Patent Description:
In the related art, a structure of a drive axle assembly of a vehicle is complex, a finished drive axle assembly is expensive, and an assembly volume is relatively large. After the drive axle assembly is assembled on the vehicle, a ground clearance of the vehicle is relatively small. In addition, the drive axle assembly is relatively heavy. During travelling of the whole vehicle, a very large torque is generated on an attachment surface of the axle assembly and a power assembly. As a result, the attachment surface easily cracks or has a relatively large strain, resulting in an oil leakage. In addition, a gear shifting manner of the existing drive axle assembly is gear shifting by an electro-hydraulic module. The entire module has a complex structure, is expensive, and requires high maintenance costs. When the drive axle assembly is transmitting a torque, all gears are in a working state and no gear is idle. Therefore, the service life of the gears is relatively short and the noise of the whole assembly is relatively large.

In addition, heights of some shafts and a gear center in the drive axle assembly are lower than a height of a differential. After the drive axle assembly is mounted to a vehicle, the shafts and the gears are completely immersed in gear oil. When the power assembly of the drive axle assembly works, the gears on the shaft throw oil at a high speed, which easily leads to a relatively high oil temperature in the entire power assembly, thus causing failure of components.

For example, document <CIT> discloses a transmission including a first planetary gear mechanism, a second planetary gear mechanism, an input shaft, an intermediate shaft, a first synchronizer, and a second synchronizer. A second planet carrier in the second planetary gear mechanism is connected to an output end of the transmission. The input shaft is connected to a first sun gear. A first ring gear is connected to the intermediate shaft. The intermediate shaft is connected to a second sun gear. The first synchronizer secures a first planet carrier to a housing of the transmission or connects the first planet carrier to the first sun gear. The second synchronizer secures a second ring gear to the housing of the transmission or connects the second ring gear to the first ring gear.

According to the invention, a drive axle assembly of a vehicle is provided according to independent claim <NUM>; dependent claims relate to preferred embodiments. The invention is intended to resolve at least one of the technical problems existing in related art. The invention is intended to provide a drive axle assembly of a vehicle. The drive axle assembly of a vehicle has low operating noise.

The drive axle assembly of a vehicle includes: a motor; a first shaft and a second shaft, connected with the motor in sequence; a gearbox; a right shifting fork, movable between a first position and a second position; a right inner ring-gear support; a right sun gear, a right inner planet gear, and a right outer planet gear, disposed in the right inner ring-gear support, where the right inner planet gear is meshed with the right sun gear; the right outer planet gear is meshed with both the right inner planet gear and the right inner ring-gear support; and the right sun gear is configured to rotate synchronously with the first shaft; a right planet support, connected with both the right inner planet gear and the right outer planet gear; a left shifting fork, movable between a third position and a fourth position; a left inner ring-gear support; a left sun gear and a left planet gear, disposed in the left inner ring-gear support, where the left sun gear is configured to rotate coaxially with the right inner ring-gear support; the left planet gear is meshed with both the left sun gear and the left inner ring-gear support; and the left sun gear is configured to rotate synchronously with the second shaft; a driving gear, configured to rotate synchronously with the left planet gear by using a left planet support; and a differential, connected with the driving gear. When the right fork is at the first position, the right planet support is connected with the gearbox. When the right fork is at the second position, the right planet support is connected with the first shaft. When the left fork is at the third position, the left inner ring-gear support is connected with the gearbox. When the left fork is at the fourth position, the left inner ring-gear support is connected with the second shaft.

According to the drive axle assembly of a vehicle in the invention, the gearbox of the drive axle assembly of the invention uses a coaxial arrangement of double planetary rows, so that a ground clearance of the vehicle can be increased. In addition, when gears in the drive axle assembly transmit a torque, no gear is idle. In this way, a power loss caused by oil churning by the gears is reduced, transmission efficiency of the drive axle assembly is improved, and operating noise of the vehicle is reduced.

In some examples of the invention, an axis of the first shaft is on a same straight line as an axis of the second shaft.

In some examples of the invention, when the right fork is at the first position and the left fork is at the third position, a transmission ratio of transmission by the motor to the differential is i1. When the right fork is at the second position and the left fork is at the third position, the transmission ratio of the transmission by the motor to the differential is i2. When the right fork is at the first position and the left fork is at the fourth position, the transmission ratio of the transmission by the motor to the differential is i3. When the right fork is at the second position and the left fork is at the fourth position, the transmission ratio of the transmission by the motor to the differential is i4. <NUM>, i2, i3, and i4 are in descending order or ascending order in sequence.

According to the invention, the drive axle assembly of a vehicle further includes a shift solenoid valve, connected with the left fork and the right fork to drive the left fork and the right fork to move.

In some examples of the invention, the shift solenoid valve includes: an intake pipe, in communication with a gas source; a vent pipe; a right valve seat, being a hollow structure and having a first gas channel and a second gas channel; a right valve core, movably disposed in the right valve seat to separate an inner space of the right valve seat into a first cavity and a second cavity, where the first gas channel is in communication with the first cavity, the second gas channel is in communication with the second cavity; the right valve core is pushed to move by controlling atmospheric pressure of the first cavity and the second cavity; and the right valve core is connected with the right fork; a first solenoid valve, connected and in communication with the first gas channel, the intake pipe, and the vent pipe to control the first gas channel to allow or prevent flow of a gas through the first gas channel; a second solenoid valve, connected and in communication with the second gas channel, the intake pipe, and the vent pipe to control the second gas channel to allow or prevent flow of a gas through the second gas channel; a left valve seat, being a hollow structure and having a third gas channel and a fourth gas channel; a left valve core, movably disposed in the left valve seat to separate an inner space of the left valve seat into a third cavity and a fourth cavity, where the third gas channel is in communication with the third cavity, the fourth gas channel is in communication with the fourth cavity, the left valve core is pushed to move by controlling atmospheric pressure of the third cavity and the fourth cavity, and the left valve core is connected with the left fork; a third solenoid valve, connected and in communication with the third gas channel, the intake pipe, and the vent pipe to control the third gas channel to allow or prevent flow of a gas through the third gas channel; and a fourth solenoid valve, connected and in communication with the fourth gas channel, the intake pipe, and the vent pipe to control the fourth gas channel to allow or prevent flow of a gas through the fourth gas channel.

