A magnetorheological fluid slow-speed non-drive axle and vehicle

Abstract

The present invention relates to the field of vehicle technology, and specifically to a magnetorheological fluid slow-speed non-driven axle and a vehicle. The non-driven axle provided by the present invention comprises: a non-driven axle housing and a wheel input shaft, wherein the two ends of the non-driven axle housing are respectively connected to the wheel input shaft, and further comprises: a working chamber, a screw and an oil storage chamber, wherein the working chamber is a closed chamber located in the non-driven axle housing, and the two ends of the side walls of the working chamber are respectively provided with a closable oil inlet and an oil outlet, and an electromagnetic device is also provided outside the side walls of the working chamber; the screw is located in the working chamber and is arranged corresponding to the electromagnetic device, connected in series to the inner end of the wheel input shaft, and meshed with the stator of the working chamber to form a screw pump structure; the oil storage chamber forms a circulating oil circuit between the oil storage chamber and the working chamber, and adopts magnetorheological fluid to improve the heat dissipation and lubrication performance, and the magnitude of the screw torque can be controlled by controlling the magnetic force of the electromagnetic device.

Description

Technical Field

[0001] The present invention relates to the technical field of vehicles, and in particular to a magnetorheological fluid retarding non-drive axle and a vehicle. Background Art

[0002] Urban roads have many intersections, dense bus stops, and heavy passenger flow, so buses often have to brake frequently. Mountain roads are steep and have many sharp turns, so medium and large trucks and buses that travel on mountain roads for a long time also often need to brake.

[0003] When the brakes are working for a long time and used frequently, the brake shoes will wear out quickly, the service life of the brake friction pads will be shortened, and the braking ability will be lost or the braking performance will be greatly reduced due to the thermal decay of the brakes, which has become the main reason for frequent traffic accidents. Therefore, it is necessary to equip the vehicle with an auxiliary braking system.

[0004] The retarder is currently the main auxiliary braking component of the vehicle. It reduces the maximum load of the vehicle's braking system by acting on the vehicle's transmission system, allowing the vehicle to decelerate evenly, thereby improving the reliability of the vehicle's braking system, extending the service life of the braking system, and significantly reducing the cost of vehicle use.

[0005] When existing retarders are used on medium and large vehicles, they are mostly arranged in parallel or series behind the gearbox and cannot act directly on the non-drive axle. This often results in the tractor braking while the heavily loaded trailer is not braking when going down a long slope, which leads to brake folding and traffic accidents. At the same time, the independently set retarder is too large in size, high in cost, heavy in body, consumes a lot of electricity and is greatly affected by the ambient temperature, so it cannot play its value in actual use. Summary of the invention

[0006] (I) The technical problem to be solved by the present invention is that the existing retarder has the problem that the torque size is uncontrollable and cannot directly act on the non-drive axle, which makes the independently set retarder large in size, high in cost, and easily affected by the surrounding external environment, causing safety problems.

[0007] (II) Technical solution

[0008] In order to solve the above technical problems, an embodiment of the present invention provides a non-drive axle, including a non-drive axle housing and a wheel input shaft, wherein the wheel input shaft is internally connected to both ends of the non-drive axle housing, and further including a working chamber, a screw and an oil storage chamber, wherein:

[0009] A working chamber is a closed chamber located in the non-drive axle housing, and the non-drive axle housing constitutes the side wall of the working chamber. A stator is arranged in the working chamber, and a closable oil inlet and an oil outlet are respectively arranged at both ends of the side wall. An electromagnetic device is also arranged outside the side wall of the working chamber;

[0010] A screw, located in the working chamber and arranged corresponding to the electromagnetic device, connected in series to the inner end of the wheel input shaft, and meshing with the stator in the working chamber to form a screw pump structure;

[0011] The oil storage chamber is located in the non-drive axle housing, is externally connected to an oil inlet circuit and an oil outlet circuit, and is connected to the oil inlet through the oil inlet circuit and to the oil outlet through the oil outlet circuit, so that a circulating oil circuit is formed between the oil storage chamber and the working chamber.

