Three-gear wheel-side speed reducer for truck rear axle

Abstract

The application discloses a three-gear wheel-side speed reducer for a truck rear axle, which is composed of a main transmission module and a brake control module. Through the meshing of gears and the engagement relationship with the brake, the combination and disconnection of two brakes are used to realize three modes of large transmission ratio, normal transmission ratio and neutral gear. The large transmission ratio mode is suitable for steep slope slow speed demand, the normal transmission ratio mode can be used for the driving demand of conventional roads, and the neutral gear mode can be used for the demand of a trailer. The double planetary row structure formed by the gear set is adopted in the wheel-side speed reducer, which is small in size, light in weight, good in stability, low in cost and helpful to improve the utilization rate of the rear axle space. The three gears are arranged to realize the multifunctional gear adjustment, meet the normal deceleration and driving demand of the truck in the normal road, improve the stability, safety and comfort of the truck during driving, and effectively protect the brake parts.

Description

Technical Field

[0001] This invention belongs to the field of heavy-duty truck deceleration, specifically relating to a three-speed wheel-side reducer for the rear axle of a truck. Background Technology

[0002] With the rapid development of social productivity and the logistics industry, people have increasingly higher requirements for the load-bearing capacity and transportation of trucks. While the load-bearing capacity and truck size are increasing, the requirements for deceleration and braking are also becoming more stringent. Traditional truck rear axles inevitably suffer from overheating or damage to brake components due to prolonged braking on long, steep slopes, which can easily lead to reduced braking performance or even brake failure, posing significant safety hazards. With the development of science and technology, there is an urgent need to improve truck rear axles. Wheel-side reducers can further enhance the deceleration effect of trucks. By setting a large reduction ratio, they can achieve the truck's slowing function on steep slopes. A normal reduction ratio can meet the normal driving needs of the truck, and neutral gear can be used for towing operations, thus protecting the gear set and significantly improving the stability and safety of the truck. They also feature a compact structure and high reliability, and can protect the rear axle and braking components. Furthermore, to realize the characteristics of wheel-side reducers and simplify gears, improving operability, a design scheme for a three-speed wheel-side reducer for truck rear axles that integrates the main drive system and brakes into the wheel hub is proposed.

[0003] Patent document CN104696445B discloses a wheel-side reducer, which includes a reducer bracket, a reducer assembly, a brake hub, an end cover assembly, an oil-gas separator assembly, and an oil pump lubrication assembly. The reducer bracket includes a reducer cover and a hollow hub fixing shaft extending outward from the bottom of the reducer cover. The reducer assembly includes an input shaft, a first planetary gear, a first planetary carrier, a second planetary gear, a second planetary carrier, an output half-shaft, and an internal gear ring. The first and second planetary gears are arranged side by side in the internal gear ring. The first planetary gear meshes with a first sun gear mounted on the input shaft, and the second planetary gear meshes with a second sun gear mounted on the first planetary carrier. This technical solution adopts a two-stage planetary gear structure with two-stage planetary gears sharing the same gear ring, making the structure more compact. The second sun gear is mounted on the first planetary carrier and meshes with the second planetary gear, effectively saving space and solving the problem of limited wheel-side space. However, it is only suitable for high-speed gear transmission, is not adjustable, and is not suitable for the diversity and complexity of current vehicle driving roads.

[0004] A wheel-side reducer is disclosed in patent document CN112648358A, comprising: a sun gear, which is the power input component of the wheel-side reducer; a gear ring, which is coaxially arranged with the sun gear and can rotate relative to the sun gear, serving as the power output component of the wheel-side reducer; a planet carrier, which is coaxially mounted with the sun gear and can rotate relative to the planet carrier; and planet gears, including a first gear and a second gear coaxially fixed, wherein the pitch circle diameter of the first gear is larger than that of the second gear, the planet gears are mounted on the planet carrier, the first gear can mesh with the sun gear for transmission, and the second gear can mesh with the internal teeth of the gear ring for transmission. This technical solution can be adapted to engineering vehicle axles requiring large reduction ratios, but the planet gears occupy a large space, are difficult to process, have high manufacturing costs, and the gear ratios are not adjustable, making it only suitable for conditions requiring large reduction ratios. Summary of the Invention

[0005] This invention addresses the shortcomings of existing technologies by providing a three-speed wheel-side reducer for the rear axle of trucks, taking into account the high deceleration requirements during truck operation, especially the high risk factor when driving on long, steep slopes. The reducer integrates a gear-based transmission system and brakes within the wheel hub, enabling the conversion between large and normal reduction ratios and towing functionality. The large reduction ratio facilitates steep slope descent during prolonged downhill driving, preventing overheating or damage to brake components due to prolonged braking, thus improving the safety and comfort of truck operation.