In some examples of the invention, a muffler is disposed on the vent pipe.

In some examples of the invention, the left fork is inserted in the left valve seat, and the left fork is connected with the left valve core by a left threaded member.

In some examples of the invention, the right fork is inserted in the right valve seat, and the right fork is connected with the right valve core by a right threaded member.

In some examples of the invention, the drive axle assembly of a vehicle further includes: a left half shaft, connected with the differential; and a right half shaft, connected with the differential by a differential lock, where the differential lock is switchable between a locked state and an unlocked state. When the differential lock is in the locked state, the left half shaft and the right half shaft rotate at a same speed. When the differential lock is in the unlocked state, the left half shaft and the right half shaft rotate at different speeds.

In some examples of the invention, a left gear sleeve is disposed on the left half shaft, and a right gear sleeve is disposed on the right half shaft and movably sleeved on the right half shaft; The differential lock includes: a stop rod, disposed in the differential; a fork rod, sleeved on the stop rod, movable between a locked position and an unlocked position along the stop rod, and connected with the right gear sleeve; a pneumatic assembly, connected with the fork rod to drive the fork rod to move; a spring, sleeved on the stop rod to drive the fork rod to switch to the unlocked position. When the fork rod is at the locked position, the differential lock is in the locked state. When the fork rod is at the unlocked position, the differential lock is in the unlocked state.

Additional aspects and advantages of this application will be given in the following description, some of which will become apparent from the following description or may be learned from practices of the invention.

The following describes embodiments of the invention in detail. Examples of the embodiments are shown in the accompanying drawings, and same or similar reference signs in all the accompanying drawings indicate same or similar components or components having same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and used only for explaining this application, and should not be construed as a limitation on the invention.

A drive axle assembly <NUM> of a vehicle in the embodiments of the invention is described below with reference to <FIG>.

As shown in <FIG>, the drive axle assembly <NUM> in the embodiments of the invention includes: a motor <NUM>, a first gear <NUM>, a second gear <NUM>, a first shaft <NUM>, a second shaft <NUM>, a gearbox <NUM>, a right fork <NUM>, a right inner ring-gear support <NUM>, a right sun gear <NUM>, a right inner planet gear <NUM> and a right outer planet gear <NUM>, a right planet support <NUM>, a left fork <NUM>, a left inner ring-gear support <NUM>, a left sun gear <NUM>, a left planet gear <NUM>, a driving gear <NUM>, and a differential <NUM>. An output shaft of the motor <NUM>, the first gear <NUM>, the second gear <NUM>, the first shaft <NUM>, and the second shaft <NUM> are connected in sequence. The first shaft <NUM> and the second shaft <NUM> are configured as hollow shafts. The right fork <NUM> is movable between a first position and a second position. The first position is a left end of the right fork <NUM> in <FIG>, and the second position is a right end of the right fork <NUM> in <FIG>. The right sun gear <NUM>, the right inner planet gear <NUM>, and the right outer planet gear <NUM> are disposed in the right inner ring-gear support <NUM>. The right inner planet gear <NUM> is meshed with the right sun gear <NUM>. The right outer planet gear <NUM> is meshed with the right inner planet gear <NUM> and the right inner ring-gear support <NUM>. The right sun gear <NUM> is connected with the first shaft <NUM>. The right sun gear <NUM> is configured to rotate synchronously with the first shaft <NUM>.

The right planet support <NUM> is connected with both the right inner planet gear <NUM> and the right outer planet gear <NUM>. The left fork <NUM> is movable between a third position and a fourth position. The third position is a right end of the left fork <NUM> in <FIG>, and the fourth position is a left end of the right fork <NUM> in <FIG>. The left sun gear <NUM> and the left planet gear <NUM> are disposed in the left inner ring-gear support <NUM>. The left sun gear <NUM> is configured to rotate coaxially with the right inner ring-gear support <NUM>. The left planet gear <NUM> is meshed with the left sun gear <NUM> and the left inner gear ring support <NUM>. The left sun gear <NUM> is connected with the second shaft <NUM>. The left sun gear <NUM> is configured to rotate synchronously with the second shaft <NUM>. The driving gear <NUM> is configured to rotate synchronously with the left planetary gear <NUM> by using a left planet support. The differential <NUM> is connected with the driving gear <NUM>. When the right fork <NUM> is at the first position, the right planet support <NUM> is connected with a housing of the gearbox <NUM>. When the right fork <NUM> is at the second position, the right planet support <NUM> is connected with the first shaft <NUM>. When the left fork <NUM> is at the third position, the left inner ring-gear support <NUM> is connected with the gearbox <NUM>. When the left fork <NUM> is at the fourth position, the left inner ring-gear support <NUM> is connected with the second shaft <NUM>.

