CN110798047A

CN110798047A - Internal cooling type eddy current brake device with double coils for vehicle

Info

Publication number: CN110798047A
Application number: CN201911192399.7A
Authority: CN
Inventors: 叶乐志; 张宇龙; 李德胜
Original assignee: Beijing University of Technology
Current assignee: Beijing University of Technology
Priority date: 2019-11-28
Filing date: 2019-11-28
Publication date: 2020-02-14

Abstract

The invention discloses a double-coil inner-cooling type eddy current brake device for a vehicle, which consists of a stator, a rotor, coils and a controller, wherein the stator is arranged on the rotor; the device has adopted inside water-cooling mode, and direct cooling heating surface and coil, eddy current brake performance is more stable, satisfies long-time continuous braking demand, promotes retarder unit volume's braking force. By adopting the structural design of the double coils and the double rotors, the axial space can be effectively utilized in the limited outer diameter size, the magnetic circuit efficiency is improved, the manufacturing and the assembly are easy, the grading control is easy, and the control cost is low. The internal cooling mode of the device reduces the influence of the casting process on the magnetic efficiency, is easy to manufacture and assemble and has low cost; the device has wide application range and can be assembled at the positions of an axle, a transmission shaft, a gearbox and the like; easy to control in different stages and can use relay to control in low cost.

Description

Internal cooling type eddy current brake device with double coils for vehicle

Technical Field

The invention relates to a water-cooled eddy current brake device, and belongs to the field of automobile auxiliary braking.

Background

China is a mountainous country, roads in mountainous areas account for a considerable proportion, and the driving safety of heavy commercial vehicles in road transportation is threatened by high speed, heavy load, long-time downhill slope and frequent braking. As an expedient for solving the overheating of the brake, many drivers spray water to the brake or cool the brake in a cooling liquid for braking dedicated to a parking lot on a highway, but frequent water spraying causes a reduction in the life of the brake pad and an increase in the use cost, and water spraying in winter causes the road surface to be frozen. The auxiliary braking device can greatly reduce the number of times of stepping on the brake, has obvious effect on brake overheating or emergency braking, can avoid traffic accidents caused by brake failure due to overheating of the main brake, and can greatly improve the running safety of the vehicle. The vehicle with the auxiliary braking device can prolong the service life of a transmission system, a braking system and tires of the vehicle, reduce the fuel consumption, effectively reduce the use cost of the vehicle and reduce the environmental noise caused by braking of the vehicle. Auxiliary braking devices on the market at present comprise engine braking, exhaust braking, an eddy current retarder and a hydraulic retarder. The eddy current retarder is rapidly popularized on a passenger car due to the advantages of low cost, good low-speed braking performance, flexible installation mode and the like. However, the eddy current retarder has the problems of high temperature, heat fading of braking force, heavy weight and the like when in work, so the application and popularization of the eddy current retarder on a truck are inferior to those of a hydraulic retarder. However, the hydrodynamic retarder also has the defects of poor low-speed performance, high possibility of water leakage of high-pressure dynamic seal, high cost and the like.

An auxiliary brake device (eddy current retarder) based on the eddy current principle utilizes an electromagnetic coil to generate a magnetic field, and forms a magnetic circuit with air gaps among a stator, a rotor and a stator rotor. The automobile converts kinetic energy into heat energy through a magnetic field in the driving process to be consumed, and then the non-contact deceleration effect is achieved. The traditional eddy current retarder adopts an air cooling mode to dissipate heat, so that the temperature of the retarder is overhigh, the performance is seriously reduced, the retarder continuously works for 10 minutes, and the braking torque is reduced by more than 50 percent. At present, most of water-cooled eddy current retarders are provided with a water channel through a stator, eddy current heat is taken away by using engine cooling liquid or a self-contained cooling system, but the eddy current heat source is not in contact with liquid at the generating position and is in a heat conduction mode, so that the temperature of an eddy current surface can also reach more than 300 ℃.

