CN108194515A - Hub-bearing unit based on double reduction mechanism - Google Patents

Abstract

The invention discloses a wheel hub bearing unit based on a two-stage reduction mechanism, which belongs to the field of auto parts. It is mainly composed of three parts: hub bearing body, first-stage and second-stage planetary gear reduction mechanism. A two-stage planetary gear mechanism consists of an outer ring housing, a planetary gear set, and a sun gear. The outer ring housing of the first-stage planetary gear mechanism is fixedly connected with the outer ring of the hub bearing body, the sun gear is fixedly connected with the inner ring of the hub bearing body, and the rotation shaft of the planetary gear is uniformly arranged on the sun gear of the second-stage planetary gear mechanism. The planet carrier of the second-stage planetary gear mechanism is fixedly connected with the outer ring housing of the first-stage planetary gear mechanism. The power is input from the inner ring of the hub bearing body, transmitted through the two-stage reduction mechanism, and finally output by the outer ring housing of the second-stage planetary gear mechanism. The invention organically combines the two-stage wheel reducer with the hub bearing, which can greatly increase the transmission ratio of the wheel reducer in a limited axial space, increase the driving force of the car, and reduce the load of the drive train at the same time. Effectively improve the life of the drive train.

Description

Hub bearing unit based on two-stage reduction mechanism

technical field

The invention relates to the field of auto parts, in particular to a wheel hub bearing unit based on a two-stage reduction mechanism.

Background technique

As an important part of the car, the hub bearing unit is mainly used to bear weight and provide precise guidance for the rotation of the hub bearing. At present, the constant velocity universal joint and the third-generation hub bearing unit are generally used in cars. The hub bearing unit is connected with the wheel, and the constant velocity universal joint is matched with the inner flange by splines. This structure has many parts and complex assembly. The equipped vehicle has a small turning radius. With the current development trend of lightweight automobiles, the requirements for the integration and compactness of various parts in automobiles are constantly increasing.

The wheel reducer is the last stage of deceleration and torque increasing device in the automobile transmission system. On heavy trucks, off-road vehicles and large trucks, when a larger main transmission ratio and a larger ground clearance are required, the double The gear mechanism of the second-stage reducer in the first-stage final reducer is made into two sets of the same, which are respectively installed near the driving wheels on both sides and are called wheel-side reducers. With the continuous development of the economy, the load capacity of various heavy vehicles continues to increase, and the requirements for power performance are also continuously improved, and the requirements for the transmission ratio of the drive train will also increase accordingly. As the transmission ratio requirements continue to increase, it is difficult for the transmission ratio of a single-stage wheel reducer to meet the requirements, and a double-stage or even multi-stage reducer can better meet this requirement. However, the double-stage reducer will inevitably increase the axial size of the reducer. Considering that the space inside the wheel is extremely limited, it is necessary to effectively control its size under the condition of increasing the transmission ratio of the wheel-side reducer. The integrated design of other parts is a good solution.

On May 31, 2017, Chinese invention patent application CN 106763523 A disclosed a reduction hub bearing, including an outer ring, an inner ring and a transmission arranged in the inner circle space of the inner ring, and the inner ring or outer ring and the hub drive Connection; the power output end of the transmission is connected to the inner ring or outer ring connected to the hub drive. In this invention, the reduction mechanism is placed inside the hub bearing, which increases the diameter of the hub bearing and greatly reduces the fatigue life of the hub bearing. In addition, this structure is only suitable for a single-stage wheel-side reducer, and the transmission ratio is smaller than that of a two-stage reducer, which cannot meet the requirements of a certain type of heavy-duty vehicle.

Contents of the invention

The technical problem to be solved by the present invention is to provide a wheel hub bearing unit based on a two-stage reduction mechanism with a large transmission ratio, small axial dimension and compact structure in view of the defects involved in the background technology. The integrated unit can not only greatly increase the transmission ratio of the wheel reducer, but also reduce the axial size of the wheel reducer and the hub bearing, thereby improving the compactness.