[0006] To achieve its objectives, the present invention employs the following technical solution:

[0007] The three-speed wheel-side reducer for truck rear axle of the present invention is characterized by being composed of a main transmission module and a braking control module;

[0008] The main transmission module is a gear transmission structure, including a first spur gear, an upper double right gear, an upper double left gear, a small spur gear, an internal gear, a lower double right gear, a lower double left gear, a second spur gear, a third spur gear, an input shaft, and a planetary carrier;

[0009] The input shaft is fixedly connected to the first spur gear via a key. The upper end of the first spur gear meshes with the upper double right gear to form a gear pair. The lower end of the first spur gear meshes with the lower double right gear to form a gear pair. The upper double right gear is fixedly connected to the upper double left gear. The lower double right gear is fixedly connected to the lower double left gear. The upper double left gear meshes with the internal gear to form an internal gear pair. The upper double left gear meshes with the second spur gear to form a gear pair. The second spur gear meshes with the small spur gear to form a gear pair. The lower double left gear meshes with the third spur gear to form a gear pair. The third spur gear meshes with the small spur gear to form a gear pair. The lower end of the central shaft of the second spur gear is fixedly connected to the end of the input shaft via a bearing. The upper end passes through the center of the upper double left gear and the upper double right gear and is connected to the planetary carrier via a flange ring, so that the gear transmission structure constitutes a double planetary gear set.

[0010] The braking control module includes a left brake, a right brake, and a frame. The brake pad at the tail end of the internal gear is fixedly connected to the inner ring of the left brake, and the brake pad at the tail end of the small spur gear is fixedly connected to the inner ring of the right brake. The internal gear is fixedly connected to the frame via bearings.

[0011] The three-speed wheel-side reducer for the rear axle of a truck, as described in this invention, is also characterized by:

[0012] In neutral mode, the main drive module is connected as follows: the brake pads connected to the left brake and the internal gear are kept separate; the brake pads connected to the right brake and the pinion are kept separate; both the upper double right gear and the lower double right gear are engaged with the first spur gear; both the upper double left gear and the lower double left gear are engaged with the internal gear; the upper double left gear and the second spur gear are engaged; and the lower double left gear and the third spur gear are engaged.

[0013] The three-speed wheel-side reducer for the rear axle of a truck, as described in this invention, is also characterized by:

[0014] In the high transmission ratio mode, the main transmission module is connected as follows: the left brake is engaged with the brake pad connected to the internal gear, the right brake is separated from the brake pad connected to the pinion, the upper double right gear and the lower double right gear are both engaged with the first spur gear, the upper double left gear and the lower double left gear are both engaged with the internal gear, the upper double left gear and the second spur gear are engaged, and the lower double left gear and the third spur gear are engaged.

[0015] The three-speed wheel-side reducer for the rear axle of a truck, as described in this invention, is also characterized by:

[0016] In the normal transmission ratio mode, the main transmission module is connected as follows: the brake pads connected to the left brake and the internal gear remain separated; the brake pads connected to the right brake and the pinion are engaged; both the upper double right gear and the lower double right gear are meshed with the first spur gear; both the upper double left gear and the lower double left gear are meshed with the internal gear; the upper double left gear and the second spur gear are meshed; and the lower double left gear and the third spur gear are meshed.

[0017] Compared with existing technologies, the beneficial effects of this invention are reflected in:

[0018] 1. This invention introduces the main transmission module and braking control module into the wheel-side reduction device to achieve a double planetary gear set structure formed by the gear set. This structure has advantages such as small size, light weight, good stability, and low cost, which helps to improve the utilization rate of the rear axle space. It also has three gears, which can realize multi-functional gear adjustment and meet the normal deceleration and driving needs of trucks on normal roads. When in neutral, it can be used for towing, avoiding damage to the gear set in the wheel-side reduction device.

[0019] 2. The three-speed reducer of the present invention has a large transmission ratio gear, with a reduction ratio of 52, which realizes the slowing function of trucks on long-distance steep slopes, avoids the safety hazards caused by overheating or even failure of brake drums due to prolonged braking, improves the stability, safety and comfort of trucks when driving, and can effectively protect the braking components. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the three-speed wheel-side reducer for the rear axle of a truck according to the present invention;

[0021] Figure 2 This is a power transmission route diagram for advancing one gear in this invention;

[0022] Figure 3 This is a diagram showing the power transmission route for advancing two gears in this invention.

