A three-section transmission shaft

Abstract

The present invention discloses a three-section transmission shaft, comprising a first section consisting of a front flange fork, a front welding fork, a front axle tube and a sleeve fork, a second section consisting of a middle welding fork, a middle axle tube and a ball cage flange, and a third section consisting of a ball cage bell shell end, a rear axle tube, a rear welding fork and a rear flange fork. The weight of the transmission shaft is concentrated on the universal joint, and the acting force between the front sleeve fork and the transfer case is relatively small. The three-section transmission shaft proposed by the present invention increases the natural frequency, can avoid the engine excitation resonance zone, reduce abnormal wear of the transmission shaft, increase the transmission shaft stiffness, and improve the NVH performance of the whole vehicle.

Description

Technical Field

[0001] The invention belongs to the technical field of automobile transmission shaft assemblies, and in particular relates to a three-section transmission shaft. Background Art

[0002] The drive shaft belongs to the automobile transmission system and is an important component for transmitting power. The power output by the engine is transmitted to the wheels through the gearbox, drive shaft, and drive axle to drive the wheels to rotate. Ordinary passenger cars mostly use two-section drive shafts due to wheelbase requirements. For long-wheelbase models, the defects of using a two-section drive shaft are as follows: the natural frequency of the drive shaft is small, and it is easy to be stimulated by the engine to resonate, resulting in shaking and roaring, and it will also increase the wear of the drive shaft; the total length of each section is relatively long, and the runout of a single shaft tube is difficult to control. When the drive shaft rotates at high speed, the bending stiffness is insufficient and it is easily affected by the imbalance, resulting in noise, shaking and other defects; in order to increase the natural frequency, some two-section drive shafts choose to thicken the diameter of the shaft tube, which also has the problem of reduced transmission efficiency and difficult to control circular runout due to increased mass.

[0003] Therefore, it is not ideal to use a two-section drive shaft for long-wheelbase models. Therefore, long-wheelbase models mostly use a three-section drive shaft. However, the existing three-section drive shaft has the following disadvantages: the common three-section drive shaft has two intermediate supports located on the same section, and there is no support on the front section. The gravity of the front section is mainly borne by the front sleeve fork, and the transfer case output shaft and oil seal are prone to eccentric wear due to gravity; the front section has two universal joint swing angles, which is relatively loose in structure. Under severe working conditions, there may even be a risk of the front section sleeve fork coming out. In order to achieve higher transmission efficiency and transmission stability, higher design requirements need to be put forward for the three-section drive shaft. Summary of the invention

[0004] The technical problem to be solved by the present invention is: when long-wheelbase non-independent suspension commercial vehicles and passenger cars use a two-section transmission shaft, there are defects such as driving stability and transmission shaft life.

[0005] In order to solve the above technical problems, the present invention proposes a three-section transmission shaft, including a first section, a second section and a third section.

[0006] The first section is composed of a front flange fork, a front welding fork, a front axle tube and a sleeve fork;

[0007] The second section consists of a center welded fork, a center shaft tube, and a flanged end of the ball cage;

[0008] The third section consists of the ball cage bell housing end, rear axle tube, rear welded fork and rear flange fork;

[0009] The first section and the second section are placed in the grooves of the two intermediate supports respectively and fixed to the vehicle body through the intermediate supports;

[0010] The welding end of the middle welding fork is connected to the spline shaft welding end of one end of the middle shaft tube and the flange end of the ball cage at the other end of the middle shaft tube by welding;

[0011] The spline shaft welding end in the bell housing end of the ball cage is connected to one end of the rear axle tube, and the other end of the rear axle tube is connected to the rear welding fork welding end by welding;

[0012] The front flange fork and the front welding fork, the sleeve fork and the middle welding fork, and the rear welding fork and the rear flange fork are assembled and connected through the cross shaft in the universal joint;

[0013] The flange end of the ball cage and the bell housing end of the ball cage are assembled by a ball cage universal joint assembly method;

[0014] The casing fork is assembled according to the casing fork assembly method.

[0015] As a further improvement of the welding method of the present invention, the welding method is one of double welding, brazing or friction welding.

[0016] As a further improvement of the welding method of the present invention, the welding method is friction welding.

[0017] As a further improvement of the present invention, components capable of eliminating noise are provided in the front axle tube, the middle axle tube and the rear axle tube.

[0018] As a further improvement of the present invention, the component capable of eliminating noise is sound-absorbing paper.

[0019] As a further improvement of the present invention, the component capable of eliminating noise is a punched sound-absorbing cotton.

[0020] As a further improvement of the present invention, the length of the second section is shorter than the lengths of the first section and the third section.

