CN118040992B - A heat dissipation motor system for underwater equipment and a design method thereof - Google Patents

Abstract

The invention provides a heat dissipation motor system of an underwater device and a design method thereof, which belong to the field of motor design of the underwater device. According to the invention, the space resources of the underwater equipment are fully utilized, and no heat dissipation equipment is additionally arranged, so that the cooling system can realize self-adaptive cooling of the motor rotor assembly and the stator assembly under different sailing working conditions under the condition of greatly reducing the weight of the motor cabin section, and the working safety of the motor is ensured.

Description

A heat dissipation motor system for underwater equipment and a design method thereof

Technical Field

The invention belongs to the technical field of underwater equipment, and in particular relates to an underwater equipment heat dissipation motor system and a design method thereof.

Background technique

Due to the requirements of high speed and range of underwater equipment, the motor needs to have higher output power and efficiency. When the motor works under high power and high speed conditions, it will quickly generate a lot of heat. The motor compartment of general underwater equipment is sealed. If the heat cannot be dissipated in time, the motor will overheat and cannot continue to work. Motor overheating will affect the safe operation of the motor.

The patent document with publication number CN208820621U discloses an underwater energy-saving heat dissipation motor, the cooling system of which needs to be equipped with additional cooling equipment for cooling, such as a radiator and a coolant. However, since the motor compartment of the underwater equipment is a confined space, the cooling equipment will occupy a large amount of internal space of the underwater equipment, limiting the arrangement of other components in the cabin. In addition, when the underwater equipment is sailing at high speed, that is, the speed is greater than 30Kn, the required motor torque and power increase sharply, and the heat generated by the motor also increases accordingly. In order to ensure the safe operation of the motor when sailing at high speed, the art usually considers designing and optimizing the cooling system to improve the cooling effect of the motor, but often ignores that the design process will add additional weight, which is not conducive to the lightweight design of the underwater equipment, and will lead to a decrease in the navigation performance of the underwater equipment, requiring greater thrust to maintain the navigation speed.

Therefore, how to design the motor system while taking into account the navigation conditions, confined space, lightweight and motor safety performance of underwater equipment is an urgent problem that needs to be solved.

Summary of the invention

The purpose of the present invention is to overcome the shortcomings of the prior art in that the motor system is not designed taking into account the confined space, lightweight and navigation conditions of underwater equipment, and to provide an underwater equipment heat dissipation motor system and a design method thereof.

The inventive concept of the present invention is:

The water pump in the present invention adopts a passive driving mode, and the water pump is directly driven by the motor rotor shaft to work, and seawater is introduced into the heat dissipation channel through the center hole of the rotor shaft to cool the motor. Since the water pump is driven by the motor, in the low-speed navigation stage of the underwater equipment, that is, generally when the speed is about 5kn, the motor rotor shaft rotates at a relatively low speed, and the motor generates little heat. The motor cooling system can achieve adaptive cooling of the motor heat as the rotor shaft speed increases to meet the motor's safe working requirements. In the high-speed navigation stage of the underwater equipment, that is, when the speed is greater than 30kn, the required motor torque and power increase sharply, the motor rotor shaft speed increases, the motor heat generation increases, and the water pump pressure also increases with the increase of the rotor shaft speed, and the cooling effect is improved. However, after the rotor shaft speed increases, the motor heat generation increases significantly, and the water pump pressure is not enough to dissipate the motor heat generation, resulting in the motor temperature exceeding the safety working requirements.

In order to solve the heat dissipation problem of underwater equipment during high-speed navigation, the research on the motor system of underwater equipment generally focuses on the cooling performance of the cooling system, that is, simply improving the heat dissipation effect by optimizing the structural parameters of the cooling system, and not associating it with the adopted motor structure and the total weight requirements of the underwater equipment. However, the present invention innovatively starts from the total weight and space requirements of the underwater equipment, based on the application scenario of the underwater equipment using passive pumps for cooling, evaluates the heat generation of the motor and the heat dissipation performance of the cooling system at different speeds of the underwater equipment, and quantitatively designs the structural parameters of the motor structure and the cooling system heat dissipation flow channel to ensure that the motor temperature is within the safe working range during the high-speed navigation stage of the underwater equipment, while achieving the lightweight design of the motor compartment of the underwater equipment.

