An off-road rally car

Abstract

The present application relates to the field of racing car technology, and more particularly to a cross-country rally car, comprising a frame and a transmission system mounted on the frame, and wheels mounted on the frame through a suspension system. The transmission system comprises a gearbox mounted at the rear of the frame and a differential mounted at the front of the frame; the gearbox and the differential are drivingly connected through a first transmission shaft arranged front and back. The suspension system comprises front horns respectively located at the inner sides of the two front wheels, and the two front horns are fixed to the front side of the frame through upper double wishbone suspensions and lower double wishbone suspensions. The cross-country rally car has the advantages of lighter overall vehicle, compact structure, good operability, excellent passability, high safety, etc. The lighter vehicle has sufficient power performance, and the vehicle has small self-friction resistance during travel, good passability on uneven roads, and is not prone to overturning, which is conducive to improving the competition results.

Description

Technical Field

[0001] This invention relates to the field of racing technology, and more particularly to an off-road rally car. Background Technology

[0002] The BAJA (Baja in China) racing series originated in the United States and is the predecessor to the Formula Student Grand Prix. The BAJA requires participating teams to undergo a variety of static and dynamic tests. These dynamic tests include traction testing, hill climbing, straight-line acceleration testing, and endurance testing. The competition places stringent demands on the car's power, handling stability, and braking performance, while also requiring good endurance. Therefore, the cars need high strength, low weight, and good dynamic response to complete all aspects of the competition.

[0003] Most traditional racing cars in China use a truss-frame structure. While this type of frame meets reliability requirements, it suffers from high weight. Other components of traditional racing cars are also mostly made of steel, resulting in robust structures but similarly high weight. Therefore, it is necessary to optimize the car's components from both material and structural perspectives to reduce weight and improve performance.

[0004] Traditional brake systems consist of four brake discs located at each wheel, comprising a brake pump, brake discs connected to the wheels, and brake calipers on the discs. During braking, high-pressure hydraulic fluid pushes pistons, forcing brake pads against the brake discs to produce a braking effect. For the relatively small size of BAJA race cars, the brake discs account for a large proportion of the vehicle's mass. While the brake discs can provide sufficient braking force, their significant mass negatively impacts the car's dynamics.

[0005] In existing technologies, the steering angle of the front steering knuckle of a racing car is limited and not large enough, resulting in a small steering ratio and inflexibility. This leads to a large turning radius, low handling sensitivity, poor passability, and a high risk of safety accidents.

[0006] Domestic single-seat small-displacement racing cars are mostly two-wheel drive, while large-displacement off-road racing cars use four-wheel drive. Moreover, due to cost and other issues, the overall power and transmission system structure layout is generally not reasonable, not compact enough, and the safety protection design is not well considered. This results in large overall size, excessive material usage, heavy weight, poor acceleration performance, low off-road passability, and inadequate safety protection. Summary of the Invention

[0007] The technical problem to be solved by the present invention is to provide an off-road rally racing car that is lighter, more compact, easier to handle, has better passability, and is safer. The lighter vehicle has sufficient power performance and has low frictional resistance during the vehicle's movement. It has good passability on uneven roads, is less prone to rollover, and is conducive to improving race results.

[0008] To solve the above problems, the technical solution adopted by the present invention is as follows:

[0009] An off-road rally car includes a frame and a drivetrain mounted on the frame, with wheels mounted on the frame via a suspension system; the drivetrain includes a gearbox mounted at the rear of the frame and a differential mounted at the front of the frame; the gearbox and the differential are connected by a first driveshaft positioned at the front and rear of the frame.

[0010] The gearbox includes a housing and a drive shaft rotatably mounted on the housing;

[0011] The drive shaft is provided with a second spline section, and a floating central brake disc is installed on the second spline section; the floating central brake disc is floatingly installed on the second spline section through a spline flange.

[0012] As an improvement, the gearbox further includes a rear reversing shaft rotatably mounted on the housing; the rear reversing shaft is horizontally arranged in the front-to-back direction, the drive shaft is horizontally arranged in the left-to-right direction, and the axis of the drive shaft is perpendicular to the axis of the rear reversing shaft; a large bevel gear is fixedly mounted on the drive shaft, and a small bevel gear that meshes with the large bevel gear is fixedly mounted on the rear reversing shaft; both ends of the first drive shaft are respectively connected to the front reversing shaft and the rear reversing shaft through a first universal joint.

[0013] As an improvement, the transmission ratio between the small bevel gear and the large bevel gear is the same as the transmission ratio between the driving gear and the ring gear.

[0014] As an improvement, a spline flange is installed on the second spline segment, and a spline hole with a size adapted to the second spline segment is provided in the middle of the spline flange. The second spline segment passes through the spline hole, and the spline flange can move along the axial direction of the second spline segment; a floating central brake disc is fixed on the spline flange.

[0015] As an improvement, a central brake caliper adapted to the floating central brake disc is also included, with the floating central brake disc located in the gap between the two brake pads of the central brake caliper; when the floating central brake disc rotates with the drive shaft, the floating central brake disc is located between the two brake pads of the central brake caliper.

[0016] As an improvement, the differential includes a housing fixed to the frame and a ring gear rotatably mounted on the housing, as well as a front reversing shaft rotatably mounted on the frame. The end of the front reversing shaft is provided with a drive gear that meshes with the ring gear. The axis of the front reversing shaft is perpendicular to the axis of the ring gear, and both the ring gear and the drive gear are bevel gears.