Specifically, after the drive axle assembly <NUM> is mounted to the vehicle, when the vehicle is operating at the first gear, the right fork <NUM> is at the first position, the left fork <NUM> is at the third position, the right planet support <NUM> is connected with the housing of the gearbox <NUM>, and the left inner ring-gear support <NUM> is connected with the housing of the gearbox <NUM>. Power of the motor <NUM> is successively transmitted to the first gear, the second gear, and the first shaft. Then the first shaft drives the right sun gear <NUM> to rotate. Next, the right sun gear <NUM> successively transmits the power to the right inner planet gear <NUM>, the right outer planet gear <NUM>, the right inner ring-gear support <NUM>, and the second shaft. Then the second shaft drives the left sun gear <NUM> to rotate. Afterwards, the left sun gear <NUM> successively transmits the power to the left planet gear <NUM>, a left planet rack <NUM>, and the driving gear <NUM>, and then the driving gear <NUM> transmits the power to the differential <NUM>. The differential <NUM> transmits the power to a left half shaft <NUM> and a right half shaft <NUM>. In this way, driving the vehicle gears to rotate is achieved.

Further, when the vehicle is operating at a second gear, the right fork <NUM> is at the second position, the left fork <NUM> is at the third position, the right planet support <NUM> is connected with the first shaft <NUM>, the left inner ring-gear support <NUM> is connected with the housing of the gearbox <NUM>. The power of the motor <NUM> is successively transmitted to the first gear, the second gear, and the first shaft. Then the first shaft drives the right planet support <NUM> to drive the right inner planet gear <NUM> and the right outer planet gear <NUM> to rotate. Next, the right outer planet gear <NUM> drives the right inner ring-gear support <NUM> and thereby drives the second shaft to rotate. Then the second shaft drives the left sun gear <NUM> to rotate. Afterwards, the left sun gear <NUM> successively transmits the power to the left planet gear <NUM>, the left planet rack <NUM>, and the driving gear <NUM>, and then the driving gear <NUM> transmits the power to the differential <NUM>. The differential <NUM> transmits the power to the left half shaft <NUM> and the right half shaft <NUM>. In this way, driving the vehicle gears to rotate is achieved.

Further, when the vehicle is operating at a third gear, the right fork <NUM> is at the first position, the left fork <NUM> is at the fourth position, the right planet support <NUM> is connected with the housing of the gearbox <NUM>, and the left inner ring-gear support <NUM> is connected with the second shaft <NUM>. The power of the motor <NUM> is successively transmitted to the first gear, the second gear, and the first shaft. Then the first shaft drives the right sun gear <NUM> to rotate. Next, the right sun gear <NUM> successively transmits the power to the right inner planet gear <NUM>, the right outer planet gear <NUM>, the right inner ring-gear support <NUM>, and the second shaft. Afterwards, the second shaft drives the left inner ring-gear support <NUM> to drive the left planet gear <NUM> to rotate, and then the left planet gear <NUM> transmits the power to the left planet rack <NUM> and the driving gear <NUM>. Then the driving gear <NUM> transmits the power to the differential <NUM>. The differential <NUM> transmits the power to the left half shaft <NUM> and the right half shaft <NUM>. In this way, driving the vehicle gears to rotate is achieved.

Further, when the vehicle is operating in a fourth gear, the right fork <NUM> is at the second position, the left fork <NUM> is at the fourth position, the right planet support <NUM> is connected with the first shaft <NUM>, and the left inner ring-gear support <NUM> is connected with the second shaft <NUM>. The power of the motor <NUM> is successively transmitted to the first gear, the second gear, and the first shaft. Then the first shaft drives the right planet support <NUM> to drive the right inner planet gear <NUM> and the right outer planet gear <NUM> to rotate. Next, the right outer planet gear <NUM> drives the right inner ring-gear support <NUM> and thereby drives the second shaft to rotate. Then the second shaft drives the left inner ring-gear support <NUM> and thereby drives the left planet gear <NUM> to rotate. Afterwards, the left planet gear <NUM> transmits the power to the left planet rack <NUM> and the driving gear <NUM>, and then the driving gear <NUM> transmits the power to the differential <NUM>. The differential <NUM> transmits the power to a left half shaft <NUM> and a right half shaft <NUM>. In this way, driving the vehicle gears to rotate is achieved.

In addition, the first gear <NUM>, the second gear <NUM>, and the first shaft <NUM> may all be configured as gears. The motor <NUM> is driven by an external three-phase line power supply. The motor <NUM> may be fixed to the housing of the gearbox <NUM> by bolts. External splines of the output shaft of the motor <NUM> are mated with internal splines of the first gear <NUM> to output the power to the first gear <NUM>. Angular contact ball bearings are disposed on two ends of the first gear <NUM>, to support the first gear <NUM> on the housing of the gearbox <NUM>. The first gear <NUM> transmits the power to the second gear <NUM>. The second gear <NUM> is mounted to the housing of the gearbox <NUM> by using a pair of tapered roller bearings. The second gear <NUM> transmits the power to the first shaft <NUM>. Cylindrical roller bearings are disposed on two ends of the first shaft <NUM> and are supported on the housing of the gearbox <NUM>. Internal splines machined on a left end of the first shaft <NUM> are connected with the right sun gear <NUM>. External splines machined on a right end of the first shaft <NUM> are connected with a right engagement gear <NUM>. The right sun gear <NUM> is meshed with the right inner planet gear <NUM> for transmission, and the right inner planet gear <NUM> is meshed with the right outer planet gear <NUM> for transmission. The right inner planet gear <NUM> and the right outer planet gear <NUM> may be assembled to the right planet support <NUM> by using a planet shaft pin <NUM>. The right outer planet gear <NUM> is meshed with a right ring gear <NUM>. The right ring gear <NUM> is connected with the right inner ring-gear support <NUM> by a helical gear. The right planet support <NUM> is connected with a right gear holder <NUM> by splines. An outer diameter of the right planet support <NUM> may be fixed to the housing of the gearbox <NUM> by using a cylindrical pin <NUM>.

