Patent Description:
With the gradual depletion of oil resources and increasingly worsening of air pollution, the call for new energy vehicles, such as pure electric, hybrid, and fuel cell vehicles, is getting louder. The emergence of new energy vehicles has greatly reduced the dependence on oil and air pollution. Compared with the conventional internal combustion engine vehicle, due to the different forms of energy supply, great changes have made on both the vehicle layout structure and the drive system assembly in new energy vehicles. The drive system assembly is very important for the vehicle; it not only undertakes the load-bearing function and drive function, but also directly determines the safety and comfort performance of the vehicle.

At present, the aisle width of new energy commercial buses provided with a wheel-side motor drive axle is determined by the distance between the left and right drive motor end faces of the wheel-side motor drive axle. However, in order to ensure large driving torque, the size of the drive motor is made large, which reduces the distance between the two drive motor end faces of the wheel-side motor drive axle, and further results in smaller bus aisle width and low comfort of passengers.

<CIT> is the closest prior art which relates to the field of new energy vehicles, in particular to a new energy vehicle wheel motor drive axle. The wheel edge motor drive axle comprises a beam assembly and a wheel edge motor drive system symmetrically arranged on both sides of the beam assembly. The wheel edge motor drive system comprises a drive motor assembly, a primary reducer assembly, a secondary reducer assembly, a wheel hub assembly, a hydraulic brake assembly and a parking brake assembly, By setting a hydraulic brake on the housing of the primary reducer assembly of the wheel side motor drive system or on the half axle sleeve, the hydraulic brake is matched with the brake disc set on the wheel hub to achieve hydraulic braking of the wheel hub, with fast braking response and low braking noise, thus meeting the braking requirements of light high-level buses. In addition, the hydraulic braking mode is used to make the entire drive axle compact in structure and small in space.

In view of the above problems, the present invention provides a sunken wheel-side motor drive axle to solve or partially solve the above problems.

In order to achieve the above object, the present invention adopts the following technical solutions.

The sunken wheel-side motor drive axle has the following advantages.

By arranging the drive motor assembly at the bottom of the axle beam assembly and using multi-stage reducers, the present invention reduces requirement for the torque output of the drive motor while ensuring the same wheel-side drive torque, and further effectively reduces the size of the drive motor and reduces the space occupied by the drive motor assembly, and makes the boundary of the brake air chambers a decisive factor for limiting the bus aisle width. Therefore, the wheel-side motor drive axle provided by the present invention can effectively increase the bus aisle width and improve the comfort of passengers.

In the drawings: <NUM>. left third-stage reducer assembly; <NUM>. left hub assembly; <NUM>. left brake disc; <NUM>. left second-stage reducer assembly; <NUM>. left brake air chamber; <NUM>. left first-stage reducer assembly; <NUM>. left drive motor assembly; <NUM>. axle beam assembly; <NUM>. right third-stage reducer assembly; <NUM>. right hub assembly; <NUM>. right brake disc; <NUM>. right second-stage reducer assembly; <NUM>. right brake air chamber; <NUM>. right first-stage reducer assembly; <NUM>. right drive motor assembly; A. boundary between left and right brake air chambers symmetrically disposed.

Illustrative embodiments of the present invention will be described in more detail with reference to the drawings.

The first embodiment of the present invention discloses a sunken wheel-side motor drive axle, which comprises an axle beam assembly <NUM>, drive motor assemblies, reducer assemblies and hub assemblies. The structure of wheel-side motor drive axle is shown in <FIG>.

The drive motor assemblies include a left drive motor assembly <NUM> and a right drive motor assembly <NUM>. The left drive motor assembly <NUM> and the right drive motor assembly <NUM> are symmetrically disposed at the bottom of the left and right ends of the axle beam assembly <NUM> respectively. By arranging the drive motor assemblies at the bottom of the axle beam assembly <NUM>, the boundary A between the left and right symmetrically arranged brake chambers becomes the decisive factor for limiting the bus aisle width , thereby increasing the bus aisle width.

In addition, the drive motor assemblies transmit power to the reducer assemblies, and the reducer assemblies drive the hub assemblies to rotate. The reducer assemblies include a left reducer assembly and a right reducer assembly. The hub assemblies include a left hub assembly <NUM> and a right hub assembly <NUM>. The left and right reducer assemblies and the left and right hub assemblies are left and right symmetrically arranged. The left drive motor assembly <NUM> transmits power to the left reducer assembly, and then the left reducer assembly drives the left hub assembly <NUM>; the right drive motor assembly <NUM> transmits power to the right reducer assembly, and then the right reducer assembly drives the right hub assembly <NUM>.

In a preferred embodiment, the drive motor assembly is an oil-cooled motor with small diameter, high power density and high rotation speed, so as to ensure large torque output and reduce the space occupied by the drive motor assembly. Of course, according to specific requirements, the drive motor assembly may be other small volume and high-power motors, and is not limited to oil-cooled motors.

In an embodiment, the reducer assemblies are provided with brake air chambers. The brake air chambers include a left brake air chamber <NUM> and a right brake air chamber <NUM>. The left brake air chamber <NUM> is disposed on the left reducer assembly; the right brake air chamber <NUM> is disposed on the right reducer assembly. The brake air chambers cooperate with brake discs, and the bus aisle width is limited by the brake air chambers. As can be seen from <FIG>, the boundary A between the left and right brake chambers becomes the decisive factor for limiting the width bus aisle.

In an embodiment, the brake discs are disposed on the inner side of the hub assemblies. The brake discs include a left brake disc <NUM> and a right brake disc <NUM>. The left and right brake discs are symmetrically arranged on the inner side of the left and right hub assemblies respectively for braking the left and right hub assemblies.

