Transfer assembly method

Abstract

To prevent a seal lip from being turned up when a transfer is assembled.SOLUTION: A gear guide part 22 is inserted into a gear attachment hole 6 of a transfer case 2 from below and an upper end of a fitting surface 22a provided at the gear guide part 22 is disposed above a seal member 12 attached to the gear attachment hole 6. Next, a drive gear 3 is fitted in a fitting surface 22a of the gear guide part 22 from above. Then, in a state that the drive gear 3 and the fitting surface 22a of the gear guide part 22 are fitted, the drive gear 3 is inserted into an inner periphery of the seal member 12.SELECTED DRAWING: Figure 5

Description

[Technical Field]

[0001] The present invention relates to a method for assembling a transfer for an automobile. [Background Art]

[0002] An automobile transfer is a mechanism for distributing the rotational driving force of an engine output from a transmission to front wheels and rear wheels, and generally includes a drive gear, an output shaft, and a chain wound around the drive gear and the output shaft. A drive shaft extending from the transmission is connected to the drive gear, and the rotational driving force of the drive shaft is transmitted to the output shaft via the drive gear and the chain.

[0003] For example, the following Patent Document 1 discloses a transfer jig used for assembling a transfer. In this method, as shown in Fig. 8, the drive gear 102 around which the chain 104 is wound and the output shaft 103 are positioned and held by the transfer jig 111, and in this state, the integrated product of the drive gear 102, the output shaft 103, and the chain 104 is assembled into the transfer case 101 from above (see the arrow in Fig. 8). [Prior Art Literature] [Patent Literature]

[0004] [Patent Document 1] Japanese Unexamined Patent Publication No. 2022-149825 [Summary of the Invention] [Problem to be Solved by the Invention]

[0005] Incidentally, the transfer case is provided with sealing members 105 and 106 to prevent oil from leaking out between the transfer case 101 and the drive gear 102 and output shaft 103. Specifically, the sealing members 105 and 106 are fixed to the inner circumferential surfaces of the gear mounting hole 101a and the shaft mounting hole 101b, respectively, in the transfer case 101, and the sealing lips provided on each sealing member 105 and 106 are brought into sliding contact with the outer circumferential surface (sealing surface) of the drive gear 102 and the outer circumferential surface (sealing surface) of the output shaft 103.

[0006] During transfer assembly, after attaching the sealing members 105 and 106 to the gear mounting holes 101a and shaft mounting holes 101b of the transfer case 101, the drive gear 102 and output shaft 103, held by the jig 111, are inserted into the gear mounting holes 101a and shaft mounting holes 101b of the transfer case 101, and further inserted into the inner circumference of the sealing members 105 and 106. However, in the example shown in Figure 8, since only the upper end of the drive gear 102 is held by the jig 111, the axis of the drive gear 102 is tilted with respect to the axis of the gear mounting hole 101a, and the lower end of the drive gear 102 may be misaligned horizontally with the axis of the gear mounting hole 101a. If the drive gear 102 is inserted into the inner circumference of the sealing member 105 in this state, the lower end of the drive gear 102 may interfere with the sealing member 105, causing the seal lip to bend over and potentially rendering the sealing function ineffective.

[0007] The same problems can also occur when the output shaft 103 is inserted into the inner circumference of the sealing member 106.

[0008] Therefore, the present invention aims to prevent the seal lip from peeling off when assembling the transfer case. [Means for solving the problem]

[0009] To solve the aforementioned problems, the present invention provides a device for assembling a drive gear and an output shaft, on which a chain is stretched, into gear mounting holes and shaft mounting holes provided in a transfer case, from one axial side, It comprises a case support portion that supports the transfer case and a gear guide portion having a fitting surface that engages with the drive gear, The present invention provides a transfer assembly apparatus in which the gear guide portion is inserted into the gear mounting hole of the transfer case from the other axial side, and at least a portion of the fitting surface can be positioned on one axial side of the sealing member attached to the gear mounting hole.

