Final drive

Abstract

The utility model relates to transmission mechanisms with two intermeshing gears for use in off-road vehicles. The technical result is achieved in that a final drive comprises a drive shaft, a drive pinion, a driven pinion, a hub, a brake disc, a stationary shaft, and a bearing, wherein the drive pinion is rigidly mounted on the drive shaft and is disposed inside the driven pinion, which is rigidly mounted to the hub, wherein the driven pinion is internally toothed and has a protective coating applied to the outer surface thereof, and wherein the stationary shaft has a longitudinal port of an inflation system, the bearing is mounted in the hub, and the stationary shaft is rigidly mounted to a support flange. This results in an increase in the reliability of the final drive.

Description

[0001] Description

[0002] Final drive

[0003] The utility model relates to transmission mechanisms with two intermeshing gear wheels used in off-road vehicles.

[0004] Known is a CYLINDRICAL INTERNAL GEAR TRANSMISSION WITH SUPPORT OF A ROTATING WHEEL ALONG THE OUTER DIAMETER OF A RIM, mounted in a housing, including shafts with wheels with external teeth, which engage with a wheel with internal teeth, characterized in that, in order to ensure the output of the shafts of the wheels with external teeth fixed relative to the housing in the axial direction in both directions from the plane of rotation, the shaft with a disk or spokes from the hub to the cylindrical rim is excluded from the wheel with internal teeth and the latter rests on the housing with fixation in the axial direction through a radial rolling or sliding bearing, which ensures the preservation of the geometric axis of rotation of the wheel with internal teeth, which is a transmission link between the driving wheel with external teeth and other wheels with external teeth, varying the number of which ensures the achievement of a certain gear ratio and rotation frequency.[RU2787798C1, published 12.01.2023].

[0005] The disadvantage of the analogue is that the lack of a rigid central connection can lead to deformation of the driven gear, which causes insufficient rigidity of the structure, which can lead to a decrease in its reliability.

[0006] The closest technical solution is the FINAL TRANSMISSION, which consists of a closed gear transmission containing a drive pinion mounted on the splines of the axle shaft, which is positioned in such a way that the final drive is a gearbox with internal engagement of the gear teeth; a driven pinion, rigidly connected by bolted connections to a hub mounted on two double-row bearings on a fixed axle without the need for adjustments, which is bolted to the gearbox housing; a brake disc is mounted on the hub.

[0007] [RU211021U1, published 18.05.2022].

[0008] The disadvantage of the closest technical solution is the lack of a protective coating on the outer side of the driven gear, which can lead to a decrease in the reliability of the final drive due to a decrease in corrosion resistance.

[0009] The technical problem solved by the utility model is to eliminate the shortcomings of analogues.

[0010] The objective of the claimed utility model is to create an onboard transmission with increased reliability.

[0011] The technical result consists in increasing the reliability of the final drive. The said technical result is achieved in that the final drive comprises a drive shaft, a pinion gear, a driven gear, a hub, a brake disc, a fixed axle and a bearing, where the pinion gear is rigidly mounted on the drive shaft and is located inside the driven gear, rigidly mounted to the hub and made with internal teeth and containing a protective coating applied to its outer surface, where the fixed axle contains a longitudinal hole for the pumping system, and the bearing is mounted in the hub, while the fixed axle is rigidly mounted to the support flange.

[0012] In particular, it contains an additional bearing;

[0013] In particular, the number of additional bearings is more than one; In particular, the protective coating is made in the form of chrome;

[0014] In particular, the protective coating is made in the form of nickel;

[0015] In particular, the hub contains a cover;

[0016] In particular, the fixed axis contains an auxiliary bearing for the driven gear;

[0017] In particular, the fixed axis contains a support-cradle;

[0018] In particular, a seal is mounted between the fixed axle and the hub; In particular, the support flange contains a seal.

[0019] The final drive is characterized by images:

[0020] Fig. 1 shows a longitudinal section of the final drive;

[0021] Fig. 2 shows the driving gear and driven gear of the final drive; Fig. 3 shows the support-cradle of the final drive;

[0022] The following are indicated on the figures: 1 - drive shaft, 2 - drive gear, 3 - driven gear, 4 - hub, 5 - brake disc, 6 - bearing, 7 - outer surface, 8 - longitudinal hole, 9 - fixed axis, 10 - additional bearing, 11 - support flange, 12 - cover, 13 - seal, 14 - auxiliary bearing, 15 - support-cradle, 16 - liner.