In a preferred embodiment, the reducer assemblies comprise two first-stage reducer assemblies (left and right first-stage reducer assemblies), two second-stage reducer assemblies (left and right second-stage reducer assemblies) and two third-stage reducer assemblies (left and right third-stage reducer assemblies). The first-stage reducer assemblies, the second-stage reducer assemblies and the third-stage reducer assemblies are disposed on the left and right symmetrically. By providing first-stage reducers, second-stage reducers and third-stage reducers, the present invention realizes three-stage speed reducing transmission, and can effectively increase the transmission speed ratio, reduce the torque output requirements of the drive motor while ensuring the same wheel side driving torque, and further effectively reduce the size of the drive motor and reduce its occupied space, and thus further increase the bus aisle width.

In an embodiment, the output shaft of the drive motor assembly is connected with the driving gear of the first-stage reducer assembly through splines, the output shaft of the driven gear of the first-stage reducer assembly is connected with the driving gear of the second-stage reducer assembly, and the driven gear of the second-stage reducer assembly transmits power to the input end of the third-stage reducer assembly. The left drive motor assembly <NUM> transmits power to the left third-stage reduction assembly <NUM> through the power transmission process; the right drive motor assembly <NUM> transmits the power to the right third-stage reducer assembly <NUM> through the power transmission process. The motor output shaft of the drive motor assembly is connected with the driving gear of the first-stage reducer through external splines to transmit the power of the drive motor to the first-stage reducer assembly. The output shaft of the driven gear of the first-stage reducer is connected with the driving gear of the second-stage reducer to transmit power to the second-stage reducer assembly. Finally, the power is transmitted to the third-stage reducer through the intermediate shaft of the second-stage reducer and the output shaft of the driven gear eccentrically arranged from the driving gear.

The second-stage reducer assembly comprises a driving gear, an intermediate shaft and a driven gear. The intermediate shaft is meshed with the driving gear and driven gear respectively. The driving gear transmits power to the driven gear through the intermediate shaft, which can effectively increase the transmission speed ratio.

In an embodiment, the driven gear of the second-stage reducer assembly and the driving gear of the second-stage reducer assembly are eccentrically arranged. When the driven gear output shaft of the first-stage reducer assembly drives the driving gear of the second-stage reducer assembly to rotate, the driven gear of the second-stage reducer assembly also rotates.

In an embodiment, the input end and output end of the third-stage reducer are located on the same side. The third-stage reducer includes a sun gear, a planet gear and a ring gear. The sun gear is driven by the driven gear of the second-stage reducer assembly, the planet gear is meshed with the sun gear and fixed on a planet carrier, the planet gear is meshed with the ring gear, and the ring gear is meshed with the gear disc on the hub assembly, so as to drive the hub assembly to rotate. There are two sets of the above driving structure which are arranged symmetrically on the left and right.

In an embodiment, the drive motor assembly, the first-stage reducer assembly and the second-stage reducer assembly are lubricated by a spray condensation integrated cooling and lubrication system, so as to enhance the cooling and lubrication effect and improve the cooling and lubrication efficiency. Similarly, other lubrication systems with the same effect as the spray condensation integrated cooling and lubrication system may also be selected for lubrication.

In sum, the present invention discloses a sunken wheel-side motor drive axle, which comprises an axle beam assembly, drive motor assemblies, reducer assemblies and hub assemblies; the drive motor assemblies comprise a left drive motor assembly and a right drive motor assembly symmetrically disposed at a bottom of the left and right ends of the axle beam assembly respectively; and the drive motor assemblies transmit power to the reducer assemblies, and the reducer assemblies drive the hub assemblies to rotate. The wheel side electric drive axle in the present invention increases the transmission speed ratio through the three-stage speed reducing transmission, reduces the requirement for the output torque of the drive motor while ensuring the same wheel end drive torque, and thus can effectively reduce the size of the drive motor; the drive motors are arranged at the bottom of the axle beam assembly, thereby reducing the occupied space, increasing the aisle width of new energy commercial bus, and improving the comfort of passengers.

Claim 1:
A sunken wheel-side motor drive axle, comprising an axle beam assembly (<NUM>), and further comprising two drive motor assemblies (<NUM>, <NUM>), two reducer assemblies and two hub assemblies (<NUM>, <NUM>) respectively disposed at left and right ends of the axle beam assembly (<NUM>);
the drive motor assemblies (<NUM>, <NUM>) transmit power to the reducer assemblies, and the reducer assemblies drive the hub assemblies (<NUM>, <NUM>) to rotate,
the reducer assembly comprises two first-stage reducer assemblies (<NUM>, <NUM>), two second-stage reducer assemblies (<NUM>, <NUM>) and two third-stage reducer assemblies (<NUM>, <NUM>), and the first-stage reducer assemblies (<NUM>, <NUM>), the second-stage reducer assemblies (<NUM>, <NUM>) and the third-stage reducer assemblies (<NUM>, <NUM>) are arranged symmetrically on the left and right,
characterized in that,
the drive motor assemblies (<NUM>, <NUM>) are symmetrically disposed at a bottom of the left and right ends of the axle beam assembly (<NUM>) respectively,
an output shaft of the drive motor assembly is connected with a driving gear of the first-stage reducer assembly (<NUM>, <NUM>) through splines, and a driven gear output shaft of the first-stage reducer assembly (<NUM>, <NUM>) is connected with a driving gear of the second-stage reducer assembly (<NUM>, <NUM>), a driven gear of the second-stage reducer assembly (<NUM>, <NUM>) transmits power to an input end of the third-stage reducer assembly (<NUM>, <NUM>);
the second-stage reducer assembly (<NUM>, <NUM>) comprises a driving gear, an intermediate shaft and a driven gear, and the intermediate shaft is meshed with the driving gear and the driven gear respectively.