Application number 200520068140.9 discloses an eddy current retarder, which utilizes eddy current to generate braking torque, but has high temperature, difficult heat dissipation and serious heat fading; the double-salient-pole liquid-cooled eddy current retarder with the application number of 201320792505.7 adopts water-cooling heat dissipation, solves the problem of overhigh continuous braking temperature, reduces heat fading, but has heavy rotor weight and only has a single-coil structure; the application number 201610383587.8 discloses a rotor embedded electromagnetic liquid-cooled retarder which adopts a rotor embedded structure and water-cooling heat dissipation, the heat dissipation effect is good, the weight of a rotor is small, and only a single-coil structure is adopted; a liquid cooling electromagnetic retarder of application number 201711052419.1 adopts double coil and big magnetic circuit design, and magnetic circuit is not walked to intermediate bottom, but stator water course structure is complicated, and is with high costs, and excitation coil does not adopt effective cooling measure. Therefore, it is necessary to further propose a more optimized solution to the above problems.

Disclosure of Invention

The invention aims to provide an inner-cooling type eddy current brake device which can be used for auxiliary braking of passenger cars and trucks. The device has adopted inside water-cooling mode, and direct cooling heating surface and coil, eddy current brake performance is more stable, satisfies long-time continuous braking demand, promotes retarder unit volume's braking force. By adopting the structural design of the double coils and the double rotors, the axial space can be effectively utilized in the limited outer diameter size, the magnetic circuit efficiency is improved, the manufacturing and the assembly are easy, the grading control is easy, and the control cost is low. The invention adopts the design of small magnetic circuit, the total magnetic flux is shunted, and the weight of the stator is reduced

The invention adopts the technical scheme that the automotive double-coil inner-cooling type eddy current brake device is composed of a stator, a rotor, coils and a controller. The stator includes an outer vortex tube and an inner vortex tube, and the rotor includes a rotor disk and rotor teeth. The rotor is located inside the stator, the stator is coaxial with the rotor teeth, and the rotor teeth, the outer vortex cylinder and the inner vortex cylinder are provided with working air gaps. The coil is fixed in the stator, coaxial with the rotor and arranged on two sides of the rotor. And a sealing ring is arranged between the stator and the rotor and used for sealing the internal cooling liquid.

The working method of the device is as follows: the stator is fixed, the stator is filled with cooling liquid, when the controller controls the coil to be electrified, a magnetic circuit is formed among the stator, the rotor teeth and the air gap, the rotor is driven to rotate by a vehicle transmission shaft, and the air gap magnetic flux density is periodically changed along with the rotation of the rotor teeth, so that the stator cuts magnetic lines emitted by the rotating rotor teeth. Thus, eddy currents are generated in the inner layer of the outer eddy current cylinder of the stator and the outer layer of the inner eddy current cylinder, and the magnetic field generated by the eddy currents interacts with the air gap magnetic field, thereby generating a braking torque that resists rotation of the rotor teeth, which is ultimately transmitted to the vehicle drive shaft, creating a braking resistance to the vehicle. The braking device converts the kinetic energy of the vehicle into heat energy on the stator, the heat energy is taken away through cooling liquid, the cooling liquid enters from the water inlet, flows out from the water outlet and is connected with a vehicle heat dissipation system to form circulating cooling.

The outer vortex cylinder and the inner vortex cylinder of the stator are coaxially designed and can form a cooling liquid sealing structure, and the stator is provided with a water inlet and a water outlet and is connected with a cooling circulation system of the whole vehicle.

The stator is made of a material with excellent magnetic permeability, such as low-carbon steel.

The rotor disc is made of non-magnetic conducting materials and is generally made of aluminum or stainless steel materials.

The rotor teeth are gear-shaped, generally comprise two, each rotor tooth comprises 8-16 teeth, are arranged on two sides of the rotor disc, and are made of materials with excellent magnetic conductivity, such as low-carbon steel.

And a certain gap is reserved between the rotor teeth and the inner and outer vortex cylinders of the stator, and the gap is generally 0.5-2.5 mm.

The coils are formed by winding copper wires or aluminum wires, generally two coils are wound, a single group or multiple groups of coils are wound, and the coils are soaked in cooling liquid.

The water inlet is generally arranged at the lower end, and the water outlet is arranged at the upper end.

The controller is used for controlling the on-off and the size of current in the coil, and can be controlled by a relay or an electronic component.