Based on the above inventive concept, the technical solution provided by the present invention is:

An underwater equipment heat dissipation motor system, which is special in that it includes an underwater equipment shell, a motor and a cooling system; the underwater equipment shell includes a motor compartment section and a tail compartment section;

The motor comprises a motor front end cover, a rotor assembly, a stator assembly and a motor rear end cover;

The front end cover and the rear end cover of the motor are respectively fixedly arranged at two ends of the motor compartment cavity in a radial direction, and the rotor assembly and the stator assembly are coaxially arranged between the front end cover and the rear end cover of the motor; the rotor assembly has a rotor shaft for driving the propeller of the underwater equipment to rotate;

The cooling system is an open passive adaptive cooling system, including a heat dissipation channel and a water pump arranged at the front end of the rotor shaft; the rear end of the rotor shaft extends out of the tail compartment and communicates with the ocean;

The heat dissipation channel includes a seawater suction hole, a first connecting channel, a double helical channel, a second connecting channel and an annular jet hole; the double helical channel is a spiral groove symmetrically opened on the inner wall of the motor compartment; the seawater suction hole is the central hole of the rotor shaft; the annular jet hole is coaxially opened on the rotor shaft and opened along the rear end of the rotor shaft to the outlet position of the second connecting channel;

The water pump is provided with two flow channel outlets, which are respectively connected with the input port of the double helix flow channel through symmetrically arranged first connecting flow channels, and the output ports of the double helix flow channel are respectively connected with the annular jet holes through symmetrically arranged second connecting flow channels; the water pump is driven by the motor rotor shaft to suck seawater from the central hole of the rotor shaft to cool the rotor assembly, and allows the seawater to cool the stator assembly along the double helix flow channel, and after cooling, it flows out from the second connecting flow channel outlet and is discharged into the ocean through the annular jet hole.

The heat dissipation motor system is determined by simulation optimization so that the cooling system can dissipate heat and cool the motor under different navigation conditions of the underwater equipment while meeting the weight and strength requirements of the motor compartment, thereby ensuring the safe operation of the motor.

Furthermore, the second connecting flow channel includes a liquid flow channel radially opened on the rear end cover of the motor, a lip-shaped sealing chamber, and a liquid flow hole opened on the rotor shaft;

Two ends of the liquid flow channel radially opened on the rear end cover of the motor are respectively connected with the output port of the double helix flow channel and the lip-shaped sealing cabin;

The lip-shaped sealing cabin is arranged in the central hole of the rear end cover of the motor, and the inner wall of the lip-shaped sealing cabin is interference-fitted with the outer wall of the rotor shaft;

A plurality of liquid flow holes are radially arranged on the side wall of the rotor shaft at the position matching with the lip-shaped sealing chamber, and the liquid flow holes are connected with the annular jet hole;

The cooling waste water discharged through the double helix flow channel is discharged into the ocean through the liquid flow channel, lip-shaped sealing cabin, liquid flow hole and annular jet hole on the rear end cover of the motor in sequence.

Furthermore, the rotor assembly comprises the rotor shaft, the rotor core and the permanent magnet; the rotor shaft, the rotor core and the permanent magnet are coaxially nested and fixedly connected from the inside to the outside in sequence;

The stator assembly is sleeved on the outer wall of the rotor assembly, and there is a gap between the stator assembly and the rotor assembly. The stator assembly includes a stator core and a stator winding. The outer wall of the stator core is fixed to the inner wall of the motor compartment section, and the stator winding is wound inside the stator core. Under the magnetic force of the permanent magnet and the stator winding, the rotor core, the permanent magnet and the rotor shaft rotate together, and the rotor shaft drives the propeller of the underwater equipment to rotate.

Furthermore, the cross-sectional area ratio of the seawater suction hole to the annular jet hole is 3:1.

Furthermore, in order to ensure the inner wall strength of the rotor shaft, the wall thickness between the seawater suction hole and the annular jet hole is not less than 8 mm.

Furthermore, the rear shaft of the rotor shaft is connected to the tail compartment through a sliding bearing arranged in the tail compartment of the underwater equipment, and one end face of the sliding bearing is in contact with the inner end face of the tail compartment;

A fixing bracket fixedly connected to the tail compartment body is radially provided in the tail compartment chamber, and the middle shaft body of the rotor shaft is connected to the center hole of the fixing bracket through another sliding bearing.

Furthermore, the fixing bracket is in the shape of a disk as a whole, a center hole is provided on the fixing bracket along the axis, and the fixing bracket is connected to the outer wall of the rotor shaft through a sliding bearing;

A plurality of connecting rods are radially arranged on the side wall of the fixing bracket, and the ends of the connecting rods are connected to lugs arranged on the inner wall of the motor compartment section.

