Pinch type transfer gearbox

Abstract

A pinch type transfer gearbox comprises a base, a box body is fixedly arranged on the base, a box cover is arranged at the top of the box body, an input shaft is rotationally arranged at the geometric center position of an inner cavity of the box body, the two ends of the input shaft penetrate through the box body and extend to the outer side, and the input shaft is sleeved with an input gear; the input gear is fixedly connected with the input shaft through a locking mechanism; a first output shaft in transmission connection with the input shaft and a plurality of middle shafts are arranged in an inner cavity of the box body in the circumferential direction of the input shaft, a plurality of second output shafts in transmission connection with the middle shafts are arranged on the two sides of the input shaft of the box body, and the output ends of the first output shaft and the second output shafts penetrate through the box body. The utility model has the advantages of reliable connection, convenience in assembly, long service life of the gear, stable multi-path power distribution and the like.

Description

TECHNICAL FIELD

[0001] The utility model relates to a kind of gearboxes, in particular to a kind of pinch sending type transfer gearbox. BACKGROUND

[0002] Transfer gearbox is the key transmission component in mechanical equipment for distributing single power source to multiple output ends, and is widely used in the field of engineering machinery, mining equipment, ship propulsion system etc.. The traditional transfer gearbox usually adopts key connection, flange connection or simple interference fit to fix input gear on input shaft. When bearing heavy load, impact load or alternating torque, the traditional key connection is easy to produce stress concentration, resulting in keyway wear, deformation or even shear failure, while interference fit may cause loose fit due to fretting after long-term operation, affecting transmission accuracy and stability. In addition, the root of input gear is the stress concentration area, which is easy to produce fatigue cracks. Meanwhile, the connecting part of gear hub and shaft also bears huge stress when transmitting torque, and the traditional structure design lacks effective reinforcement and stress optimization means. SUMMARY

[0003] The utility model aims at solving the deficiency of prior art, and provides a pinch sending type transfer gearbox which is reliable in connection, convenient in assembly, long in gear life and capable of realizing stable multi-way power distribution.

[0004] The utility model discloses a kind of pinch sending type transfer gearbox, including base, the base is fixed with box body, the box body top is equipped with box cover, the geometric center position of the box body inner chamber is rotationally equipped with input shaft, the both ends of the input shaft extend to outside and penetrate the box body, input gear is set on the input shaft, and the input gear is fixedly connected with input shaft by locking mechanism;The first output shaft and the multiple intermediate shafts that are transmissionally connected with input shaft are equipped in the box body inner chamber along the circumference of input shaft, the box body is equipped with the multiple second output shafts that are transmissionally connected with intermediate shaft on the both sides of input shaft, and the output end of the first output shaft, second output shaft penetrates the box body.

[0005] Preferably, the input gear includes a toothed portion and a hub portion at the center, the hub portion is provided with a spline hole connected with the input shaft, the surface of the spline hole is formed with a nitriding treatment layer, the input shaft is provided with an internal spline connected with the input gear, and the internal spline on the input shaft is in interference fit with the spline hole of the input gear.

[0006] Preferably, the input gear is made of high-strength alloy steel near-carburizing quenching low-temperature tempering, the tooth root of the toothed portion is provided with a transition fillet, and the surface of the transition fillet is subjected to shot peening strengthening treatment to form a residual compressive stress layer.

[0007] As preferred, the locking mechanism comprises a locking sleeve and a locking nut, the locking sleeve is sleeved on the outer periphery of the hub portion of the input gear, the inner wall of the locking sleeve is an inner conical surface, the corresponding outer wall of the hub portion is an outer conical surface matched with the locking sleeve, the input shaft is provided with an external thread segment, the locking nut is screwed with the external thread segment and presses the locking sleeve, so that the locking sleeve is axially pressed along the inner conical surface, thereby the hub portion is elastically contracted in the radial direction to tightly hold the inner spline of the input shaft.

[0008] As preferred, the taper of the inner conical surface of the locking sleeve is 1:10 to 1:30, the locking sleeve is provided with a pressing flange at one axial end, the pressing flange presses the end surface of the input gear on the input shaft, the input shaft is sleeved with a disc spring between the pressing flange and the locking nut, at least one stress release slot is formed on the outer conical surface of the hub portion in the circumferential direction.

[0009] As preferred, the first output shaft is sleeved with a first output gear engaged with the input gear, a plurality of the intermediate shafts are each sleeved with an intermediate gear engaged with the input gear, the second output shafts located on the same side of the input shaft are arranged side by side, the second output shafts are each sleeved with a second output gear, the second output gears on the adjacent two second output shafts are engaged, the second output gear on the second output shaft close to the intermediate shaft is engaged with the intermediate gear on the intermediate shaft, the first output shaft, the intermediate shaft, the second output shaft and the first output gear, the intermediate gear and the second output gear are all key connected.

