CN111692244A

CN111692244A - Heavy-load electric vehicle wheel-side power and brake system assembly

Info

Publication number: CN111692244A
Application number: CN202010598191.1A
Authority: CN
Inventors: 李麟; 吕家乐; 金子微; 于洋
Original assignee: Northeast Forestry University
Current assignee: Northeast Forestry University
Priority date: 2020-06-28
Filing date: 2020-06-28
Publication date: 2020-09-22
Anticipated expiration: 2040-06-28
Also published as: CN111692244B

Abstract

The invention relates to a wheel-side power and brake system assembly of a heavy-load electric vehicle and a heat dissipation method of the wheel-side power and brake system assembly, belongs to the field of vehicle brakes, and solves the problems that in the prior art, the heavy-load vehicle is poor in braking effect and the brake is heated. The invention comprises the following steps: the brake assembly, the pressurizing unit and the rotary sealing unit; the brake assembly includes: dynamic friction plates and static friction plates; the dynamic friction plate is fixedly connected with a hub of the hub reduction gear, and the hub of the hub reduction gear and a wheel rotate synchronously; the static friction plate is contacted with or separated from the dynamic friction plate under the driving action of the pressurizing unit; the brake assembly is provided with a heat dissipation air inlet channel and a heat dissipation air exhaust channel which are used for exhausting high-temperature gas in the brake assembly to dissipate heat of the brake assembly. The invention realizes the rapid braking of the wheel and the effective heat dissipation of the brake.

Description

Heavy-load electric vehicle wheel-side power and brake system assembly

Technical Field

The invention relates to the technical field of vehicle brakes, in particular to a wheel-side power and brake system assembly of a heavy-load electric vehicle.

Background

Disc brakes have been known in the early 20 s of the last century, but have not been gradually applied to the braking of trains, tanks and airplanes until the later 30 s. The advantages of disc brakes are increasingly recognized by automobile designers as manufacturing techniques advance and recognition continues to increase. At present, the disc brake is widely applied to cars and various medium and heavy-duty automobiles.

The disc brake is a substitute product of a drum brake, and the market demand is large. With the continuous development of automobile technology, low-chassis vehicles based on humanized design, air spring suspension systems based on riding comfort, ABS, ESP and other electronic systems which are more controllable during automobile braking are gradually applied to various vehicles, and disc brakes can be better matched with the advanced technologies. Therefore, the hydraulic or pneumatic disc brake has a wide prospect.

With the increase of the traffic density of wheeled vehicles and the great increase of the vehicle speed, higher and higher requirements are also put on a braking system directly related to the running safety. At present, only friction brakes used on heavy-duty automobiles are divided into drum brakes, belt brakes and disc brakes according to the structures of the friction brakes, wherein the belt brakes are generally only used as central brakes due to the problems of braking capacity, difficult arrangement and the like; drum brakes are often used in heavy vehicles due to their large size and heavy weight, and disc brakes, which are developed rapidly, are currently widely used in cars and light vehicles. The brakes used in existing vehicles are either hydraulic/pneumatic caliper disc brakes, or drum brakes. When the mass of the vehicle is large, the caliper disc brake cannot provide the required braking force. Moreover, the air pressure caliper disc type brake occupies large space outside the vehicle, is inconvenient for the design of the whole vehicle, and is greatly influenced by the environment due to the exposed caliper disc. Whereas drum brakes are easily deformed by heat and have a large volume.

Disclosure of Invention

In view of the above analysis, the present invention aims to provide a wheel-side power and brake system assembly of a heavy-duty electric vehicle and a heat dissipation method thereof, so as to solve the problems that the existing brake occupies a large space outside the vehicle, is inconvenient for the design of the whole vehicle, has a large influence on the performance of the brake due to the exposure of a brake caliper disc, and is easy to heat.

The purpose of the invention is mainly realized by the following technical scheme:

the utility model provides a heavy load electric vehicle wheel limit power and braking system assembly which characterized in that includes: the brake assembly, the pressurizing unit and the rotary sealing unit; the brake assembly includes: dynamic friction plates and static friction plates; the dynamic friction plate is fixedly connected with a hub of the hub reduction gear, and the hub of the hub reduction gear and a wheel rotate synchronously; the static friction plate is contacted with or separated from the dynamic friction plate under the driving action of the pressurizing unit; the brake assembly is provided with a heat dissipation air inlet channel and a heat dissipation air outlet channel, and the heat dissipation air inlet channel and the heat dissipation air outlet channel are used for exhausting high-temperature gas in the brake assembly to dissipate heat of the brake assembly.

Furthermore, there are a plurality of dynamic friction plates and static friction plates, and the dynamic friction plates and the static friction plates are distributed at intervals.

Further, the pressurizing unit includes: the air cylinder comprises an air cylinder pressure plate, an air cylinder air passage, an air cylinder sealing ring and an air cylinder valve; the air cylinder air passage is arranged in the brake shell, and the air cylinder valve is arranged on the brake shell and communicated with the air inlet end of the air cylinder air passage; the air cylinder sealing ring is arranged in a closed space formed by the air cylinder pressure plate and the brake shell; the cylinder sealing ring is a sealing cavity structure which stretches along the axis direction of the transmission shaft.