The present invention also provides a design method for the above heat dissipation motor system, which is special in that it includes the following steps:

Step 1: According to the space and overall weight requirements of the motor compartment of the underwater equipment, configure the motor for the motor compartment and determine the electromagnetic structure of the motor;

A simulation model of the motor and the underwater equipment shell is established, and structural parameters of the heat dissipation channel in the model are initially set; the structural parameters include the pitch, depth, cross-sectional dimensions and spiral inclination of the double helical channel, and the cross-sectional dimensions of the seawater intake hole and the annular jet hole;

The cross-sectional area ratio of the seawater suction hole to the annular jet hole is initially set to 1;

Step 2: Through simulation calculation, obtain the temperature field parameters of the heat dissipation channel and the maximum temperature _Ti of the stator winding, stator core and rotor core when the motor is working at high speed _Vi under water; where i=1, 2, 3, ..., n;

Step 3: Based on the temperature field parameters obtained in step 2, determine whether the maximum temperatures _Ti of the stator winding, stator core, and rotor core meet the motor design requirements at different speeds _Vi . If yes, proceed to step 5; otherwise, proceed to step 4 to adjust the heat dissipation channel parameters.

Step 4: Adjust the heat dissipation channel parameters by reducing the pitch of the double helix channel and/or increasing the cross-sectional size of the double helix channel. After the adjustment, if the motor compartment shell meets the strength design requirements, return to step 2 and step 3 to determine whether the maximum temperature _Ti of the stator winding, the stator core and the rotor core meets the motor design requirements. If so, proceed to step 5; otherwise, return to step 1 and redetermine the electromagnetic structure of the motor.

Step 5: Calculate and obtain the flow resistance along the double helix flow channel and the local flow resistance at the bend of the heat dissipation flow channel, and determine whether the flow resistance along the flow channel and the local flow resistance are within the range of the Q-H characteristic curve of the water pump (Q is the flow rate of the water pump, and H is the head of the water pump). If so, the required heat dissipation motor system is obtained; otherwise, adjust the cross-sectional dimensions of the seawater suction hole and the annular jet hole until the flow resistance along the double helix flow channel and the local flow resistance at the bend of the heat dissipation flow channel are within the range of the Q-H characteristic curve of the water pump after adjustment.

Furthermore, the specific process of adjusting the cross-sectional dimensions of the seawater suction hole and the annular jet hole in step 5 is as follows:

Step 5.1: setting the adjustment step of the cross-sectional area ratio of the seawater intake hole to the annular jet hole, and calculating and obtaining the cross-sectional dimensions of the seawater intake hole and the annular jet hole based on the adjustment step;

Step 5.2: Through simulation calculation, obtain the flow resistance along the double helix flow channel and the local flow resistance at the bend of the heat dissipation flow channel, and determine whether the flow resistance along the flow channel and the local flow resistance are within the range of the Q-H characteristic curve of the water pump:

If yes, then continue to increase the cross-sectional area ratio of the seawater suction hole to the annular jet hole according to step 5.1 until the flow resistance along the way and the local flow resistance are greater than the maximum value of the Q-H characteristic curve range of the water pump;

If not, then the cross-sectional area ratio of the seawater suction hole to the annular jet hole is a limit ratio. The maximum cross-sectional area ratio of the seawater suction hole to the annular jet hole within the Q-H characteristic curve of the water pump is taken as the optimal cross-sectional area ratio of the seawater suction hole to the annular jet hole, and the cross-sectional dimensions of the seawater suction hole and the annular jet hole are calculated based on this optimal cross-sectional area ratio.

The advantages of the present invention are:

1. In the present invention, the water pump is arranged on the motor rotor shaft, and the central hole of the rotor shaft is used as the seawater suction hole. A double helical flow channel is provided on the inner wall of the motor compartment shell of the underwater equipment, and the double helical flow channel contacts the outer wall of the stator assembly. The water pump arranged at the end of the rotor shaft sucks the ocean water through the central hole of the rotor shaft under the drive of the motor, and directly dissipates and cools the rotor assembly; the ocean water is connected with the double helical flow channel through the outlet of the water pump flow channel to achieve heat dissipation and cooling of the stator assembly; the output port of the double helical flow channel is connected with the annular jet hole on the rotor shaft through the liquid flow channel arranged on the rear end cover of the motor, so that the cooling wastewater is discharged to the ocean. The present invention makes full use of the space resources of the underwater equipment itself, and does not need to be equipped with an additional heat dissipation device. While greatly reducing the weight of the motor compartment of the underwater equipment, the cooling system can cool the motor rotor assembly and the stator assembly under different navigation conditions, ensuring the safe operation of the motor. The water pump works under the driving action of the motor rotor shaft, so that the cooling system passively and adaptively cools the motor according to the output power of the motor. In addition, since the double helix flow channel in the present invention is opened on the inner wall of the motor compartment shell of the underwater equipment, the motor compartment shell of the underwater equipment replaces the motor shell. While the seawater in the double helix flow channel is cooled, the outer wall of the motor compartment is in direct contact with the ocean to achieve heat exchange, which greatly improves the heat dissipation effect of the heat dissipation flow channel.