[0012] According to one embodiment of the present invention, the outer wall of the non-drive axle housing is also connected to a heat exchange device. During the deceleration process, the screw stirs the magnetorheological fluid to convert the vehicle's driving kinetic energy into thermal energy, and the heat is dissipated through the outer wall of the non-drive axle housing. By adding a heat exchange device to the outer wall of the non-drive axle housing, the heat dissipation can be accelerated.

[0013] According to one embodiment of the present invention, an electric control valve is further provided on the oil inlet line, and the electric control valve is used to control the on-off of the oil inlet line.

[0014] According to one embodiment of the present invention, the screw is a single screw or a plurality of screws connected in series, or a multi-stage screw, so as to increase the single-turn displacement and improve the deceleration torque.

[0015] According to an embodiment of the present invention, the screw rod and the wheel input shaft are connected in series via a universal joint assembly, thereby ensuring that the instantaneous angular velocities of the two are always equal.

[0016] According to one embodiment of the present invention, the inner end of the wheel input shaft is externally connected to the first fixed bearing, and the inner end of the screw rod is externally connected to the second fixed bearing, with a certain distance between them, which is conducive to forming a working chamber between the first fixed bearing and the second fixed bearing.

[0017] According to one embodiment of the present invention, an electromagnetic device is also provided on the outside of the oil outlet passage.

[0018] According to an embodiment of the present invention, a first solenoid valve is provided on the oil outlet line. The first solenoid valve may be an electromagnetic proportional valve. The main control system may effectively control the diameter of the oil outlet line.

[0019] According to an embodiment of the present invention, the oil inlet circuit is further connected to an air inlet hole controlled by a second solenoid valve, and the air inlet hole can unload the working chamber in the magnetorheological fluid retarding non-drive axle when no-load.

[0020] Another aspect of the present invention provides a vehicle, comprising the non-drive axle described in any one of the above embodiments.

[0021] The beneficial effects of the present invention are as follows: since large vehicles have a large number of non-drive axles and require a relatively low deceleration power, the non-drive axle provided by the present invention forms an auxiliary deceleration structure through the oil circuit setting and the screw rod built into the non-drive axle housing, and the medium adopts magnetorheological fluid, so that the overall heat dissipation and lubrication performance of the magnetorheological fluid deceleration non-drive axle are improved, and the size of the screw torque can be controlled by controlling the size of the magnetic force of the electromagnetic device. The compact structure saves a lot of space while effectively reducing costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the specific implementation methods of the present invention or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0023] Figure 1 A schematic diagram of the partial structure of the magnetorheological fluid retarding non-driving bridge provided in one embodiment of the present invention.

[0024] Icons: 1. Non-drive axle housing; 2. Wheel input shaft; 10. Working chamber; 101. Oil inlet; 102. Oil outlet; 103. Stator; 20. Screw; 30. Oil storage chamber; 40. Oil inlet circuit; 401. First solenoid valve; 402. Air inlet; 403. Electric control valve; 404. Second solenoid valve; 50. Oil outlet circuit; 60. Heat exchange device; 70. Universal joint assembly; 80. First fixed bearing; 90. Second fixed bearing; 100. Electromagnetic device. DETAILED DESCRIPTION

[0025] In order to more clearly understand the above-mentioned purposes, features and advantages of the present invention, the present invention is further described in detail below in conjunction with the accompanying drawings and specific embodiments. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention. In the absence of conflict, the embodiments of the present application and the features in the embodiments can be combined with each other.

[0026] The present invention adopts a series screw pump mechanical structure, the medium is a magnetorheological fluid, which is arranged inside the axle housing of a non-driving axle and forms a magnetorheological fluid slow-speed non-driving axle.