Furthermore, a plurality of dynamic friction plates are fixed on a dynamic friction plate frame side by side, and the dynamic friction plate frame is fixedly connected with a hub of the hub reduction gear; the plurality of static friction plates are fixed on the static friction plate frame side by side, and the static friction plate frame is fixedly connected with the air cylinder pressing plate.

Further, the rotary seal unit includes: the rotary sealing moving plate and the rotary sealing static plate; the rotary sealing moving plate is fixedly connected with a hub of the hub reduction gear; the rotary sealing stator is fixedly connected with the brake shell; the rotary seal moving plate and the rotary seal static plate are both of annular structures and are in close contact.

Further, the cylinder pressure plate is connected with the brake housing through a return spring and can move relative to the brake housing.

Furthermore, the brake shell is fixedly connected with one end of the rotating shaft through a bolt, and the rotating shaft is fixed relative to the vehicle body; the hub of the hub reduction gear is arranged on the rotating shaft through a bearing.

Further, the heat dissipation air inlet channel is arranged on the brake shell and communicated with the cylinder air channel through an overflow valve. The brake shell is provided with a heat dissipation air inlet channel, and the wheel shaft is provided with a heat dissipation exhaust channel; an overflow valve is arranged between the inlet of the heat dissipation air inlet channel and the air channel of the cylinder, and the overflow valve is used for automatically switching on when the pressure in the cylinder reaches a certain value, so that cooling air flow enters the brake assembly to drive the walking friction plate and the static friction plate to generate heat through friction.

Further, an air inlet is arranged on the static friction plate frame; the movable friction plate frame is provided with an exhaust hole.

The air cylinder pressure plate is connected with the brake shell through a positioning column; the air cylinder pressing plate is provided with an installation through hole, the positioning column is sleeved in the installation through hole, and the air cylinder pressing plate can move relative to the positioning column; the brake casing is equipped with the screw hole, and the one end of reference column is equipped with the screw thread and passes through threaded connection with the brake casing, and return spring is established to the other pot head of reference column, and the cylinder clamp plate is located between return spring and the brake casing.

And a sealing ring is arranged between the hub of the hub reduction gear and the rotating shaft.

The power output by the electric/power generation integrated machine is transmitted to wheels through a transmission shaft and a wheel reduction gear; the hub reduction gear includes: hub of the hub reducer, sun gear, planetary gear of the hub reducer and gear ring.

The wheel is fixedly connected with a planetary gear of the wheel-side reducer, and the planetary gear of the wheel-side reducer is respectively in meshing transmission with the sun gear and the gear ring; the gear ring is fixedly connected with the rotating shaft; the sun wheel is fixedly connected with the transmission shaft; the hub of the hub reduction gear is fixedly connected with the planetary gear of the hub reduction gear through a reduction gear shell.

A heat dissipation method for a heavy-duty electric vehicle wheel-side power and brake system assembly comprises the following steps:

step S1: cooling gas is conveyed to the interior of the brake assembly through the air passage of the air cylinder;

step S2: when the air pressure in the air passage of the cylinder reaches the opening pressure of the overflow valve, the heat dissipation air inlet passage is communicated with the air passage of the cylinder;

step S3: the cooling air flow flows into the brake assembly through the air passage of the air cylinder, the overflow valve, the heat dissipation air inlet channel and the air inlet hole in sequence, and the high-temperature air flow in the brake assembly flows out of the brake assembly through the exhaust hole and the heat dissipation exhaust channel to take away heat generated by friction of the dynamic friction plate and the static friction plate so as to cool the brake assembly.

The invention has at least one of the following beneficial effects:

1) good thermal stability and no self-setting action: the surface pressure is uniformly distributed compared with the drum type, the friction plate is heated to expand axially little, the radial expansion does not influence the efficiency, the radius of the heated expansion friction surface of the brake drum of the drum type brake is increased, the friction surface can only contact with the brake shoe in the middle, the contact area is reduced, the pressure distribution is uneven, and uneven abrasion and reduced braking efficiency are caused. The brake of the present invention is small in size and weight under a certain output torque condition.

2) The friction plate is not thick and has a much smaller tendency to form hot cracks (spots) at high temperatures during operation than the drum. The friction plate set has small axial expansion caused by heating, and can not cause large pedal stroke change caused by expansion like a drum type, and the invention automatically adjusts the clearance, simplifies the mechanism and saves the installation space.

3) The friction plate of the disc brake is easy to replace, and lubricating oil is added into the brake, so that the friction plate is easy to maintain. Furthermore, the parts which are easy to wear of the disc brake are only the friction plates and the sealing elements, so that the long-term use of the brake can be maintained only by replacing the friction plates and the sealing elements of the pressurizing cylinder, the maintenance is convenient, and the service life is prolonged.

