JPH0592327A - Manufacture of compound gear and compound gear - Google Patents

Abstract

PURPOSE:To simplify the manufacturing process of a compound gear to be used for a final speed reducer for transmitting a large torque. CONSTITUTION:A compound gear 30 is integrally provided with a parallel gear 40A and with a bevel gear 50A having a pitch circle diameter smaller than that of the parallel gear. The parallel gear member 40 has a recessed part on one side of the body 42, and in the bottom of the recessed part a taper surface 47 is formed. The bevel gear member 50 has a bevel gear 50A on the front surface and an inversed taper surface 57 on the rear surface. The outside diameter of the bevel gear member 50 has an interference to the inside diameter of the recessed part of the parallel gear member 40. The bevel gear member 50 is pressedly fitted into the recessed part and is brought into close contact with the taper surface. The axes of both members are brought into line, and the taper surfaces are electron-beam welded.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a compound gear and a compound gear incorporated in a speed reducer of a drive system of a vehicle.

[0002]

2. Description of the Related Art Various gear mechanisms are used in a speed reducer equipped in a drive system of a vehicle. Japanese Unexamined Patent Publication No. 1-143444
The through-shaft tandem final reducer for large vehicles disclosed in Japanese Patent Laid-Open No. 7 and Japanese Patent Application Laid-Open No. 143463 is disclosed in FIG.
It has the structure shown in. The through shaft tandem final reduction gear 1 has a rear shaft having a two-axis structure, and therefore an inter-differential unit 10 for transmitting an input to the rear front shaft and the rear rear shaft.
Equip. The input shaft 5 is connected to a spider shaft 8, and a bevel gear 20 is rotatably supported by the spider shaft. The bevel gear 20 simultaneously meshes with the first bevel gear 17 and the second bevel gear 50, and the first bevel gear 17 drives the rear and rear shafts via the shaft 15. The second bevel gear 50 transmits power to the drive gear 30, and the drive gear 30 passes through the helical gear 40 formed on the outer peripheral portion of the mating gear 80.
Mesh with. The gear 80 is a differential 18 for the rear and front shafts.
To drive. The drive gear 30 has a parallel gear (helical gear) 40 on the outer peripheral portion, and has a bevel gear 50 having a pitch circle diameter dimension smaller than the parallel gear on the side portion, which is a composite gear structure.

[0003]

If the parallel gear and the bevel gear forming the compound gear are separately machined and combined, the distance between the shafts becomes long and the final reduction gear as a whole becomes large. Therefore, it is conceivable to process this composite gear as one component by the precision forging method. However, the parallel gear has a large tooth width dimension in order to transmit a large torque. A large forging press capacity is required to integrally forge a bevel gear on the side of a parallel gear having a large tooth width, and a large forging press capacity is required to manufacture a single compound gear. Will turn into. Also, if you try to cut parallel gears and bevel gears from one material,
Since the pitch circle diameter of the bevel gear is small, the length of the bevel gear increases when trying to avoid the interference of gear cutting. A technique for joining two members prepared in advance by electron beam welding is disclosed in, for example, JP-A-57-36083 and JP-A-5-36083.
It is disclosed in Japanese Patent Publication No. 6-19989. The present invention provides a method and a composite gear that use an electron beam welding method to easily manufacture a compact composite gear that has a bevel gear with a small pitch diameter on a side portion of a parallel gear and transmits a large torque. It is a thing.

[0004]

The parallel gear member and the bevel gear member of the composite gear of the present invention are processed separately, and the outer peripheral portion of the bevel gear member is press-fitted into the recess provided in the side surface of the parallel gear member, The joining portion between the bottom of the recess and the back surface of the bevel gear is integrated by electron beam welding.

[0005]

With the above structure, a compound gear that transmits a large torque can be manufactured inexpensively and compactly.

[0006]

1 is an explanatory view showing the structure of a compound gear according to the present invention, FIG. 2 is a sectional view showing the upper half from the center line of a parallel gear member, and FIG. 3 is an upper half from the center line of a bevel gear member. FIG. The parallel gear member 40 includes a parallel gear 40A such as a helical gear on the outer peripheral portion of the main body 42 and a cylindrical hole 44 on the inner peripheral portion. The clutch teeth 4 are provided on one side surface of the main body 42.
0B and a recess 45 on the other side surface. Recess 4
5 is surrounded by an inner cylinder portion 46 having an inner diameter of D1 and a conical taper portion 47. An intersecting surface 48B of the conical tapered portion 47 and the cylindrical hole 44 is formed with a depth L1 inside the side surface 48B of the main body 42 from the side surface 48B. The bevel gear member 50 is
A bevel gear 50A such as a bevel gear is provided on one side surface of the main body 52, and an outer peripheral portion 52 thereof is formed in a cylindrical shape.
A cylindrical hole 54 is provided in the inner peripheral portion of the main body 52, and the bevel gear 5
The other side of 0A has an inverted conical tapered surface 57.

