Idle gear assembly and engine

Abstract

The utility model relates to the technical field of engines, and discloses an idle gear assembly and an engine, the idle gear assembly comprises a small gear shaft of a hollow structure, a helical tooth structure is formed on the outer circular surface of the small gear shaft, grooves are formed in two shaft end surfaces of the small gear shaft, and the grooves are arranged along the circumferential direction of the shaft end surfaces; the large gear is fixedly connected with the outer circular surface of the small gear shaft; the outer ring of the lining is fixedly connected with the inner wall of the pinion shaft; the idler shaft and the inner ring of the lining are arranged in a spaced mode so that the lining can be rotationally arranged outside the idler shaft in a sleeving mode. According to the utility model, the groove is formed in the end part of the pinion shaft, so that the rigidity of the two ends of the pinion shaft is reduced, and when the bushing is loaded, the end part of the pinion shaft is properly deformed outwards, so that the stress of the bushing is reduced, the abrasion of the bushing is reduced, and ablation is avoided.

Description

Technical Field

[0001] The utility model relates to the technical field of engines, in particular to an idler gear assembly and an engine. Background Art

[0002] Diesel engines often use stepped idlers. In order to increase the smoothness of gear meshing and reduce transmission noise, helical gears are generally used. For systems with PTO (power take off) gears, the idler gear assembly has a large load and the helical gear generates axial force, which is not conducive to the operation of the idler gear, and there is a risk of wear or even ablation of the gear bushing. Utility Model Content

[0003] In view of this, the utility model provides an idler gear assembly and an engine to solve the problem of wear and even ablation of the gear bushing in the idler gear assembly in the prior art.

[0004] In the first aspect, the utility model provides an idler gear assembly, comprising: a pinion shaft, which is a hollow structure, the outer cylindrical surface of the pinion shaft is formed with a helical tooth structure, and the two axial end surfaces of the pinion shaft are provided with grooves, and the grooves are arranged along the circumferential direction of the axial end surfaces; a large gear, which is fixedly connected to the outer cylindrical surface of the pinion shaft; a bushing, the outer ring of the bushing is fixedly connected to the inner wall of the pinion shaft; and an idler shaft, which is provided with a gap with the inner ring of the bushing so that the bushing can be rotatably sleeved on the outside of the idler shaft.

[0005] Beneficial effect: By opening a groove at the end of the pinion shaft, the stiffness of both ends of the pinion shaft is reduced. When the bushing is loaded, the end of the pinion shaft will deform outward appropriately, reducing the force on the bushing, alleviating bushing wear and avoiding ablation.

[0006] In an optional embodiment, the pinion shaft forms an inner ring portion on the inner side of the groove and an outer ring portion on the outer side of the groove, and along the axial direction of the pinion shaft, the shaft end surface corresponding to the outer ring portion is higher than the shaft end surface corresponding to the inner ring portion.

[0007] Beneficial effect: After the idler shaft is assembled with the bushing and the pinion shaft, the shaft end surface corresponding to the inner ring portion does not contact other components, thereby reducing the axial force and section bending moment borne by the inner ring portion.

[0008] In an optional implementation, a height difference between the shaft end face corresponding to the outer ring portion and the shaft end face corresponding to the inner ring portion ranges from 0.4 mm to 0.6 mm.

[0009] In an optional embodiment, the thickness of the inner ring portion gradually increases in a concave direction from the shaft end toward the groove.

[0010] Beneficial effect: while ensuring that the inner ring portion can produce appropriate deformation at one end close to the shaft end face, the overall strength of the inner ring portion is ensured to avoid the inner ring portion from breaking.

[0011] In an optional embodiment, the shaft end surface is further provided with an oil discharge groove, and the oil discharge groove penetrates the inner and outer sides of the shaft end surface along the radial direction of the pinion shaft.

[0012] Beneficial effect: By providing the oil discharge groove, the lubricating oil flowing through the shaft end surface can be discharged to the outside of the idler gear assembly.