4) The disc brake of the invention realizes the switching between braking and non-braking of the brake by the contact or separation of the pressurizing unit, namely the air pressure driving friction plates, therefore, the disc brake of the invention is easy to combine with ABS and ESP, and controls the braking time and the braking force by controlling the driving time of the air pressure driving and the magnitude of the driving force, thus leading the vehicle to have better braking performance and higher reliability.

5) The friction plate chamber full-sealing structure enables the wheeled vehicle to be wider in use region, namely, the wheeled vehicle can be used on land and also can be applied to sea and shoals with serious seawater and salt spray corrosion.

6) The invention carries out service braking by matching the motor/generator with the air pressure full-disc brake: in the braking starting stage, the motor/generator works in a power generation mode to generate braking force and recover energy; and in the tail sound braking stage, the air pressure multi-plate full-disc brake works to finally brake the vehicle. In addition, the invention also provides a heat dissipation system for the air pressure full-disc brake, and the overflow valve automatically distributes the gas in the brake cylinder to the brake assembly and discharges the gas out of the brake assembly.

In the invention, the technical schemes can be combined with each other to realize more preferable combination schemes. Additional features and advantages of the invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. The objectives and other advantages of the invention will be realized and attained by the structure particularly pointed out in the written description and drawings.

Drawings

The drawings are only for purposes of illustrating particular embodiments and are not to be construed as limiting the invention, wherein like reference numerals are used to designate like parts throughout.

FIG. 1 is a schematic diagram of the wheel-side power and braking system assembly of a heavy-duty electric vehicle of the present invention;

fig. 2 is an enlarged view of the heat dissipation air inlet.

Reference numerals:

1-a wheel, 2-a hub reduction gear, 3-a rotary sealing unit, 4-a brake assembly, 5-a pressurizing unit, 6-a cylinder return spring, 7-a rotating shaft, 8-a transmission shaft, 9-a bearing, 10-a cylinder sealing ring, 11-a static friction plate, 12-a dynamic friction plate, 13-a rotary sealing static plate, 14-a rotary sealing dynamic plate, 15-a gear ring, 16-a planet wheel, 17-a sun wheel, 18-a hub reduction gear hub, 19-a dynamic friction plate frame, 20-a reduction gear shell, 21-a brake shell, 22-a cylinder pressure plate, 23-a cylinder air passage and 24-a cylinder valve; 25-1-a first bolt; 25-2-second bolt; 26-a sealing ring; 27-electric/power generation integrated machine; 28-relief valve; 29-a muffler; 30-an all-in-one motor/generator rotor; 31-an all-in-one motor/generator stator; 32-heat dissipation air inlet channel; 33-heat dissipation exhaust passages; 34-an air intake; 35-air vent.

Detailed Description

The accompanying drawings, which are incorporated in and constitute a part of this application, illustrate preferred embodiments of the invention and together with the description, serve to explain the principles of the invention and not to limit the scope of the invention.

With the increase of the traffic density of wheeled vehicles and the great increase of the vehicle speed, higher and higher requirements are also put on a braking system directly related to the running safety. With the trend that electric vehicles are becoming the most dominant transportation vehicles, the driving and braking system assembly structure for distributed driving heavy-duty electric vehicles needs to be designed.

One embodiment of the present invention discloses a heavy-duty electric vehicle wheel-side power and brake system assembly, as shown in fig. 1-2, comprising: brake housing 21, brake assembly 4, rotary seal unit 3 and pressurizing unit (drive unit) 5, wherein brake assembly 4 includes: the dynamic friction plate 12 and the static friction plate 11, the dynamic friction plate 12 is fixedly connected with a hub 18 of the hub reducer, namely, during normal running, the dynamic friction plate 12 and a wheel rotate synchronously, and the static friction plate 11 is still; in the braking state, the static friction plate 11 contacts with the dynamic friction plate 12 under the driving action of the pressurizing unit 5 and generates friction, so that the dynamic friction plate 12 is accelerated to decelerate or stop rotating. That is, the static friction plates 11 are brought into contact with or separated from the dynamic friction plates 12 by the driving action of the pressurizing unit 5, whereby the switching between the braking state and the non-braking state of the brake is realized.

Further, the brake housing 21 is of an inverted U-shaped structure, the brake housing 21 is fixedly connected with the rotating shaft 7 of the vehicle through the first bolt 25-1, and the rotating shaft 7 is fixed relative to the vehicle body. The brake friction plates 12, the brake static friction plates 11, and the pressurizing unit 5 are all disposed inside the brake housing 21.

Further, during the running of the vehicle, the hub 18 of the hub reducer rotates in synchronization with the wheel 1.

Further, the brake assembly 4 further includes: the brake comprises an air cylinder return spring 6, a rotating shaft 7, a bearing 9, a dynamic friction plate frame 19, a static friction plate frame, a brake shell 21 and an air cylinder pressure plate 22;

the dynamic friction plate 12 is fixedly connected with a hub 18 of the hub reduction gear, and the static friction plate 11 is fixedly connected with a cylinder pressure plate 22.