2. The double helix flow channels of the present invention are symmetrically arranged, and seawater flows in opposite directions through the double helix flow channels, which increases the turbulence effect of the fluid, is conducive to the uniform distribution of the fluid, accelerates the transfer and dissipation of heat in the motor and the motor compartment, improves the cooling effect of the motor, and ensures the safety of the motor.

3. In the present invention, the outlet of the double helical flow channel is connected to the annular jet hole provided on the rotor shaft through the second connecting flow channel. The annular jet hole is coaxially designed with the central hole of the rotor shaft, so that the cooling wastewater can provide axial propulsion to the underwater equipment while being discharged, greatly improving the working efficiency of the vehicle power system.

4. The heat dissipation motor system of the present invention is not only applicable to underwater vehicles, such as AUV and UUV, but also to other underwater equipment such as torpedoes. AUV is an autonomous underwater vehicle (AUV for short), and UUV is an unmanned underwater vehicle (UUV for short).

BRIEF DESCRIPTION OF THE DRAWINGS

FIG1 is a perspective schematic diagram of the appearance of an aircraft in an embodiment of the present invention;

FIG2 is a quarter cross-sectional view of the three-dimensional structure of the heat dissipation motor system according to an embodiment of the present invention. In order to reflect the double helical flow channel structure, this figure retains the cut-away double helical flow channel structure;

3 is a two-dimensional full cross-sectional view along the axial direction of the heat dissipation motor system according to an embodiment of the present invention;

FIG. 4 is a schematic diagram of the flow direction of seawater in the heat dissipation channel of the present invention.

Explanation of the reference numerals: 1-water pump; 2-rotor shaft; 201-seawater suction hole; 202-annular jet hole; 3-first connecting flow channel; 4-double helical flow channel; 401-upper spiral flow channel; 402-lower spiral flow channel; 5-second connecting flow channel; 6-lip-shaped sealing cabin; 7-motor front end cover; 8-rotor core; 9-stator assembly; 10-permanent magnet; 11-motor rear end cover; 12-sliding bearing; 13-fixed bracket; 14-motor compartment section; 15-tail compartment section.

Detailed ways

An embodiment of the present invention is described in detail below by taking an underwater vehicle as an example. The embodiment is exemplary and is intended to be used to explain the present invention, but should not be construed as limiting the present invention.

1-3, an underwater vehicle heat dissipation motor system includes an underwater vehicle housing, a motor and a cooling system;

The underwater vehicle housing includes a motor compartment section 14 and a tail compartment section 15;

The motor comprises a motor front end cover 7, a rotor assembly, a stator assembly 9 and a motor rear end cover 11;

The motor front end cover 7 and the motor rear end cover 11 are radially fixed at both ends of the motor compartment section 14 cavity, and the rotor assembly and the stator assembly 9 are coaxially arranged between the motor front end cover 7 and the motor rear end cover 11;

The rotor assembly includes a rotor shaft 2, a rotor core 8 and a permanent magnet 10; the rotor shaft 2, the rotor core 8 and the permanent magnet 10 are coaxially nested and fixedly connected from the inside to the outside in sequence;

The stator assembly 9 is mounted on the outer wall of the rotor assembly, and there is a gap between the inner wall of the stator assembly and the outer wall of the rotor assembly. The stator assembly 9 includes a stator core and a stator winding. The outer wall of the stator core is fixed to the inner wall of the motor compartment section 14, and the stator winding is wound inside the stator core. Under the magnetic force of the permanent magnet 10 and the stator winding, the rotor core 8, the permanent magnet 10 and the rotor shaft 2 rotate together, and the rotor shaft 2 drives the propeller of the underwater vehicle to rotate. It should be noted that the propeller of the underwater vehicle is not shown in the figure.

The cooling system adopts an open passive cooling system, which includes a heat dissipation channel and a water pump 1. The water pump 1 is arranged at the front end of the rotor shaft 2 and works passively under the driving action of the motor rotor shaft. The rear end of the rotor shaft 2 extends out of the shell of the tail section 15 and communicates with the ocean; the shaft body of the tail section of the rotor shaft 2 is connected to the shell of the tail section through a sliding bearing 12 arranged in the tail section 15, and the end face of the sliding bearing 12 is in contact with the inner end face of the shell of the tail section 15. A fixing bracket 13 fixedly connected to the shell of the tail section is radially arranged in the chamber of the tail section 15, and the shaft body of the rotor shaft 2 is connected to the center hole of the fixing bracket 13 through another sliding bearing 12.

The fixing bracket 13 is disc-shaped as a whole, with a central hole in the middle along the axis, and connected to the outer wall of the rotor shaft 2 through a sliding bearing. The side wall of the fixing bracket 13 is radially provided with a plurality of connecting rods, and the ends of the connecting rods are connected to the lugs arranged on the inner wall of the underwater vehicle shell.