[0013] In an optional embodiment, the oil unloading groove forms a first sub-groove corresponding to the inner ring portion, and the oil unloading groove forms a second sub-groove corresponding to the outer ring portion, and the bottom surface of the first sub-groove is higher than the bottom surface of the second sub-groove.

[0014] Beneficial effect: It is convenient for lubricating oil to flow to the outside, which is beneficial for heat dissipation.

[0015] In an optional implementation, a height difference between a bottom surface of the first sub-groove and a bottom surface of the second sub-groove ranges from 0.1 mm to 0.3 mm.

[0016] In an optional embodiment, two bushings are arranged at intervals along the axial direction of the idler shaft, one of the bushings is arranged corresponding to the helical tooth structure of the pinion shaft, and the other bushing is arranged corresponding to the large gear.

[0017] In an optional embodiment, an oil inlet passage is provided in the idler shaft, the oil inlet passage passes through the end surface of the idler shaft to form an oil inlet, the oil inlet passage passes through the outer circumferential surface of the idler shaft to form an oil outlet, at least two oil outlets are provided, and each bushing corresponds to at least one oil outlet; and / or, an oil unloading passage is provided in the idler shaft, the oil unloading passage passes through the outer circumferential surface of the idler shaft to form an oil unloading port, the oil unloading port is located between the two bushings, and the oil unloading passage passes through the end surface of the idler shaft to form an oil discharge port.

[0018] In a second aspect, the utility model also provides an engine, comprising the above-mentioned idler gear assembly. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the specific implementation methods of the utility model or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0020] Figure 1 This is a schematic diagram of the overall structure of an idler gear assembly according to an embodiment of the utility model (the thrust ring is not shown);

[0021] Figure 2 It is a schematic cross-sectional structure diagram of an idler gear assembly in an axial direction at a non-oil unloading groove position according to an embodiment of the utility model;

[0022] Figure 3 for Figure 2 A is a schematic diagram of the partially enlarged structure of the middle part;

[0023] Figure 4 It is a schematic cross-sectional structure diagram of an idler gear assembly in an embodiment of the utility model at an oil unloading tank position along the axial direction;

[0024] Figure 5 for Figure 4 A schematic diagram of the partially enlarged structure of B in the middle;

[0025] Figure 6 This is a schematic structural diagram of a pinion shaft according to an embodiment of the utility model;

[0026] Figure 7 It is a structural schematic diagram of the oil inlet channel of an embodiment of the utility model;

[0027] Figure 8 This is a schematic structural diagram of the oil unloading channel of an embodiment of the utility model;

[0028] Fig. 9 The total pressure simulation result of the large gear end bushing of the idler gear assembly of the embodiment of the utility model;

[0029] Fig.10 The simulation result of the rough contact pressure of the bushing at the large gear end of the idler gear assembly of the embodiment of the utility model;

[0030] Fig.11 The simulation result of the total pressure of the pinion end bushing of the idler gear assembly of the embodiment of the utility model;

[0031] Fig.12 The simulation result of the rough contact pressure of the pinion end bushing of the idler gear assembly of the embodiment of the utility model;

[0032] Fig.13 The total pressure simulation result of the bushing at the large gear end of the idler gear assembly of the helical gear + bushing in the related art;

[0033] Fig.14 The simulation result of the rough contact pressure of the bushing at the large gear end of the idler gear assembly of the helical gear + bushing in the related art;

[0034] Fig.15It is the simulation result of the total pressure of the bushing at the pinion end of the helical gear + bushing idler gear assembly in the related art;

[0035] Fig.16 The simulation result of the rough contact pressure of the bushing at the pinion end of the helical gear + bushing idler gear assembly in the related art;

[0036] Fig.17 It is the result of the bushing force simulation analysis of the idler gear assembly of the helical gear + bushing in the related technology.