The right fork <NUM> is controlled to move to drive a right slidable gear sleeve <NUM> to move between the first position and the second position, so that a speed ratio and transmission power of the drive axle assembly <NUM> can be changed. The second shaft <NUM> may be fixed to the housing of the gearbox <NUM> and the left planet rack <NUM> by using the angular contact bearings and needle roller bearings. External splines of the second shaft <NUM> are connected with the right inner ring-gear support <NUM>. A middle of the second shaft <NUM> is connected with the left sun gear <NUM>. A left end of the second shaft <NUM> is connected with a left engagement gear <NUM>. The left end of the second shaft <NUM> is connected with a sensing gear <NUM>. The gear shifting is controlled by a connected vehicle speed sensor <NUM>. The left sun gear <NUM> is meshed with the left planet gear <NUM>. The left planet gear <NUM> is meshed with a left ring gear <NUM>. The left ring gear <NUM> is connected with the left inner ring-gear support <NUM> by a helical gear. The left inner ring-gear support <NUM> is connected with a left gear holder <NUM> by splines. The left planet gear <NUM> is assembled to the left planet rack <NUM> by using a planet shaft. A right side of the left planet rack <NUM> is supported on the housing of the gearbox <NUM> by using two cylindrical roller bearings. The left fork <NUM> may be fixed to the housing of the gearbox <NUM> by using the cylindrical pin <NUM>. The movement of the left fork <NUM> drives the left slidable gear sleeve <NUM> to move between the third position and the fourth position, thereby changing the speed ratio and transmitting the power. The driving gear <NUM> is connected with the left planet rack <NUM> by splines. The differential <NUM> is fixed to the housing of the gearbox <NUM> by using bolts. The power outputted from the gearbox <NUM> is transmitted to an output gear <NUM> of the differential <NUM> by the driving gear <NUM>.

The drive axle assembly <NUM> in the invention uses a double planet row shifting structure, and has only one main shaft, that is, the second shaft <NUM>. The shifting gear train is small in size, easy to machine, and low in cost. The entire drive axle assembly <NUM> is light in weight and small in size. Double sets of planet gear trains are used to control the movement of the slidable gear sleeve to control the planet rack to be fixed or not, thereby achieving <NUM>-gear power transmission. In this way, a coverage area of the speed ratio is large, and the transmission torque is larger. Therefore, a plurality of complex working conditions can be dealt with. The entire power assembly uses a helical gear, so that the transmission of the entire drive axle assembly <NUM> is smooth, and the noise is lower. During operation at the different gears, some meshed gears do not rotate relative to each other, and the entire left planet row does not move at a neutral position. In this way, the service life of the gears can be increased.

It should be noted that, compared with the prior art, the drive axle assembly <NUM> configured by using the above technical solutions has a small size, and can be conveniently arranged on a vehicle. Therefore, a ground clearance of the vehicle is larger, and the trafficability characteristic of the vehicle is more desirable. In addition, the motor <NUM> is smaller in size and lighter in weight, and has a higher rotation speed. A moment of inertia of the motor <NUM> is smaller, facilitating gear shifting. Maximum efficiency of the motor <NUM> is also relatively improved. An efficiency range of the rotation speed of the entire motor <NUM> is larger, and a proportion of efficiency above <NUM>% to the total efficiency range is <NUM>%. In this way, the economic efficiency of use can be effectively improved. Moreover, the drive axle assembly <NUM> uses the double planet gear train shifting structure, and the second shaft <NUM> is the main shaft. The shifting gear is small in size, easy to machine, and low in cost. During travelling of the whole vehicle, a relatively small torque is generated on an attachment surface of the axle assembly and the power assembly. In this way, an oil leakage and oil penetration caused by cracking of the attachment surface or a relatively large strain are prevented. In addition, when the gears in the drive axle assembly <NUM> transmit a torque, no gear is idle. In this way, transmission efficiency of the drive axle assembly <NUM> can be improved, and operating noise of the vehicle can be reduced.

Moreover, the drive axle assembly <NUM> has many gears. Therefore, the drive axle assembly can adapt to different road conditions such as an uphill or a flat road, and the energy consumption is proper and low. A gear-side planetary reducer is further disposed on the drive axle assembly <NUM>. Therefore, the size of the electric power assembly can be effectively reduced, the arrangement is more proper, the transmission ratio is large, and the output torque is large, thereby satisfying a large load requirement.

The gearbox <NUM> of the drive axle assembly <NUM> of the invention uses a coaxial arrangement of double planetary rows, so that the structure is simple and compact, the weight is small, and a ground clearance of the vehicle after the drive axle assembly <NUM> is assembled to the vehicle can be increased. In addition, when the gears in the drive axle assembly <NUM> transmit a torque, no gear is idle. In this way, a power loss caused by oil churning by the gears is reduced, the transmission efficiency of the drive axle assembly <NUM> can be improved, and the operating noise of the vehicle can be reduced.

In some examples of the invention, the right sun gear <NUM> has a right central oil passage <NUM> and a right radial oil passage <NUM> in communication with the right central oil passage <NUM>. The right central oil passage <NUM> is in communication with the first shaft <NUM>. The left sun gear <NUM> has a left central oil passage <NUM> and a left radial oil passage <NUM> in communication with the left central oil passage <NUM>. The left central oil passage <NUM> is in communication with the second shaft <NUM>. The first shaft <NUM> is in communication with the second shaft <NUM>. Oil in the first shaft <NUM> can flow into the second shaft <NUM> to supply oil to the second shaft <NUM>. After the oil enters the oil passage of the first shaft <NUM>, the oil flows into the right central oil passage <NUM>, and then the oil flows into the right radial oil passage <NUM> from the right central oil passage <NUM>. In addition, the oil also flows into the second shaft <NUM>, and then the oil successively flows into the left central oil passage <NUM> and the left radial oil passage <NUM> from the second shaft <NUM>. During meshing of the right sun gear <NUM> and the left sun gear <NUM> with other gears, the right sun gear <NUM> and the left sun gear <NUM> can deliver the oil to different components, so that the oil can reach different positions on the drive axle assembly <NUM>. In this way, a flowing range of the oil can be increased, thereby enhancing the effect of lubricating the drive axle assembly <NUM>.