The heat dissipation channel includes a seawater suction hole 201 , a first connecting channel 3 , a double helical channel 4 , a second connecting channel 5 and an annular jet hole 202 .

The seawater suction hole 201 is a central hole opened along the axis of the rotor shaft 2, and the seawater suction hole 201 is connected to the liquid flow inlet of the water pump 1. An annular jet hole 202 is opened on the rotor shaft 2, and the annular jet hole 202 is coaxially arranged with the seawater suction hole 201, and the annular jet hole is opened along the rear end face of the rotor shaft 2 to the position of the rear end cover 11 of the motor. A plurality of liquid flow holes are radially arranged on the side wall of the rotor shaft 2 and located at the rear end cover of the motor, and the liquid flow holes are connected to the annular jet hole. In order to ensure the mechanical strength of the rotor shaft, in this embodiment, the cross-sectional area ratio of the seawater suction hole 201 to the annular jet hole is preferably taken as 3:1. If the wall thickness between the seawater suction hole 201 and the annular jet hole is too small, the wall strength of the rotor shaft 2 will be reduced; if the wall thickness is too large, the structural integration will be low. Therefore, the wall thickness between the seawater suction hole and the annular jet hole is not less than 8 mm.

Two spiral grooves are symmetrically opened on the inner wall of the motor compartment section 14, and the top wall of the spiral groove is fixedly fitted with the outer wall of the stator assembly 9 to form the double spiral flow channel 4, which includes an upper spiral flow channel 401 and a lower spiral flow channel 402. The pitch, depth, spiral inclination and cross-sectional parameters of the two spiral flow channels are the same. The design of the double spiral flow channel 4 increases the turbulent effect of the fluid, is conducive to the uniform distribution of the fluid, accelerates the transfer and dissipation of heat, and realizes efficient and balanced cooling of the motor.

The water pump 1 has two flow channel outlets, which are connected to the input ports of the upper spiral flow channel 401 and the lower spiral flow channel 402 through two first connecting flow channels 3 symmetrically opened on the inner wall of the front end of the motor compartment section 14, and the output ports of the upper spiral flow channel 401 and the lower spiral flow channel 402 are connected to the annular jet hole 202 through the second connecting flow channels 5 symmetrically arranged on the rear end cover 11 of the motor. When working, the impeller speed in the water pump is the same as the speed of the motor rotor shaft. When the motor output power is greater, the impeller speed is greater, which increases the flow rate of seawater in the heat dissipation channel, and the motor cooling effect is also improved.

Since the rotating rotor shaft cannot be directly connected to the fixed second connecting flow channel 5, a lip seal cabin 6 is provided in the center hole of the motor rear end cover 11, and the outer wall of the rotor shaft 2 is connected to the center hole of the lip seal cabin 6 by interference fit. The outlet end of the second connecting flow channel 5 is connected to the liquid flow hole provided on the rotor shaft through the chamber of the lip seal cabin 6, so that the cooling wastewater can flow into the annular jet hole 202 through the lip seal cabin and the liquid flow hole, and finally discharged into the ocean.

Referring to FIG4 , when working, the water pump 1 works passively under the drive of the motor rotor shaft, sucks seawater through the seawater suction hole 201 on the rotor shaft 2, and the seawater cools the rotor assembly during the process of flowing in through the seawater suction hole; the seawater flows into the upper spiral flow channel 401 and the lower spiral flow channel 402 through the two flow channel outlets on the water pump 1, respectively, through the first connecting flow channel 3 arranged vertically symmetrically, to cool the stator assembly 9; the cooling wastewater flows out from the double helical flow channel, flows into the lip seal cabin 6 through the second connecting flow channel 5 arranged on the rear end cover 11 of the motor for liquid exchange, and then flows through the liquid flow hole on the rotor shaft through the annular jet hole 202 and is discharged into the ocean. At the same time, since the double helical flow channel is opened on the inner wall of the motor compartment 15 of the underwater vehicle, the shell of the underwater vehicle is in direct contact with the ocean water, and there is heat exchange between the ocean water in the double helical flow channel and the ocean water outside the shell of the underwater vehicle, which reduces the temperature of the ocean water in the double helical flow channel, further improves the heat dissipation in the motor and the motor compartment, and improves the cooling effect. The cooling system of the present invention realizes uniform heat dissipation of the motor. At the same time, since the cooling waste water is discharged through the annular jet holes arranged on the rotor shaft, it provides forward thrust for the vehicle and improves the efficiency of the underwater vehicle power system.