[0023] Figure 4 This is a schematic diagram of the structure of the gap in the present invention;

[0024] The numbers in the diagram are: 1 First spur gear; 2 Upper double right gear; 201 Upper double left gear; 3 Small spur gear; 4 Internal gear; 5 Frame; 6 Lower double right gear; 601 Lower double left gear; 7 Second spur gear; 8 Third spur gear; 9 Input shaft; B1 Left brake; B2 Right brake; H Planetary carrier. Detailed Implementation

[0025] See Figure 1 In this embodiment, the three-speed wheel-side reducer for the rear axle of the truck consists of a main drive module and a brake control module;

[0026] like Figure 1 As shown, the main transmission module is a gear transmission structure, including a first spur gear 1, an upper double right gear 2, an upper double left gear 201, a small spur gear 3, an internal gear 4, a lower double right gear 6, a lower double left gear 601, a second spur gear 7, a third spur gear 8, an input shaft 9, and a planetary carrier H;

[0027] like Figure 1 As shown, in this embodiment, the gear sets on the left and right sides of the middle axle differential are symmetrical. The input shaft 9 of the middle axle differential is fixedly connected to the first straight gear 1 via a key. The upper end of the first straight gear 1 meshes with the upper double right gear 2 to form a gear pair, and the lower end of the first straight gear 1 meshes with the lower double right gear 6 to form a gear pair. The upper double right gear 2 is fixedly connected to the upper double left gear 201, and the lower double right gear 6 is fixedly connected to the lower double left gear 601. The upper double left gear 201 meshes with the internal gear 4 to form an internal gear pair. The upper double left gear 201 meshes with the second spur gear 7 to form a gear pair, the second spur gear 7 meshes with the small spur gear 3 to form a gear pair, the lower double left gear 601 meshes with the third spur gear 8 to form a gear pair, the third spur gear 8 meshes with the small spur gear 3 to form a gear pair, the lower end of the central shaft of the second spur gear 7 is fixedly connected to the end of the input shaft 9 through a bearing, and the upper end passes through the center of the upper double left gear 201 and the upper double right gear 2 and is connected to the planetary carrier H through a flange ring, so that the gear transmission structure constitutes a double planetary gear set;

[0028] The braking control module includes a left brake B1, a right brake B2 and a frame 5. The tail brake pad of the internal gear 4 is fixedly connected to the inner ring of the left brake B1, the tail brake pad of the small spur gear 3 is fixedly connected to the inner ring of the right brake B2, and the internal gear 4 is fixedly connected to the frame 5 through bearings.

[0029] In neutral mode, the main drive module is connected as follows: the brake pads connected to the left brake B1 and the internal gear 4 are kept separate; the brake pads connected to the right brake B2 and the pinion 3 are kept separate; the upper double right gear 2 and the lower double right gear 6 are both engaged with the first spur gear 1; the upper double left gear 201 and the lower double left gear 601 are both engaged with the internal gear 4; the upper double left gear 201 and the second spur gear 7 are engaged; and the lower double left gear 601 and the third spur gear 8 are engaged.

[0030] In the high transmission ratio mode, the main transmission module is connected as follows: the left brake B1 engages with the brake pad connected to the internal gear 4, the right brake B2 remains separated from the brake pad connected to the pinion 3, the upper double right gear 2 and the lower double right gear 6 are both meshed with the first spur gear 1, the upper double left gear 201 and the lower double left gear 601 are both meshed with the internal gear 4, the upper double left gear 201 is meshed with the second spur gear 7, and the lower double left gear 601 is meshed with the third spur gear 8.

[0031] In the normal transmission ratio mode, the main transmission module is connected as follows: the brake pads connected to the left brake B1 and the internal gear 4 are separated; the brake pads connected to the right brake B2 and the pinion 3 are engaged; the upper double right gear 2 and the lower double right gear 6 are both meshed with the first spur gear 1; the upper double left gear 201 and the lower double left gear 601 are both meshed with the internal gear 4; the upper double left gear 201 and the second spur gear 7 are meshed; and the lower double left gear 601 and the third spur gear 8 are meshed.

[0032] Working principle:

[0033] Based on the high requirements for deceleration effect during truck operation and in combination with the expected reducer ratio, the number of teeth and module of each gear are designed as shown in Table 1.