The present invention adopts the following technical solutions for solving the problems of the technologies described above:

A hub bearing unit based on a two-stage reduction mechanism, including a hub bearing body, a first-stage planetary gear reduction mechanism, a second-stage planetary gear reduction mechanism, a fixed column, a first flange, and a second flange;

Both the first-stage planetary gear reduction mechanism and the second-stage planetary gear reduction mechanism include an outer ring housing, a planetary gear set, and a sun gear. The inner wall of the outer ring housing is provided with an inner ring gear, and the sun gear is respectively It meshes with each gear in the planetary gear set, and each gear in the planetary gear set meshes with the ring gear;

The outer ring housing of the first-stage planetary gear reduction mechanism is fixedly connected with the outer ring of the hub bearing body, the sun gear is fixedly connected with the inner ring of the hub bearing body, and the rotating shafts of each gear in the planetary gear set are uniformly arranged on the sun gear of the second-stage planetary gear reduction mechanism;

The second-stage planetary gear reduction mechanism also includes a planetary carrier, and the rotation shafts of each gear of the planetary gear set in the second-stage planetary gear reduction mechanism are fixed on the planetary carrier, and the planetary carrier and the first-stage planetary gear decelerate The outer ring shell of the mechanism is fixed;

The center of the sun gear of the first-stage planetary gear reduction mechanism away from the hub bearing body is provided with a fixed column; the center of the sun gear of the second-stage planetary gear reduction mechanism is provided with a A through hole; the outer ring housing of the second-stage planetary gear reduction mechanism is provided with an end cover on the side away from the hub bearing body, and the center of the end cover is provided with a through hole matching the fixed column; the The fixing column sequentially passes through the through hole in the center of the sun gear and the through hole in the center of the end cover of the second-stage planetary gear reduction mechanism;

The sun gear of the second-stage planetary gear reduction mechanism is connected to the fixed column through the first rolling bearing and the second rolling bearing, wherein the inner rings of the first rolling bearing and the second rolling bearing are fixedly connected to the fixing column, The outer rings of the first rolling bearing and the second rolling bearing are fixedly connected to the inner wall of the central through hole of the sun gear of the second-stage planetary gear reduction mechanism;

The end cover is connected to the fixed column through the third rolling bearing, wherein the inner ring of the third rolling bearing is fixedly connected to the fixed column, and the outer ring is fixedly connected to the inner wall of the central through hole of the end cover;

The fixed column, the sun gear of the first-stage planetary gear reduction mechanism, the sun gear of the second-stage planetary gear reduction mechanism, the inner ring of the hub bearing body, and the outer ring of the hub bearing body are arranged coaxially;

The end of the fixed column away from the sun gear of the first-stage planetary gear reduction mechanism is provided with a thrust bearing for axially fixing the end cover;

The first flange is arranged on the outer ring of the hub bearing body for connection with the vehicle suspension;

The second flange is arranged on the outer ring housing of the second-stage planetary gear reduction mechanism, and is used for connecting with the wheel.

As a further optimization scheme of the hub bearing unit based on the two-stage reduction mechanism of the present invention, the hub bearing body includes an inner ring, an outer ring and at least two sets of rolling mechanisms;

The rolling mechanism includes several balls and a cage matched with the balls;

A raceway corresponding to the rolling mechanism is provided between the inner ring and the outer ring, and the several groups of rolling mechanisms are arranged in the corresponding raceway in a one-to-one correspondence.

As a further optimization scheme of the hub bearing unit based on the two-stage reduction mechanism of the present invention, the hub bearing body further includes a first sealing ring and a second sealing ring;

The first sealing ring and the second sealing ring are respectively arranged at two ends of the hub bearing body, are located between the outer ring and the inner ring, and include each group of rolling mechanisms.

As a further optimization scheme of the hub bearing unit based on the two-stage reduction mechanism of the present invention, the hub bearing body includes an inner ring, an outer ring, a reinforcing ring and at least two sets of rolling mechanisms;

The rolling mechanism includes several balls and a cage matched with the balls;

The material strength of the reinforcing ring is greater than that of the inner ring, and it is installed on the column wall of the inner ring close to the sun gear of the first-stage planetary gear reduction mechanism in an interference fit manner;

A raceway is provided between the reinforcing ring and the outer ring, and a set of rolling mechanisms are built in;

The inner ring and the outer ring are cooperatively provided with raceways corresponding to the remaining rolling mechanisms one by one, and the remaining sets of rolling mechanisms are arranged in the raceways between the inner ring and the outer ring in one-to-one correspondence.

As a further optimization scheme of the hub bearing unit based on the two-stage reduction mechanism of the present invention, the hub bearing body further includes a first sealing ring and a second sealing ring;

The first sealing ring is arranged between the reinforcing ring and the outer ring;

The second sealing ring is arranged at the end of the hub bearing body away from the sun gear of the first-stage planetary gear reduction mechanism, and is located between the outer ring and the inner ring;

The first sealing ring and the second first sealing ring include each group of rolling mechanisms.

As a further optimization scheme of the hub bearing unit based on the two-stage reduction mechanism of the present invention, the number of gears in the planetary gear set of the first-stage planetary gear reduction mechanism is at least 4, and the planetary gear of the second-stage planetary gear reduction mechanism The number of gears in the group is at least five.