In order to minimize the impact of the cooling system on the overall weight of the vehicle and to improve the maneuverability and range performance of the vehicle, the motor structure needs to be designed to be lightweight. In addition, due to the different navigation conditions of underwater vehicles, the actual motors carried have different requirements for heat dissipation. To improve the heat dissipation effect, a larger heat dissipation surface area can be obtained by reducing the pitch of the spiral flow channel or increasing the depth and cross-sectional size of the spiral flow channel. At the same time, according to the actual motor performance parameters, the pitch, spiral inclination, cross-sectional size and depth of the double helix flow channel are optimized and adjusted to change the speed and direction of seawater flow to improve the cooling effect. At the same time, the double helix flow channel opened on the inner wall of the underwater vehicle shell will not reduce the strength of the underwater vehicle shell to avoid slight swinging of the underwater vehicle due to the vibration of the motor during navigation.

In addition, the sudden change of water flow will produce instantaneous pressure changes in the heat dissipation flow channel, which is called water hammer. When other conditions remain unchanged, the water hammer will increase as the water flow velocity increases. Water hammer may damage the flow channel, especially at the connection position between the double helix flow channel and the annular jet hole, where the water flow enters the annular jet hole at an angle of 90°. The sudden increase of water hammer will cause serious damage to the rotor shaft.

Therefore, when designing and determining the size of the annular jet hole, it is necessary to consider the relationship between the flow resistance and the load of the water pump according to the actual motor carried, and to maximize the inlet and outlet pressure difference to achieve the effect of the water flow propelling the vehicle. This embodiment obtains appropriate cross-sectional dimensions of the seawater intake hole and the annular jet hole by design, so that the flow resistance of the heat dissipation flow channel is within the range of the water pump Q-H characteristic curve (Q is the flow rate of the water pump, and H is the head of the water pump), and provides a greater forward thrust to the underwater vehicle as much as possible.

Based on the above considerations, this embodiment provides a design method for the above underwater vehicle heat dissipation motor system, which specifically includes the following steps:

Step 1: According to the space and overall weight requirements of the motor compartment of the underwater vehicle, configure the motor for the motor compartment and determine the electromagnetic structure of the motor;

Establishing a simulation model of the motor and the underwater vehicle shell; initially setting the structural parameters of the heat dissipation channel in the model; the structural parameters include the pitch, depth, cross-sectional dimensions and spiral inclination of the double helical channel, and the cross-sectional dimensions of the seawater intake hole and the annular jet hole;

The cross-sectional area ratio of the seawater suction hole to the annular jet hole is initially set to 1;

Step 2, through simulation calculation, obtain the temperature field parameters of the heat dissipation channel and the maximum temperature _Ti of the stator winding, stator core and rotor core when the motor is working at different speeds _{Vi of} the underwater vehicle; where i=1, 2, 3, ..., n. Considering that the stator winding generates a large amount of heat when the underwater vehicle is sailing at a low speed, and the stator core and rotor core generate a large amount of heat when the underwater vehicle is sailing at a high speed, therefore, we only focus on whether the maximum temperature of the stator winding, stator core and rotor core is within the safe operating temperature range of the motor.

Step 3, based on the temperature field parameters obtained in step 2, determine whether the maximum temperatures _Ti of the stator winding, stator core, and rotor core meet the design requirements for the safe operating temperature of the motor at different speeds _Vi . If yes, proceed to step 5; otherwise, proceed to step 4 to adjust the heat dissipation channel parameters;

Step 4, adjusting the heat dissipation channel parameters by reducing the pitch of the double helix channel and/or increasing the cross-sectional size of the double helix channel. After the adjustment, if the motor compartment shell meets the strength design requirements, return to step 2 and step 3 to determine whether the maximum temperature _Ti of the stator winding, the stator core and the rotor core meets the motor safe operating temperature design requirements. If so, proceed to step 5; otherwise, return to step 1 and redetermine the electromagnetic structure of the motor;

Step 5, calculate and obtain the flow resistance along the double helix flow channel and the local flow resistance at the bend of the heat dissipation flow channel, and determine whether the flow resistance along the flow channel and the local flow resistance are within the range of the Q-H characteristic curve of the water pump: if so, the required heat dissipation motor system is obtained; otherwise, adjust the cross-sectional dimensions of the seawater suction hole and the annular jet hole until the flow resistance along the double helix flow channel and the local flow resistance at the bend of the heat dissipation flow channel are within the range of the Q-H characteristic curve of the water pump after adjustment.