[0027] like Figure 1As shown, an embodiment of the present invention provides a magnetorheological fluid retarding non-drive axle, which is applied to medium and large vehicles to assist in retarding and braking. One or more groups of magnetorheological fluid retarding non-drive axles may be provided. The magnetorheological fluid retarding non-drive axles include a non-drive axle housing 1 and a wheel input shaft 2. The two ends of the non-drive axle housing 1 are respectively connected to the wheel input shaft 2. The non-drive axle housing 1 also includes a working chamber 10, a screw 20 and an oil storage chamber 30, wherein:

[0028] The working chamber 10 is a closed chamber located in the non-drive axle housing 1, and the non-drive axle housing 1 constitutes the side wall of the working chamber 10. The working chamber 10 is provided with a stator 103, and the two ends of the side wall are respectively provided with a closable oil inlet 101 and an oil outlet 102. The side wall of the working chamber 10 is also provided with an electromagnetic device 100;

[0029] The screw 20 is located in the working chamber 10 and is arranged corresponding to the electromagnetic device 100, is connected in series to the inner end of the wheel input shaft 2, can rotate under the drive of the wheel input shaft 2, and meshes with the stator 103 in the working chamber 10 to form a screw pump structure;

[0030] The oil storage chamber 30 is used to store magnetorheological fluid. Magnetorheological fluid (MR fluid for short) is a controllable fluid that can exhibit high viscosity and low fluidity under the action of a certain magnetic field strength. The oil storage chamber 30 is located in the non-drive axle housing 1, and is externally connected to the oil inlet circuit 40 and the oil outlet circuit 50. The oil inlet circuit 40 is connected to the oil inlet port 101. The screw 20 rotates and engages with the stator 103, and pump pressure is generated in the working chamber 10, so that the magnetorheological fluid in the oil storage chamber 30 can pass through the oil inlet circuit 40, the oil inlet port 101, the working chamber 10, the oil outlet port 102 and the oil outlet circuit 50 in sequence, and finally flow back to the oil storage chamber 30, thereby forming a circulating oil circuit.

[0031] Furthermore, the above structures can be symmetrically arranged on both sides of the magnetorheological fluid retarding non-driving bridge, and share an oil storage cavity 30.

[0032] Furthermore, the outer wall of the non-drive axle housing 1 is also connected to a heat exchange device 60. During the deceleration process, the screw 20 stirs the magnetorheological fluid to convert the vehicle's driving kinetic energy into thermal energy, and the heat is dissipated through the outer wall of the non-drive axle housing 1. By adding a heat exchange device 60 to the outer wall of the non-drive axle housing 1, the heat dissipation can be accelerated.

[0033] Furthermore, an electrically controlled valve 403 is provided on the oil inlet circuit 40 , and the electrically controlled valve 403 is used to control the on-off of the oil inlet circuit 40 . The electrically controlled valve 403 may be a one-way valve controlled by an auxiliary pump, and its direction is the same as that of the oil inlet circuit 40 .

[0034] Furthermore, the oil storage chamber 30 is arranged in the middle of the non-drive axle housing 1. Being arranged in the middle can make the overall stability and balance of the magnetorheological fluid retarding non-drive axle better.

[0035] Furthermore, the screw 20 is a single screw or a plurality of screws 20 connected in series, or a multi-stage screw 20, so as to increase the single-turn displacement and improve the deceleration torque.

[0036] Furthermore, the screw rod 20 and the wheel input shaft 2 are connected in series via a universal joint assembly 70, thereby ensuring that the instantaneous angular velocities of the two are always equal.

[0037] Furthermore, the inner end of the wheel input shaft 2 is externally connected to the first fixed bearing 80 , and the inner end of the screw rod 20 is externally connected to the second fixed bearing 90 , with a certain distance between them, which is conducive to forming a working chamber 10 between the first fixed bearing 80 and the second fixed bearing 90 .

[0038] Furthermore, an electromagnetic device 100 is also provided on the oil outlet passage 50 to improve the deceleration torque.

[0039] Furthermore, the oil outlet passage 50 is provided with a first solenoid valve 401 , which may be an electromagnetic proportional valve, and the main control system may effectively control the diameter of the oil outlet passage 50 .

[0040] Specifically: when the vehicle encounters a downhill slope or passes a sharp bend and needs to slow down, the main control system controls the electronically controlled valve 403 to open the oil inlet circuit 40, and the first solenoid valve 401 controls and reduces the diameter of the oil outlet circuit 50, so that the diameter of the oil inlet circuit 40 is larger than the diameter of the oil outlet circuit 50, thereby generating a pressure difference in the working chamber 10, and at the same time, the electromagnetic device 100 is energized to increase the viscosity of the magnetorheological fluid and further increase the resistance.