[0023] A vehicle's final drive is a mechanism in the transmission that transmits torque from the axle shaft to the wheel via additional gears. It is used to increase ground clearance and reduce the load on other transmission components. It is primarily used in off-road vehicles to ensure maneuverability in extreme conditions.

[0024] According to the claimed utility model, the final drive comprises a drive shaft 1, a driving gear 2, a driven gear 3, a hub 4, a brake disc 5 mounted to the hub 4, a fixed axle 9 and a bearing 6 (Fig. 1), where the driving gear 2 is rigidly mounted on the drive shaft 1, for example, by welding or a splined connection, and the driven gear 3 is rigidly mounted, for example, by a bolted connection, to the hub 4, where the driving gear 2 is pressed onto the drive shaft 1 or installed on splines, which eliminates rotation, and is located inside the driving gear 2.The rigid connection of the pinion gear 2 and the drive shaft 1 eliminates play and rotation, i.e., the absence of a movable connection between the drive shaft 1 and the pinion gear 2, which reduces the likelihood of destruction of splines or loose fasteners, reduces the load on the fasteners, i.e., evenly distributes the load over the entire mating area, reducing the risk of fatigue failure, and also increases durability due to the absence of micro-movements, which reduces wear and the likelihood of failure of the connection, thereby increasing the reliability of the entire final drive structure.

[0025] According to the utility model, the driven gear 3 is made with internal teeth, and the driving gear 2 is located inside the driven gear 3, which makes it possible to make a final drive design with internal engagement of teeth.

[0026] The use of internal gearing allows for a significant reduction in the final drive's size. This is especially important in confined spaces, such as vehicle wheel assemblies. The internal gearing between pinion gear 2 and driven gear 3 is characterized by a large number of simultaneously operating teeth, which distributes the load evenly. This reduces tooth wear and increases the durability of the gear. Furthermore, the tooth root of driven gear 3 is located at a larger diameter than that of an external gear, significantly increasing operating loads. At the same time, thanks to the internal gearing and close tooth contact, these gears minimize frictional energy losses.

[0027] The placement of pinion gear 2 within driven gear 3 in the final drive increases its reliability by reducing the load on drive shaft 1. This arrangement allows for more compact and efficient torque transmission, and torque is transmitted more uniformly, reducing bending loads on drive shaft 1. Driven gear 3, positioned around pinion gear 2, distributes the load more evenly, reducing the risk of premature tooth wear and lateral loads on transmission components. This arrangement also allows for the implementation of a planetary gear system or a compact gear train with a high gear ratio, which is especially important for heavy-duty SUVs where maximum torque is required.

[0028] According to the utility model, driven gear 3 comprises a protective coating applied to the outer surface 7 (Fig. 2) of driven gear 3, which significantly increases the reliability of the entire final drive by protecting driven gear 3 from rust and corrosion. This is especially important for operation in conditions of high humidity, dirt, or chemically active environments (e.g., on salty roads, in swampy or snowy areas), thereby extending the service life of driven gear 3, reducing the need for repair and replacement. The protective coating can also add additional strength to the material of driven gear 3, preventing the formation of cracks, microcracks, and other defects that may occur during operation under high loads or impact conditions. The coating also acts as a barrier, preventing the penetration of dirt, water, and other contaminants onto the teeth of driven gear 3. This is important for operation in dirty or sandy conditions, where the presence of particles can accelerate wear.If necessary, the protective coating can be chrome plated, which can further enhance the reliability of the final drive by further increasing the wear resistance of the driven gear 3. Chrome has high chemical inertness, protecting metal components from moisture, dirt, chemical reagents, and salts, which extends the service life of the final drive, especially in humid, off-road, and winter conditions.

[0029] If necessary, the protective coating can be nickel-plated, which can further enhance the final drive's reliability by increasing corrosion resistance. Nickel forms a dense, chemically resistant layer that protects the metal from moisture, dirt, acids, and salts, making it particularly useful for final drives operating in high humidity, dirt, or winter conditions with chemicals.