The taper angle of the inverted conical taper surface 57 of the bevel gear member 50 is equal to that of the conical taper surface 4 of the parallel gear member 40.
The taper angle of 7 is formed evenly, and both taper surfaces are in close contact with each other. The outer diameter dimension D2 of the bevel gear member 50 is slightly larger than the inner diameter dimension D1 of the recess 45 of the parallel gear member 40, and a press-fitting interference is provided between them. The parallel gear member 40 and the bevel gear member 50 can be easily manufactured by an ordinary processing means such as cutting or forging. Next, a means for joining these members to obtain a compound gear will be described. First, the bevel gear member 50 is pressed into the recess 45 of the parallel gear member 40. Since the joint portion 110 has a tightening margin between both members, both members are firmly joined by press fitting.

By completely press-fitting the bevel gear member 50 into the recess 45 of the parallel gear member 40, the parallel gear member 40
The reverse taper surface 57 of the bevel gear member 50 comes into close contact with the taper surface 47 of. Due to this press-fitting process, the axes of both members are completely aligned. Next, the electron beam 100 is irradiated toward the tapered joint surface 120 to perform electron beam welding.
Since the joining surface is a tapered surface, the electron beam 100 can be easily and accurately irradiated to the joining surface 120 from the inner diameter hole. By this electron beam welding, both members are completely integrated. After that, the inner diameter hole and the like are finished and the composite gear 30 is completed. Since both members are integrated by press fitting, the accuracy is high, the machining allowance for finishing can be set small, and the productivity is high.

[0009]

As described above, according to the present invention, the compound gear incorporated in the final reduction gear of the vehicle is a parallel gear having a large width dimension.
Focusing on a combination with a bevel gear having a pitch circle diameter smaller than the pitch circle diameter of the parallel gear, the bevel gear is joined in a recess provided in the parallel gear. In manufacturing, a parallel gear member and a bevel gear member are prepared by an ordinary processing method. The bevel gear member is press-fitted into the concave portion provided on the side surface of the parallel gear member to fix both members. The reverse taper surface formed on the back surface of the bevel gear member is in close contact with the taper surface formed on the bottom surface of the recess of the parallel gear member. After that, electron beam welding is applied to the taper joint surface to completely integrate both members. The recess formed in the parallel gear member is filled with the bevel gear member, so that the rigidity of the completed composite gear is high. Therefore, a large torque can be transmitted with a compact structure. Further, the parallel gear and the bevel gear can be brought close to each other as much as possible. The axial dimension can also be shortened.

[Brief description of drawings]

FIG. 1 is an explanatory view showing a manufacturing method and structure of a composite gear according to the present invention.

FIG. 2 is a cross-sectional view showing the upper half of the parallel gear member from the center line.

FIG. 3 is a cross-sectional view showing the upper half from the center line of the bevel gear member.

FIG. 4 is an explanatory diagram showing an outline of a final reduction gear to which the present invention is applied.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Final reducer 10 Inter-differential part 30 Composite gear 40 Parallel gear member 42 Main body 45 Recess 46 Inner peripheral part 47 Tapered part 50 Bevel gear member 52 Main body 56 Outer peripheral part 57 Reverse taper part 100 Electron beam 110 Press-fitting joint 120 Electron beam welding Department

Claims (2)

[Claims] 1. A method for manufacturing a hollow composite gear, wherein a bevel gear having a pitch diameter dimension smaller than a pitch diameter dimension of the parallel gear is integrally provided on a side portion of the parallel gear, and a cylindrical outer peripheral portion. A step of processing a bevel gear member having a reverse taper surface formed on the back surface and an inner diameter hole, a parallel gear formed on the outer periphery and a recess provided on one side, Of a parallel gear member having an inner diameter portion having a clearance and a tapered surface provided on the bottom surface, and a parallel gear member having an inner diameter hole, a step of press-fitting a bevel gear member into the recess portion of the parallel gear member, and a taper of the parallel gear member. A method for manufacturing a compound gear, comprising: a step of irradiating an electron beam from the inner diameter hole side to an electron beam to weld the surface and the reverse tapered surface of the bevel gear member to perform electron beam welding. 2. A composite gear having an inner diameter hole integrally formed with a bevel gear having a pitch diameter dimension smaller than the pitch diameter dimension of the parallel gear on a side portion of the parallel gear, wherein the parallel gear member has a side surface. The bevel gear member has a recess into which the bevel gear member is press-fitted, and the tapered surface formed on the bottom of the recess of the parallel gear member and the reverse taper surface formed on the back surface of the bevel gear member are in close contact to form an electron beam welding surface. Compound gear.