When the vehicle runs, the dynamic friction plate 12 rotates with the hub 18 of the hub reducer and the wheel 1, and the static friction plate 11 is static relative to the rotating shaft 7, namely the vehicle body. When the vehicle is braked, the cylinder presser plate 22 is moved toward the dynamic friction plates 12 by the driving of the pressurizing unit 5, and the plurality of static friction plates 11 are brought into contact with the dynamic friction plates 12 adjacent thereto, respectively, and rub against each other. The friction resistance of the static friction plate 11 to the dynamic friction plate 12 reduces or prevents the dynamic friction plate 12 from rotating, thereby realizing the braking of the wheel 1.

Further, there are a plurality of dynamic friction plates 12 and static friction plates 11, the number of the dynamic friction plates 12 is the same as that of the static friction plates 11, and the dynamic friction plates 12 are distributed at intervals with the static friction plates 11, or the dynamic friction plates 12 are arranged across the static friction plates 11, as shown in fig. 1.

The dynamic friction plates 12 are arranged on a dynamic friction plate frame 19 side by side, and the dynamic friction plate frame 19 is fixedly connected with a hub 18 of the hub reduction gear through a second bolt 25-2; the static friction plates 11 are fixed on the static friction plate frame side by side, and the static friction plate frame is fixedly connected with the air cylinder pressure plate 22; the dynamic friction plate frame 19 and the static friction plate frame are both of a cylindrical structure with an L-shaped section, as shown in FIG. 1. The dynamic friction plate 12 and the static friction plate 11 are both in a thin plate annular structure, the dynamic friction plate 12 is fixed on the outer side of a dynamic friction plate frame 19, the static friction plate 11 is fixed on the inner side of the static friction plate frame, the dynamic friction plate frame 19 is sleeved in the static friction plate frame, and the dynamic friction plates 12 and the static friction plates 11 are distributed in a staggered mode (in an interdigital state). During braking, the adjacent dynamic friction plate 12 and static friction plate 11 are in close contact, and the static friction plate 11 applies braking force to the dynamic friction plate 12.

The dynamic friction plate 12 and the static friction plate 11 are designed like a clutch pressure plate, and the difference is that the static friction plate 11 of the invention only linearly displaces relative to the axial direction of the rotating shaft 7, and does not generate rotary motion relative to the rotating shaft 7.

According to the invention, the plurality of static friction plates 11 and the plurality of dynamic friction plates 12 are respectively in contact friction to reduce the rotating speed of the dynamic friction plates 12, and finally the braking of the wheel 1 is realized, the plurality of friction plates are arranged at intervals, so that the uniform distribution of braking torque in space is realized, and the damage or damage of the suddenly appeared braking torque to the structure of the hub 18 of the hub reducer is avoided.

The contact mode of the static friction plate 11 and the dynamic friction plate 12 can effectively reduce the friction force/braking torque born by a single friction plate, when a certain braking torque needs to be applied to the hub 18 of the wheel-side speed reducer, the more the dynamic friction plate 12 and the static friction plate 11 are, the smaller the friction force distance born by the single friction plate is, the damage to the friction plate in the braking process can be effectively reduced, the braking effect of the brake is improved, and meanwhile, the service life of the brake is prolonged.

Further, the pressurizing unit 5 is driven in at least two ways: hydraulic drive, pneumatic drive. The air cylinder pressure plate 22 is driven by hydraulic pressure or air pressure to move towards the dynamic friction plate 12, and the static friction plate 11 is further driven to be in contact with the dynamic friction plate 12, so that braking is realized.

In this embodiment, the structural design of the pressurizing unit 5 will be described by taking pneumatic driving as an example.

The pressurizing unit 5 includes: cylinder pressure plate 22, cylinder air passage 23, cylinder valve 24 and cylinder seal ring 10.

Because the cylinder seal ring 10 is a sealed cavity structure which can be extended and shortened along the direction of the transmission shaft 8, the cylinder seal ring 10 is communicated with the cylinder air passage 23. Thus, the cylinder air passage 23 is in fact made of an elastic and stretchable material in the cylinder interior. The air cylinder pressing plate 22 is pushed to move along the axial direction of the transmission shaft 8 in the process of extending and retracting of the air cylinder.

Further, the invention is provided with a return spring 6, and the return spring 6 is used for realizing the return of the cylinder pressure plate 22 and the static friction plate 11 after the braking is finished. Specifically, the return spring has two mounting modes: (1) the return spring 6 is arranged between the cylinder pressure plate 22 and the brake shell 21; (2) the return spring 6 is provided on one side of the cylinder platen 22.

(1) When the return spring 6 is disposed between the cylinder platen 22 and the brake housing 21: two ends of the return spring 6 are fixedly connected with the air cylinder pressure plate 22 and the brake shell 21 through welding respectively, when the air cylinder pressure plate 22 moves towards the direction of the dynamic friction plate 12 under the driving of the pressurizing unit 5, the return spring 6 is stretched, after the pressurizing unit 5 stops braking and pressurizing, the return spring 6 has the tendency of recovering the initial length, and in the process that the return spring 6 recovers the initial length, the air cylinder pressure plate 22 returns to the initial position under the elastic force action of the return spring 6.