[0017] The ring gear has two spaced planetary gear carriers, each with a rotating planetary gear whose axis is perpendicular to the ring gear's axis. The frame also has two rotating half-shafts, each with a fixed half-shaft gear. The half-shafts are located inside the ring gear, and their axes coincide with the ring gear's axis. Both planetary gears mesh with the two half-shaft gears for transmission. Both the half-shaft gears and the planetary gears are bevel gears.

[0018] As an improvement, the suspension system includes front steering knuckles located inside the two front wheels, both of which are fixed to the front side of the frame by upper double wishbone suspension and lower double wishbone suspension.

[0019] Both the upper double wishbone suspension and the lower double wishbone suspension are A-type structures;

[0020] The tips of the upper double wishbone suspension and the lower double wishbone suspension are hinged to the upper and lower connecting parts of the front steering knuckle, respectively; the two ends of the other end of the upper double wishbone suspension and the two ends of the other end of the lower double wishbone suspension are hinged to the front of the vehicle frame, respectively.

[0021] As an improvement, both the tip of the upper double wishbone suspension and the tip of the lower double wishbone suspension are provided with mounting holes. A bearing outer ring is fixed in the mounting holes, and a rotatable spherical bearing inner ring is provided on the inner side of the bearing outer ring. A through connecting hole is provided in the middle of the bearing inner ring, and a spherical bolt is provided in the connecting hole. The bolt head of the spherical bolt is a spherical surface that matches the shape of the bearing inner ring. The ends of the upper double wishbone suspension and the lower double wishbone suspension are respectively fixed to the upper and lower connecting parts of the front spherical bolt by means of spherical bolts.

[0022] As an improvement, the suspension system further includes a horizontally arranged front axle and a front wheel hub fixed to the end of the front axle; the front axle or the front wheel hub is rotatably connected to the front steering axle; the front steering axle has a horizontally penetrating through hole in the middle, the front wheel hub is rotatably installed in the through hole, and a bearing is provided between the front steering axle and the front wheel hub;

[0023] The front wheel hub has a flange structure, including a cylindrical body and a flange located at the end of the body. The flange has four evenly arranged mounting holes. The flange is fixedly connected to the wheel hub. A brake disc is fixed on the side of the flange away from the wheel hub.

[0024] The main body is rotatably installed in the through hole of the front saddle shaft;

[0025] The front wheel hub has a through hole running through the middle of its body, and the front wheel axle passes through the through hole. The front wheel axle has a first spline segment, and the through hole has a spline hole that matches the outer dimensions of the first spline segment. The first spline segment is installed in the spline hole. The front wheel hub and the front wheel axle are connected by the first spline segment and the spline hole to achieve circumferential fixation between them. The end of the front wheel axle has a threaded section, and a nut is installed on the threaded section for axial fixation of the front wheel hub on the front wheel axle.

[0026] The front axle extends from the inner side of the off-road rally car to the outer side of the front wheel hub, where a second universal joint is located. The second universal joint is connected to the half-shaft via a second drive shaft. One end of the second drive shaft is connected to the ball joint of the second universal joint, and the other end is connected to the ball joint of the half-shaft. A front brake caliper, adapted to the brake disc, is fixedly mounted on the front steering knuckle.

[0027] The present invention adopts the above technical solution and has the following advantages compared with the prior art:

[0028] The off-road rally car based on this technical solution has the advantages of being lighter, more compact, easier to handle, better passability, and safer. The lighter vehicle has sufficient power performance, and its own friction resistance is small during the movement of the vehicle. It has good passability on uneven roads, is not easy to roll over, and is conducive to improving the race results.

[0029] The braking system of this off-road rally car adopts a centrally mounted rear axle disc brake structure. The floating central brake disc is matched with the opposed four-piston brake caliper. The gearbox is integrated with the drive axle braking system of the off-road rally car, reducing the number of brakes. The structure is compact and non-redundant, which not only meets the braking performance requirements, but also meets the requirements of vehicle lightweight design.

[0030] This off-road rally car uses a floating central brake disc mechanism, which reduces the assembly clearance between the brake disc and the caliper and brake pads, improves braking sensitivity, and avoids increased drag caused by contact between the brake disc and brake pads due to assembly and component dimensional accuracy issues. This structural design makes the floating central brake disc and central brake caliper structure more compact, reduces the requirements for the machining and installation accuracy of the floating central brake disc and central brake caliper, reduces installation difficulty, and facilitates the installation and adjustment of the floating central brake disc and central brake caliper.

[0031] The main reducer in the off-road rally car's gearbox uses a two-stage spur gear transmission, and the third output shaft is equipped with a bevel gear to achieve front wheel drive distribution. It is integrated with the vehicle's rear axle braking system into a single structure, which is supported on the frame. This makes the drive axle braking system and gearbox structure compact, small in size, relatively light in weight, highly robust, and well protected, thus better meeting the requirements of vehicle lightweight and safety design.