[0010] As preferred, the box body is provided with end covers at both ends of the intermediate shaft, the box body is provided with output flange covers at the output end of the input shaft, the output end of the first output shaft and the output end of the second output shaft, and is provided with an input flange cover at the input end of the input shaft.

[0011] As preferred, hooks for hanging the box body are fixedly arranged on the side walls of the box body.

[0012] The utility model discloses beneficial effects:

[0013] 1. Discard the traditional single key connection or interference fit on the input shaft and input gear, adopt a set of mechanical locking mechanism composed of locking sleeve, locking nut and taper surface cooperation, tighten the locking nut, push the locking sleeve with the inner conical surface to move axially, utilize the taper surface effect to convert the axial compression force into huge radial contraction force, force the hub portion of the input gear to produce elastic deformation, thereby actively and powerfully hold the inner spline of the input shaft, this mode is more reliable than static interference fit, the pre-tightening force is adjustable, and micro-motion wear can be effectively inhibited.

[0014] 2. The stress release groove is arranged on the outer conical surface of the hub part, which reduces the radial rigidity of the hub part, makes the locking sleeve more easily and uniformly generate the required elastic contraction deformation, ensures the uniform distribution of the clamping force, avoids excessive stress concentration, improves the fatigue resistance of the hub in the repeated clamping and loosening process, and prolongs the service life of the gear;

[0015] 3. The input gear is made of high-strength alloy steel and is subjected to carburizing quenching and low-temperature tempering treatment, so that the high hardness and high wear resistance of the tooth part and the strong toughness of the core part are ensured, shot peening is performed at the tooth root transition fillet to form a residual compressive stress layer, the bending fatigue resistance of the gear is significantly improved, nitrogenization treatment is performed on the surface of the spline hole of the hub to form a high-hardness and high-wear-resistance nitrogenized layer, and the nitrogenized layer has the characteristics of friction reduction, the anti-wear and anti-seizure abilities of the spline connecting part are greatly enhanced, the interference fit and the clamping mechanism work together to ensure the long-term reliability of the connection;

[0016] 4. The radial transmission layout with the input shaft as the geometric center, the input gear is meshed with the first output gear on the first output shaft and the intermediate gears on the plurality of intermediate shafts at the same time, the initial power distribution is realized, the intermediate gears are further transmitted to the second output shafts on both sides of the input shaft, the adjacent second output shaft gears are meshed with each other, the secondary power distribution and synchronous output are realized, the layout structure is compact, the power flow is clear, the load transmission path is short, the symmetry and balance of the box structure are beneficial to be realized, and the system stiffness and operation stability are improved. BRIEF DESCRIPTION OF DRAWINGS

[0017] Figure 1 is the overall structure schematic view of the embodiment of the utility model;

[0018] Figure 2 is the structure schematic view of the box inner cavity of the utility model;

[0019] Figure 3 is the C place enlarged view of the utility model Figure 2 ;

[0020] Figure 4 is the A-A section view of the utility model Figure 2 ;

[0021] Figure 5 is the B-B section view of the utility model Figure 2 ;

[0022] Figure 6 is the D place enlarged view of the utility model Figure 5 .

[0023] In the diagram: 1. Base; 2. Housing; 3. Cover; 4. Input shaft; 5. Input gear; 6. First output shaft; 7. Intermediate shaft; 8. Second output shaft; 9. Gear teeth; 10. Hub; 11. Spline hole; 12. Nitriding layer; 13. Internal spline; 14. Transition fillet; 15. Residual compressive stress layer; 16. Locking sleeve; 17. Locking nut; 18. Inner conical surface; 19. Outer conical surface; 20. External thread section; 21. Compression flange; 22. Disc spring; 23. Stress relief groove; 24. First output gear; 25. Intermediate gear; 26. Second output gear; 27. End cover; 28. Output flange cover; 29. ​​Input flange cover; 30. Hook. Detailed Implementation

[0024] The technical solution of this utility model will be further described in detail below through specific embodiments and in conjunction with the accompanying drawings.

[0025] Example: Figures 1 to 6 The clamping type transfer gearbox shown includes a base 1, a box body 2 fixedly mounted on the base 1, a box cover 3 on the top of the box body 2, and hooks 30 for hanging the box body 2 fixedly mounted on both side walls of the box body 2.

