CN205331352U - Spur gear differential mechanism - Google Patents

Abstract

The utility model relates to a spur gear differential. The purpose of the utility model is to provide a spur gear differential with compact structure, adaptable to high speed working conditions, stable operation, good lubrication, low noise and low cost. The technical scheme of the utility model is: a housing composed of the left planetary gear frame and the right planetary gear frame fixed together, the housing is connected with a differential support, and the housing is provided with a sun gear set and two pairs of planetary gears The sun gear set is composed of the left sun gear and the right sun gear arranged coaxially. The left sun gear is rotatably connected to the left planetary gear carrier through bush II, and the right sun gear is rotatably connected to the right planet gear carrier through bush I. The planetary gear sets are symmetrically arranged on the circumference centered on the sun gear set axis. Each pair of planetary gear sets has two planetary gears. The planetary gears have a gear shaft. Circle II, the two ends of the gear shaft are rotatably connected to the left and right planetary gear carriers.

Description

Spur Gear Differential

technical field

The utility model relates to a spur gear differential. Suitable for motor drive axle transmission system.

Background technique

At present, the drive axle usually adopts the classic straight-toothed bevel gear differential, which has a compact structure, mature technology, relatively simple manufacturing and installation, and a high degree of generalization of components. It is mainly used in low-speed and heavy-load conditions. Due to the characteristic that the motor drive axle differential is directly connected to the high-speed output end of the motor, at high speeds, the meshing between the sun gear and the planetary gear, the cooperation between the sun gear and the output shaft, and the cooperation between the sun gear and the housing , The impact caused by the matching error between the planetary wheel and the housing will be amplified, resulting in wear of the gear, wear of the shaft hole matching surface, increase in noise, and shortening of life. In order to meet the performance requirements, it is necessary to have higher requirements on the manufacturing and installation precision of the differential, thereby increasing the manufacturing cost of the differential.

In order to meet the high-speed output characteristics of the differential, the straight-toothed cylindrical gear is used instead of the straight-toothed bevel gear to ensure the precision of gear manufacturing and installation, and to ensure uniform meshing of the gears and stable power output at high speeds. The drive axle motor occupies most of the space, and the space provided for the differential is usually small, so the differential must meet the relatively small appearance size. Compared with the bevel gear differential, it is mainly reflected in the axial size. In the axial dimension, it is mainly reflected in the tooth width. The tooth width is used to judge the transmission torque standard. The wider the tooth mesh, the greater the torque that can be transmitted. The wider the tooth mesh design, the The differential requires more installation space in the axial direction.

Contents of the invention

The technical problem to be solved by the utility model is: aiming at the above existing problems, provide a spur gear differential with compact structure, adaptable to high speed working conditions, stable operation, good lubrication, low noise and low cost .

The technical scheme adopted by the utility model is: a spur gear differential, which has a housing, and the housing is connected with a differential support. The gear frame and the right planetary gear frame are composed of a sun gear set and two pairs of planetary gear sets in the housing;

The sun gear set is composed of a left sun gear and a right sun gear coaxially arranged, the left sun gear is rotatably connected to the left planetary gear carrier through bush II, and the right sun gear is rotatably connected to the right planet gear carrier through bush I;

Two pairs of planetary gear sets are symmetrically arranged on a circle centered on the axis of the sun gear set. Each pair of planetary gear sets has two planetary gears. The planetary gears are spur gears. The planetary gears have a gear shaft. Ring gear Ⅰ is made, and ring gear Ⅱ is made at one end of the gear shaft. The ring gear Ⅰ of the two planetary gears in each pair of planetary gear sets meshes with the ring gear Ⅰ, and the ring gear Ⅱ of one of the planetary gears meshes with the left sun gear. The ring gear II of the other planetary gear meshes with the right sun gear, and the two ends of the gear shaft are rotatably connected to the left and right planetary gear carriers.

One end of the left sun gear is rotatably connected with one end of the right sun gear.

The cooperation between the gear shaft and the left and right planetary gear carriers adopts full complement needle roller bearings.

Ring gear I and ring gear II are integrated into one body on the gear shaft.

The degree of meshing between the planetary gear and the left and right sun gears, and between the planetary gears and the planetary gears can reach more than 1.2.

The beneficial effects of the utility model are: the utility model adopts the straight-toothed cylindrical gear instead of the bevel gear, which reduces the manufacturing and installation precision of parts and improves the meshing condition of the gears while realizing the differential speed of the whole vehicle. The use of two pairs of planetary gear sets can not only meet the load requirements, but also save radial space. The ring gear of the planetary gear is processed as one with the axis of rotation around it, which not only ensures the strength, but also reduces the difficulty of processing and assembly. The radial space is compact enough. The two pairs of planetary gear sets are distributed symmetrically around the center of revolution, separated from each other, and the space separated is sufficient to accommodate the structural parts of the shell connection load, so that the outer dimensions of the differential can not be too large, and the gears can be kept open. state, which is convenient for the lubrication of gears. The rotation of the gear shaft is no longer a sliding friction relative to the housing, but a full complement needle bearing is added to change the friction form into a sliding friction, so as to meet the durable and smooth rotation of the planetary gear shaft at high speed and avoid the wear of the shaft hole.

Description of drawings

Fig. 1 is a schematic cross-sectional view of the utility model.

Fig. 2 is a sectional view along line I-I of Fig. 1 .

Fig. 3 is a sectional view of II-II in Fig. 1 .

Fig. 4 is a III-III sectional view of Fig. 1 .