(2) When the return spring 6 is disposed on one side of the cylinder platen 22: as shown in fig. 1, the cylinder pressure plate 22 and the brake housing 21 are connected by a positioning column. Specifically, the cylinder pressing plate 22 is provided with a mounting through hole, the brake housing 21 is provided with a threaded hole, one end of the positioning column is provided with threads and is connected with the brake housing 21 through the threads, and the positioning column is sleeved in the mounting through hole of the cylinder pressing plate 22. The other end of reference column is equipped with spacing cap, and spacing cap diameter is greater than return spring 6 diameter, and return spring 6 cover is established on the reference column, and is located between spacing cap and the cylinder clamp plate 22, and spring one end is spacing through spacing cap, and the other end and cylinder clamp plate 22 contact.

The return spring adopts a second installation mode in this embodiment, and the installation process of the positioning column and the return spring 6 is as follows: after the return spring 6 is sleeved on the positioning column, the positioning column passes through a through hole of the air cylinder pressure plate 22 and is screwed into a threaded hole of the brake shell 21.

After the installation, the positioning column is fixedly connected with the brake housing 21 through threads, and the return spring 6 and the cylinder pressing plate 22 can slide relative to the positioning column. When the brake is braked, the air cylinder pressure plate 22 moves towards the direction of the dynamic friction plate 12 under the driving action of the pressurizing unit 5, and the air cylinder pressure plate 22 compresses the return spring 6; when the brake stops braking, the pressurizing unit 5 does not apply pressure to the cylinder pressing plate 22 any more, and the spring force of the return spring 6 pushes the cylinder pressing plate 22 to return to the initial position.

Further, the rotary seal unit 3 includes: a rotary seal rotor 14 and a rotary seal stator 13. The rotary seal rotor 14 and the rotary seal stator 13 are both annular structures and are made of elastic material, such as rubber.

The rotary seal rotor 14 is fixedly connected to the hub 18 of the hub reduction gear by means of bonding, engagement, or the like. The rotary seal stator 13 is fixedly connected to the brake housing 21 by bonding, engaging, or the like. When the vehicle runs, the rotary sealing rotor 14 and the hub 18 of the hub reducer rotate synchronously, the rotary sealing stator 13 is static relative to the rotating shaft 7/vehicle body, and the rotary sealing rotor 14 and the rotary sealing stator 13 are tightly attached and rotate relatively to realize sealing of the inner space of the brake shell 21.

Further, the hub 18 of the hub reduction gear is rotatably connected to the rotating shaft 7 via a bearing 9, so that the hub reduction gear 18 can rotate with respect to the rotating shaft 7.

Further, a seal ring 26 is provided between the hub 18 of the wheel reduction gear and the rotating shaft 7, the seal ring 26 is interposed between the hub 18 of the wheel reduction gear and the rotating shaft 7, and the seal ring 26 and the hub 18 of the wheel reduction gear are rotationally sealed when the vehicle is running. The sealing ring 26 is a standard component, is made of rubber, has elasticity, and is used for preventing impurities in the friction sheet bin from entering the bearing 9 and the gear bin and preventing lubricating oil from being polluted, and the installation mode is manual pressing.

Further, a sealing gasket is arranged between the brake housing 21 and the rotating shaft 7.

Under the combined action of the rotary sealing unit 3, the sealing ring 26 and the sealing gasket, the sealing of oil in the inner space of the brake is realized, and the overflow of the oil in the brake is prevented.

Further, the wheel 1 inputs power through a transmission shaft 8, and the rotating speed input by the transmission shaft 8 is reduced by a wheel reduction gear 2 according to a fixed transmission ratio and then is transmitted to the wheel 1. Specifically, the hub reduction gear 2 includes: a hub reduction housing 20, a ring gear 15, planet wheels 16, a sun wheel 17 and a hub reduction hub 18.

As shown in fig. 1, the ring gear 15 is fixedly connected to the rotating shaft 7, that is, the ring gear 15 is fixed to the vehicle body, and the ring gear 15 does not rotate at all times during traveling.

The sun gear 17 is fixedly connected with the transmission shaft 8, and the sun gear synchronously transmits the rotation of the transmission shaft 8. The planet wheel 16 is respectively meshed with the sun wheel 17 and the gear ring 15, the planet wheel 16 rotates around the sun wheel 17 while rotating, and the rotating speed input by the transmission shaft 8 is reduced according to a certain transmission ratio and then is output to the hub 18 of the hub reduction gear and the wheel 1.

The hub 18 of the hub reducer is connected with the planet wheel 16, the hub 18 of the hub reducer rotates around the axis of the transmission shaft 8, or the hub 18 of the hub reducer rotates around the central axis of the sun wheel 17, and the rotation speed of the hub 18 of the hub reducer is the same as that of the planet wheel 16 rotating around the sun wheel 17.

The wheel 1 is fixedly connected with a hub 18 of the hub reducer, and the wheel 1 and the hub 18 of the hub reducer rotate synchronously. The hub 18 of the hub reduction gear is fixedly connected with the planetary gear 16 of the hub reduction gear through a shell 20 of the reduction gear.