[0034] Table 1. Number of Gear Teeth and Module

[0035]

[0036] The actuators for each gear position are shown in Table 2:

[0037] Table 2 Working Table of Shift Actuating Elements

[0038]

[0039] Note: In the table, "●" indicates combination, and "○" indicates separation;

[0040] Combination Figure 1 , Figure 2 , Figure 3 , Figure 4 According to Table 2, the transmission routes for each gear are as follows:

[0041] 1. Gaps (N positions)

[0042] like Figure 4As shown, in neutral, the left brake B1 remains disengaged from the brake pad connected to the internal gear 4, and the right brake B2 remains disengaged from the brake pad connected to the pinion 3. The power output from the main reducer drives the first spur gear 1 to rotate via the middle bridge differential and input shaft 9. The upper double right gear 2 and the lower double right gear 6 are both meshed with the first spur gear 1. The rotation of the first spur gear 1 simultaneously drives the upper double right gear 2 and the lower double right gear 6 to rotate, and the upper double left gear 201 and the lower double left gear 601 also rotate accordingly. Both the upper double left gear 201 and the lower double left gear 601 are meshed with the internal gear 4. The rotation of the double left gear 601 drives the internal gear 4 to idle. The upper double left gear 201 and the second spur gear 7 are in a meshing state. The rotation of the upper double left gear 201 drives the second spur gear 7 to rotate. The lower double left gear 601 and the third spur gear 8 are in a meshing state. The rotation of the lower double left gear 601 drives the third spur gear 8 to rotate. Both the second spur gear 7 and the third spur gear 8 are in a meshing state with the small spur gear 3. The rotation of the second spur gear 7 and the third spur gear 8 drives the small spur gear 3 to idle. No braking force is transmitted to the wheel hub. At this time, the vehicle relies on inertia to drive or tow, thus achieving the purpose of protecting the gear set.

[0043] 2. Drive (D)

[0044] (1) Move forward one gear (D1 gear, large reduction ratio)

[0045] like Figure 2 As shown, when shifting to first gear, the left brake B1 engages with the brake pad connected to the internal gear 4, while the right brake B2 remains disengaged from the brake pad connected to the pinion 3. The power output from the main reducer drives the first spur gear 1 to rotate via the middle bridge differential and input shaft 9. The upper double right gear 2 and the lower double right gear 6 are both meshed with the first spur gear 1. The rotation of the first spur gear 1 simultaneously drives the upper double right gear 2 and the lower double right gear 6 to rotate, and the upper double left gear 201 and the lower double left gear 601 also rotate accordingly. Both the upper double left gear 201 and the lower double left gear 601 are internally meshed with the internal gear 4. The rotation of the lower double left gear 601 drives the internal gear 4 to rotate. At this time, the braking force generated by the left brake B1 is transmitted to the wheel hub, causing the wheels on both sides to decelerate. The upper double left gear 201 and the second spur gear 7 are in a meshing state. The rotation of the upper double left gear 201 drives the second spur gear 7 to rotate. The lower double left gear 601 and the third spur gear 8 are in a meshing state. The rotation of the lower double left gear 601 drives the third spur gear 8 to rotate. Both the second spur gear 7 and the third spur gear 8 are in a meshing state with the small spur gear 3. The rotation of the second spur gear 7 and the third spur gear 8 causes the small spur gear 3 to spin freely, without generating braking force to be transmitted to the wheel hub.

[0046] (2) Move forward to second gear (D2 gear)

[0047] like Figure 3 As shown, in second gear, the left brake B1 remains disengaged from the brake pad connected to the internal gear 4, while the right brake B2 engages with the brake pad connected to the pinion 3. The power output from the main reducer drives the first spur gear 1 to rotate via the middle bridge differential and input shaft 9. The upper double-linked right gear 2 and the lower double-linked right gear 6 are both meshed with the first spur gear 1. The rotation of the first spur gear 1 simultaneously drives the upper double-linked right gear 2 and the lower double-linked right gear 6 to rotate, and the upper double-linked left gear 201 and the lower double-linked left gear 601 also rotate accordingly. Both the upper double-linked left gear 201 and the lower double-linked left gear 601 are internally meshed with the internal gear 4. The rotation of the left gear 201 and the lower double left gear 601 causes the internal gear 4 to idle. The upper double left gear 201 and the second spur gear 7 are in a meshing state. The rotation of the upper double left gear 201 drives the second spur gear 7 to rotate. The lower double left gear 601 and the third spur gear 8 are in a meshing state. The rotation of the lower double left gear 601 drives the third spur gear 8 to rotate. Both the second spur gear 7 and the third spur gear 8 are in a meshing state with the small spur gear 3. The rotation of the second spur gear 7 and the third spur gear 8 drives the small spur gear 3 to rotate. At this time, the braking force generated by B2 is transmitted to the wheel hub, causing the wheels on both sides to decelerate slowly.