Fig. 5 is a structural schematic diagram of the planetary gear in the utility model.

detailed description

As shown in Figures 1 to 4, this embodiment is a spur gear differential, including a differential support 10, a housing, and a pair of sun gear sets and two pairs of planets arranged in the housing. The gear set, the housing is made up of the left planetary carrier 1 and the right planetary carrier 7, and the differential support 10, the left planetary carrier 1 and the right planetary carrier 7 are positioned and fixed by positioning pins.

In this embodiment, the sun gear set is composed of the left sun gear 8 and the right sun gear 6, the left and right sun gears 8 and 6 are coaxially arranged, and one end of the left sun gear 8 is rotatably connected to one end of the right sun gear 6, The other end of the left sun gear 8 is rotatably connected to the left planetary carrier 1 through the bush II9, and the other end of the right sun gear 6 is rotatably connected to the right planetary carrier 7 through the bush I5.

In this example, the two pairs of planetary gear sets are located on a circle centered on the axis of the sun gear set, and are arranged symmetrically around the axis of the sun gear set. Each pair of planetary gear sets has two planetary gears 2, and the planetary gears 2 are spur gears. As shown in Figure 5, the planetary gears have a gear shaft 21, and the middle section of the gear shaft is formed with a ring gear I22. There is ring gear II 23 (ring gear I 22 and ring gear II 23 are integrated). The ring gear I of the planetary gear 2 in each pair of planetary gear sets meshes with the ring gear I on the other planetary gear 2, and the ring gear II of one planetary gear 2 meshes with the left sun gear 8, and the ring gear II of the other planetary gear 2 meshes with the left sun gear 8. II meshes with the right sun gear 6. In this embodiment, both ends of the gear shaft 21 are respectively rotatably connected to the left and right planetary gear carriers 1, 7 through the full complement needle roller bearings 4 .

In this embodiment, the degree of coincidence between the planetary gear 2 and the left and right sun gears 8 and 6, and between the planetary gear 2 and the planetary gear 2 reaches more than 1.2.

The power transmission route of this embodiment is: the power of the motor is input through the spline connection of the differential support 10, and the left and right output shafts are respectively output to the left and right wheels through the spline connection of the left sun gear 8 and the right sun gear 6 power. The transmission status and the corresponding running status of each component are divided into two types:

One is the non-differential speed state: when the vehicle is running straight on a flat road, the left and right ends of the planetary gear set are in a balanced state at this time, and the planetary gear 2 does not rotate, but only revolves around the axis of the sun gear set with the casing, and the left and right ends of the planetary gear set are in a balanced state. , The angular velocity of the right sun gear 8, 6 is equal to the angular velocity of the differential case, that is, the left and right drive wheels also move at the same angular velocity.

Another state is the differential speed state: when the vehicle is turning, the balance state of the left and right ends of the planetary gear set is broken at this time, and the planetary gear 2 not only revolves around the axis of the sun gear set at a peripheral speed ω1 with the casing, but also ω2 rotates around its own central axis, and the peripheral speeds of a pair of planetary gears 2 meshing with each other are equal and in opposite directions. At this time, the output peripheral speeds of the left and right sun gears 8 and 6 are respectively ω3=ω1+ω2, ω4=ω1-ω2, It can be obtained that ω3+ω4=(ω1+ω2)+(ω1-ω2)=2ω1, that is, the sum of the rotation speeds of the left and right sun gears is equal to twice the rotation speed of the differential case, and has nothing to do with the rotation speed of the planetary gear 2. This is consistent with the kinematic characteristics of a symmetrical bevel gear differential with equal diameters of the two half-shaft gears, and can also achieve the same differential effect.

Claims (5)

1. A spur gear differential, with a housing, the housing is connected with a differential support (10), characterized in that: the housing is fixed together by the left planetary carrier (1) Composed of the right planetary gear carrier (7), the housing is provided with a sun gear set and two pairs of planetary gear sets; The sun gear set is composed of the left sun gear (8) and the right sun gear (6) arranged coaxially. (6) The right planetary gear frame (7) can be rotatably connected through the bushing I (5); Two pairs of planetary gear sets are arranged symmetrically on a circle centered on the axis of the sun gear set. Each pair of planetary gear sets has two planetary gears (2). The planetary gears (2) are spur gears. The planetary gears have The gear shaft (21), the middle section of the gear shaft is formed with the ring gear I (22), and one end of the gear shaft is formed with the ring gear II (23), and the ring gears I of the two planetary gears (2) in each pair of planetary gear sets mesh with each other , the ring gear II of one planetary gear (2) meshes with the left sun gear (8), the ring gear II of the other planetary gear (2) meshes with the right sun gear (6), and the two ends of the gear shaft (21) It can be rotatably connected to the left and right planetary gear carriers (1, 7). 2. The spur gear differential according to claim 1, characterized in that: one end of the left sun gear (8) is rotatably connected to one end of the right sun gear (6). 3. The spur gear differential according to claim 1 or 2, characterized in that: the cooperation between the gear shaft (21) and the left and right planetary gear carriers (1, 7) adopts full complement needle roller bearings (4). 4. The spur gear differential according to claim 1, characterized in that: the ring gear I (22) and the ring gear II (23) on the gear shaft (21) are integrally connected. 5. The spur gear differential according to claim 1, characterized in that: between the planetary gear (2) and the left and right sun gears (8, 6), between the planetary gear (2) and the planetary gear (2) The degree of overlap between the meshes reaches 1.2 or more.