[0037] Description of reference numerals:

[0038] 1. Pinion shaft; 11. Helical tooth structure; 12. Groove; 13. Inner ring; 14. Outer ring; 15. Oil unloading groove; 151. First sub-groove; 152. Second sub-groove; 2. Large gear; 3. Bushing; 4. Idle shaft; 41. Oil inlet channel; 411. Oil inlet port; 412. Oil outlet port; 42. Oil unloading channel; 421. Oil unloading port; 422. Oil drain port; 43. Shaft end flange; 5. Thrust ring. DETAILED DESCRIPTION

[0039] In order to make the purpose, technical solution and advantages of the embodiment of the utility model clearer, the technical solution in the embodiment of the utility model will be clearly and completely described below in conjunction with the drawings in the embodiment of the utility model. Obviously, the described embodiment is a part of the embodiment of the utility model, not all the embodiments. Based on the embodiment of the utility model, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the utility model.

[0040] In the related art, the idler gear assembly usually adopts the helical gear + bushing scheme. The gear dynamics simulation of this scheme is carried out, and the calculation results are as follows: Fig.13 As shown in Figure 2, the maximum total pressure of the bushing at the large gear end is 1221 MPa; Fig.14 As shown in Figure 2, the maximum rough contact pressure of the bushing at the large gear end is 338 MPa; Fig.15 As shown, the maximum total pressure of the bushing at the pinion end is 2103MPa; Fig.16 As shown in the figure, the maximum contact pressure of the pinion end bushing is 387MPa. The above calculation results do not meet the requirements.

[0041] In order to solve the above problems, the relevant technology also proposed two other solutions. The first solution is the spur gear + bushing solution, and the second solution is the helical gear + rolling bearing solution. For the first solution, the gear dynamics simulation is performed, and the calculation results are as follows: the maximum total pressure of the bushing at the large gear end is 180MPa, the maximum rough contact pressure of the bushing at the large gear end is 77MPa, the maximum total pressure of the bushing at the small gear end is 26MPa, and the maximum rough contact pressure of the bushing at the small gear end is 10MPa; the calculation results meet the requirements. However, for the first solution, since the use of spur gears will increase the vibration and noise of the gear system, the gear load-bearing capacity will decrease, and the gear reliability will decrease; for the second solution, the rolling bearing structure is relatively complex, the radial size is large, the cost is high, and the noise is large at high speed.

[0042] In order to solve the above technical problems, the present application provides an idler gear assembly, Figures 1 to 12 , describing an embodiment of the utility model.

[0043] According to an embodiment of the utility model, on the one hand, an idler gear assembly is provided, comprising: a pinion shaft 1, a large gear 2, a bushing 3 and an idler shaft 4. The pinion shaft 1 is a hollow structure, and the outer cylindrical surface of the pinion shaft 1 is formed with a helical tooth structure 11, and the two axial end surfaces of the pinion shaft 1 are provided with grooves 12, and the grooves 12 are arranged along the circumferential direction of the axial end surfaces. The large gear 2 is fixedly connected to the outer cylindrical surface of the pinion shaft 1, and the outer ring of the bushing 3 is fixedly connected to the inner wall of the pinion shaft 1. The idler shaft 4 and the inner ring of the bushing 3 are provided with a gap so that the bushing 3 can be rotatably sleeved on the outside of the idler shaft 4.

[0044] By opening a groove 12 at the end of the pinion shaft 1, the rigidity of both ends of the pinion shaft 1 is reduced. When the bushing 3 is loaded, the end of the pinion shaft 1 will deform outward appropriately, reducing the force on the bushing 3, alleviating the wear of the bushing 3 and avoiding ablation.

[0045] It is worth mentioning that please refer to Fig.17 , the force analysis of the bushing 3 in the helical gear + bushing 3 solution in the related art shows that the areas where the bushing 3 is subjected to the greatest force are the two ends along the axial direction. Therefore, in this embodiment, by providing grooves 12 at both ends of the pinion shaft 1, the force on the two ends of the bushing 3 can be reduced.