Therefore, by means of the plurality of oil passages, the oil can be delivered to the components required to be lubricated during the operation of the drive axle assembly <NUM>. In this way, the transmission efficiency of the drive axle assembly <NUM> can be improved, the operating noise of the vehicle can be reduced, and the service life of each component in the drive axle assembly <NUM> can be increased.

In some examples of the invention, as shown in <FIG>, the gearbox <NUM> may include a right end cover <NUM>. The right end cover <NUM> may have a pump body. The pump body has an oil inlet and an oil outlet. The oil outlet is in communication with the first shaft <NUM>, and the oil inlet is in communication with inside of the gearbox <NUM>. The inside of the gearbox <NUM> may have oil. When the pump body is operating, the oil may be pumped into the pump body through the oil inlet, and then the oil flows into the first shaft <NUM> through the oil outlet, thereby delivering the oil to each component.

In some examples of the invention, as shown in <FIG>, a filter <NUM> may be disposed at the oil inlet, and the filter <NUM> can provide filtering. Before the oil flows into the oil inlet, the filter <NUM> may filter out impurities such as scrap iron in the oil, to prevent the impurities such as the scrap iron from flowing into the first shaft <NUM>, thereby preventing the impurities such as the scrap iron from blocking the first shaft <NUM>.

In some examples of the invention, as shown in <FIG>, the right end cover <NUM> may have a first oil supply branch <NUM> therein. The filter <NUM> and the oil inlet are brought into communication with each other by using the first oil supply branch <NUM>. By means of the arrangement, the oil filtered by the filter <NUM> can be delivered to the oil inlet.

In some examples of the invention, as shown in <FIG>, the right end cover <NUM> may have a second oil supply branch <NUM> therein. The second oil supply branch <NUM> is in communication with the oil outlet. The second oil supply branch <NUM> supplies oil to a meshed position between the first gear <NUM> and the second gear <NUM> by using a connected pipe <NUM>. After the oil flows out of the oil outlet, at least part of the oil flows into the second oil supply branch <NUM>. By means of the second oil supply branch <NUM>, the oil can be delivered to the meshed position between the first gear <NUM> and the second gear <NUM>. During rotation of the first gear <NUM> and the second gear <NUM>, the oil can be delivered to other components. In this way, the delivery range of the oil can be further expanded, thereby further enhancing the effect of lubricating other components in the drive axle assembly <NUM>.

In some examples of the invention, as shown in <FIG>, a plurality of right radial oil passages <NUM> may be disposed, and a plurality of left radial oil passages <NUM> may be disposed. In this way, the oil can quickly flow to each component, so that the component can be lubricated in time, thereby preventing a failure of each component.

Specifically, as shown in <FIG>, the components in the drive axle assembly <NUM> are lubricated by splash lubrication and a pressure circulation lubrication respectively. The differential <NUM> is lubricated by splash lubrication. The entire differential <NUM> is half immersed in gear oil. Driven by an input gear of the differential <NUM>, an output gear <NUM> on the differential <NUM> rotates to drive the oil to lubricate the entire differential <NUM>. The remaining components in the drive axle assembly <NUM> are lubricated from the inside to outside by the pressure circulation. During operation in the drive axle assembly <NUM>, a gear on the first shaft <NUM> rotate to drive a splined sleeve <NUM> to rotate. The splined sleeve <NUM> is connected with an inner rotor assembly by splines. An outer rotor assembly is assembled between the right end cover <NUM> and an oil pump cover. A gear on the first shaft <NUM> drives the splined sleeve <NUM> to rotate, so as to drive the inner rotor assembly to rotate. The inner rotor assembly drives the outer rotor assembly to rotate to form a pressure difference. After the iron scrap in the gear oil is filtered out by the filter <NUM>, the gear oil enters a low pressure oil inlet passage of the right end cover <NUM> (that is, the first oil supply branch <NUM>). High and low pressure oil passages and a countersunk hole for mounting the outer rotor are formed on the right end cover <NUM>. After pressurized by the oil pump, the gear oil forms high pressure oil and is split into two paths. One path goes upward and passes through a high pressure oil pipe (that is, the second oil supply branch <NUM>) to lubricate the first gear <NUM>, the second gear <NUM>, and respective angular contact bearings. An other path passes through splined sleeve <NUM> through the oil pump cover to enter the central oil passage of the right sun gear <NUM>. Radial oil passages are all respectively formed on the right sun gear <NUM>, a right planet rack, and a right planet pin shaft. The high pressure oil passes through the radial oil passage of the right sun gear <NUM> and enters the radial oil passage of the right planet rack, and then the high pressure oil passes through a right planet shaft to lubricate each needle roller bearing and each gear, and thereby lubricate an entire right planet row assembly. The high pressure oil enters the second shaft <NUM> through the right sun gear <NUM>. A plurality of radial oil passages are also respectively formed on the second shaft <NUM>, the left planet rack <NUM>, and a left planet shaft <NUM>. The high pressure oil enters the left planet rack <NUM> and the left planet shaft <NUM> through the radial oil passage of the left sun gear <NUM>, lubricates the bearings and each gear, to lubricate the bearings and the gears, and thereby lubricate a left planet row assembly. A pressure sensor <NUM> is mounted to the high pressure oil passage of the right end cover <NUM>. The pressure sensor <NUM> can effectively control the circulation of the oil to avoid damage to the gears and the bearings caused by the failure of the lubrication system. By means of the pressure circulation lubrication from inside to outside, the oil temperature can be effectively controlled to reduce, and the loss of transmission efficiency can be reduced. Therefore, the pressure circulation lubrication from inside to outside has huge advantages.