[0032] The present invention will now be described in detail with reference to the accompanying drawings and embodiments. Attached Figure Description

[0033] Figure 1 This is a three-dimensional structural diagram of an off-road rally car according to the present invention;

[0034] Figure 2 This is a schematic diagram of the structure of an off-road rally car according to the present invention;

[0035] Figure 3 for Figure 2 Top view;

[0036] Figure 4 for Figure 2 A bottom view;

[0037] Figure 5 for Figure 2 The left view;

[0038] Figure 6 for Figure 2 The right view;

[0039] Figure 7 Schematic diagram of the transmission system Figure 1 ;

[0040] Figure 8 Schematic diagram of the transmission system Figure 2 ;

[0041] Figure 9 for Figure 7 Schematic diagram of the center differential Figure 1 ;

[0042] Figure 10 for Figure 7 Schematic diagram of the center differential Figure 2 ;

[0043] Figure 11 for Figure 7 Schematic diagram of the intermediate gearbox Figure 1 ;

[0044] Figure 12 for Figure 7 Schematic diagram of the intermediate gearbox Figure 2 ;

[0045] Figure 13 for Figure 12 Side view;

[0046] Figure 14 for Figure 13 AA section view in the middle;

[0047] Figure 15 Schematic diagram of the suspension system at the front wheels Figure 1 ;

[0048] Figure 16 Schematic diagram of the suspension system at the front wheels Figure 2 ;

[0049] Figure 17 Schematic diagram of the suspension system at the front wheels Figure 3 ;

[0050] Figure 18 for Figure 17 BB section view in the middle;

[0051] Figure 19 This is a schematic diagram of the suspension system at the rear wheels;

[0052] Figure 20 for Figure 19 CC section view;

[0053] Wherein: 1-Frame, 2-Transmission system, 3-Suspension system, 4-Wheel, 5-Gearbox, 6-Differentiation, 7-First driveshaft, 8-First universal joint, 9-Front reversing shaft, 10-Rear reversing shaft, 11-Large bevel gear, 12-Small bevel gear, 13-House housing, 14-Ring gear, 15-Front wheel hub, 16-Brake disc, 17-Front steering knuckle, 18-Front axle, 19-Wheel hub, 20-Second driveshaft, 21-Front brake caliper, 22-Upper double wishbone suspension, 23-Lower double wishbone suspension 24-Upper connecting part, 25-Lower connecting part, 26-Front connecting part, 27-Steering tie rod, 28-Upper fixed part, 29-Lower fixed part, 30-Trapezoidal front end, 31-Cage roll cage, 32-Support frame, 33-Cockpit, 34-First spline section, 35-Spline hole, 36-Mounting hole, 37-Bearing outer ring, 38-Bearing inner ring, 39-Strut bolt, 40-Second universal joint, 41-Body, 42-Flange, 43-Mounting part, 44-Front steering shaft, 45-Rear steering shaft 46-Rear wheel axle, 47-Rear wheel hub, 48-Clearing area, 49-Third universal joint, 50-Third drive shaft, 51-Half shaft, 52-Half shaft gear, 53-Planetary gear, 54-Drive gear, 55-Planetary gear carrier, 56-Drive shaft, 57-Carrier, 58-Bearing with seat, 59-Second spline section, 60-Floating central brake disc, 61-Spline flange, 62-Central brake caliper, 63-Upper pull rod, 64-Lower pull rod, 65-Spherical head, 66-Tractor arm, 67-Input shaft, 68-Intermediate shaft, 69-First spur gear, 70-Second spur gear, 71-Third spur gear, 72-Fourth spur gear, 73-Bore circlip, 74-Horn bolt spacer, 75-Shaft shoulder. Detailed Implementation

[0054] For ease of explanation rather than limitation, when using terminology in off-road rally racing, the direction to the driver's left is defined as left, and the direction to the driver's right is defined as right; the direction in front of the driver is defined as forward, and the direction behind the driver is defined as backward, as well as the derived terms up and down. The position closest to the center of the off-road rally car is defined as inside, and the opposite direction is defined as outside.

[0055] Example

[0056] like Figures 1 to 6 As shown, an off-road rally car includes a truss-type frame 1 and a transmission system 2 mounted on the frame 1. The frame 1 is equipped with four wheels 4 via a suspension system 3. The frame 1 is made of high-strength steel tubing to form a steel tubular truss-type frame, achieving a lightweight design of the frame 1 while ensuring strength.

[0057] The wheel 4 includes a hub 19 and a tire mounted on the hub 19. Preferably, the hub 19 is a 10-inch off-road hub made of aluminum alloy with a flange; the tires of the two front wheels 4 are 22*7*10mm cross-pattern tires, and the tires of the two rear wheels 4 are 22*7*10mm figure-eight pattern tires.

[0058] like Figures 7 to 8 As shown, the transmission system 2 includes a gearbox 5 mounted at the rear of the frame 1 and a differential 6 mounted at the front of the frame 1; the gearbox 5 and the differential 6 are connected by a first drive shaft 7 arranged at the front and rear.

[0059] like Figure 7 , Figure 8 , Figure 9 , Figure 10 As shown, the differential 6 includes a housing 13 fixed to the frame 1 and a ring gear 14 rotatably mounted on the housing 13, as well as a front reversing shaft 9 rotatably mounted on the frame 1. The end of the front reversing shaft 9 is provided with a drive gear 54 that meshes with the ring gear 14. The axis of the front reversing shaft 9 is perpendicular to the axis of the ring gear 14. Both the ring gear 14 and the drive gear 54 are bevel gears.

[0060] The ring gear 14 has two spaced-apart planetary gear carriers 55, each with a rotatably mounted planetary gear 53. The axis of the planetary gear 53 is perpendicular to the axis of the ring gear 14. The two planetary gears 53 are arranged opposite each other. The frame 1 also has two rotatably mounted half-shafts 51, with half-shaft gears 52 fixed to their ends. The half-shafts 51 are located inside the ring gear 14, and their axes coincide with the axis of the ring gear 14. Each planetary gear 53 meshes with two half-shaft gears 52 for transmission. Both the half-shaft gears 52 and the planetary gears 53 are bevel gears.