[0026] An input shaft 4 is rotatably mounted at the geometric center of the inner cavity of the housing 2. Both ends of the input shaft 4 extend outward through the housing 2. An input gear 5 is mounted on the input shaft 4. The input gear 5 includes a toothed portion 9 and a hub portion 10 located at the center. The hub portion 10 has a spline hole 11 connected to the input shaft 4. A nitrided layer 12 is formed on the surface of the spline hole 11. An internal spline 13 connected to the input gear 5 is provided on the input shaft 4. The internal spline 13 on the input shaft 4 and the spline hole 11 of the input gear 5 are interference fit. The input gear 5 is made of high-strength alloy steel and is subjected to low-temperature tempering treatment by near-carburizing and quenching machine. A transition fillet 14 is provided at the root of the toothed portion 9. The surface of the transition fillet 14 is subjected to shot peening to form a residual compressive stress layer 15. The input gear 5 is made of high-strength alloy steel and undergoes carburizing, quenching, and low-temperature tempering treatment to ensure high hardness, high wear resistance, and strong toughness of the core. Shot peening is performed at the tooth root transition fillet 14 to form a residual compressive stress layer 15, which significantly improves the gear's resistance to bending fatigue. Nitriding treatment is performed on the surface of the spline hole 11 of the hub to form a high-hardness, high-wear-resistant nitrided layer with friction-reducing properties, which greatly enhances the wear resistance and anti-seize ability of the spline connection. Together with the interference fit and clamping mechanism, it ensures the long-term reliability of the connection.

[0027] The input gear 5 is fixedly connected with the input shaft 4 through a locking mechanism; the locking mechanism comprises a locking sleeve 16 and a locking nut 17, the locking sleeve 16 is sleeved on the outer periphery of the wheel hub part 10 of the input gear 5, the inner wall of the locking sleeve 16 is an inner conical surface 18, the corresponding outer wall of the wheel hub part 10 is an outer conical surface 19 matched with the locking sleeve 16, the input shaft 4 is provided with an external thread section 20, the locking nut 17 is screwed with the external thread section 20 and presses the locking sleeve 16, so that the locking sleeve 16 is axially pressed along the inner conical surface 18, thereby the wheel hub part 10 is elastically contracted in the radial direction to tightly hold the inner spline 13 of the input shaft 4; the taper of the inner conical surface 18 of the locking sleeve 16 is 1:10, the locking sleeve 16 is provided with a pressing flange 21 at one axial end, the pressing flange 21 presses the end surface of the input gear 5 on the input shaft 4, the input shaft 4 is sleeved with a disc spring 22 between the pressing flange 21 and the locking nut 17, at least one stress release groove 23 is formed on the outer conical surface 19 of the wheel hub part 10 in the circumferential direction; the traditional single key connection or interference fit is abandoned on the input shaft 4 and the input gear 5, and a mechanical locking mechanism composed of the locking sleeve 16, the locking nut 17 and the conical surface is adopted, the locking nut 17 is screwed, the locking sleeve 16 with the inner conical surface 18 is axially moved, the conical surface effect is used to convert the axial pressing force into a huge radial contraction force, so that the wheel hub part 10 of the input gear 5 is elastically deformed, thereby the inner spline 13 of the input shaft 4 is actively and strongly held, this mode is more reliable than the static interference fit, the pre-tightening force is adjustable, and the fretting wear can be effectively inhibited; the stress release groove 23 is arranged on the outer conical surface 19 of the wheel hub part 10, on one hand, the radial stiffness of the wheel hub part 10 is reduced, so that the locking sleeve 16 can more easily and uniformly make the required elastic contraction deformation, thereby the holding force is uniformly distributed, on the other hand, the stress is avoided from being excessively concentrated, the anti-fatigue performance of the wheel hub in the repeated clamping and loosening process is improved, and the service life of the gear is prolonged.

[0028] The inner cavity of the box 2 is provided with a first output shaft 6 and a plurality of intermediate shafts 7 in the circumferential direction of the input shaft 4, the box 2 is provided with a plurality of second output shafts 8 on both sides of the input shaft 4 and in transmission connection with the intermediate shafts 7, the output ends of the first output shaft 6 and the second output shaft 8 penetrate the box 2, the first output shaft 6 is sleeved with a first output gear 24 engaged with the input gear 5, the intermediate shafts 7 are each sleeved with an intermediate gear 25 engaged with the input gear 5, the second output shafts 8 on the same side of the input shaft 4 are arranged side by side, the second output shafts 8 are each sleeved with a second output gear 26, the second output gears 26 on the adjacent second output shafts 8 are engaged with each other, the second output gear 26 on the second output shaft 8 close to the intermediate shaft 7 is engaged with the intermediate gear 25 on the intermediate shaft 7, the first output shaft 6, the intermediate shaft 7 and the second output shaft 8 are all in key connection, the input shaft 4 is the geometric center of the radial transmission layout, the input gear 5 is engaged with the first output gear 24 on the first output shaft 6 and the intermediate gear 25 on the intermediate shaft 7 at the same time, the power is initially divided, the intermediate gear 25 is further transmitted to the second output shaft 8 on both sides of the input shaft 4, the gears on the adjacent second output shafts 8 are engaged with each other, the power is secondarily distributed and synchronously output, the layout structure is compact, the power flow is clear, the load transmission path is short, which is beneficial to realize the symmetry and balance of the box 2 structure, improves the system stiffness and running stability.