In some examples of the invention, an axis of the first shaft <NUM> and an axis of the second shaft <NUM> are located on a same straight line. In a height direction of the drive axle assembly <NUM>, a height of the axis of the first shaft <NUM> and a height of the axis of the second shaft <NUM> are both larger than a height of a center of the differential <NUM>. The axis of the first shaft <NUM> and the axis of the second shaft <NUM> are not immersed in the gear oil. When the drive axle assembly <NUM> operates, the gear oil is not driven by the gear to throw at a high speed. In this way, the oil temperature can be effectively control to reduce, thereby avoiding a failure of the components and reducing the loss of transmission efficiency.

In some examples of the invention, when the right fork <NUM> is at the first position and the left fork <NUM> is at the third position, a transmission ratio of transmission by the motor <NUM> to the differential <NUM> is i1. The transmission ratio il is a transmission ratio at a first gear. When the right fork <NUM> is at the second position and the left fork <NUM> is at the third position, the transmission ratio of the transmission by the motor <NUM> to the differential <NUM> is i2. The transmission ratio i2 is a transmission ratio at a third gear. When the right fork <NUM> is at the first position and the left fork <NUM> is at the fourth position, the transmission ratio of the transmission by the motor <NUM> to the differential <NUM> is i3. The transmission ratio i3 is a transmission ratio at a second gear. When the right fork <NUM> is at the second position and the left fork <NUM> is at the fourth position, the transmission ratio of the transmission by the motor <NUM> to the differential <NUM> is i4. The transmission ratio i4 is a transmission ratio at a fourth gear. i1, i2, i3, and i4 are in descending order or ascending order in sequence. In this way, the gear of the vehicle can be changed, so that the vehicle can travel at different gears.

In some examples of the invention, as shown in <FIG>, the drive axle assembly <NUM> may further include a shift solenoid valve <NUM>. The shift solenoid valve <NUM> is connected with the left fork <NUM> and the right fork <NUM>. The shift solenoid valve <NUM> can drive the left fork <NUM> and the right fork <NUM> to move. By means of the arrangement, the fork and the right fork <NUM> can be driven to move, thereby realizing the shift function of the vehicle.

In some examples of the invention, as shown in <FIG>, the shift solenoid valve <NUM> may include an intake pipe <NUM>, a vent pipe <NUM>, a right valve seat <NUM>, a right valve core <NUM>, a first solenoid valve <NUM>, a second solenoid valve <NUM>, a left valve seat <NUM>, a left valve core <NUM>, a third solenoid valve <NUM>, and a fourth solenoid valve <NUM>. The intake pipe <NUM> is in communication with a gas source. The right valve seat <NUM> is configured as a hollow structure. The right valve seat <NUM> has a first gas channel <NUM> and a second gas channel <NUM>. The right valve core <NUM> is movably disposed in the right valve seat <NUM>. The right valve core <NUM> may be adapted to separate an inner space of the right valve seat <NUM> into a first cavity and a second cavity. The first gas channel <NUM> is in communication with the first cavity, and the second gas channel <NUM> is in communication with the second cavity. The right valve core <NUM> is pushed to move by controlling gas pressure of the first cavity and the second cavity. The right valve core <NUM> is connected with the right fork <NUM>. In this way, driving the right fork <NUM> to move is realized. The first solenoid valve <NUM> is connected and in communication with the first gas channel <NUM>, the intake pipe <NUM>, and the vent pipe <NUM>. The first solenoid valve <NUM> may control the first gas channel <NUM> to allow or prevent flow of a gas through the first gas channel. The second solenoid valve <NUM> is connected and in communication with the second gas channel <NUM>, the intake pipe <NUM>, and the vent pipe <NUM>. The second solenoid valve <NUM> may control the second gas channel <NUM> to allow or prevent flow of a gas through the second gas channel.

In addition, the left valve seat <NUM> may be configured as a hollow structure. The left valve seat <NUM> has a third gas channel <NUM> and a fourth gas channel <NUM>. The left valve core <NUM> is movably disposed in the left valve seat <NUM>. The left valve core <NUM> may be adapted to separate an inner space of the left valve seat <NUM> into a third cavity and a fourth cavity. The third gas channel <NUM> is in communication with the third cavity, and the fourth gas channel <NUM> is in communication with the fourth cavity. The left valve core <NUM> is pushed to move by controlling gas pressure of the third cavity and the fourth cavity. The left valve core <NUM> is connected with the left fork <NUM>. The third solenoid valve <NUM> is connected and in communication with the third gas channel <NUM>, the intake pipe <NUM>, and the vent pipe <NUM>. The third solenoid valve <NUM> may control the third gas channel <NUM> to allow or prevent flow of a gas through the third gas channel. The fourth solenoid valve <NUM> is connected and in communication with the fourth gas channel <NUM>, the intake pipe <NUM>, and the vent pipe <NUM>. The fourth solenoid valve <NUM> may control the fourth gas channel <NUM> to allow or prevent flow of a gas through the fourth gas channel.

Specifically, the intake pipe <NUM> is in communication with an air compressor gas source on the vehicle. The first solenoid valve <NUM>, the second solenoid valve <NUM>, the third solenoid valve <NUM>, and the fourth solenoid valve <NUM> are all connected with a shift control harness. The solenoid valve is controlled to turn on or off by the shift control harness. High pressure air in the air compressor is controlled to enter the intake pipe <NUM>, to control the left fork <NUM> and the right fork <NUM> to move. The shift solenoid valve <NUM> has no cumbersome mechanism such as a synchronizer, and has a simple structure, can be conveniently maintained and repaired, and has a lower price. In addition, since the vehicle speed sensor <NUM> is disposed on the left end of the second shaft, scrap iron of an axle is prevented from being attached to a magnetic head of the sensor and affecting the shift function. A signal outputted by the vehicle speed sensor <NUM> is transmitted to a vehicle controller. The vehicle controller controls the solenoid valve to turn on or off by using the shift control harness, to realize automatic shifting. The operational performance is desirable.

