape of which also needs to be designed according to the actual thrust or the like. In the present invention, the area of the end of the electric unit 40 close to the propeller 60 may be referred to as a proximal end area 42. It is not limited to the point closest to the propeller 60 but may indicate an area closer to the propeller 60 on the electric unit 40, particularly on the housing 44 thereof, than the other end. Correspondingly, the region of the electric unit 40, in particular of its housing 44, which is closer to the other end or is further away from the propeller 60 is referred to as the distal region 41.

The boat propulsion device 100 further includes a hanger structure 50 connecting the electric unit 40 with the slewing bearing disk 30. The hanger structure shown in fig. 2 forms an approximately triangular shape when viewed in the view of the figure. Its bearing end 56 adjacent to the slew bearing disc 30 has a smaller cross-section that can engage the slew bearing disc 30. The body 55 of the hanger structure 50 extends from the bearing end 56 towards the electric unit 40. The body 55 is surrounded by the hanger case 54 to form a hollow structure. The hanger shell 54 is shaped such that the hanger structure 50 is streamlined in cross-section in the direction of water flow. The hanger shell 54 forms two legs at an end remote from the bearing end 56. One of the first legs 51 is connected to the distal region 41 of the housing 44 of the electric unit 40 axially remote from the propeller, and the other second leg 52 is intended to be connected to the proximal region 42 of the housing 44 of the electric unit 40 axially close to the propeller. Due to the mutual spacing between the first leg 51 and the second leg 52, a gap 53 is formed between the first leg and the second leg, which gap 53 itself is also formed by the hanger shell 54, spanning between the first leg and the second leg like a "bridge", such that at least part of the housing 44 between the proximal end region 42 and the distal end region 41 of the housing 44 of the motor unit 40 is not covered by the hanger shell of the hanger structure 50. Therefore, the hanging bracket structure with the 'two-end hanging type' structure can not only keep the firmness of the covering type hanging bracket, namely the strength of the covering type hanging bracket can be kept without a heavy structure, but also enable the shell 44 of the electric unit to be exposed in water in a large area, and realize sufficient heat dissipation. Therefore, the structure is improved, and the advantages of the L-shaped cantilever structure and the full-coverage hanger structure are combined.

Although not shown in fig. 2, it is contemplated that the housing 44 of the motor unit 40 is also hollow. On the other hand, the interiors of the first leg 51 and the second leg 52 formed by the hanger case 54 may be hollow, so that the inner cavity of the hanger structure 50 can communicate with the inner space of the electric unit 40. It should be noted that the ends of the first leg 51 and the second leg 52 may be open ends (i.e., the hanger case 54 is not closed at the ends of the first leg 51 and the second leg 52, but is open, so that the inner cavity of the hanger case 54 can be communicated with the inner cavity of the housing 44 of the electric unit through the first leg and the second leg). Or the ends of the first leg 51 and the second leg 52 are closed, heat can be dissipated by means of the housing 44 not covered by the hanger structure or by means of a fan. Of course, one of the first leg 51 and the second leg 52 may be closed and one may be open.

Fig. 3 shows a schematic view of the cross section III-III in fig. 2, the invention further optimizes the heat dissipation performance of the electric unit 40 of the marine propulsion device by a new design of the housing structure of the electric motor 47. As shown, the motor 47 includes a rotor 471 which is rotatably supported on a motor shaft 470. The rotor 471 is surrounded on its circumferential outer side by a stator 473 of the electric motor. The construction of the motor is known in the art and will not be described in detail here.