[0041] Furthermore, the oil inlet circuit is also connected to an air inlet hole 402 controlled by a second solenoid valve 404. The opening of the air inlet hole 402 can unload the working chamber 10 in the magnetorheological fluid retarding non-drive bridge when it is unloaded. The unloading process is achieved by controlling the opening of the air inlet hole 402 through the second solenoid valve 404. The screw pump structure in the working chamber 10 continues to operate, discharges the liquid in the working chamber 10 and inhales air. Due to the entry of air, the pump structure is in an empty state, and the oil inlet circuit 40 is closed. No new oil enters, so the pump structure no longer generates torque. A small amount of oil still exists in the pump structure for lubrication.

[0042] Another embodiment of the present invention further provides a vehicle, especially a medium to large vehicle, comprising the magnetorheological fluid retarded non-drive axle described in any of the above embodiments. According to the actual needs of the vehicle, the magnetorheological fluid retarded non-drive axle can be provided with one or more groups.

[0043] Since the retarder is arranged in the non-drive axle housing, it not only effectively utilizes the space, but also can generate a certain braking force to prevent brake folding. In addition, the current hydraulic retarder cannot achieve anti-lock due to its slow control response. The retarder medium adopts magnetorheological fluid medium, and the control frequency response can reach hundreds of hertz, which can achieve anti-lock. This solves the problem that the current retarder cannot be used on slippery roads.

[0044] The deceleration principle of the magnetorheological fluid deceleration non-drive bridge is:

[0045] When deceleration is required, the input shaft rotates under the drive of the wheel and drives the screw 20 to rotate. Since the screw 20 is meshed with the stator 103 in the working chamber 10, a screw pump structure is formed. The oil inlet circuit 40 switch is controlled by the electric control valve 403. During the rotation of the screw 20, a certain pump pressure can be generated to suck the magnetorheological fluid pre-stored in the oil storage chamber 30 into the working chamber 10, so that the working chamber 10 is filled with the magnetorheological fluid. Since the magnetorheological fluid is between the screw 20 and the stator 103, a volumetric pump is formed. By controlling the magnetic force of the electromagnetic device 100, the viscosity of the magnetorheological fluid is controlled, so that the resistance generated when the screw 20 in the working chamber 10 rotates can be controlled, thereby realizing the controllable braking torque and achieving different deceleration effects according to the actual needs of the vehicle.

[0046] At present, conventional retarders are all mixed flow pumps, namely hydraulic retarders, eddy current retarders, and positive displacement pump retarders, which are mostly arranged behind the gearbox, at the input end of the drive axle, or inside the drive axle.

[0047] The present invention adopts a series screw pump mechanical structure, the medium is a magnetorheological fluid, which is arranged in the non-drive axle housing, especially in the trailer non-drive axle housing, and is integrated into a slow-speed non-drive axle. An oil storage chamber is set in the middle, and permanent magnet blocks are evenly distributed at the outer diameter of the housing and the screw to reduce the leakage of the meshing gap. Each output port is combined into a porous electromagnetic damping structure, and the damping increases when the current increases, and the damping is minimal when the power is off. When slowing down, power is added according to requirements to generate corresponding pump pressure and torque.

[0048] Compared with other high viscosity media, the use of magnetorheological fluid can also make the working chamber 10 less prone to oil leakage, so that the processing accuracy of the non-drive axle can be appropriately reduced, and the heat dissipation and lubrication properties of magnetorheological fluid are better than those of high viscosity oil media. The viscosity of the magnetorheological fluid can be increased by controlling the electromagnetic device 100, effectively increasing the braking torque during braking, and the electromagnetic control frequency can reach more than 500Hz, so the optimal tire braking slip rate can be accurately utilized to achieve the most ideal braking distance.