[0021] As a further improvement of the cross shaft of the present invention, the cross shaft is fixed by a retaining spring.

[0022] Beneficial effects of the present invention:

[0023] The three-section transmission shaft proposed by the present invention has the following advantages.

[0024] 1. The natural frequency is increased, which can avoid the engine excitation resonance area, reduce abnormal wear of the drive shaft, and improve the NVH performance of the vehicle;

[0025] 2. It has lower requirements on layout space, can match more non-independent suspension models, and has smaller telescopic volume under the same road conditions;

[0026] 3. The total length of each section is relatively short, and the vibration of a single shaft tube is easier to control. When the transmission shaft rotates at high speed, the bending stiffness of the shaft tube can be improved, the influence of the imbalance can be reduced, and the noise, shaking and other adverse problems can be avoided;

[0027] 4. Compared with solving the above problems by increasing the diameter of the shaft tube, the use of a three-section drive shaft can effectively improve transmission efficiency and control circular runout, and is suitable for a variety of commercial vehicles and passenger vehicles. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 It is a schematic diagram of the three-section transmission shaft structure of the present invention, wherein 1-front flange fork, 2-front welding fork, 3-front axle tube, 4, 8-intermediate support, 5-sleeve fork, 6-welding fork, 7-middle axle tube, 9-ball cage flange end, 10-ball cage bell shell end, 11-rear axle tube, 12-rear welding fork 13-rear flange fork;

[0029] Figure 2 It is a schematic diagram of the existing three-section transmission shaft structure;

[0030] Figure 3 Schematic diagram of the distribution position and force distribution of the three-section transmission shaft in the prior art;

[0031] Figure 4 This is a schematic diagram of the distribution position and force of the three-section transmission shaft of the present invention. DETAILED DESCRIPTION

[0032] The present invention will be further described in detail below in conjunction with the accompanying drawings.

[0033] The three-section transmission shaft proposed by the present invention comprises a first section, a second section and a third section. Figure 1 The three-section transmission shaft comprises a first section, a second section and a third section, wherein the first section is composed of a front flange fork 1, a front welding fork 2, a front axle tube 3 and a sleeve fork 5.

[0034] The second section is composed of a center welding fork 6, a center shaft tube 7 and a flange end 9 of the ball cage.

[0035] The third section is composed of a ball cage bell housing end 10, a rear axle tube 11, a rear welding fork 12 and a rear flange fork 13.

[0036] The first section and the second section are placed in the grooves of the two middle supports 4 and 8 respectively, and are fixed to the vehicle body through the middle supports 4 and 8.

[0037] The welding end of the middle welding fork 6 is connected to one end of the middle shaft tube 7 and the spline shaft welding end of the ball cage flange end 9 at the other end of the middle shaft tube 7 by welding. The welding method can be double welding, brazing, and friction welding. In actual application and production, the welding method is selected according to performance requirements and processing environment.

[0038] The spline shaft welding end in the bell-shaped housing end 10 of the ball cage is connected to one end of the rear axle tube 11, and the other end of the rear axle tube 11 is connected to the welding end of the rear welding fork 12 by welding.

[0039] The front flange fork 1 and the front welding fork 2, the sleeve fork 5 and the middle welding fork 6, and the rear welding fork 12 and the rear flange fork 13 are assembled and connected through the cross shaft in the universal joint. The cross shaft is fixed by a retaining spring to ensure that the cross shaft is fixed and can rotate around the axis.

[0040] The flange end 9 of the ball cage and the bell shell end 10 of the ball cage are assembled by a ball cage universal joint assembly method. The ball cage universal joint generally includes a front spline shaft, a front ball cage universal joint (including a star sleeve), a bell shell, a flange and a rear spline shaft. The assembly method of the ball cage universal joint is as follows: the star sleeve of the front ball cage universal joint is pressed into the assembly end of the front spline shaft, the inner end face of the star sleeve contacts the press-fit step of the front spline shaft, and the outer end face of the star sleeve is fixed by a retaining spring to ensure that the star sleeve is firmly installed on the front spline shaft. The front ball cage universal joint and the front spline shaft assembled together with the ball are pushed into the bell shell together; the flange sleeve end is pressed into the assembly end of the rear spline shaft and contacts the press-fit step of the rear spline shaft. The rear spline shaft assembly end is fastened with a nut to ensure that the flange is firmly installed on the rear spline shaft; the bell shell assembly end and the flange assembly end are assembled together by fastening with nuts and bolts.