The housing 44 is a housing 44 extending in the axial direction of the motor, and the housing 44 surrounds the motor 47. The housing 44 is typically cylindrical, extending in the direction of the motor axis x, but it may also be, for example, of rectangular, in particular square, cross-section (not shown). In a preferred embodiment, the III-III cross-section is circular, thereby forming an annular first annular void 448 between the housing 44 and the stator 473 of the motor. In the embodiment according to the present invention, at least one heat radiation bar 441 is disposed between an inner side 445 of the housing 44 facing the motor stator and an outer surface 446 of the stator 473. The heat sink bars 441 are preferably clamped between the housing 44 and the stator 473. In the embodiment shown in fig. 3, a plurality of heat dissipation bars 441 are provided by way of example, and the length of the heat dissipation bars 441 is the same as the length of the stator 473, but may be shorter than the length of the stator. These heat dissipation bars 441 are preferably arranged in parallel at equal intervals along the length direction of the case 44. In particular, the heat dissipation bars 441 are configured to be the same size (have the same cross-sectional area and shape). Thus, the gap 442 between each two adjacent heat dissipation strips 441 also has a width of similar magnitude. The heat dissipation bars 441 are made of a metal having good thermal conductivity, such as copper or an aluminum alloy. In the illustrated embodiment, the heat sink strips are copper strips having a height of 2cm and a width of about 3cm, with a spacing of 1cm to 3cm between each two copper strips 441, thereby forming a series of axial ventilation channels. The heat dissipating bars 441 are pressed against the inner surface 445 of the housing 44 and the outer surface 446 of the stator 473, so that part of the heat from the stator can be directly conducted to the housing 44 through the heat conducting heat dissipating bars 441, and the heat can be conducted to the water through the housing 44. On the other hand, air may also pass through the gap between the rotor 471 and the permanent magnet and the gap between the rotor 471 and the stator 473, then take away heat through the gap of the terminal, and transfer the heat to the housing through the gap 442 between the housing 44 and the stator 473, and finally be introduced into water.

Fig. 3 shows a preferred embodiment of the present invention, and in practice, a smaller number of heat dissipation bars can be selected, and the width and height of the heat dissipation bars can be set according to practical situations. For example, in the illustrated embodiment, the ratio of the length of the heat dissipation strip 441 in the circumferential direction of the housing 44 to the length of the gap in the circumferential direction of the housing 44 is 1: 1 or 3: 2. In addition, the optimal proportional relation can be determined by calculation of a flow field and a temperature field according to the size of the motor, the heat dissipation capacity of each component, the wind pressure of the fan, the material of the component and the like. When the cross section of the housing 44 is not circular but advantageously rectangular, the heat sink strips arranged in different positions can then be designed in different shapes, so that at least some regions of the heat sink strips can simultaneously come into contact with the inner side 445 of the housing and the outer surface 446 of the stator. It is noted that the heat radiating strips 441 may be separate members that are sandwiched between the inner side surface 445 of the housing 44 and the outer surface 446 of the stator 473 by means of clamping force; the heat radiation bars 441 may be ribs formed integrally with the housing 44 or the outer surface 446 of the stator.

Further, since the heat dissipation bars 441 are clamped between the housing 44 and the stator 473, the width of the heat dissipation bars 441 can be designed larger when the number of the heat dissipation bars 441 provided is small. In addition, the shape of the heat dissipation bars 441 may be designed to be a fan shape in order to further closely attach to the housing 44 and the stator 473. Whereby the arc-shaped side surfaces can be better fitted to the inner peripheral surface of the housing 44 and the outer surface of the stator 473.

Fig. 4 shows an exemplary air flow diagram of the interior of an electric machine 47 according to an embodiment of the invention. In this embodiment, the ends of the first and

second legs

51, 52 of the hanger structure 50 are closed. That is, the interior cavity of the hanger structure 50 is not in communication with the interior of the housing 44 of the motor 47. Thus, in order to achieve better heat dissipation, in addition to the housing 44 of the electrical unit by means of a large area of exposure to water, further heat dissipation can be achieved by mounting a fan 49 on the motor shaft. As indicated by arrows 70, the fan 49 forces air to flow in the gap 442 between the inner side 445 of the housing 44 of the motor and the outer surface of the stator 473; on the other hand, the air may also pass through the gap between the rotor 471 and the permanent magnet and the second annular gap 449 between the rotor 471 and the stator 473, then take away the heat through the gap of the terminal, and transfer the heat to the housing through the gap 442 between the housing 44 and the stator 473, and finally be introduced into the water. Of course, by providing the heat radiation bars 441, a large portion of heat can be conducted directly to the water through the stator 473, the heat radiation bars 441, and the housing 44. Thereby, the electric unit can be made to have excellent heat radiation performance.