Compared with the prior art, the present invention adopts the above technical scheme and has the following technical effects:

The use of two-stage wheel-side reducers can greatly increase the transmission ratio, increase the driving force of the car, and at the same time reduce the load on the transmission, final drive, differential and other transmission systems, effectively improving the life of the transmission system. For some models, the main reducer can even be omitted, which greatly improves the ground clearance and enhances the passability. Through the integrated design of the reducer and the hub bearing, the axial dimension of the inner structure of the wheel can be effectively reduced and the compactness of the structure can be improved.

Description of drawings

Fig. 1 is the structural schematic diagram of the wheel hub bearing unit based on the two-stage reduction mechanism of the present invention;

Fig. 2 is a partial enlarged view of place A in Fig. 1;

Fig. 3 is a partially enlarged view of the place B in Fig. 1 .

In the figure, 1-inner ring, 2-second sealing ring, 3-rolling element, 4-outer ring, 4-1-first flange, 5-cage, 6-strengthening ring, 7-first seal Ring, 8-first-stage outer ring housing, 9-first-stage planetary gear, 10-second-stage planetary carrier, 10-1-second-stage planetary gear reduction mechanism planetary gear set gear, 11-second Stage outer ring housing, 11-1-Second flange, 12-Lock nut, 13-Thrust bearing, 14-Third rolling bearing, 15-Second rolling bearing, 16-Second stage planetary gear, 17- The second-stage sun gear, 17-1-the rotating shaft of the gear in the planetary gear set of the first-stage planetary gear reduction mechanism, 18-the first rolling bearing, 19-end cover, 20-screw, 21-the first-stage sun gear, 21- 1 fixed column.

Detailed ways

Below in conjunction with accompanying drawing, technical scheme of the present invention is described in further detail:

This invention may be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. In the drawings, components are exaggerated for clarity.

As shown in Figure 1, the side of the hub bearing body in the figure is the right side, and the side of the two-stage planetary gear mechanism is the left side. The hub bearing part in the present invention includes the inner ring of the hub bearing body, the sealing ring, the rolling elements, Ring, cage, strengthening ring. The inner ring of the hub bearing body is formed with inner splines, and the transmission shaft of the drive axle is connected with the inner ring through splines to input power. There is a groove on the surface of the left end of the inner ring, and the groove is used for installing the reinforcing ring. The reinforcing ring is installed in the groove by means of interference fit, and the material with higher strength than the inner ring is used. Since existing studies have shown that the outer row of rolling elements of the wheel hub bearing is subject to greater stress, the fatigue life of the wheel hub bearing can be significantly improved by using materials with higher strength for the stressed parts of the outer row of rolling elements. There is an inner raceway on the reinforcement ring and the inner ring respectively, and two outer raceways corresponding to it are arranged on the outer ring. Two rows of rolling bodies are installed between the inner and outer raceways, and a cage is used between each row of rolling bodies. orientation. In addition, there are grooves on the inner ring on the right side of the right row of rolling elements, grooves on the reinforcement ring on the left side of the left row of rolling elements, and corresponding grooves on the outer ring. Used to install elastomeric seals. The left end of the inner ring is fixedly connected with the sun gear of the first-stage planetary gear mechanism, and the two are made into one.

A first flange is formed on the outer ring, and the first flange is connected with the suspension through bolts to fix the outer ring. The inner wall of the outer ring housing of the first-stage planetary gear mechanism is provided with an inner ring gear, and the outer ring of the hub bearing body is fixedly connected with the first-stage outer ring housing, and the two are integrated. The left side of the first-stage outer ring housing There are screw holes on the side end surface, which are connected with the second-stage planetary carrier by bolts, so the second-stage planetary carrier is also fixed. The rotating shaft of the first-stage planetary gear is evenly arranged on the right side end face of the second-stage sun gear, and the two are integrated. The rotating shafts of the second-stage planetary gears are evenly arranged on the second-stage planet carrier, and the two are integrated.

The first-stage sun gear meshes with each gear in the first-stage planetary gear set, and each gear of the first-stage planetary gear set meshes with the inner ring gear on the outer ring housing to form a first-stage planetary gear mechanism. The shell of the stage outer ring is fixed, and the power is input from the first stage sun gear through the first stage planetary gear mechanism and output to the first stage planetary gear shaft, and the first stage planetary gear shaft drives the second stage sun gear to rotate. Considering that this structure is mainly suitable for heavy-duty vehicles, taking a larger number of planetary wheels can effectively reduce the average load of the gears, improve the stability of transmission, and improve the overall fatigue life. Therefore, the number of planetary wheels in the first stage should be at least 4, and the number of The transmission ratio of the first-stage planetary gear mechanism is generally about 2.5~5 according to the gear size.