[0010] Furthermore, the present invention relates to a method for assembling a drive gear and an output shaft, on which a chain is stretched, into gear mounting holes and shaft mounting holes provided in a transfer case, from one axial side. The process involves inserting a gear guide portion into the gear mounting hole of the transfer case from the other axial side, and positioning at least a portion of the fitting surface provided on the gear guide portion to one axial side of the sealing member attached to the gear mounting hole, The process involves fitting the drive gear onto the fitting surface of the gear guide portion from one axial side, The present invention provides a transfer assembly method comprising the steps of inserting the drive gear into the inner circumference of the sealing member while the drive gear and the fitting surface of the gear guide portion are fitted together.

[0011] As described above, in the present invention, when assembling the drive gear to the transfer case, the gear guide portion is inserted into the gear mounting hole of the transfer case from the other axial side (e.g., from below), and at least a portion of the fitting surface of the gear guide portion is positioned on one axial side (e.g., above) of the seal member. In this state, by fitting the drive gear to the fitting surface of the gear guide portion from one axial side (e.g., from above), the drive gear can be centered with respect to the gear guide portion, and consequently, with respect to the seal member. In this state, by inserting the drive gear into the inner circumference of the seal member, interference between the drive gear and the seal member is avoided, thus preventing the seal lip from peeling.

[0012] In the above apparatus and method, it is preferable to fit the fitting surface of the gear guide portion with the vicinity of the other axial end of the drive gear. This allows the vicinity of the other axial end (e.g., the lower end) of the drive gear that is inserted into the inner circumference of the seal member to be centered with respect to the seal member.

[0013] It is preferable that the gear guide portion is axially movable relative to the case support portion. This allows the gear guide portion to be positioned at any axial position relative to the transfer case supported by the case support portion, making it easier to position at least a portion of the fitting surface of the gear guide portion to one axial side of the sealing member attached to the transfer case.

[0014] The present invention can also be applied to the assembly of the output shaft into the transfer case. That is, the present invention is a device for assembling a drive gear and an output shaft, on which a chain is stretched, into gear mounting holes and shaft mounting holes provided in the transfer case from one axial side, The transfer case is supported by a case support portion, and the shaft guide portion has a fitting surface that engages with the output shaft. The present invention provides a transfer assembly apparatus in which the shaft guide portion is inserted into the shaft mounting hole of the transfer case from the other axial side, and at least a portion of the fitting surface can be positioned on one axial side of the sealing member attached to the shaft mounting hole.

[0015] Furthermore, the present invention relates to a method for assembling a drive gear and an output shaft, on which a chain is stretched, into gear mounting holes and shaft mounting holes provided in a transfer case, from one axial side. The steps include inserting the shaft guide portion into the shaft mounting hole of the transfer case from the other axial side, and positioning at least a portion of the fitting surface provided on the shaft guide portion to one axial side of the sealing member attached to the shaft mounting hole, The process involves fitting the output shaft to the fitting surface of the gear guide portion from one axial side, The present invention provides a transfer assembly method comprising the steps of inserting the output shaft into the inner circumference of the sealing member while the output shaft and the fitting surface of the gear guide portion are fitted together. [Effects of the Invention]

[0016] As described above, according to the present invention, when assembling the transfer case, it is possible to prevent the seal lip from peeling off and to avoid a decrease in the sealing function. [Brief explanation of the drawing]

[0017] [Figure 1] This is a cross-section of the transfer. [Figure 2] This is a cross-sectional view showing the temporary assembly of parts set on the temporary assembly stand. [Figure 3] This is a cross-sectional view of a transfer assembly apparatus according to one embodiment of the present invention, showing the state in which the transfer case is set. [Figure 4] The above is a cross-sectional view of the transfer assembly device, showing the gear guide section and shaft guide section in a raised position. [Figure 5] It is a cross-sectional view of the above-described transfer assembly apparatus, showing a state where a temporarily assembled component is set on a gear guide portion and a shaft guide portion. [Figure 6] It is a cross-sectional view of the above-described transfer assembly apparatus, showing a state where the temporarily assembled component is assembled to a transfer case. [Figure 7] It is a cross-sectional view of the above-described transfer assembly apparatus, showing a state where the gear guide portion and the shaft guide portion are lowered. [Figure 8] It is a cross-sectional view of a conventional transfer assembly apparatus, showing a state where a drive gear and an output shaft are fixed to a transfer case. DESCRIPTION OF EMBODIMENTS OF THE INVENTION

[0018] Hereinafter, embodiments of the present invention will be described with reference to the drawings.