[0030] The fixed axle 9 contains a longitudinal opening 8 for the inflation system. The inflation system, located within the fixed axle, is protected from external contaminants (dirt, sand, water). This reduces the risk of damage or clogging of the system components, as the inflation elements are hidden from the external environment and are subject to less wear. When the inflation system is concealed within the fixed axle, it is not directly exposed to rocks, branches, or other objects that could damage it if exposed. This increases its durability and reliability when used on challenging trails.Moreover, placing the inflation system within the fixed axle 9 reduces the number of moving components, such as external pipes and valves, which can be subject to wear and be a source of mechanical losses. This can significantly increase the risk of the inflation system components getting caught in the final drive's moving components, which can significantly reduce the final drive's reliability due to the inflation system components getting caught in its components. The fixed axle 9 has a sufficiently large longitudinal opening 8 to ensure high-performance tire inflation, allowing tire inflation without the need to stop and connect separate pumps. This is especially useful in rough terrain, where pressure adjustments are required depending on the surface type (sand, mud, asphalt).

[0031] According to the utility model, bearing 6 is mounted in hub 4 and is necessary to ensure uniform rotation of hub 4. The use of bearing 6, installed in hub 4, plays a key role in improving the reliability of the final drive, reducing friction and wear. Bearing 6 reduces friction between rotating elements, ensuring smooth and efficient movement of hub 4 around fixed axle 9. This significantly reduces friction between fixed axle 9 and adjacent elements, extending service life and enhancing the reliability of the entire final drive. Bearing 6 can also withstand high radial and axial loads, which is especially important for heavy SUVs and military vehicles. It evenly distributes the load, reducing localized overloads and reducing the likelihood of mechanical damage.If necessary, an additional bearing 10 can be mounted in hub 4. Its use can further enhance the final drive's reliability by better distributing radial and axial loads, reducing pressure on main bearing 6. This reduces the risk of overload and premature failure of one bearing 6, which is especially important for heavy equipment and off-road vehicles. Furthermore, the number of additional bearings 10 can be greater than one, which can further enhance the final drive's reliability under increased loads.

[0032] According to the utility model, fixed axle 9 is rigidly mounted, for example by means of a bolted connection, to support flange 11. Rigidly attaching fixed axle 9 to support flange 11 significantly improves the reliability of the final drive by, for example, eliminating play and displacement. The rigid connection eliminates play and displacement of fixed axle 9 relative to support flange 11, preventing loosening of the connection and premature wear. This is especially important for heavy equipment operating under constant shock loads. Off-road equipment experiences high dynamic loads, which can lead to deformation of weak connections. Rigidly fixing fixed axle 9 to support flange 11 eliminates the possibility of displacement and distortion, preventing uneven wear of gears and bearings. Thus, the rigid connection of fixed axle 9 to support flange 11 significantly improves the reliability of the entire final drive.

[0033] The final drive may additionally include a seal 13 mounted between the fixed axle 9 and the hub 4. The seal between the hub 4 and the fixed axle 9 serves to prevent lubricant leakage and protect against dirt, dust, and water ingress. This is especially important in operating conditions where the final drive is subject to significant loads and environmental influences and can further enhance the final drive's reliability during operation. The seal may be, for example, a lip seal or a stuffing box seal.

[0034] If necessary, the final drive may contain a cover 12 mounted on the end portion of the hub 4, and which is sealed, for example, by a seal 13, for example a gland or cuff seal to the pumping channel of the fixed axle 9 and thereby ensures the tightness of the unit (hub bearings), protects from aggressive environments and increases their service life, which can additionally increase the reliability of the final drive by protecting against the ingress of fine dust from the wheel through the pumping system when regulating the pressure in the tire of the car.

[0035] If necessary, support flange 11 can contain an auxiliary bearing 14 for driven gear 3. Auxiliary bearing 14 reduces the load on pinion gear 2, thereby reducing wear on its teeth. Auxiliary bearing 14 makes the system more resistant to bending and distortion, especially under high loads, which can be beneficial for heavy equipment operating under high dynamic loads, which, taken together, can further improve the reliability of the entire final drive.

[0036] If necessary, the support flange 11 may contain a seal mounted between the support flange 11 and the driven gear 3, which may further improve the reliability of the final drive by preventing dust and dirt from entering the device.

[0037] If necessary, the drive gear 2 may have an additional support point in the form of a support cradle 15 (Fig. 3) or a foundation mounted on a fixed axle 9, which may house a bearing 16, such as a rolling or friction bearing. The support cradle, into which the bearing 16 (friction bearing) is installed, serves as a supporting element, further enhancing the support of the drive shaft 1 under heavy loads.