In step 5, the specific process of adjusting the cross-sectional dimensions of the seawater suction hole and the annular jet hole so that the flow resistance along the double helical flow channel and the local flow resistance at the bend of the heat dissipation flow channel are within the range of the Q-H characteristic curve of the water pump is as follows:

Step 5.1, set the adjustment step of the cross-sectional area ratio of the seawater intake hole and the annular jet hole, and calculate the cross-sectional dimensions of the seawater intake hole and the annular jet hole based on the adjustment step. In this embodiment, the proportional adjustment step is 0.5, and the proportional adjustment step can also be reduced to obtain more accurate design parameters;

Step 5.2, through simulation calculation, obtain the flow resistance along the double helix flow channel and the local flow resistance at the bend of the heat dissipation flow channel, and determine whether the flow resistance along the flow channel and the local flow resistance are within the range of the Q-H characteristic curve of the water pump:

If yes, then continue to increase the cross-sectional area ratio of the seawater suction hole to the annular jet hole according to step 5.1 until the flow resistance along the way and the local flow resistance are greater than the maximum value of the Q-H characteristic curve range of the water pump;

If not, then the cross-sectional area ratio of the seawater suction hole to the annular jet hole is a limiting ratio. The maximum cross-sectional area ratio of the seawater suction hole to the annular jet hole within the Q-H characteristic curve of the water pump is taken as the optimal cross-sectional area ratio of the seawater suction hole to the annular jet hole, and the cross-sectional dimensions of the seawater suction hole and the annular jet hole are calculated using this optimal cross-sectional dimension ratio.

The above description is only a specific implementation mode of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can easily think of various equivalent modifications or substitutions within the technical scope disclosed in the present invention, and these modifications or substitutions should be included in the protection scope of the present invention.

Claims (8)

1. The underwater equipment heat dissipation motor system is characterized by comprising an underwater equipment shell, a motor and a cooling system; the underwater equipment shell comprises a motor cabin section and a tail cabin section;

the motor comprises a motor front end cover, a rotor assembly, a stator assembly and a motor rear end cover;

The motor front end cover and the motor rear end cover are respectively and radially fixedly arranged at two ends of the motor cabin section cavity, and the rotor assembly and the stator assembly are coaxially arranged between the motor front end cover and the motor rear end cover; the rotor assembly has a rotor shaft for driving the underwater equipment propeller to rotate;

The cooling system is an open type passive self-adaptive cooling system and comprises a heat dissipation flow channel and a water pump arranged at the front end of the rotor shaft; the rear end of the rotor shaft extends out of the tail cabin section and is communicated with the ocean;

the heat dissipation runner comprises a seawater suction hole, a first connecting runner, a double-spiral runner, a second connecting runner and an annular jet hole; the double spiral flow channel is a spiral groove symmetrically arranged on the inner wall of the motor cabin section; the seawater suction hole is a central hole of the rotor shaft; the annular jet hole is coaxially arranged on the rotor shaft and is arranged at the position of the outlet of the second connecting flow passage along the rear end of the rotor shaft;

The water pump is provided with two flow passage outlets which are respectively communicated with the input port of the double-spiral flow passage through first connecting flow passages which are symmetrically arranged, and the output port of the double-spiral flow passage is respectively communicated with the annular jet hole through second connecting flow passages which are symmetrically arranged; the water pump sucks seawater from a central hole of the rotor shaft under the drive of the motor rotor shaft, cools the rotor assembly, cools the stator assembly along the double spiral flow passage, flows out of an outlet of the second connecting flow passage after cooling, and is discharged into the sea through the annular jet hole;

the second connecting flow passage comprises a flow passage radially arranged on the rear end cover of the motor, a lip-shaped seal cabin and a flow hole arranged on the rotor shaft;

two ends of a liquid flow channel radially arranged on a rear end cover of the motor are respectively communicated with an output port of the double-spiral flow channel and the lip-shaped sealing cabin;

The lip seal cabin is arranged in a central hole of the rear end cover of the motor, and the inner wall of the lip seal cabin is in interference fit with the outer wall of the rotor shaft;

A plurality of liquid flow holes are radially formed in the side wall of the rotor shaft and at the position matched with the lip seal cabin, and the liquid flow holes are communicated with the annular jet holes;

the cooling wastewater discharged through the double spiral flow channels is discharged into the ocean through the liquid flow channel, the lip seal cabin, the liquid flow hole and the annular jet hole on the rear end cover of the motor in sequence.

2. The heat-dissipating motor system of claim 1, wherein the rotor assembly comprises the rotor shaft, a rotor core, and a permanent magnet; the rotor shaft, the rotor core and the permanent magnet are nested and fixedly connected from inside to outside coaxially in sequence;

The stator assembly is sleeved on the outer wall of the rotor assembly, a gap exists between the stator assembly and the rotor assembly, the stator assembly comprises a stator core and a stator winding, the outer wall of the stator core is fixed on the inner wall of the motor compartment, and the stator winding is wound in the stator core; under the action of the magnetic force of the permanent magnet and the stator winding, the rotor iron core, the permanent magnet and the rotor shaft rotate together, and the rotor shaft drives the propeller of the underwater equipment to rotate.