[0046] Please note that Figures 2 to 5 Along the axial direction of the bushing 3 , the end of the bushing 3 extends to be arranged close to the axial end face of the pinion shaft 1 .

[0047] The idler gear assembly of this embodiment is subjected to gear dynamics simulation, and the calculation results are as follows: Fig. 9 As shown, the maximum total pressure of bushing 3 at the end of large gear 2 is 212MPa; Fig.10As shown, the maximum rough contact pressure of bushing 3 at the end of large gear 2 is 50MPa; Fig.11 As shown, the maximum total pressure of the pinion end bushing 3 (bushing 3 corresponding to the helical gear structure 11) is 63 MPa; Fig.12 As shown, the maximum rough contact pressure of the pinion end bushing 3 (bushing 3 corresponding to the helical gear structure 11) is 23 MPa. The above calculation results all meet the requirements.

[0048] Comparing the solution of helical gear + bushing 3, the solution of spur gear + bushing 3 in the related art, and the solution of this embodiment, as shown in Table 1, the solution of this embodiment has greatly improved load bearing compared with the solution of helical gear + bushing 3 in the related art, and is basically equivalent to the solution of spur gear + bushing 3 in the related art.

[0049] Table 1 Comparison of calculation results

[0050]

[0051] In one embodiment, Figures 2 to 6 As shown, the pinion shaft 1 forms an inner ring portion 13 on the inner side of the groove 12 and an outer ring portion 14 on the outer side of the groove 12. Along the axial direction of the pinion shaft 1, the shaft end surface corresponding to the outer ring portion 14 is higher than the shaft end surface corresponding to the inner ring portion 13. After the idler shaft 4 is assembled with the bushing 3 and the pinion shaft 1, the shaft end surface corresponding to the inner ring portion 13 does not contact other components, thereby reducing the axial force and section bending moment borne by the inner ring portion 13.

[0052] It is worth noting that if Figure 2 and Figure 4 As shown, one end of the idler shaft 4 contacts the axial end surface of the pinion shaft 1 through the shaft end flange 43, and the other end of the idler shaft 4 is sleeved with a thrust ring 5, and contacts the axial end surface of the pinion shaft 1 through the thrust ring 5. For details, please refer to Figure 2 and Figure 3 The shaft end surfaces corresponding to the outer ring portions 14 at both ends of the pinion shaft 1 are in contact with the shaft end flange 43 and the thrust ring 5 respectively, while the shaft end surfaces corresponding to the inner ring portions 13 at both ends of the pinion shaft 1 have gaps with the shaft end flange 43 and the thrust ring 5 respectively.

[0053] In one embodiment, Figure 3 As shown, the height difference between the shaft end surface corresponding to the outer ring portion 14 and the shaft end surface corresponding to the inner ring portion 13 ranges from 0.4 mm to 0.6 mm.

[0054] Please note that Figure 3 The height difference between the shaft end surface corresponding to the outer ring portion 14 and the shaft end surface corresponding to the inner ring portion 13 is h1.

[0055] It is worth noting that if the value of h1 is too large, the stiffness of the outer ring portion 14 will be reduced, which is not conducive to the load-bearing of the outer ring portion 14; if the value of h1 is too small, when the shaft end flange 43 and / or the thrust ring 5 undergo a large deformation, it is easy to contact the shaft end face corresponding to the inner ring portion 13.

[0056] In one embodiment, Figure 3 and Figure 5 As shown, the thickness of the inner ring portion 13 gradually increases from the shaft end surface to the concave direction of the groove 12. While ensuring that the inner ring portion 13 can be properly deformed near one end of the shaft end surface, the overall strength of the inner ring portion 13 is ensured to prevent the inner ring portion 13 from breaking.