In some examples of the invention, as shown in <FIG>, a muffler <NUM> may be disposed on the vent pipe <NUM>. The muffler <NUM> has a noise reduction function. By means of the arrangement, the operating noise of the shift solenoid valve <NUM> can be reduced, so that the travelling noise of the vehicle can be reduced, thereby improving user satisfaction.

In some examples of the invention, as shown in <FIG>, the left fork <NUM> is inserted in the left valve seat <NUM>. The left fork <NUM> is connected with the left valve core <NUM> by a left threaded member. By means of the arrangement, the left fork <NUM> and the left valve core <NUM> can be reliably assembled together, and the left fork <NUM> can move together with the left valve core <NUM>. In this way, the operating performance of the solenoid valve can be ensured, thereby ensuring that the vehicle can shift the gear.

In some examples of the invention, the right fork <NUM> is inserted in the right valve seat <NUM>. The right fork <NUM> is connected with the right valve core <NUM> by a right threaded member. By means of the arrangement, the right fork <NUM> and the right valve core <NUM> can be reliably assembled together, and the right fork <NUM> can move together with the right valve core <NUM>. In this way, the operating performance of the solenoid valve can be ensured, thereby ensuring that the vehicle can shift the gear.

In some examples of the invention, as shown in <FIG> and <FIG>, the drive axle assembly <NUM> may further include a left half shaft <NUM> and a right half shaft <NUM>. The left half shaft <NUM> is connected with the differential <NUM>, and the right half shaft <NUM> is connected with the differential <NUM>. The right half shaft <NUM> may be connected with the differential <NUM> by a differential lock <NUM>. The differential lock <NUM> may be switched between a locked state and an unlocked state. When the differential lock <NUM> is in the locked state, that is, the left half shaft <NUM> and the right half shaft <NUM> are connected as a whole, the left half shaft <NUM> and the right half shaft <NUM> rotate at a same speed. When the differential lock <NUM> is in the unlocked state, that is, the left half shaft <NUM> and the right half shaft <NUM> are separated from each other, and the left half shaft <NUM> and the right half shaft <NUM> rotate at different speeds. The differential lock <NUM> is configured to connect the left half shaft <NUM> to the right half shaft <NUM>. When the left half shaft <NUM> is connected with the right half shaft <NUM>, the left half shaft <NUM> and the right half shaft <NUM> rotate at the same speed, so that gear speeds of the vehicle are the same. When the left half shaft <NUM> is not connected with the right half shaft <NUM>, the left half shaft <NUM> and the right half shaft <NUM> may rotate at different speeds, so that the gear speeds of the vehicle are different. Therefore, the vehicle can be controlled to travel in different working conditions. In this way, the vehicle can adaptively travel on different roads.

In some examples of the invention, as shown in <FIG>, a left gear sleeve <NUM> (that is, the left slidable gear sleeve <NUM>) is disposed on the left half shaft <NUM>, and a right gear sleeve <NUM> (that is, the right slidable gear sleeve <NUM>) is disposed on the right half shaft <NUM>. The right gear sleeve <NUM> is movably sleeved on the right half shaft <NUM>. The differential lock <NUM> may include a stop rod <NUM>, a fork rod <NUM>, a pneumatic assembly <NUM>, and a spring <NUM>. The stop rod <NUM> is disposed in the differential <NUM>, and the fork rod <NUM> is sleeved on the stop rod <NUM>. In addition, the fork rod <NUM> is movable between the locked position and the unlocked position along the stop rod <NUM>. The fork rod <NUM> is connected with the right gear sleeve <NUM>. The pneumatic assembly <NUM> is connected with the fork rod <NUM>. The pneumatic assembly <NUM> can drive the fork rod <NUM> to move. The spring <NUM> is sleeved on the stop rod <NUM>. The spring <NUM> sleeve can drive the fork rod <NUM> to switch to the unlocked position. When the fork rod <NUM> is at the locked position, the differential lock <NUM> is in the locked state. When the fork rod <NUM> is at the unlocked position, the differential lock <NUM> is in the unlocked state.

Specifically, the pneumatic assembly <NUM> may include a switch piston <NUM> and a differential lock cylinder <NUM>. The switch piston <NUM> is assembled on the differential lock cylinder <NUM>, and the differential lock cylinder <NUM> is mounted to a rear cover of the differential <NUM> by a bolt. One end of the stop rod <NUM> is connected with the switch piston <NUM>, and an other end is mounted to the rear cover of the differential <NUM> in a manner of being mated with the spring <NUM>. The stop rod <NUM> passes through the fork rod <NUM>, and the fork rod <NUM> is snapped into a groove of the right gear sleeve <NUM>. The right gear sleeve <NUM> may be mated with the right half shaft <NUM> by splines. A threaded vent hole is machined in the differential lock cylinder <NUM> to connect the vehicle gas source. During venting, air compressed by the air compressor enters through the threaded vent hole of the differential lock cylinder <NUM>. When thrust acting on the switch piston <NUM> is greater than an elastic force of the spring <NUM>, the stop rod <NUM> moves under the thrust of the switch piston <NUM>, and drives the fork rod <NUM> to move. The fork rod <NUM> moves axially along the right half shaft <NUM> until a gear of right gear sleeve <NUM> is meshed with a gear of the left gear sleeve <NUM>, thereby locking the differential <NUM>.