[0019] As shown in FIG. 1, a transfer 1 includes a transfer case 2, a drive gear 3, an output shaft 4, and a chain 5. In FIG. 1, only the case main body 2a of the transfer case 2 is shown, and a cover is attached to the upper side of the case main body 2a in the drawing. The case main body 2a of the transfer case 2 is provided with a gear mounting hole 6 and a shaft mounting hole 7. The axis of the gear mounting hole 6 is parallel to the axis of the shaft mounting hole 7. Hereinafter, the axial direction of the gear mounting hole 6 and the shaft mounting hole 7 will be referred to as "axial direction".

[0020] The drive gear 3 has a substantially cylindrical shape, and a sprocket 3a is integrally provided at an axially intermediate portion (near the axially central portion in the illustrated example). On the outer peripheral surface of the drive gear 3, a cylindrical sealing surface 3b is provided in a region near the lower end, specifically in a region below the lower rolling bearing 9. On the inner peripheral surface of the drive gear 3, a cylindrical surface 3c is provided in a region near the lower end, specifically in a region below the lower rolling bearing 9. That is, in the drive gear 3, the sealing surface 3b is provided on the outer peripheral surface of the cylindrical portion provided below the rolling bearing 9, and the cylindrical surface 3c is provided on the inner peripheral surface of the same cylindrical portion.

[0021] The drive gear 3 is mounted to the transfer case 2 via rolling bearings 8 and 9 provided on both axial sides of the sprocket 3a. The inner rings of the rolling bearings 8 and 9 are fixed to the outer surface of the drive gear 3, for example, by press-fitting. The outer ring of the upper rolling bearing 8 fits into the inner surface of the cover (not shown) of the transfer case 2 with a small radial gap. The outer ring of the lower rolling bearing 9 fits into the inner surface of the gear mounting hole 6 of the case body 2a of the transfer case 2 with a small radial gap.

[0022] The output shaft 4 is a solid shaft, and a sprocket 4a is integrally provided at the axial middle portion (near the upper end in the illustrated example). A cylindrical sealing surface 4b is provided on the outer circumferential surface of the output shaft 4, in the region near the lower end, specifically the region below the lower rolling bearing 9.

[0023] The output shaft 4 is attached to the transfer case 2 via rolling bearings 10 and 11 provided on both axial sides of the sprocket 4a. The inner rings of the rolling bearings 10 and 11 are fixed to the outer surface of the output shaft 4, for example, by press-fitting. The outer ring of the upper rolling bearing 10 fits into the inner surface of the cover (not shown) of the transfer case 2 with a small radial gap. The outer ring of the lower rolling bearing 11 fits into the inner surface of the shaft mounting hole 7 of the case body 2a of the transfer case 2 with a small radial gap.

[0024] A sealing member 12 is fixed near the lower end of the gear mounting hole 6 in the case body 2a. By sliding the sealing lip of the sealing member 12 against the sealing surface 3b of the drive gear 3, the gap between the outer surface of the drive gear 3 and the inner surface of the gear mounting hole 6 is sealed, preventing oil from leaking out of the transfer case 2. In addition, a sealing member 13 is fixed at the lower end of the shaft mounting hole 7 in the case body 2a. By sliding the sealing lip of the sealing member 13 against the sealing surface 4b of the output shaft 4, the gap between the outer surface of the output shaft 4 and the inner surface of the shaft mounting hole 7 is sealed, preventing oil from leaking out of the transfer case 2.

[0025] The chain 5 is stretched between the sprocket 3a of the drive gear 3 and the sprocket 4a of the output shaft 4. This transmits the rotational driving force of the drive gear 3 to the output shaft 4 via the chain 5.

[0026] The following describes the procedure for assembling Transfer 1 as described above.