[0057] It is worth mentioning that please refer to Figure 3 and Figure 5 The inner ring portion 13 is inclined toward the inner wall of one side of the groove 12. Figure 3 and Figure 5 In the axial cross section shown, the inner wall of the inner ring portion 13 on the side facing the groove 12 is in an arc shape. Of course, in other alternative embodiments, it may also be in a straight line shape.

[0058] It should be noted that, in this embodiment, the web is removed from the large gear 2 , so as to increase the rigidity of the large gear 2 and reduce the axial bending deformation of the large gear 2 caused by meshing force, thereby reducing the force load on the bushing 3 .

[0059] In one embodiment, Figure 1 and Figure 6 As shown, the shaft end surface is also provided with an oil discharge groove 15, which penetrates the inner and outer sides of the shaft end surface along the radial direction of the pinion shaft 1. By providing the oil discharge groove 15, the lubricating oil flowing through the shaft end surface can be discharged to the outside of the idler gear assembly.

[0060] In one embodiment, Figure 5 and Figure 6 As shown, the oil unloading groove 15 forms a first sub-groove 151 corresponding to the inner ring portion 13, and the oil unloading groove 15 forms a second sub-groove 152 corresponding to the outer ring portion 14, and the bottom surface of the first sub-groove 151 is higher than the bottom surface of the second sub-groove 152. This facilitates the flow of lubricating oil to the outside and is beneficial to heat dissipation.

[0061] In one embodiment, Figure 5 As shown, the height difference between the bottom surface of the first sub-groove 151 and the bottom surface of the second sub-groove 152 ranges from 0.1 mm to 0.3 mm.

[0062] Please note that Figure 5 The height difference between the bottom surface of the first sub-groove 151 and the bottom surface of the second sub-groove 152 is h2.

[0063] It is worth noting that if the value of h2 is too small, the flow effect of the lubricating oil is not obvious, resulting in poor heat dissipation effect; if the value of h2 is too large, the flow rate of the lubricating oil is too large, resulting in increased power loss.

[0064] In one embodiment, Figure 1 and Figure 6 As shown, a plurality of oil removal grooves 15 are spaced apart along the circumference of the shaft end surface.

[0065] In one embodiment, Figure 2 and Figure 4 As shown, two bushings 3 are arranged at intervals along the axial direction of the idler shaft 4 , one bushing 3 is arranged corresponding to the helical tooth structure 11 of the pinion shaft 1 , and the other bushing 3 is arranged corresponding to the large gear 2 .

[0066] In one embodiment, Figure 7 As shown, an oil inlet channel 41 is opened in the idler shaft 4, and the oil inlet channel 41 passes through the end surface of the idler shaft 4 to form an oil inlet port 411, and the oil inlet channel 41 passes through the outer peripheral surface of the idler shaft 4 to form an oil outlet port 412. There are at least two oil outlet ports 412, and each bushing 3 corresponds to at least one oil outlet port 412.

[0067] In one embodiment, Figure 8 As shown, an oil discharge channel 42 is opened in the idler shaft 4, and the oil discharge channel 42 penetrates the outer peripheral surface of the idler shaft 4 to form an oil discharge port 421, and the oil discharge port 421 is located between the two bushings 3. The oil discharge channel 42 penetrates the end surface of the idler shaft 4 to form an oil discharge port 422.

[0068] It is worth noting that the lubricating oil enters the oil inlet channel 41 through the oil inlet port 411, and then flows out through the oil inlet channel 41 to the space between the bushing 3 and the idler shaft 4 through the oil outlet port 412, thereby lubricating the bushing 3. Afterwards, the lubricating oil flows out through the gap between the bushing 3 and the idler shaft 4, a portion of which enters the oil discharge port 421, flows through the oil discharge channel 42 to the oil discharge port 422 for discharge, and the other portion flows out through the oil discharge groove 15.

[0069] It should be noted that the gap between the bushing 3 and the idler shaft 4 is 30 μm to 50 μm.