The invention provides a double-coil inner-cooling type eddy current brake device which is used for auxiliary braking of a vehicle. The device adopts a stator and rotor sealing structure, realizes that internal water cooling can achieve better cooling effect, and the eddy current braking performance is more stable; the coil is designed to be water-cooled, so that the requirement of long-time continuous braking is met; the double-coil and double-rotor structural design can effectively utilize the axial space within the limited outer diameter size, and the unit volume braking force of the device is improved; the double-air-gap structure maximally utilizes the eddy surface of the magnetic circuit, and the braking efficiency is greatly improved compared with that of the traditional braking; the internal cooling mode of the device reduces the influence of the casting process on the magnetic efficiency, is easy to manufacture and assemble and has low cost; the device has wide application range and can be assembled at the positions of an axle, a transmission shaft, a gearbox and the like; easy to control in different stages and can use relay to control in low cost.

Drawings

Fig. 1 is a schematic structural view of the braking device of the present invention.

FIG. 2 is a layout view of the whole vehicle eddy current braking device of the present invention.

Fig. 3 is a schematic diagram of the controller circuit of the present invention.

Fig. 4 is a three-dimensional schematic view of a rotor of the present invention.

FIG. 5 is a schematic representation of a rear-mounted gearbox configuration according to an embodiment of the present invention.

In the figure: 1 electric eddy current brake device, 2 engine, 3 gearbox, 4 radiator, 5 thermostat, 6 flange, 7 vehicle rear axle and 8 universal joint

1101 stator outer eddy current barrel 1102 stator inner eddy current barrel 1201 rotor teeth 1202 rotor disc 1301 coil 1401 controller 1501 coolant liquid 1502 oil seal 1503 sealing ring 1601 bearing 1602 spline 1701 drive shaft 1702 flange 1901 water inlet 1902 water outlet 11001 bolted connection

14011 control circuit 14012 control switch 14013 electric eddy current brake equipment working indicator lamp 14014 electric eddy current brake equipment circuit

3101 the support frame for an eddy current brake assembly.

Detailed Description

The invention is described in more detail below with reference to the accompanying drawings of embodiments:

referring to fig. 1 and 2, the eddy current braking device 1 is disposed between the transmission case 3 and the rear axle 7 of the vehicle, when the vehicle is running, the engine 2 generates power to transmit the rotation to the eddy current braking device 1 through the transmission case 3 and the transmission shaft, and the eddy current braking device 1 transmits the rotation to the rear axle 7 of the vehicle through the transmission shaft, so as to drive the vehicle to run. And a transmission shaft is connected between the gearbox 3 and the eddy current brake device 1 and between the eddy current brake device 1 and a vehicle rear axle 7 through universal joints and flanges 6. When the eddy current brake device 1 is operated, the braking torque on the transmission shaft 1701 is transmitted to the engine 2 and the rear axle 7 of the vehicle through the flange 6, the flange 1702 and the universal joint, thereby completing the braking operation of the vehicle.

Referring to fig. 1, when a drive shaft 1701 rotates, the drive shaft 1701 drives a rotor disc 1202 to rotate through a spline 1602, rotor teeth 1201 are fixed to the rotor disc 1202 by bolts and rotate along with the rotor disc 1202 in a stator outer vortex cylinder 1101 and a stator inner vortex cylinder 1102, the stator inner vortex cylinder 1102 and the drive shaft 1701 are matched by bearings, the stator outer vortex cylinder 1101 and the stator inner vortex cylinder 1102 are fixed on a vehicle body, a closed space is formed by the stator inner vortex cylinder 1102, the stator outer vortex cylinder 1101, the rotor disc 1202 and a sealing ring 1503, and cooling liquid 1501 is filled in the closed space. When the controller 1401 controls the coil 1401 to be electrified, a magnetic loop is formed among the stator outer eddy current cylinder 1101, the stator inner eddy current cylinder 1102, the rotor teeth 1201 and air gaps among the stator outer eddy current cylinder 1101, the stator inner eddy current cylinder 1102, the rotor teeth 1201 and the air gaps, and the air gap magnetic flux density is periodically changed along with the rotation of the rotor teeth 1201 in the rotation process of the rotor teeth 1201, so that the stator cuts magnetic lines of force emitted by the rotating rotor teeth 1201. Accordingly, eddy currents are generated in the inner layer of the stator outer eddy current bobbin 1101 and the outer layer of the inner eddy current bobbin 1102, and a magnetic field generated by the eddy currents interacts with the air-gap magnetic field, thereby generating a braking torque that prevents the rotor teeth 1201 from rotating, which is finally transmitted to the vehicle drive shaft 1701, thereby performing a braking operation on the vehicle.