[0048] Combination Figure 1 , Figure 2 , Figure 3 and Figure 4 The gear shifting process is as follows:

[0049] When shifting from neutral to first gear, the shift control unit energizes and engages the brake pad connected to the internal gear 4 via B1, while de-energizing and disengaging the brake pad connected to the pinion 3 via B2, thus achieving the shift from neutral to first gear.

[0050] When shifting from neutral to second gear, the shift control unit disconnects the brake pads connected to internal gear 4 and keeps them separate, while energizing the brake pads connected to pinion 3 and engaging them, thus achieving the shift from neutral to second gear.

[0051] To shift from second gear to first gear, the shift control unit disconnects the brake pads connected to pinion 3 and energizes the brake pads connected to internal gear 4 via de-energization, thus achieving the shift from second gear to first gear.

Claims

1. A three-speed wheel-side reducer for a truck rear axle, characterized in that: It consists of a main drive module and a braking control module; The main transmission module is a gear transmission structure, including a first spur gear (1), an upper double right gear (2), an upper double left gear (201), a small spur gear (3), an internal gear (4), a lower double right gear (6), a lower double left gear (601), a second spur gear (7), a third spur gear (8), an input shaft (9), and a planetary carrier (H); The input shaft (9) is fixedly connected to the first spur gear (1) via a key. The upper end of the first spur gear (1) meshes with the upper double right gear (2) to form a gear pair, and the lower end of the first spur gear (1) meshes with the lower double right gear (6) to form a gear pair. The upper double right gear (2) is fixedly connected to the upper double left gear (201), and the lower double right gear (6) is fixedly connected to the lower double left gear (601). The upper double left gear (201) meshes internally with the internal gear (4) to form an internal gear pair, and the upper double left gear (201) meshes with the second... A spur gear (7) meshes to form a gear pair, the second spur gear (7) meshes with the small spur gear (3) to form a gear pair, the lower double left gear (601) meshes with the third spur gear (8) to form a gear pair, the third spur gear (8) meshes with the small spur gear (3) to form a gear pair, the lower end of the central shaft of the second spur gear (7) is fixedly connected to the end of the input shaft (9) through a bearing, and the upper end passes through the center of the upper double left gear (201) and the upper double right gear (2) and is connected to the planet carrier (H) through a flange ring, so that the gear transmission structure constitutes a double planetary gear set; The braking control module includes a left brake (B1), a right brake (B2) and a frame (5). The tail brake pad of the internal gear (4) is fixedly connected to the inner ring of the left brake (B1), the tail brake pad of the small spur gear (3) is fixedly connected to the inner ring of the right brake (B2), and the internal gear (4) is fixedly connected to the frame (5) through a bearing.

2. The three-speed wheel-side reducer for truck rear axles according to claim 1, characterized in that: In neutral mode, the main drive module is connected as follows: the brake pads connected to the left brake (B1) and the internal gear (4) are kept separate; the brake pads connected to the right brake (B2) and the small spur gear (3) are kept separate; the upper double right gear (2) and the lower double right gear (6) are both meshed with the first spur gear (1); the upper double left gear (201) and the lower double left gear (601) are both meshed with the internal gear (4); the upper double left gear (201) is meshed with the second spur gear (7); and the lower double left gear (601) is meshed with the third spur gear (8).

3. The three-speed wheel-side reducer for truck rear axles according to claim 1, characterized in that: In the high transmission ratio mode, the main transmission module is connected as follows: the brake pads of the left brake (B1) and the internal gear (4) are engaged, the brake pads of the right brake (B2) and the small spur gear (3) are kept separate, the upper double right gear (2) and the lower double right gear (6) are both meshed with the first spur gear (1), the upper double left gear (201) and the lower double left gear (601) are both meshed with the internal gear (4), the upper double left gear (201) and the second spur gear (7) are meshed, and the lower double left gear (601) and the third spur gear (8) are meshed.

4. The three-speed wheel-side reducer for truck rear axles according to claim 1, characterized in that: In the normal transmission ratio mode, the main transmission module is connected as follows: the brake pads connected to the left brake (B1) and the internal gear (4) are kept separate, the brake pads connected to the right brake (B2) and the small spur gear (3) are engaged, the upper double right gear (2) and the lower double right gear (6) are both meshed with the first spur gear (1), the upper double left gear (201) and the lower double left gear (601) are both meshed with the internal gear (4), the upper double left gear (201) is meshed with the second spur gear (7), and the lower double left gear (601) is meshed with the third spur gear (8).

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