[0070] According to an embodiment of the present utility model, on the other hand, an engine is provided, comprising the above-mentioned idler gear assembly.

[0071] Although the embodiments of the present invention are described in conjunction with the accompanying drawings, those skilled in the art may make various modifications and variations without departing from the spirit and scope of the present invention, and such modifications and variations are all within the scope defined by the appended claims.

Claims

1. An idler gear assembly, characterized in that: include: The pinion shaft (1) is of a hollow structure, the outer cylindrical surface of the pinion shaft (1) is formed with a helical tooth structure (11), and two shaft end surfaces of the pinion shaft (1) are provided with grooves (12), and the grooves (12) are arranged along the circumference of the shaft end surface; A large gear (2) is fixedly connected to the outer circumferential surface of the small gear shaft (1); A bushing (3), the outer ring of the bushing (3) being fixedly connected to the inner wall of the pinion shaft (1); The idler shaft (4) is provided with a clearance between itself and the inner ring of the bushing (3), so that the bushing (3) can be rotatably sleeved on the outside of the idler shaft (4).

2. The idler gear assembly according to claim 1, characterized in that: The pinion shaft (1) forms an inner ring portion (13) on the inner side of the groove (12) and an outer ring portion (14) on the outer side of the groove (12); along the axial direction of the pinion shaft (1), the shaft end surface corresponding to the outer ring portion (14) is higher than the shaft end surface corresponding to the inner ring portion (13).

3. The idler gear assembly according to claim 2, characterized in that: The height difference between the shaft end surface corresponding to the outer ring portion (14) and the shaft end surface corresponding to the inner ring portion (13) ranges from 0.4 mm to 0.6 mm.

4. The idler gear assembly according to claim 2, characterized in that: From the axial end facing the concave direction of the groove (12), the thickness of the inner ring portion (13) gradually increases.

5. The idler gear assembly according to any one of claims 2 to 4, characterized in that: The shaft end surface is also provided with an oil discharge groove (15), and the oil discharge groove (15) penetrates the inner and outer sides of the shaft end surface along the radial direction of the pinion shaft (1).

6. The idler gear assembly according to claim 5, characterized in that: The oil unloading groove (15) forms a first sub-groove (151) corresponding to the inner ring portion (13), and the oil unloading groove (15) forms a second sub-groove (152) corresponding to the outer ring portion (14), and the groove bottom surface of the first sub-groove (151) is higher than the groove bottom surface of the second sub-groove (152).

7. The idler gear assembly according to claim 6, characterized in that: The height difference between the bottom surface of the first sub-groove (151) and the bottom surface of the second sub-groove (152) ranges from 0.1 mm to 0.3 mm.

8. The idler gear assembly according to any one of claims 1 to 4, characterized in that: Two bushings (3) are arranged at intervals along the axial direction of the idler shaft (4), one of the bushings (3) is arranged corresponding to the helical tooth structure (11) of the pinion shaft (1), and the other bushing (3) is arranged corresponding to the large gear (2).

9. The idler gear assembly according to claim 8, characterized in that: An oil inlet passage (41) is provided in the idler shaft (4), the oil inlet passage (41) penetrates the end surface of the idler shaft (4) to form an oil inlet port (411), the oil inlet passage (41) penetrates the outer peripheral surface of the idler shaft (4) to form an oil outlet port (412), at least two oil outlet ports (412) are provided, and each bushing (3) corresponds to at least one oil outlet port (412); and / or, An oil discharge channel (42) is provided in the idler shaft (4), and the oil discharge channel (42) penetrates the outer peripheral surface of the idler shaft (4) to form an oil discharge port (421). The oil discharge port (421) is located between the two bushings (3), and the oil discharge channel (42) penetrates the end surface of the idler shaft (4) to form an oil discharge port (422).

10. An engine, characterized in that: An idler gear assembly comprising any one of claims 1 to 9.

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