Referring to fig. 2, the eddy current braking device is provided with a water inlet and a water outlet, and is connected with a cooling circulation system of the whole vehicle. When the vehicle runs, the cooling liquid 1501 flows into the eddy current brake device 1 under the driving of the engine 2, the cooling liquid 1501 flows through the inner cavity of the eddy current brake device, takes away heat on the stator outer eddy current cylinder 1101, the stator inner eddy current cylinder 1102 and the coil 1301, flows out of the water outlet 1902, flows to the thermostat 5 to judge whether the temperature of the cooling liquid 1501 is proper or not, flows into the radiator 4 if the temperature is too high, is cooled by the radiator 4 and then flows back to the engine to finish the cooling process, and then the next cycle is carried out; if the temperature is not high, the coolant flows into the engine 2, completes the cooling process, and then proceeds to the next cycle.

Referring to fig. 3, a schematic diagram of a controller circuit is shown, three relays (K1-K3) and 6 diodes (D1-D6) are used to receive the current signal of the control switch 14012 to determine the operating gear, control of the peripheral component electric eddy current brake indicator 14013 and the coil 14014 is completed according to the gear information, and the electric eddy current brake 14013 is controlled according to the low-speed driving state of the vehicle and the ABS signal. The relays K1 and K2 are normally open when being contacted, and the relay K3 is normally closed when being contacted. When the control switch 14012 is shifted to 1 gear, the first gear signal causes the relay K1 to be attracted through the coil loop of the relay K1 in the control circuit 14011, the 24V power signal passes through the contact of the relay K1 to electrify the coil L1 of the eddy current brake device, and the eddy current brake device 1 starts to work. The 24V power supply signal passes through a contact diode D2 of a relay K1 and an operating indicator lamp 14013 of the eddy current brake device, so that the indicator lamp 14013 is operated and lightened, and the retarder is in an operating state. When the control switch 14012 is shifted to the 2-gear, the second-gear signal causes the relay K2 to be attracted through the coil loop of the relay K2 in the control circuit 14011, the 24V power signal passes through the contact of the relay K2, the coil L2 of the eddy current brake device is electrified, and the braking torque of the eddy current brake device 1 is enhanced. When the running speed of the vehicle is lower than a certain speed or a low-level signal generated by an ABS and a temperature sensor enters a coil loop of the relay K3, the contact of the relay K3 is disconnected, and the eddy current brake device stops working.

Referring to FIG. 4, a three-dimensional schematic view of a rotor is shown, the rotor comprising rotor disk 1202 and rotor teeth 1201, rotor teeth 1201 are secured to both sides of rotor disk 1202 by bolting, and rotor disk 1202 is circumferentially connected to drive shaft 1701 by splines 1602. Rotor teeth 1201 are made of magnetically permeable material and rotor disk 1202 is made of magnetically non-permeable material.

Referring to fig. 5, which is a schematic diagram of a rear structure of a transmission case according to an embodiment of the present invention, an eddy current braking device 1 is fixed to the transmission case through an eddy current braking device bracket 3101, a flange 6 is fixedly connected to a transmission shaft of the transmission case, the flange 6, a rotor disc 1201 and a universal joint 8 are circumferentially fixed by a bolt connection 11001, and when the transmission shaft of the transmission case rotates, the transmission shaft of the transmission case drives the rotor to rotate and transmits the rotation to a rear axle 7 of a vehicle. When the eddy current braking device 1 works, a magnetic circuit is formed among the stator outer eddy current cylinder 1101, the stator inner eddy current cylinder 1102, the rotor teeth 1201 and air gaps among the stator outer eddy current cylinder 1101, the stator inner eddy current cylinder 1102, the rotor teeth 1201 and the air gaps among the rotor teeth, and the air gap magnetic flux density changes periodically along with the rotation of the rotor teeth 1201 in the rotation process of the rotor teeth 1201, so that the stator cuts magnetic lines of force emitted by the rotating rotor teeth. Therefore, eddy currents are generated in the inner layer of the stator outer eddy current cylinder 1101 and the outer layer of the inner eddy current cylinder 1102, and a magnetic field generated by the eddy currents interacts with the air-gap magnetic field, so that a braking torque for preventing the rotor teeth 1201 from rotating is generated, and the braking torque is finally transmitted to a transmission shaft of a vehicle, thereby completing a braking operation of the vehicle.