[0061] like Figure 7 , Figure 8 , Figures 11 to 14 As shown, the gearbox 5 includes a housing 57 and a drive shaft 56 and a rear reversing shaft 10 rotatably mounted on the housing 57. The rear reversing shaft 10 is horizontally arranged along the forward-backward direction of the off-road rally car, and the drive shaft 56 is horizontally arranged along the left-right direction, with the axis of the drive shaft 56 perpendicular to the axis of the rear reversing shaft 10. A large bevel gear 11 is fixedly mounted on the drive shaft 56, and a small bevel gear 12 that meshes with the large bevel gear 11 is fixedly mounted on the rear reversing shaft 10. The two ends of the first drive shaft 7 are respectively connected to the front reversing shaft 9 and the rear reversing shaft 10 through a first universal joint 8. Preferably, in this embodiment, the first universal joint 8 is a cross universal joint.

[0062] The transmission ratio between the small bevel gear 12 and the large bevel gear 11 is the same as the transmission ratio between the driving gear 54 and the ring gear 14. The large bevel gear 11 and the ring gear 14 have the same structure and parameters, and the small bevel gear 12 and the driving gear 54 have the same structure and parameters.

[0063] The above structural design allows the half-shaft 51 and drive shaft 56 to rotate at low speeds, while the first drive shaft 7 rotates at high speeds. When transmitting the same power, the first drive shaft 7 operates at high speed and low torque; that is, when transmitting the same power, the higher the speed of the first drive shaft 7, the lower the torque, allowing for a smaller shaft diameter, reducing the overall weight of the off-road rally car and increasing its service life. Preferably, a fixed bearing 58 is provided on the frame 1, and the first drive shaft 7 passes through and is rotatably mounted within the bearing 58. The bearing 58 provides effective support for the middle section of the first drive shaft 7, making its rotation more stable.

[0064] Both ends of the drive shaft 56 extend to the outside of the housing 57. One end of the drive shaft 56 is provided with a second spline section 59, which is located outside the housing 57. A floating central brake disc 60 is mounted on the second spline section 59. Specifically, a spline flange 61 is mounted on the second spline section 59. The spline flange 61 has a spline hole in its middle that matches the size of the second spline section 59. The second spline section 59 passes through the spline hole, and the spline flange 61 can move axially along the second spline section 59. Both the spline flange 61 and the floating central brake disc 60 are provided with rivet holes, and the spline flange 61 and the floating central brake disc 60 are riveted together by rivets. The floating central brake disc 60 is floatingly mounted on the second spline section 59 via the spline flange 61.

[0065] A central brake caliper 62, adapted to the floating central brake disc 60, is provided on the outside of the housing 57 at a position corresponding to the floating central brake disc 60. The central brake caliper 62 is fixedly mounted on the housing 57, or fixedly mounted on the frame 1, or fixedly mounted between the housing 57 and the frame 1. Preferably, in this embodiment, the central brake caliper 62 is an opposed four-piston brake caliper. The floating central brake disc 60 is located in the gap between the two brake pads of the central brake caliper 62. When the floating central brake disc 60 rotates with the drive shaft 56, it is located between the two brake pads of the central brake caliper 62. When the floating central brake disc 60 contacts one of the brake pads of the central brake caliper 62, the floating central brake disc 60 is subjected to the force of the brake pad and will momentarily move axially along the second spline segment 59 until it separates from the brake pad. This structural design ensures that the floating central brake disc 60 will not rub against the brake pads when rotating, reducing resistance during the off-road rally car's movement. Furthermore, this structural design makes the floating central brake disc 60 and central brake caliper 62 more compact, reducing the requirements for the machining and installation accuracy of the floating central brake disc 60 and central brake caliper 62, lowering the installation difficulty, and facilitating the installation and adjustment of the floating central brake disc 60 and central brake caliper 62.

[0066] In the above structural design, the braking system adopts a centrally mounted rear axle disc brake structure, with a floating central brake disc 60 matched with opposed four-piston brake calipers. The gearbox 5 is integrated with the braking system of the drive shaft 56 of the off-road rally car, reducing the number of brakes. The structure is compact and non-redundant, meeting the requirements of vehicle lightweight design while satisfying braking performance.

[0067] like Figure 7 , Figure 8 , Figures 11 to 14 As shown, the gearbox 5 also includes an input shaft 67 and an intermediate shaft 68 arranged parallel to the drive shaft 56. The input shaft 67, intermediate shaft 68, and drive shaft 56 are arranged in a triangular pattern to minimize the overall size of the structure. The input shaft 67 is connected to the power system. A first spur gear 69 is fixedly mounted on the input shaft 67, a second spur gear 70 and a third spur gear 71 are mounted on the intermediate shaft 68, and a fourth spur gear 72 is mounted on the drive shaft 56. The first spur gear 69 meshes with the second spur gear 70, and the third spur gear 71 meshes with the fourth spur gear 72. Furthermore, the first spur gear 69 is a pinion, and the second spur gear 70 is a large gear. The third spur gear 71 is a pinion, and the fourth spur gear 72 is a large gear. This structural design allows the main reducer in the off-road rally car gearbox 5 to adopt a two-stage spur gear transmission and integrate it with the vehicle's rear axle braking system, resulting in a compact, small-sized, and relatively lightweight gearbox that better meets the requirements of lightweight vehicle design.