When the differential <NUM> is locked, the spring <NUM> is in a compressed state. When the differential lock cylinder <NUM> is no longer supplied with air, the spring <NUM> has elastic potential energy generated by the compression, and is to release the energy to restore an original state. The spring <NUM> pushes the stop rod <NUM>, and drives the fork rod <NUM> and the right gear sleeve <NUM> to move, so as to return to an original position, thereby finally realizing locking or differential speeds of the left half shaft <NUM> and the right half shaft <NUM>. A differential lock stroke sensor <NUM> is mounted to the differential lock cylinder <NUM>. The differential lock stroke sensor <NUM> and the vehicle harness are connected with a dashboard in a cab. When the switch piston <NUM> moves under the action of atmospheric pressure, the whole circuit is connected under the action of an internal top pin of the sensor of the differential lock <NUM>. The signal is displayed on the dashboard of the whole vehicle, and a driver can directly see in the cab whether the differential <NUM> is operating. When a driving gear is skidding, the differential <NUM> and the half shaft are locked as a whole, so that the differential <NUM> loses the differential function. In this way, all torques can be equally assigned to the two half shafts.

It should be noted that, the drive axle assembly <NUM> mainly includes an electric power assembly and an axle housing assembly. The axle housing assembly is a main supporting frame. A brake <NUM> is connected with a brake mounting flange <NUM> of the axle housing assembly by bolts, and a hub assembly <NUM> is mounted to a half shaft sleeve of the axle housing assembly. The hub assembly <NUM> is rotatable about the half shaft sleeve. The hub assembly <NUM> is axially locked by a round nut. Meanwhile, a clearance of the hub bearing is adjusted. An anti-skid brake system (ABS) sensor assembly <NUM> is fastened and assembled on the brake mounting flange <NUM> by screws. An induced voltage signal is formed during rotation of the magnetic head of the sensor and a sensing ring gear of the hub assembly <NUM>. The signal is outputted to the vehicle control system to control the brake <NUM> to performing locking during braking. The differential lock <NUM> is assembled on the rear cover of the differential <NUM>, and may indirectly control the slidable gear sleeve and the slidable gear sleeve on the differential <NUM> to be engaged or separated by connecting or disconnecting the gas source, thereby realizing the synchronization and different speeds of the driving gears. A planet gear of the gear-side planetary reducer <NUM> is assembled with the inner ring gear, and is fastened with the hub assembly <NUM> by screws to reduce a rotation speed outputted by the half shaft and then transmit the rotation speed to the gears of the vehicle. Finally, a brake drum <NUM> is assembled finally. The brake drum is fastened with the hub assembly <NUM> and the gear-side planetary reducer <NUM> by screws. Splines are formed on two ends of the half shaft. One end is connected with the differential <NUM>, and an other end is connected with the planetary reducer. The power outputted by the differential <NUM> is outputted to the planetary reducer by using the half shaft, and then the power is transmitted to the hub assembly <NUM> and the brake drum <NUM>, to drive the gears to rotate.

In the descriptions of this specification, descriptions using reference terms "an embodiment", "some embodiments", "an exemplary embodiment", "an example", "a specific example", or "some examples" mean that specific characteristics, structures, materials, or features described with reference to the embodiment or example are included in at least one embodiment or example of the invention. In this specification, schematic descriptions of the foregoing terms do not necessarily point at a same embodiment or example. In addition, the described specific features, structures, materials, or characteristics may be combined in a proper manner in any one or more of the embodiments or examples.

Claim 1:
A drive axle assembly of a vehicle, comprising:
a motor (<NUM>);
a first shaft (<NUM>) and a second shaft (<NUM>), connected with the motor in sequence;
a gearbox (<NUM>);
a right fork (<NUM>), movable between a first position and a second position;
a right inner ring-gear support (<NUM>);
a right sun gear (<NUM>), a right inner planet gear (<NUM>), and a right outer planet gear (<NUM>), disposed in the right inner ring-gear support (<NUM>), wherein the right inner planet gear (<NUM>) is meshed with the right sun gear (<NUM>), the right outer planet gear (<NUM>) is meshed with both the right inner planet gear (<NUM>) and the right inner ring-gear support (<NUM>), and the right sun gear (<NUM>) is configured to rotate synchronously with the first shaft (<NUM>);
a right planet support (<NUM>), connected with both the right inner planet gear (<NUM>) and the right outer planet gear (<NUM>);
a left fork (<NUM>), movable between a third position and a fourth position;
a left inner ring-gear support (<NUM>);
a left sun gear (<NUM>) and a left planet gear (<NUM>), disposed in the left inner ring-gear support (<NUM>), wherein the left sun gear (<NUM>) is configured to rotate coaxially with the right inner ring-gear support (<NUM>), the left planet gear (<NUM>) is meshed with both the left sun gear (<NUM>) and the left inner ring-gear support (<NUM>), and the left sun gear (<NUM>) is configured to rotate synchronously with the second shaft (<NUM>);
a driving gear (<NUM>), configured to rotate synchronously with the left planet gear (<NUM>) by using a left planet support;
a differential (<NUM>), connected with the driving gear (<NUM>), wherein
when the right fork (<NUM>) is at the first position, the right planet support (<NUM>) is connected with the gearbox (<NUM>);
when the right fork (<NUM>) is at the second position, the right planet support (<NUM>) is connected with the first shaft (<NUM>);
when the left fork (<NUM>) is at the third position, the left inner ring-gear support (<NUM>) is connected with the gearbox; and
when the left fork (<NUM>) is at the fourth position, the left inner ring-gear support (<NUM>) is connected with the second shaft (<NUM>), characterized in that the drive axle assembly further comprises
a shift solenoid valve (<NUM>), connected with the left fork (<NUM>) and the right fork (<NUM>) to drive the left fork and the right fork to move.