Further, in consideration of the fact that the static friction plate 11 and the dynamic friction plate 12 are always in a mutual friction state in the braking process, a large amount of heat is easily generated due to friction heat generation, the temperature of the brake friction plate is too high, the braking performance of the brake is reduced, the brake is easily damaged, and the service life of the brake is shortened, the brake is further provided with the heat dissipation unit to dissipate heat.

Further, the heat dissipating unit includes: the brake comprises a relief valve 28, a silencer 29, a heat dissipation air inlet passage 32 arranged on a brake shell 21, a heat dissipation air outlet passage 33 arranged on a rotating shaft 7, an air outlet hole 35 arranged on a dynamic friction plate frame 19 and an air inlet hole 34 arranged on a static friction plate frame.

The exhaust hole 35 and the intake hole 34 are used to exhaust high-temperature gas in a sealed space formed when the dynamic friction plate 12 and the static friction plate 11 contact each other (the high-temperature gas is a relative concept, and means that the temperature of the gas is increased by frictional heat generated by the dynamic friction plate 12 and the static friction plate 11).

Further, the exhaust hole 35 is communicated with the heat dissipation exhaust passage 33, or the exhaust hole 35 is communicated with a closed space formed when the dynamic friction plate 12 is contacted with the static friction plate 11 and a middle cavity of the brake assembly 4; the high temperature gas can exit the brake assembly 4 via the exhaust vent 35, the heat sink exhaust vent 33, for cooling the brake assembly 4.

Further, the air inlet holes 34 are communicated with the heat dissipation air inlet channel 32, specifically, the air inlet holes 34 are communicated with the closed space formed when the dynamic friction plates 12 and the static friction plates 11 are contacted and the heat dissipation air inlet channel 32, and the heat dissipation air inlet channel 32 can introduce low-temperature gas (relative to the concept, relative to high-temperature gas in the closed space) into the brake assembly 4, so as to reduce the temperature of the brake assembly 4.

Further, the heat dissipation air inlet passage 32 is communicated with the cylinder air passage 23 through the overflow valve 28, or the overflow valve 28 is installed between the inlet of the heat dissipation air inlet passage 32 and the cylinder air passage 23, and when the pressure in the cylinder reaches a certain value, the overflow valve 28 is opened, and the heat dissipation air inlet passage 32 is automatically communicated with the cylinder air passage 23.

After the heat dissipation air inlet channel 32 is communicated with the air channel of the air cylinder, cooling air flows sequentially flow through the air channel 23 of the air cylinder, the overflow valve 28, the heat dissipation air inlet channel 32 and the air inlet 34 to enter the brake assembly 4, and high-temperature air flows out of the brake assembly 4 through the exhaust hole 35 and the heat dissipation air outlet channel 33 to take away heat generated by friction of the dynamic friction plate 12 and the static friction plate 11 and cool the brake assembly 4.

Further, the intake hole 34 and the exhaust hole 35 are each provided in plurality.

Furthermore, a silencer 29 is additionally arranged at the tail end of the heat dissipation exhaust passage 33, so that noise generated in the braking and heat dissipation processes of the brake is reduced.

Further, the integrated electric/power generation machine 27 includes: an all-in-one motor/generator rotor 30 and an all-in-one motor/generator stator 31; wherein, the rotor 30 of the electric/power generation integrated machine is fixedly connected with the transmission shaft 8, and the stator 31 of the electric/power generation integrated machine is fixedly connected with the rotating shaft 7; when the electric/power generation integrated machine 27 works in the motor mode, power is output to the wheels through the transmission shaft 8; when braking, firstly, the motor/generator integrated machine 27 works in a generator mode, the motor/generator integrated machine 27 generates braking torque to convert the mechanical energy of the vehicle into electric energy to be stored in a battery, and the braking energy can be partially recovered.

When in implementation:

the rotary element (i.e. dynamic friction plate 12) and the static element (i.e. static friction plate 11) of the wheel-side air pressure full-disc brake of the vehicle are made of composite material discs working in end face contact. When the automobile brake is in operation, friction surfaces between the friction plates are in complete contact, so that a larger braking torque is generated to brake the automobile.

The fixed friction element and the rotating element of the vehicle wheel-side air pressure full-disc brake are both disc-shaped, and the friction surfaces of the discs are all contacted when braking, so that the working principle of the brake is like a friction clutch, and the brake is a clutch type brake. The brake of the invention adopts a plurality of plates, the friction coefficient is particularly small when the plates brake, and the heat generated by the braking between the plates is also small, so the heat can be dissipated through the shell of the brake.

When braking, firstly, the motor/generator integrated machine (27) works in a generator mode, and the motor/generator integrated machine (27) generates braking torque to convert the mechanical energy of the vehicle into electric energy to be stored in a battery; and after the vehicle speed is reduced, braking is carried out through the friction plate.