The second-stage sun gear meshes with the second-stage planetary gear, and the second-stage planetary gear meshes with the ring gear on the second-stage outer ring housing to form a second-stage planetary gear mechanism. The second-stage planetary carrier is fixed, and the power is input from the second-stage sun gear through the transmission of the second-stage planetary gear mechanism and output from the second-stage outer ring housing. The second-stage outer ring housing is equipped with a second flange. The bolts are connected to the wheels, and the power is output to the wheels. After the deceleration and torque increase of the first-stage planetary gear mechanism, the load on the second-stage planetary gear mechanism is obviously greater than that of the first stage, so the teeth of the second-stage planetary gear mechanism can be effectively improved by using materials with higher strength than the first-stage Life, the number of second-stage planetary gears is greater than the number of first-stage planetary gears, at least 5. The transmission ratio of the second-stage planetary gear mechanism is 1.5~4, and the total transmission ratio of the two-stage planetary gear reducer can reach 4~20.

As shown in Figure 3, the center of the side of the first-stage sun gear away from the hub bearing body is provided with a fixed column. The fixed column is a three-stage stepped shaft. The shaft shoulder is used for positioning the first and second rolling bearings, and the middle and end are threaded. . The center of the second-stage sun gear is provided with a through hole matching the fixed post, and the fixed post extends into the hole. The two ends of the central through hole of the second stage sun gear have large diameters and a small middle diameter, and the steps made on the inner circle are used for the positioning of the first and second rolling bearings. The steps on the inner circles on both sides of the center through hole of the second stage sun gear respectively withstand the outer rings of the first and second rolling bearings, the inner ring of the first rolling bearing bears against the shaft shoulder, and the left side of the second rolling bearing is positioned with a lock nut, so that The axial positioning of the second stage sun gear has just been completed.

The outer ring housing of the second-stage planetary gear mechanism is provided with an end cover on a side away from the hub bearing body, and a through hole matching the fixed post is provided in the center of the end cover, and the fixed post extends into the hole. The right side of the central through hole of the end cover has a large diameter and the left side has a small diameter, and the steps made on the inner circle are used for the positioning of the third rolling bearing. The inner ring of the third rolling bearing bears against the shaft shoulder, and the outer ring bears against the step on the inner circle of the end cover of the second-stage outer ring housing. A thrust bearing is installed on the mounting column on the left side of the second-stage outer ring housing. The right side of the thrust bearing is close to the end cover of the second-stage outer ring housing, and the left side is fixed with a lock nut, so that The bearing positioning of the outer ring housing of the second-stage planetary gear mechanism is completed.

As shown in Figure 2, the two ends of the center hole of the first-stage planetary gear have large diameters and the middle diameter is small. The steps made on the inner circle are used for the installation of rolling bearings. The outer ring of the rolling bearing at the end, the shaft shoulder of the first stage planetary gear shaft withstands the inner ring of the left end bearing, the right side of the right end bearing is fixed axially with the bearing end cover, and the bearing end cover is fixed with screws, thus completing the first stage The planetary gears are axially fixed. The second-stage planetary gears are also fixed axially in the same way.

The power driving the car is driven by the drive shaft through the spline connection to drive the inner ring of the hub bearing body to rotate, and then the power is transmitted by the two-stage reduction mechanism and then output by the outer ring housing of the second-stage planetary gear mechanism.

Those skilled in the art can understand that, unless otherwise defined, all terms (including technical terms and scientific terms) used herein have the same meaning as commonly understood by those of ordinary skill in the art to which this invention belongs. It should also be understood that terms such as those defined in commonly used dictionaries should be understood to have a meaning consistent with the meaning in the context of the prior art, and will not be interpreted in an idealized or overly formal sense unless defined as herein explain.

The specific embodiments described above have further described the purpose, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above descriptions are only specific embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included within the protection scope of the present invention.