[0038] First example of implementation:

[0039] The final drive comprises a drive shaft 1, a driving gear 2, a driven gear 3, a hub 4, a brake disc 5, a fixed axle 9 and a bearing 6, where the driving gear 2 is rigidly mounted on the drive shaft 1 and is located inside the driven gear 3 rigidly mounted to the hub 4 and made with internal teeth and containing a protective coating applied to the outer surface 7 of the driven gear 3, where the fixed axle 9 contains a longitudinal opening 8 of the pumping system, and the bearing 6 is mounted in the hub 4, while the fixed axle 9 is rigidly mounted to the support flange 11.

[0040] Second implementation example:

[0041] The final drive comprises a drive shaft 1, a driving gear 2, a driven gear 3, a hub 4, a brake disc 5, a fixed axle 9 and a bearing 6, where the driving gear 2 is rigidly mounted on the drive shaft 1 and is located inside the driven gear 3 rigidly mounted to the hub 4 and made with internal teeth and containing a chrome coating applied to the outer surface 7 of the driven gear 3. In this case, the drive shaft 1 on the side of the driving gear 2 is mounted on a support-cradle 15. The fixed axle 9 contains a longitudinal hole 8 of the pumping system. The final drive contains a bearing 6 and an additional bearing 10, mounted in the hub 4. The fixed axle 9 is rigidly mounted to the support flange 11.

[0042] Third example of implementation:

[0043] The final drive comprises a drive shaft 1, a driving gear 2, a driven gear 3, a hub 4, a brake disc 5, a fixed axle 9 and a bearing 6, where the driving gear 2 is rigidly mounted on the drive shaft 1 and is located inside the driven gear 3 rigidly mounted to the hub 4 and made with internal teeth and containing a nickel coating applied to the outer surface 7 of the driven gear 3, where the fixed axle 9 contains a longitudinal hole 8 of the pumping system. The final drive contains a bearing 6 and two additional bearings 10 mounted in the hub 4. The fixed axle 9 is rigidly mounted to the support flange 11. The hub 4 contains a cover 12 mounted to its end part.

[0044] In order to study the improvement of the reliability of the final drive design described in the claimed utility model, the following final drives were manufactured:

[0045] Final drive No. 1 is manufactured in accordance with the first example of implementation described in this application;

[0046] Final drive No. 2 is manufactured in accordance with the second example of implementation;

[0047] Final drive No. 3 is manufactured in accordance with the third example of implementation;

[0048] Final drive No. 4 is manufactured in accordance with the closest technical solution described in RU211021U1, published 05 / 18 / 2022.

[0049] The tests were carried out on a stand simulating real loads, as well as in field conditions (off-road, extreme temperatures).

[0050] The tests measured gear tooth wear, bearing wear, vibration under load, final drive temperature, impact resistance, and corrosion resistance.

[0051]

[0052] Based on the test results, it was determined that final drive No. 4, in comparison with final drives manufactured in accordance with the declared utility model, had the highest percentage of gear tooth wear per 1000 hours, the highest level of bearing wear, higher backlash, higher temperature, low impact resistance, and critically low corrosion resistance, which together characterizes the high reliability of the final drive according to the declared utility model, relative to the final drive presented in the closest technical solution.

[0053] Thus, by the claimed method, through the use of technologies described in the claimed utility model, it was possible to significantly increase the reliability of the final drive.

Claims

FORMULA 1. A final drive comprising a drive shaft, a pinion gear, a driven gear, a hub, a brake disc, a fixed axle and a bearing, where the pinion gear is rigidly mounted on the drive shaft and is located inside the driven gear, which is rigidly mounted to the hub and is made with internal teeth and contains a protective coating applied to its outer surface, where the fixed axle contains a longitudinal opening for the pumping system, and the bearing is mounted in the hub, while the fixed axle is rigidly mounted to the support flange.

2. The final drive according to paragraph 1, characterized in that it contains an additional bearing.

3. The final drive according to paragraph 2, characterized in that the number of additional bearings is greater than one.

4. The final drive according to paragraph 1, characterized in that the protective coating is made in the form of chrome.

5. The final drive according to paragraph 1, characterized in that the protective coating is made in the form of nickel.

6. The final drive according to paragraph 1, characterized in that the hub contains a cover.

7. The final drive according to claim 1, characterized in that the fixed axle contains an auxiliary bearing for the driven gear.

8. The final drive according to paragraph 1, characterized in that the fixed axle contains a support bed.

Images