Specifically, the pressurizing cylinder pushes the cylinder platen. The air cylinder pressure plate moves to enable the dynamic brake pads and the static brake pads to be mutually compressed to increase the braking force and transmit the braking force to the friction plate set. After the clearance between the friction plates is eliminated, the friction plate groups are mutually attached and tightly held, and braking is realized. Braking and returning: when the brake pedal is released, the air pressure of the air chamber is released, and the brake cylinder is driven to return to the initial position under the action of the return spring, so that a gap is automatically generated between the friction plates. In fact, due to the friction force between the friction plates, a gap is automatically generated between the friction plates, and the friction force is negligible.

The heavy-load electric vehicle wheel-side power and brake system assembly is mainly used for braking large heavy-load vehicles, and has the advantages of small volume, compact structure, light weight, simplicity in operation, good brake performance, simplicity in maintenance, wide use region and strong corrosion and salt mist resistance. The brake device has stable brake effect, can obviously reduce brake distance and provides reliable safety guarantee for vehicles. Meanwhile, the brake noise can be significantly reduced. Effectively solving the noise pollution caused by braking.

Example 2

The embodiment provides a braking method of a hub full-disc brake in embodiment 1, which includes the following specific steps:

during braking, firstly, the motor/generator integrated machine 27 works in a generator mode, the motor/generator integrated machine 27 generates braking torque, and when the motor/generator integrated machine 27 generates the power, the rotating speed of the transmission shaft 8 can be reduced, and mechanical energy of a vehicle is converted into electric energy to be stored in a battery; and after the vehicle speed is reduced, braking is carried out through the full-disc brake.

When the brake is braked, high-pressure gas is controlled to enter the cylinder of the pressurizing unit 5 from the cylinder air passage 23 through the cylinder valve 24. The cylinder pushes the cylinder pressure plate 22 toward one side of the brake lining 12. The cylinder pressure plate 22 drives the static friction plate 11 to contact with the dynamic friction plate 12 and mutually press the static friction plate and the dynamic friction plate to generate braking torque. The braking torque is transmitted to the wheel 1 through the hub of the hub reduction gear 2, so that the vehicle is decelerated.

When the vehicle stops braking, the high-pressure gas in the pressurizing unit 5 is controlled to be discharged to the atmosphere through the cylinder air passage 23 and the cylinder valve 24, so that the pressurizing unit 5 is depressurized, and the cylinder pressure plate 22 moves towards the direction away from the dynamic friction plate under the pushing of the return spring 6. A certain gap is formed between the static friction plate 11 and the dynamic friction plate 12, so that the braking torque of the brake disappears, that is, the braking process of the vehicle is finished.

When the vehicle is normally running, the brake does not generate braking torque. The power of the vehicle is transmitted from the transmission shaft 8 to the sun gear 17 of the hub reduction gear 2, and then to the hub and the wheel 1 via the planetary gear 16.

When the wheel 1 rotates, the rotation shaft 7 and the brake housing 21 are stationary. The hub is synchronous to the rotation of the wheel, and the hub 18 of the hub reducer and the brake shell 21 rotate relatively. The rotary sealing rotor 14 also rotates along with the hub 18 of the hub reducer; the rotary seal stator 13 is stationary like the brake housing 21. Sliding friction exists between the rotary seal moving plate 14 and the rotary seal static plate 13.

Further, at the start of braking, the motor/generator operates in the generating mode to generate braking force and recover energy; and in the tail sound braking stage, the air pressure multi-plate full-disc brake works to finally brake the vehicle.

Example 3

The present embodiment provides a heat dissipation method for the wheel-side power and brake system assembly of the heavy-duty electric vehicle of embodiment 1, including the following steps:

step S1: cooling gas is conveyed to the interior of the brake assembly 4 through a cylinder air passage 23;

step S2: when the air pressure in the cylinder air passage 23 reaches the opening pressure of the overflow valve 28, the heat dissipation air inlet passage 32 is communicated with the cylinder air passage 23;

step S3: the cooling air flow sequentially flows through the air channel 23 of the air cylinder, the overflow valve 28, the heat dissipation air inlet channel 32 and the air inlet hole 34 to enter the interior of the brake assembly 4, and the high-temperature air flow in the interior of the brake assembly 4 flows out of the brake assembly 4 through the exhaust hole 35 and the heat dissipation exhaust channel 33 to take away the heat generated by friction of the dynamic friction plate 12 and the static friction plate 11 to cool the brake assembly 4.

Further, when the brake is braked, the brake assembly 4 is sealed by the rotary sealing unit 3 and the sealing ring 26.

Compared with the prior art, the invention has at least one of the following beneficial effects:

the heavy-duty vehicle wheel-side power and brake system assembly structure is generally applied to heavy-duty electric vehicles and can provide larger braking force. The static part and the rotating part of the heavy-duty electric vehicle wheel-side power and brake system assembly structure are both disc-shaped and are respectively called as a static friction plate and a rotating friction plate. All working surfaces of the static friction plate are simultaneously contacted with the rotating friction plate, so that a larger braking torque is generated to brake the automobile.