Claims (6)

1. the hub-bearing unit based on double reduction mechanism, which is characterized in that include hub bearing ontology, first order planet tooth Wheel deceleration mechanism, second level planetary gear reducing mechanism, first to third rolling bearing, first flange disk and second flange disk；

The first order planetary gear reducing mechanism, second level planetary gear reducing mechanism are comprising outer ring housing, planetary gear Group and sun gear, are equipped with ring gear on the inner wall of the outer ring housing, sun gear respectively with each tooth in planetary gear set Wheel engages, and each gear in planetary gear set is engaged with ring gear；

The outer ring of the outer ring housing of the first order planetary gear reducing mechanism and the hub bearing ontology is connected, sun gear and The inner ring of the hub bearing ontology is connected, the shaft of each gear is uniformly arranged on the second level planet in planetary gear set On the sun gear of gear reduction；

The second level planetary gear reducing mechanism is also comprising planet carrier, planetary gear set in the planetary gear reducing mechanism of the second level The shaft of each gear is each attached on the planet carrier, and the outer ring of planet carrier and the first order planetary gear reducing mechanism Housing is connected；

The center of the side of the sun gear of first order planetary gear reducing mechanism far from hub bearing ontology is equipped with fixed column； The through-hole that the center of the sun gear of the second level planetary gear reducing mechanism is equipped with and the fixed column matches；Described second The outer ring housing of grade planetary gear reducing mechanism is equipped with end cap, and the center of end cap is equipped in the side far from hub bearing ontology The through-hole to match with the fixed column；The fixed column sequentially passes through the sun gear of the second level planetary gear reducing mechanism The through-hole at center and the through-hole of end cap central；

The sun gear of the second level planetary gear reducing mechanism passes through the first rolling bearing, the second rolling bearing and the fixation Column is connected, wherein, first rolling bearing, the second rolling bearing the equal and described fixed column of inner ring be connected, first axis of rolling It holds, the outer ring of the second rolling bearing is equal and the inner wall of the sun gear central through hole of the second level planetary gear reducing mechanism is consolidated Even；

The end cap is connected by the third rolling bearing with the fixed column, wherein, the inner ring of third rolling bearing and solid Fixed column is connected, the inner wall of outer ring and the end cap central through-hole is connected；

The fixed column, the sun gear of first order planetary gear reducing mechanism, second level planetary gear reducing mechanism sun gear, The outer ring coaxial arrangement of the inner ring, hub bearing ontology of hub bearing ontology；

One end of sun gear of the fixed column far from first order planetary gear reducing mechanism is equipped with for so that the end cap The thrust bearing of axial restraint；

The first flange disk is arranged on the outer ring of the hub bearing ontology, for being connected with vehicle suspension；

The second flange disk is arranged on the outer ring housing of the second level planetary gear reducing mechanism, for wheel phase Even.

2. the hub-bearing unit according to claim 1 based on double reduction mechanism, which is characterized in that the hub spindle It holds ontology and includes inner ring, outer ring and at least two groups of rolling mechanisms；

The rolling mechanism includes several balls and the retainer with ball engagement；

Cooperation is equipped with and the one-to-one raceway of the rolling mechanism between the inner ring, outer ring, several groups of rolling mechanisms It is arranged in a one-to-one correspondence in corresponding raceway.

3. the hub-bearing unit according to claim 2 based on double reduction mechanism, which is characterized in that the hub spindle Ontology is held also comprising the first sealing ring, the second sealing ring；

First sealing ring, the second sealing ring set the both ends of hub bearing ontology respectively, will between outer ring, inner ring Each group rolling mechanism is included.

4. the hub-bearing unit according to claim 1 based on double reduction mechanism, which is characterized in that the hub spindle Ontology is held to include inner ring, outer ring, strengthen circle and at least two groups of rolling mechanisms；

The rolling mechanism includes several balls and the retainer with ball engagement；

The strength of materials for strengthening circle is more than the strength of materials of the inner ring, in an interference fit mounted on the inner ring On the post jamb of one end of first order planetary gear reducing mechanism sun gear；

Described strengthen coordinates between circle, outer ring equipped with a raceway, built-in one group of rolling mechanism；

The inner ring, outer ring cooperation are equipped with and the one-to-one raceway of remaining rolling mechanism, the residue each group rolling mechanism one One is correspondingly arranged in the raceway between inner ring, outer ring.

5. the hub-bearing unit according to claim 4 based on double reduction mechanism, which is characterized in that the hub spindle Ontology is held also comprising the first sealing ring, the second sealing ring；

First sealing ring is arranged between reinforcing circle, outer ring；

Second sealing ring is arranged on one end of the separate first order planetary gear reducing mechanism sun gear of hub bearing ontology, Between outer ring, inner ring；

Each group rolling mechanism is included by first sealing ring, the two the first sealing rings.

6. the hub-bearing unit according to claim 1 based on double reduction mechanism, which is characterized in that the first order The number of planetary gear reducing mechanism planetary gear set middle gear is at least 4, the second level planetary gear reducing mechanism row The number of star gear set middle gear is at least 5.