[0049] When the system is unloaded, the electric control valve 403 is closed to block the oil from entering the working chamber 10, and the second solenoid valve 404 is opened to allow air to enter through the air inlet 402, so that the working chamber 10 is emptied and only part of the magnetorheological fluid is left for lubrication. The screw 20 and the vehicle transmission shaft idle together, and the resistance loss is small and can be ignored. In this process, the first solenoid valve 401 can also be used to increase the diameter of the oil outlet passage 50, which can reduce the pressure when the oil is discharged, thereby reducing the resistance when the system is unloaded.

[0050] The above structure enables, when the vehicle needs to slow down, the control system controls the magnetorheological fluid retarding non-drive axle to enter the deceleration working mode, generates a certain amount of deceleration torque, reduces the use frequency of the main brake and prolongs its life. It can also completely solve the problem of only arranging the retarder on the drive axle, which causes the trailer brake to fold during deceleration, thereby reducing the occurrence of traffic accidents.

[0051] In the description of the present invention, it should be noted that the terms "upper", "lower", etc., indicating the orientation or positional relationship are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance.

[0052] The specific embodiments described herein are merely examples of the concept of the present invention. Those skilled in the art may make various modifications or additions to the specific embodiments described or replace them in similar ways, but they will not deviate from the spirit of the present invention or exceed the scope defined by the appended claims.

Claims

1. A magnetorheological fluid retarding non-drive axle, comprising a non-drive axle housing (1) and a wheel input shaft (2), wherein both ends of the non-drive axle housing (1) are respectively internally connected to the wheel input shaft (2), and characterized in that: Also includes: A working chamber (10) is a sealed chamber located in the non-drive axle housing (1), and the non-drive axle housing (1) constitutes a side wall of the working chamber (10); a stator (103) is provided in the working chamber (10), and a closable oil inlet (101) and an oil outlet (102) are respectively provided at two ends of the side wall; an electromagnetic device (100) is also provided outside the side wall of the working chamber (10); A screw (20) is located in the working chamber (10) and is arranged corresponding to the electromagnetic device (100), is connected in series to the inner end of the wheel input shaft (2), and is meshed with the stator (103) in the working chamber (10) to form a screw pump structure; The oil storage chamber (30) is used to store magnetorheological fluid and is located in the non-drive axle housing (1) and is externally connected to an oil inlet circuit (40) and an oil outlet circuit (50), wherein the oil inlet circuit (40) is connected to the oil inlet port (101), and the oil outlet circuit (50) is connected to the oil outlet port (102), so that a circulating oil circuit is formed between the oil storage chamber (30) and the working chamber (10).

2. The magnetorheological fluid retarding non-drive axle according to claim 1, characterized in that: The outer wall of the non-drive axle housing (1) is also connected to a heat exchange device (60).

3. The magnetorheological fluid retarding non-drive axle according to claim 1, characterized in that: The oil inlet line is also provided with an electric control valve (403).

4. The magnetorheological fluid retarding non-drive axle according to claim 1, characterized in that: The screw (20) is a single screw or a plurality of screws (20) connected in series.

5. The non-drive axle according to claim 1, characterized in that: The screw rod (20) and the wheel input shaft (2) are connected in series via a universal joint assembly (70).

6. The magnetorheological fluid retarding non-drive axle according to claim 1, characterized in that: The inner end of the wheel input shaft (2) is externally connected to a first fixed bearing (80), and the inner end of the screw rod (20) is externally connected to a second fixed bearing (90).

7. The magnetorheological fluid retarding non-drive axle according to claim 1, characterized in that: An electromagnetic device (100) is also provided on the outside of the oil outlet passage (50).

8. The magnetorheological fluid retarding non-drive axle according to any one of claims 1 to 7, characterized in that: The oil outlet passage (50) is provided with a first solenoid valve (401), and the first solenoid valve (401) is an electromagnetic proportional valve.

9. The magnetorheological fluid retarding non-drive axle according to claim 8, characterized in that: The oil inlet circuit (40) is also connected to an air inlet hole (402) controlled by a second solenoid valve (404).

10. A vehicle, characterized in that: A magnetorheological fluid retarding non-drive bridge comprising any one of claims 1 to 9.

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