[0068] Figures 15 to 18 As shown, the suspension system 3 includes front steering knuckles 17 located inside the two front wheels 4, each front steering knuckle 17 being fixed to the front side of the frame 1 via an upper double wishbone suspension 22 and a lower double wishbone suspension 23. Each front steering knuckle 17 includes a front steering knuckle axle 44, one end of which has an upper connecting portion 24 and a lower connecting portion 25. The front steering knuckle 17 also has a front connecting portion 26 for hinged steering tie rods 27.

[0069] Both the upper double wishbone suspension 22 and the lower double wishbone suspension 23 are A-type structures. The tips of the upper double wishbone suspension 22 and the lower double wishbone suspension 23 are hinged to the upper connecting part 24 and the lower connecting part 25 of the front steering knuckle 17, respectively. The two ends of the other end of the upper double wishbone suspension 22 and the two ends of the other end of the lower double wishbone suspension 23 are hinged to the front of the frame 1, respectively. Both the upper double wishbone suspension 22 and the lower double wishbone suspension 23 are made of BH1500 steel tubing with a diameter of 25.4 mm and a wall thickness of 1.5 mm.

[0070] like Figure 17 and Figure 18 As shown in the preferred embodiment, both the tip of the upper double wishbone suspension 22 and the tip of the lower double wishbone suspension 23 are provided with mounting holes 36. A bearing outer ring 37 is fixedly installed within the mounting holes 36. A rotatable spherical bearing inner ring 38 is provided inside the bearing outer ring 37, with both its upper and lower ends extending beyond the outer ring 37. A through connecting hole is provided in the center of the bearing inner ring 38, and a spur bolt 39 is installed within the connecting hole.

[0071] like Figure 18 As shown, taking the end structure of the tip of the double wishbone suspension 22 as an example, the bolt head of the spur bolt 39 is located above the inner ring 38 of the bearing. The bolt head of the spur bolt 39 is a spherical surface that matches the outer dimensions of the inner ring 38 of the bearing; specifically, the outer surface of the bolt head of the spur bolt 39 and the outer surface of the inner ring 38 of the bearing are located on the same spherical surface. The upper part of the mounting hole 36 is provided with a positioning step flush with the upper end of the outer ring 37 of the bearing, and the lower part of the mounting hole 36 is provided with a retaining circlip groove, in which a retaining circlip 73 is installed. The retaining circlip 73 contacts the lower end face of the inner ring 38 of the bearing and limits the lower end of the inner ring 38 of the bearing.

[0072] A spur bolt spacer 74 is provided between the inner ring 38 of the bearing and the upper connecting part 24, and the spur bolt spacer 74 is fitted onto the spur bolt 39. The upper end of the spur bolt spacer 74 is located inside the inner ring 38 of the bearing, and the lower end of the spur bolt spacer 74 abuts against the upper side of the upper connecting part 24. A shoulder 75 is provided on the spur bolt spacer 74, and the upper end of the shoulder 75 abuts against the lower end of the inner ring 38 of the bearing. The outer surface of the shoulder 75 is a spherical surface that matches the outer dimensions of the inner ring 38 of the bearing, that is, the outer surface of the shoulder 75 and the outer surface of the inner ring 38 of the bearing are located on the same spherical surface.

[0073] This structural design allows the bolt head of the spur bolt 39 to rotate within the bearing outer ring 37 following the inner ring 38 of the bearing, without interference between the bolt head of the spur bolt 39 and the outer ring 37. The spur bolt spacer 74 provides support and limitation between the inner ring 38 of the bearing and the upper connecting part 24, maintaining a certain height between them. This allows for a larger relative rotation angle and amplitude when the bolt head of the spur bolt 39 rotates within the bearing outer ring 37 following the inner ring 38 of the bearing. The end structure of the tip of the lower double wishbone suspension 23 is the same as the end structure of the tip of the double wishbone suspension 22 described above, and will not be repeated here. The ends of the upper double wishbone suspension 22 and the lower double wishbone suspension 23 are respectively fixed to the upper connecting part 24 and the lower connecting part 25 of the front spur bolt 17 by spur bolts 39.

[0074] When the end of the upper double wishbone suspension 22 or the end of the lower double wishbone suspension 23 is fixedly mounted on the upper connecting part 24 or the lower connecting part 25 by means of a steering knuckle bolt 39, the bolt head of the steering knuckle bolt 39 and the outer side of the bearing inner ring 38 are located on the same spherical surface. This allows for a larger relative rotation angle between the bearing outer ring 37 and the bearing inner ring 38, increasing the relative rotation angle between the front steering knuckle 17 and the upper double wishbone suspension 22, or between the front steering knuckle 17 and the lower double wishbone suspension 23. This allows for flexible angle adjustment, making it less prone to rollover, and improving the overall passability of the off-road rally car when encountering road undulations or obstacles.

[0075] The suspension system 3 also includes a horizontally arranged front axle 18 and a front wheel hub 15 fixed to the end of the front axle 18. The front axle 18 or the front wheel hub 15 is rotatably connected to the front steering axle 44. In this embodiment, preferably, the front steering axle 44 has a horizontally penetrating through hole in the middle, the front wheel hub 15 is rotatably installed in the through hole, and a bearing is provided between the front steering axle 44 and the front wheel hub 15.