Referring to fig. 5, there is shown in schematic view an air flow schematic of the interior of an electric machine 47 according to yet another embodiment of the present invention. In the embodiment shown in fig. 5, the ends of the first leg 51 and the second leg 52 of the hanger structure are open ends (i.e., the hanger case 54 is not closed at the ends of the first leg 51 and the second leg 52, and is open), thereby enabling the interior cavity of the hanger case 54 to communicate with the interior cavity of the housing 44 of the electric unit through the first leg and the second leg. In this embodiment, fan 49 tends to circulate air within the interior cavity of housing 44 and hanger housing 54, as indicated by arrows 70, and fan 49 forces air to flow between the interior side 445 of housing 44 and the exterior surface of stator 473; on the other hand, the air may also pass through the gap between the rotor 471 and the permanent magnet and the second annular gap 449 between the rotor 471 and the stator 473, then take away the heat through the gap of the terminal, and transfer the heat to the housing through the gap 442 between the housing 44 and the stator 473, and finally be introduced into the water. In this embodiment where the hanger housing 54 is in communication with the housing 44, further heat dissipation can be achieved by the hanger housing 54, so that the hot air between the stator and the rotor of the motor 42 is driven into the inner cavity of the hanger housing 54, and since the inner cavity of the hanger housing 54 itself has no heat generating components, and the outer surface thereof is in contact with a large amount of water, the temperature of the circulating air can be rapidly reduced, and the air after temperature reduction can enter the motor to reduce the temperature thereof. Of course, by installing fans of different sectors, the air may also circulate in the opposite direction as indicated by arrow 70.

It is conceivable that, in order to further increase the cooling effect, a speed increaser (gear) may be installed inside the housing 44, so that the fan 49 is driven by the motor shaft via the speed increaser, thereby further increasing the rotation speed of the fan 49 to make the active heat radiation effect better. The speed increaser may be arranged coaxially with the motor shaft and will not be described in detail here.

Fig. 6 shows yet another embodiment according to the invention, in which the active cooling means may be a plurality of small fans 49' distributed inside the housing 44. For example, 3 to 9 small fans 49' may be uniformly arranged along the circumference of the housing 44. The small fans are powered by an external power supply inlet wire so as to realize uniform air supply.

It will be appreciated that the arrangement of the motor according to the invention may be used not only in marine propulsion units, but also in any motor where there is a high demand for heat dissipation, especially in higher power motors.

It should be understood that although the present description has been described in terms of various embodiments, not every embodiment includes only a single embodiment, and such description is for clarity purposes only, and those skilled in the art will recognize that the embodiments described herein may be combined as suitable to form other embodiments, as will be appreciated by those skilled in the art.

The above description is only an exemplary embodiment of the present invention, and is not intended to limit the scope of the present invention. Any equivalent alterations, modifications and combinations can be made by those skilled in the art without departing from the spirit and principles of the invention.

Claims

1. An electric machine (47) comprising:

a stator (473);

a rotor (471) rotatably mounted on a motor shaft (470); and

a housing structure, comprising:

a housing (44) extending in an axial direction of the motor (47), and the housing (44) surrounding a stator (473) of the motor;

at least two heat dissipation bars (441) disposed and abutting between an inner side (445) of the housing (44) facing the stator (473) and an outer surface of the stator (473) of the electric motor;

wherein the at least two heat dissipation strips (441) are arranged at equal distances from each other in the circumferential direction of the housing (44), wherein a gap (442) is formed between every two adjacent heat dissipation strips (441), which gap forms an axial ventilation channel.

2. An electric machine according to claim 1, characterized in that at least one heat sink strip (441) extends in the axial direction of the electric machine (47).

3. The machine according to claim 1, characterized in that the ratio of the length of the heat sink strip (441) in the circumferential direction of the housing (44) to the length of the gap in the circumferential direction of the housing (44) is between 0.5 and 2.

4. The electric machine according to any of claims 1 to 3, characterized in that the length of the heat dissipation bars (441) is the same as the length of the stator (473) of the electric machine (47) in the axial direction of the electric machine.

5. The machine according to any of claims 1 to 3, characterized in that the heat sink strips (441) are made of a material that conducts heat well, in particular an alloy of copper or aluminum.

6. An electric machine according to any of claims 1-3, characterized in that the gaps (442) of the housing (44) are provided with heat-intensifying structures, in particular fins.

7. An electric machine according to any of claims 1-3, characterized in that the housing (44) is circular in cross-section, wherein the heat sink bars (441) can be clamped in an annular gap (444) between an inner side (445) of the housing (44) and an outer surface of the stator (473).

8. An electric machine as claimed in any one of claims 1 to 3, characterized in that an air cooling device (49; 49') is provided inside the housing structure of the electric machine.

9. An electric machine as claimed in claim 8, characterized in that the air cooling means (49; 49 ') is a fan (49) arranged on the motor shaft (470) or a small fan (49') arranged around the motor shaft (470) and powered by an external power supply.

10. Marine propulsion arrangement, characterized in that the electric unit of the marine propulsion arrangement comprises an electric motor according to any one of claims 1-9.