[0029] The box 2 is provided with an end cover 27 at both ends of the intermediate shaft 7, the box 2 is provided with an output flange cover 28 at the output end of the input shaft 4, the output end of the first output shaft 6 and the output end of the second output shaft 8, and the box 2 is provided with an input flange cover 29 at the input end of the input shaft 4.

[0030] The above-mentioned embodiment is only a preferred scheme of the present application, and does not limit the present application in any form, and other variants and modifications can be made without exceeding the technical scheme recited in the claims.

Claims

1. A pinch type transfer case, comprising a base (1), a case (2) fixed on the base (1), and a case cover (3) provided on the top of the case (2), characterized in that: The geometric center position of the inner cavity of the box body (2) is rotationally provided with an input shaft (4), both ends of the input shaft (4) extend to the outside through the box body (2), an input gear (5) is sleeved on the input shaft (4), and the input gear (5) is fixedly connected with the input shaft (4) through a locking mechanism; a first output shaft (6) and a plurality of intermediate shafts (7) are arranged in the inner cavity of the box body (2) along the circumference of the input shaft (4) and are in transmission connection with the input shaft (4), a plurality of second output shafts (8) are arranged on both sides of the input shaft (4) of the box body (2) and are in transmission connection with the intermediate shafts (7), and the output ends of the first output shaft (6) and the second output shaft (8) extend through the box body (2).

2. The pinch-type transfer case of claim 1, wherein: The input gear (5) comprises a tooth portion (9) and a hub portion (10) located at the center, the hub portion (10) is provided with a spline hole (11) connected with the input shaft (4), the surface of the spline hole (11) is formed with a nitriding treatment layer (12), the input shaft (4) is provided with an internal spline (13) connected with the input gear (5), and the internal spline (13) on the input shaft (4) is in interference fit with the spline hole (11) of the input gear (5).

3. The pinch-type transfer case of claim 2, wherein: The input gear (5) is made of high-strength alloy steel near-carburizing quenching low-temperature tempering treatment, the tooth root of the tooth portion (9) is provided with a transition fillet (14), and the surface of the transition fillet (14) is subjected to shot peening strengthening treatment to form a residual compressive stress layer (15).

4. The pinch-type transfer case of claim 2, wherein: The locking mechanism comprises a locking sleeve (16) and a locking nut (17), the locking sleeve (16) is sleeved on the outer periphery of the hub portion (10) of the input gear (5), the inner wall of the locking sleeve (16) is an inner conical surface (18), the corresponding outer wall of the hub portion (10) is an outer conical surface (19) matched with the locking sleeve (16), the input shaft (4) is provided with an external thread section (20), the locking nut (17) is screwed with the external thread section (20) and presses the locking sleeve (16), the locking sleeve (16) is axially pressed along the inner conical surface (18) thereof, so that the hub portion (10) is elastically contracted in the radial direction to tightly hold the internal spline (13) of the input shaft (4).

5. The pinch-type transfer case of claim 4, wherein: The taper of the inner conical surface (18) of the locking sleeve (16) is 1:10 to 1:30, one end of the locking sleeve (16) in the axial direction is provided with a pressing flange (21), the pressing flange (21) presses the end face of the input gear (5) on the input shaft (4), the disc spring (22) is sleeved between the pressing flange (21) and the locking nut (17) of the input shaft (4), and at least one stress release groove (23) is formed in the outer conical surface (19) of the hub portion (10) in the circumferential direction.

6. The pinch-type transfer case of claim 1, wherein: The first output shaft (6) is sleeved with a first output gear (24) engaged with the input gear (5), a plurality of the intermediate shafts (7) are each sleeved with an intermediate gear (25) engaged with the input gear (5), the second output shafts (8) are arranged side by side on the same side of the input shaft (4), the second output shafts (8) are each sleeved with a second output gear (26), the second output gears (26) on the adjacent two second output shafts (8) are engaged, the second output gear (26) on the second output shaft (8) close to the intermediate shaft (7) side is engaged with the intermediate gear (25) on the intermediate shaft (7), and the first output shaft (6), the intermediate shaft (7), the second output shaft (8) and the first output gear (24), the intermediate gear (25) and the second output gear (26) are all key connected.

7. The pinch-type transfer case of claim 6, wherein: The box (2) is provided with an end cover (27) at both ends of the intermediate shaft (7), the box (2) is provided with an output flange cover (28) at the output end of the input shaft (4), the output end of the first output shaft (6) and the output end of the second output shaft (8), and the box (2) is provided with an input flange cover (29) at the input end of the input shaft (4).

8. The pinch-type transfer case of claim 1, wherein: Hooks (30) for hanging the box (2) are fixedly arranged on the two side walls of the box (2).

Images