[0076] The front wheel hub 15 has a flange structure, including a cylindrical body 41 and a flange 42 located at the end of the body 41. The flange 42 has four evenly arranged mounting holes. Preferably, in this embodiment, the flange 42 is made of tempered steel and CNC machined. The flange 42 has a cross-shaped reinforcing structure and fan-shaped holes. This design increases the structural strength of the flange 42 while reducing its weight. The flange 42 is fixedly connected to the wheel hub 19 of the wheel 4 by fasteners. On the side of the flange 42 away from the wheel hub 19, there are multiple mounting parts 43 for fixing the brake disc 16. Preferably, in this embodiment, the flange 42 has four mounting parts 43. The four mounting parts 43 are located on the periphery of the body 41, and there is a gap between the mounting parts 43 and the body 41. The body 41 is rotatably mounted in the through hole of the front steering axle 44.

[0077] The front wheel hub 15 has a through hole running horizontally through its body 41. The front wheel axle 18 passes through this through hole and has a first spline section 34. The through hole has a spline hole 35 that matches the dimensions of the first spline section 34, and the first spline section 34 is installed within the spline hole 35. The front wheel hub 15 and the front wheel axle 18 are connected via the first spline section 34 and the spline hole 35, achieving circumferential fixation between them. The end of the front wheel axle 18 has a threaded section with a nut installed on it for axial fixation of the front wheel hub 15 on the front wheel axle 18.

[0078] like Figure 15 , Figure 16 , Figure 17 and Figure 18 As shown, one end of the front axle 18, near the inside of the off-road rally car, extends to the outside of the front wheel hub 15, where a second universal joint 40 is mounted. The second universal joint 40 is connected to the half-shaft 51 via a second drive shaft 20. One end of the second drive shaft 20 is ball-connected to the second universal joint 40, and the other end is ball-connected to the half-shaft 51. A front brake caliper 21, adapted to the brake disc 16, is fixedly mounted on the front steering knuckle 17.

[0079] In this embodiment, the second universal joint 40 is preferably a ball cage type universal joint, and the front wheel brake caliper 21 is a single piston floating caliper.

[0080] like Figure 19 and Figure 20As shown, the suspension system 3 also includes a horizontally arranged rear axle 46 and a rear wheel hub 47 fixed to the end of the rear axle 46, as well as a rear steering knuckle 45 located inside the rear wheel 4; the rear wheel hub 47 is fixedly connected to the rear wheel 4. A third universal joint 49 is fixedly provided at one end of the rear axle 46, the rear steering knuckle 45 is rotatably mounted in the middle of the rear axle 46, and the rear wheel hub 47 is fixed at the other end of the rear axle 46. Specifically, the rear steering knuckle 45 is fitted into the middle of the rear axle 46, and a bearing is provided between the rear steering knuckle 45 and the rear axle 46. The end of the rear axle 46 is provided with a splined section and a threaded section in sequence, the middle of the rear wheel hub 47 is provided with a splined hole, the splined hole of the rear wheel hub 47 is fitted onto the splined section of the rear axle 46, and a fastening nut is installed on the threaded section of the rear axle 46. The fastening nut secures the rear wheel core 47 to the rear wheel axle 46 from one end, thus achieving axial fixation of the rear wheel core 47 on the rear wheel axle 46.

[0081] The third universal joint 49 is connected to the drive shaft 56 via the third drive shaft 50. One end of the third drive shaft 50 is ball-jointed to the third universal joint 49, and the other end is ball-jointed to the drive shaft 56. Preferably, in this embodiment, the third universal joint 49 is a ball-cage type universal joint.

[0082] In this preferred embodiment, the rear wheel hub 47 is a cross-shaped plate structure with a concave center, made of 20CrMoTi alloy steel. The concave portion in the middle of the rear wheel hub 47 forms a clearance area 48, which provides a space for the fastening nut at the end of the rear wheel axle 46, preventing interference between the fastening nut and the wheel 4. Furthermore, this structure is compact and the components are lightweight. This design reduces the weight of the rear wheel hub 47 by 300 grams compared to existing rear wheel hub structures.

[0083] like Figure 19 and Figure 20As shown, the upper end of the rear steering knuckle 45 is provided with an upper fixing part 28, and the lower end is provided with a lower fixing part 29. The upper fixing part 28 is connected to the frame 1 via an upper pull rod 63. The lower fixing part 29 is connected to the frame 1 via a lower pull rod 64. Specifically, both ends of the upper pull rod 63 and the lower pull rod 64 are provided with spherical heads 65. The spherical heads 65 at both ends of the upper pull rod 63 are threadedly connected to the upper pull rod 63, and the threads of the two spherical heads 65 on the upper pull rod 63 are turned in opposite directions. The spherical heads 65 at both ends of the lower pull rod 64 are threadedly connected to the lower pull rod 64, and the threads of the two spherical heads 65 on the lower pull rod 64 are turned in opposite directions. In use, rotating the middle part of the upper pull rod 63 can adjust the length of the upper pull rod 63; rotating the middle part of the lower pull rod 64 can adjust the length of the lower pull rod 64. The length adjustment range of a single spherical head 65 is 5-6 mm. One end of the upper tie rod 63 has a spherical head 65 hinged to the upper fixed part 28, and the other end has a spherical head 65 hinged to the frame 1. One end of the lower tie rod 64 has a spherical head 65 hinged to the lower fixed part 29, and the other end has a spherical head 65 hinged to the frame 1. During the assembly and debugging of the off-road rally car, by adjusting the length of the upper tie rod 63 and / or the lower tie rod 64, the rear steering knuckle 45 can swing in the vertical plane, thereby adjusting the angle between the rear steering knuckle 45 and the vertical direction, and thus adjusting the vertical angle of the wheel 4 mounted on it, achieving the adjustment of wheel camber or slant.