[0041] The sleeve fork 5 is assembled in accordance with the sleeve fork assembly method. The sleeve fork generally includes a flange fork, a sleeve and a spline shaft. The sleeve fork is assembled in the following manner: the rear end of the sleeve is pressed into the assembly end of the spline shaft, the assembly end face of the sleeve contacts the press-fit step of the spline shaft, and a nut is used to tighten the threaded end of the spline shaft to ensure that the sleeve is firmly installed on the spline shaft. The flange fork assembly end and the front end of the sleeve are assembled together by tightening nuts and bolts.

[0042] In addition, to reduce noise, components capable of eliminating noise are provided in the front axle tube, the middle axle tube and the rear axle tube. The components capable of eliminating noise can be silencer paper or punched silencer cotton.

[0043] Compared with the existing common three-section transmission shaft, the existing common three-section transmission shaft is Figure 2 As shown, its two intermediate supports are located on the same section, and there is no support on the front section. The gravity of the front section is mainly borne by the front sleeve fork. The transfer case output shaft and the oil seal are easily affected by gravity and suffer eccentric wear. The two intermediate supports of the three-section transmission shaft of the present invention are located in the front and middle sections, and half of the gravity of the front section is borne by the intermediate supports. The transfer case output shaft and the oil seal are easily affected by gravity and have a small risk of eccentric wear, thereby reducing wear and increasing service life. This structure can prevent the risk of the front section even coming out under severe working conditions.

[0044] When installed on the vehicle, the transfer case axis, i.e. the first section, is generally at an angle of 0 to 3° to the horizontal, with 0° being the best, while the middle section, i.e. the second section, is generally arranged parallel to the vehicle body.

[0045] like Figure 3 , Figure 4 As shown, Figure 3This is a schematic diagram of the working position and force distribution of the existing three-section transmission shaft. Figure 4 The figure is a schematic diagram of the working position and force distribution of the three-section transmission shaft of the present invention. Since the weight of the transmission shaft is concentrated on the universal joint, the shaft tube is very light. The common three-section transmission shaft, whose transfer case needs to provide 2G of support force to the front sleeve fork, while the three-section transmission shaft of the present invention only needs to provide 1G of support force, and the force between the front sleeve fork and the transfer case is small, so that the transfer case output spline shaft and oil seal are less affected by gravity, and the risk of eccentric wear is also small.

[0046] All the universal transmission devices of the present invention can freely select cross-axis universal joints or ball cages according to the comprehensive requirements of cost and transmission efficiency. Different selections of universal transmission devices are all alternatives of the present invention.

[0047] Those skilled in the art will appreciate that changes and modifications may be made to the embodiments without departing from the principles and purpose of the present invention, and all of these changes and modifications are within the scope of protection of the present invention.

Claims

1. A three-section transmission shaft, characterized in that: Including the first, second and third sections, The first section is composed of a front flange fork (1), a front welding fork (2), a front axle tube (3) and a sleeve fork (5); The second section is composed of a center welding fork (6), a center shaft tube (7) and a ball cage flange end (9); The third section is composed of a ball cage bell housing end (10), a rear axle tube (11), a rear welding fork (12) and a rear flange fork (13); The first section and the second section are respectively placed in the grooves of the two intermediate supports (4, 8) and fixed to the vehicle body through the intermediate supports (4, 8); The welding end of the middle welding fork (6) is connected to one end of the middle shaft tube (7) and the spline shaft welding end of the ball cage flange end (9) at the other end of the middle shaft tube (7) by welding; The spline shaft welding end in the ball cage bell housing end (10) is connected to one end of the rear axle tube (11), and the other end of the rear axle tube (11) is connected to the welding end of the rear welding fork (12) by welding; The front flange fork (1) and the front welding fork (2), the sleeve fork (5) and the middle welding fork (6), and the rear welding fork (12) and the rear flange fork (13) are assembled and connected via a cross shaft in a universal joint; The ball cage flange end (9) and the ball cage bell housing end (10) are assembled by a ball cage universal joint assembly method; The sleeve fork (5) is assembled according to the sleeve fork assembly method.

2. The three-section transmission shaft according to claim 1, characterized in that: The welding method is one of double welding, brazing or friction welding.

3. The three-section transmission shaft according to claim 2, characterized in that: The welding method is friction welding.

4. The three-section transmission shaft according to claim 1, characterized in that: The front axle tube (3), the middle axle tube (7) and the rear axle tube (11) are provided with components capable of eliminating noise.

5. The three-section transmission shaft according to claim 1, characterized in that: The length of the second section is shorter than the lengths of the first section and the third section.

6. The three-section transmission shaft according to claim 1, characterized in that: The cross shaft is fixed by a retaining spring.

7. The three-section transmission shaft according to claim 4, characterized in that: The component capable of eliminating noise is sound-absorbing paper.

8. The three-section transmission shaft according to claim 4, characterized in that: The component capable of eliminating noise is injection-molded sound-absorbing cotton.

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