The heavy-duty vehicle wheel-side power and brake system assembly structure has the advantages of low noise, environmental protection, small vibration, improvement on riding comfort and the like in use. The wheel side power and braking system assembly structure of the heavy-duty electric vehicle greatly improves the directional stability of the heavy-duty electric vehicle during high-speed braking, and is beneficial to control of the operation stability of a distributed driving vehicle and recovery of braking energy, so that the heavy-duty electric vehicle becomes a necessary trend for the development of modern electric vehicle brakes.

The above description is only for the preferred embodiment of the present invention, but the scope of the present invention is not limited thereto, and any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope of the present invention are included in the scope of the present invention.

Claims

1. The utility model provides a heavy load electric vehicle wheel limit power and braking system assembly which characterized in that includes: a brake assembly (4), a pressurizing unit and a rotary sealing unit (3); the brake assembly (4) comprises: a dynamic friction plate (12) and a static friction plate (11); the dynamic friction plate (12) is fixedly connected with a hub (18) of a hub reduction gear, and the hub (18) of the hub reduction gear and the wheel (1) rotate synchronously; the static friction plate (11) is in contact with or separated from the dynamic friction plate (12) under the driving action of the pressurizing unit.

2. The heavy-duty electric vehicle wheel side power and brake system assembly according to claim 1, wherein there are a plurality of dynamic friction plates (12) and static friction plates (11), and the dynamic friction plates (12) and the static friction plates (11) are distributed at intervals.

3. The heavy-duty electric vehicle wheel-side power and brake system assembly of claim 2, wherein said compression unit comprises: the air cylinder sealing device comprises an air cylinder pressure plate (22), an air cylinder air passage (23), an air cylinder sealing ring (10) and an air cylinder valve (24); the cylinder air passage (23) is arranged inside the brake shell (21), and the cylinder valve (24) is arranged on the brake shell (21) and communicated with the air inlet end of the cylinder air passage (23); the air cylinder sealing ring (10) is arranged in a closed space formed by an air cylinder pressure plate (22) and a brake shell (21); the cylinder sealing ring (10) is of a sealing cavity structure which stretches along the axis direction of the transmission shaft (8).

4. The heavy-duty electric vehicle wheel-side power and brake system assembly according to claim 3, wherein a plurality of said dynamic friction plates (12) are fixed side by side on a dynamic friction plate frame (19), and said dynamic friction plate frame (19) is fixedly connected with a wheel-side reducer hub (18); the static friction plates (11) are fixed on the static friction plate frame side by side, and the static friction plate frame is fixedly connected with the air cylinder pressing plate (22).

5. The heavy-duty electric vehicle wheel-side power and brake system assembly according to claim 4, characterized in that the rotary seal unit (3) comprises: a rotary seal rotor (14) and a rotary seal stator (13); the rotary sealing moving plate (14) is fixedly connected with a hub (18) of the hub reduction gear; the rotary sealing static sheet (13) is fixedly connected with the brake shell (21); the rotary seal moving plate (14) and the rotary seal static plate (13) are both of annular structures and are in close contact.

6. The heavy-duty electric vehicle wheel side power and brake system assembly of claim 5, characterized in that said cylinder pressure plate (22) is connected with the brake housing (21) by a return spring (6) and is movable relative to the brake housing (21).

7. The heavy-duty electric vehicle wheel-side power and brake system assembly according to claim 6, wherein the brake housing (21) is fixedly connected with one end of the rotating shaft (7) through a bolt, and the rotating shaft (7) is fixed relative to the vehicle body; and the hub (18) of the hub reduction gear is arranged on the rotating shaft (7) through a bearing (9).

8. The heavy-duty electric vehicle wheel-side power and brake system assembly of claim 4, wherein the dynamoelectric machine rotor (30) of the dynamoelectric machine (27) is connected to the drive shaft (8), the dynamoelectric machine (27) being configured to output power as a motor and recover kinetic energy as generator regenerative braking.

9. The heavy-duty electric vehicle wheel-side power and brake system assembly as recited in claim 8, wherein the brake housing (21) is provided with a heat-dissipating air inlet duct (32), and the wheel axle (7) is provided with a heat-dissipating air outlet duct (33); an overflow valve (28) is arranged between the inlet of the heat dissipation air inlet channel (32) and the cylinder air channel (23); the static friction plate frame is provided with an air inlet hole (34); and the movable friction plate frame (19) is provided with an exhaust hole (35).

10. The method for dissipating heat from a heavy-duty electric vehicle wheel-side power and brake system assembly according to claims 1-9, comprising the steps of:

step S1: cooling gas is conveyed to the interior of the brake assembly (4) through a cylinder air passage (23);

step S2: when the air pressure in the air passage (23) of the cylinder reaches the opening pressure of the overflow valve (28), the heat dissipation air inlet passage (32) is communicated with the air passage (23) of the cylinder;

step S3: cooling air flows sequentially flow into the brake assembly (4) through the air cylinder air passage (23), the overflow valve (28), the heat dissipation air inlet channel (32) and the air inlet hole (34), high-temperature air flows in the brake assembly (4) flow out of the brake assembly (4) through the exhaust hole (35) and the heat dissipation exhaust channel (33), and heat generated by friction of the dynamic friction plate (12) and the static friction plate (11) is taken away to cool the brake assembly (4).