[0084] like Figure 19 and Figure 20 As shown, a trailing arm 66 is provided between the rear steering knuckle 45 and the frame 1. The front end of the trailing arm 66 is provided with a ball joint 65, which is hinged to the frame 1, and the rear end of the trailing arm 66 is fixed to the rear steering knuckle 45. During the assembly and debugging of the off-road rally car, the length of the trailing arm 66 can be adjusted through the ball joint 65, thereby adjusting the positive and negative and the magnitude of the toe angle of the trailing wheel 4.

[0085] The truss-type frame 1 includes a trapezoidal front end 30, a cage-type roll cage 31, and a support frame 32 connected sequentially from front to rear. The inner side of the cage-type roll cage 31 is the driver's cab 33, and the inner side of the support frame 32 is used to install the power system and gearbox 5. The cage-type roll cage 31 is welded from BH1500 steel tubing with a diameter of 30mm and a wall thickness of 1.6mm. A fiberglass sports seat is installed at the rear bottom of the driver's cab 33.

[0086] The present invention provides an off-road rally car with advantages such as lighter overall weight, compact structure, good handling, excellent passability, and high safety. The lighter vehicle has sufficient power performance, and its own friction resistance is small during the movement of the vehicle. It has good passability on uneven roads, is not easy to roll over, and is conducive to improving the race results.

[0087] Finally, it should be noted that the above descriptions are merely preferred embodiments of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. An off-road rally car characterised in that: The utility model relates to a vehicle frame, including frame (1) and drive system (2) installed on frame (1), frame (1) is installed with wheel (4) through suspension system (3), The drive system (2) includes gearbox (5) installed at the rear of frame (1) and differential (6) installed at the front of frame (1);Gearbox (5) and differential (6) are drivingly connected by first transmission shaft (7) arranged front and back; The gearbox (5) includes a box body (57) and a drive shaft (56) rotatably installed on the box body (57); The drive shaft (56) is provided with a second spline section (59), and a floating central brake disc (60) is installed on the second spline section (59); It also includes a central brake caliper (62) matched with the floating central brake disc (60), and the floating central brake disc (60) is located in the gap between the two brake pads of the central brake caliper (62);When the floating central brake disc (60) rotates with the drive shaft (56), the floating central brake disc (60) is located between the two brake pads of the central brake caliper (62);The central brake caliper (62) is fixedly installed on the box body (57); The suspension system (3) includes front horns (17) located on the inner sides of the two front wheels (4), and the two front horns (17) are fixed to the front side of the frame (1) by upper double wishbone suspensions (22) and lower double wishbone suspensions (23); The upper double wishbone suspension (22) has an A-shaped structure; The tip of the upper double wishbone suspension (22) is hingedly connected to the upper connecting portion (24) of the front horn (17), and the other end of the upper double wishbone suspension (22) is hingedly connected to the front portion of the frame (1); The tip of the upper double wishbone suspension (22) is provided with a mounting hole (36), a bearing outer ring (37) is fixedly arranged in the mounting hole (36), a spherical bearing inner ring (38) is rotatably arranged on the inner side of the bearing outer ring (37), a connecting hole is arranged through the middle portion of the bearing inner ring (38), and a horn bolt (39) is arranged in the connecting hole;The head of the horn bolt (39) is located above the bearing inner ring (38), and the head of the horn bolt (39) has a spherical surface shape matched with the shape of the bearing inner ring (38);The end of the upper double wishbone suspension (22) is fixed to the upper connecting portion (24) of the front horn (17) by the horn bolt (39), the relative rotation angle between the front horn (17) and the upper double wishbone suspension (22) is increased, the vehicle is not prone to overturning, and the overall vehicle passability of the off-road rally vehicle is better. A stud spacer sleeve (74) is arranged between the bearing inner ring (38) and the upper connecting portion (24), the stud spacer sleeve (74) is sleeved on the stud bolt (39), the upper end of the stud spacer sleeve (74) is located on the inner side of the bearing inner ring (38), the lower end of the stud spacer sleeve (74) abuts on the upper side of the upper connecting portion (24), the stud spacer sleeve (74) is provided with a shaft shoulder (75), the upper end of the shaft shoulder (75) abuts on the lower end of the bearing inner ring (38), the outer surface of the shaft shoulder (75) is a spherical surface matching the outer dimension of the bearing inner ring (38); The stud bolt head of the stud bolt (39) can rotate with the bearing inner ring (38) in the bearing outer ring (37), the stud bolt head of the stud bolt (39) will not interfere with the bearing outer ring (37); the stud spacer sleeve (74) is used for supporting and limiting between the bearing inner ring (38) and the upper connecting portion (24), and a certain height is kept between the bearing inner ring (38) and the upper connecting portion (24), so that the relative rotation angle and amplitude of the stud bolt head of the stud bolt (39) rotating with the bearing inner ring (38) in the bearing outer ring (37) are larger.