3. The heat dissipating motor system of claim 2, wherein a cross-sectional area ratio of said seawater intake port to said annular jet port is 3:1.

4. The heat-dissipating motor system of claim 3, wherein a wall thickness between the seawater intake port and the annular jet port is not less than 8 mm.

5. The heat dissipating motor system of claim 4, wherein the rear shaft body of the rotor shaft is connected to the tail section by a sliding bearing provided in the tail section of the underwater equipment, and an end face of the sliding bearing is fitted to an inner end face of the tail section;

The inner diameter of the chamber of the tail cabin section is provided with a fixed support fixedly connected with the body of the tail cabin section, and the middle section shaft body of the rotor shaft is connected with the central hole of the fixed support through another sliding bearing.

6. The heat dissipation motor system according to claim 5, wherein the fixed support is disc-shaped as a whole, a central hole is formed in the fixed support along the axis, and the fixed support is connected with the outer wall of the rotor shaft through a sliding bearing;

The fixed bolster lateral wall radially is equipped with a plurality of connecting rods, and the connecting rod tip is connected with the lug that sets up on the motor cabinet section inner wall.

7. The method for designing a heat dissipating motor system according to any one of claims 1 to 6, comprising the steps of:

Step 1: according to the space and overall weight requirements of the underwater equipment motor cabin section, configuring a motor for the motor cabin section, and determining the electromagnetic structure of the motor;

Establishing a simulation model of a motor and an underwater equipment shell, and initially setting structural parameters of a heat dissipation runner in the model; the structural parameters comprise the pitch, depth, section size and spiral inclination angle of the double spiral flow channels, and the section sizes of the seawater suction holes and the annular jet holes;

The sectional area ratio of the seawater suction hole to the annular jet hole is initially set to be 1;

Step 2: obtaining temperature field parameters of a heat dissipation runner and the highest temperature T _i of a stator winding, a stator core and a rotor core when the motor sails under water with different sailing speeds V _i through simulation calculation; wherein i=1, 2,3, …, n;

step 3: judging whether the highest temperatures T _i of the stator winding, the stator core and the rotor core meet the motor design requirements under different navigational speeds V _i based on the temperature field parameters obtained in the step 2, and if so, entering the step 5; otherwise, enter step 4 and adjust the parameter of the heat dissipation runner;

step 4: adjusting the parameters of the heat dissipation flow channel in a mode of reducing the pitch of the double-spiral flow channel and/or increasing the cross section size of the double-spiral flow channel, returning to the step 2 and the step 3 under the condition that the motor cabin shell meets the strength design requirement after adjustment, judging whether the highest temperature T _i of the stator winding, the stator core and the rotor core meets the motor design requirement, and entering the step 5 if the highest temperature T _i meets the motor design requirement; otherwise, returning to the step 1, and re-determining the electromagnetic structure of the motor;

Step 5: calculating and obtaining the along-path flow resistance of the double spiral flow channel and the local flow resistance of the bending part of the heat dissipation flow channel, judging whether the along-path flow resistance and the local flow resistance are within the range of the Q-H characteristic curve of the water pump, and if so, obtaining a required heat dissipation motor system; otherwise, the cross section sizes of the seawater suction hole and the annular jet hole are adjusted until the along-distance flow resistance of the double spiral flow channel and the local flow resistance of the bending part of the heat dissipation flow channel can be within the range of the Q-H characteristic curve of the water pump after adjustment.

8. The design method according to claim 7, wherein the specific process of adjusting the cross-sectional dimensions of the seawater intake port and the annular jet port in step 5 is:

step 5.1: setting an adjusting step of the sectional area ratio of the seawater suction hole to the annular jet hole, and calculating to obtain the sectional sizes of the seawater suction hole and the annular jet hole based on the adjusting step;

Step 5.2: obtaining the along-path flow resistance of the double spiral flow channel and the local flow resistance of the bending part of the heat dissipation flow channel through simulation calculation, and judging whether the along-path flow resistance and the local flow resistance are within the range of a Q-H characteristic curve of the water pump;

if yes, continuously increasing the sectional area ratio of the seawater suction hole to the annular jet hole according to the step 5.1 until the along-range flow resistance and the local flow resistance are larger than the maximum value of the Q-H characteristic curve range of the water pump;

If not, the sectional area ratio of the seawater suction hole to the annular jet hole is taken as the limit ratio, the sectional area ratio of the maximum seawater suction hole to the annular jet hole in the Q-H characteristic curve range of the water pump is taken as the optimal sectional area ratio of the seawater suction hole to the annular jet hole, and the sectional size of the seawater suction hole to the annular jet hole is calculated according to the optimal sectional area ratio.