Claims

1. A double-coil inner-cooling type eddy current brake device for a vehicle is characterized in that: the device consists of a stator, a rotor, a coil and a controller; the stator comprises an outer vortex cylinder and an inner vortex cylinder, and the rotor comprises a rotor disk and rotor teeth; the rotor is positioned in the stator, the stator is coaxial with the rotor teeth, and the rotor teeth, the outer vortex cylinder and the inner vortex cylinder are provided with working air gaps; the coil is fixed in the stator, coaxial with the rotor and arranged on two sides of the rotor; and a sealing ring is arranged between the stator and the rotor and used for sealing the internal cooling liquid.

2. A twin-coil internal-cooling type eddy current brake apparatus for a vehicle as claimed in claim 1, wherein: the outer vortex cylinder and the inner vortex cylinder of the stator are coaxially designed and can form a cooling liquid sealing structure, and the stator is provided with a water inlet and a water outlet and is connected with a cooling circulation system of the whole vehicle.

3. A twin-coil internal-cooling type eddy current brake apparatus for a vehicle as claimed in claim 1, wherein: the stator is made of low-carbon steel.

4. A twin-coil internal-cooling type eddy current brake apparatus for a vehicle as claimed in claim 1, wherein: the rotor disc is made of aluminum material or stainless steel.

5. A twin-coil internal-cooling type eddy current brake apparatus for a vehicle as claimed in claim 1, wherein: the rotor teeth are in a gear shape, two rotor teeth are provided, each rotor tooth comprises 8-16 teeth, the rotor teeth are arranged on two sides of the rotor disc and are made of low-carbon steel.

6. A twin-coil internal-cooling type eddy current brake apparatus for a vehicle as claimed in claim 1, wherein: and a gap of 0.5-2.5mm is reserved between the rotor teeth and the inner and outer vortex cylinders of the stator.

7. A twin-coil internal-cooling type eddy current brake apparatus for a vehicle as claimed in claim 1, wherein: the coil is formed by winding a copper wire or an aluminum wire, and the coil is wound by a single group or multiple groups and is soaked in cooling liquid.

8. A twin-coil internal-cooling type eddy current brake apparatus for a vehicle as claimed in claim 2, wherein: the water inlet is arranged at the lower end, and the water outlet is arranged at the upper end.

9. A twin-coil internal-cooling type eddy current brake apparatus for a vehicle as claimed in claim 1, wherein: the controller is used for controlling the on-off and the size of the current in the coil.

10. A twin-coil internal-cooling type eddy current brake apparatus for a vehicle as claimed in claim 1, wherein: the stator is fixed, the stator is filled with cooling liquid, when the controller controls the coil to be electrified, a magnetic loop is formed among the stator, the rotor teeth and the air gap, the rotor is driven to rotate by a vehicle transmission shaft, and the air gap magnetic flux density is periodically changed along with the rotation of the rotor teeth, so that the stator cuts magnetic lines emitted by the rotating rotor teeth; therefore, eddy currents are generated on the inner layer of the outer eddy current cylinder of the stator and the outer layer of the inner eddy current cylinder, and a magnetic field generated by the eddy currents interacts with an air gap magnetic field, so that a braking torque for preventing the rotor teeth from rotating is generated, and the braking torque is finally transmitted to a vehicle transmission shaft to generate braking resistance on a vehicle; the braking device converts the kinetic energy of the vehicle into heat energy on the stator, the heat energy is taken away through cooling liquid, the cooling liquid enters from the water inlet, flows out from the water outlet and is connected with a vehicle heat dissipation system to form circulating cooling.