2. The cross-country rally vehicle of claim 1, wherein: The gearbox (5) further comprises a rear reversing shaft (10) rotatably installed on the box body (57); the rear reversing shaft (10) is horizontally arranged along the front-rear direction, the driving shaft (56) is horizontally arranged along the left-right direction, and the axis of the driving shaft (56) is perpendicular to the axis of the rear reversing shaft (10); the driving shaft (56) is fixedly provided with a large bevel gear (11), and the rear reversing shaft (10) is fixedly provided with a small bevel gear (12) in meshing transmission with the large bevel gear (11); the two ends of the first transmission shaft (7) are respectively connected with the front reversing shaft (9) and the rear reversing shaft (10) through the first universal joint (8).

3. The cross-country racing vehicle of claim 2, wherein: The transmission ratio of the small bevel gear (12) and the large bevel gear (11) is the same as the transmission ratio of the driving gear (54) and the ring gear (14).

4. The cross-country racing vehicle of claim 1, wherein: The second spline section (59) is provided with a spline flange (61), the middle part of the spline flange (61) is provided with a spline hole matching the size of the second spline section (59), the second spline section (59) penetrates through the spline hole, and the spline flange (61) can move along the axial direction of the second spline section (59); the floating central brake disc (60) is fixed on the spline flange (61).

5. The cross-country racing vehicle of claim 1, wherein: The differential (6) comprises a housing (13) fixed on the vehicle frame (1), a ring gear (14) rotatably installed on the housing (13), and a front reversing shaft (9) rotatably installed on the vehicle frame (1), and the end of the front reversing shaft (9) is provided with a driving gear (54) in meshing transmission with the ring gear (14); the axis of the front reversing shaft (9) is perpendicular to the axis of the ring gear (14), and the ring gear (14) and the driving gear (54) are bevel gears. The annular gear (14) is provided with two spaced-apart planet gear carriers (55), each of which is provided with a planet gear (53) rotatably arranged, the axis of the planet gear (53) being perpendicular to the axis of the annular gear (14); the frame (1) is further provided with two half shafts (51) rotatably arranged, each of which is provided with a half shaft gear (52) fixedly arranged; the half shaft (51) is arranged on the inner side of the annular gear (14), the axis of the half shaft (51) coinciding with the axis of the annular gear (14); the two planet gears (53) are in meshing transmission with the two half shaft gears (52); the half shaft gears (52) and the planet gears (53) are bevel gears.

6. A cross-country rally vehicle according to any one of claims 1 to 5, characterised in that: The lower double fork arm suspensions (23) are all A-shaped structures; The tip of each lower double fork arm suspension (23) is hingedly connected to the lower connecting portion (25) of the front horn (17); the other end of each lower double fork arm suspension (23) is hingedly connected to the front portion of the frame (1).

7. The cross-country racing vehicle of claim 6, wherein: The tip of each lower double fork arm suspension (23) is provided with a mounting hole (36) in which a bearing outer ring (37) is fixedly arranged; the inner side of the bearing outer ring (37) is provided with a spherical bearing inner ring (38) rotatably arranged; the middle portion of the bearing inner ring (38) is provided with a penetrating connecting hole in which a horn bolt (39) is arranged; the head of the horn bolt (39) is a spherical surface matching the outer shape of the bearing inner ring (38); the end of each lower double fork arm suspension (23) is fixed to the lower connecting portion (25) of the front horn (17) by the horn bolt (39).

8. The cross-country racing vehicle of claim 6, wherein: The suspension system (3) further comprises a front wheel shaft (18) arranged horizontally and a front wheel core (15) fixed to the end of the front wheel shaft (18); the front wheel shaft (18) or the front wheel core (15) is rotatably connected to the front horn shaft (44); the middle portion of the front horn shaft (44) is provided with a horizontal penetrating through hole in which the front wheel core (15) is rotatably arranged; a bearing is arranged between the front horn shaft (44) and the front wheel core (15); The front wheel core (15) is a flange plate structure comprising a cylindrical body (41) and a flange plate (42) arranged at the end of the body (41); the flange plate (42) is provided with four evenly arranged mounting holes; the flange plate (42) is fixedly connected to the hub (19) of the wheel (4); the side of the flange plate (42) away from the hub (19) is fixedly provided with a brake disc (16); The body (41) is rotatably arranged in the through hole of the front horn shaft (44); The middle portion of the body (41) of the front wheel core (15) is provided with a left-right penetrating through hole; the front wheel shaft (18) penetrates the through hole; the front wheel shaft (18) is provided with a first spline section (34); the through hole is provided with a spline hole (35) matching the outer shape and size of the first spline section (34); the first spline section (34) is arranged in the spline hole (35); the front wheel core (15) and the front wheel shaft (18) are connected by the first spline section (34) and the spline hole (35) to realize the circumferential fixation therebetween; the end of the front wheel shaft (18) is provided with a threaded section on which a nut is arranged for the axial fixation of the front wheel core (15) on the front wheel shaft (18); The front wheel shaft (18) extends to the outside of the front wheel core (15) near the inner side of the cross-country rally car, and a second universal joint (40) is arranged on the front wheel shaft (18); the second universal joint (40) is in transmission connection with the half shaft (51) through a second transmission shaft (20); one end of the second transmission shaft (20) is in ball connection with the second universal joint (40), and the other end is in ball connection with the half shaft (51); the front horn (17) is fixedly provided with a front wheel brake caliper (21) matched with the brake disc (16).

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