[0027] [Parts Temporary Assembly Process] First, as shown in Figure 2, the drive gear unit 14, consisting of a drive gear 3 and rolling bearings 8 and 9, the output shaft unit 15, consisting of an output shaft 4 and rolling bearings 10 and 11, and the chain 5 are temporarily assembled on the parts temporary assembly stand 30. Specifically, the drive gear unit 14 is first inserted from above into the gear insertion hole 31 provided in the parts temporary assembly stand 30, and the drive gear unit 14 (rolling bearing 9 in the illustrated example) is placed on the shoulder surface 31a of the gear insertion hole 31. Next, the output shaft unit 15 is inserted from above into the shaft insertion hole 32 provided in the parts temporary assembly stand 30, and the output shaft unit 15 (rolling bearing 11 in the illustrated example) is placed on the shoulder surface 32a of the shaft insertion hole 32. The shaft insertion hole 32 has an elongated shape in the direction approaching and moving away from the gear insertion hole 31 (left-right direction in the figure), and the shaft unit 15 is set near the end of the shaft insertion hole 32 that is closer to the gear insertion hole 31 (see dotted line in Figure 2).

[0028] Next, the output shaft unit 15 is moved to the side away from the drive gear unit 14 (right side in Figure 2) while the chain 5 is stretched between the sprocket 3a of the drive gear 3 and the sprocket 4a of the output shaft 4. This completes the temporary assembly 16 consisting of the drive gear unit 14, the output shaft unit 15, and the chain 5.

[0029] Next, the temporary assembly of parts 16 is assembled into the case body 2a of the transfer case 2 using the transfer assembly device 20 shown in Figure 3.

[0030] [Configuration of the transfer assembly machine] The transfer assembly device 20 includes a case support section 21 that positions and supports the case body 2a of the transfer case 2, a gear guide section 22 that guides the drive gear 3, and a shaft guide section 23 that guides the output shaft 4.

[0031] The case support sections 21 are provided at least three locations that are not on the same straight line. Each case support section 21 has a support surface that supports the case body 2a from below and a positioning pin that is inserted into a positioning hole provided in the case body 2a. The multiple case support sections 21 are fixed to the fixing base 26.

[0032] The outer circumferential surface of the gear guide portion 22 is provided with a large-diameter cylindrical surface 22a, a small-diameter cylindrical surface 22b located above the large-diameter cylindrical surface 22a and having a smaller diameter than the large-diameter cylindrical surface 22a, and a tapered surface 22c that is continuous with these. The upper end of the shaft guide portion 23 is provided with a cylindrical portion 23a that opens upward. The gear guide portion 22 and the shaft guide portion 23 are axially movable relative to the case support portion 21. In the illustrated example, a lifting platform 24 to which the gear guide portion 22 and the shaft guide portion 23 are fixed, and a drive unit 25 for raising and lowering the lifting platform 24 is provided. As the drive unit 25, for example, a cylinder (for example, an air cylinder or an electric cylinder) is used.

[0033] [Case setting process] First, as shown in Figure 3, the case body 2a of the transfer case 2 is set on the case support section 21 of the transfer assembly device 20. Specifically, the case body 2a is supported from below by the support surfaces of each case support section 21, and the case body 2a is positioned vertically and horizontally by inserting the pins of each case support section 21 into the positioning holes of the case body 2a from below. A sealing member 12 is fixed in advance near the lower end of the inner circumferential surface of the gear mounting hole 6 of the case body 2a, and a sealing member 13 is fixed in advance near the lower end of the inner circumferential surface of the shaft mounting hole 7 of the case body 2a.

[0034] [Guide lifting process] Next, the drive unit 25 is driven to raise the lifting platform 24, gear guide section 22, and shaft guide section 23 together, as shown in Figure 4. This allows the gear guide section 22 and shaft guide section 23 to be inserted from below into the inner circumference of the gear mounting hole 6 and shaft mounting hole 7 of the case body 2a, which is set on the case support section 21. In this embodiment, the upper end of the large-diameter cylindrical surface 22a of the gear guide section 22 is positioned above the sealing member 12 fixed to the gear mounting hole 6 of the case body 2a, and the upper end of the cylindrical section 23a of the shaft guide section 23 is positioned above the sealing member 13 fixed to the shaft mounting hole 7 of the case body 2a.

[0035] In this embodiment, the gear guide portion 22 and the shaft guide portion 23 are made movable up and down relative to the case body 2a while maintaining a state in which they are centered with the gear mounting hole 6 and the shaft mounting hole 7 of the case body 2a set on the case support portion 21. In this way, by raising the gear guide portion 22 and the shaft guide portion 23 while they are centered with the gear mounting hole 6 and the shaft mounting hole 7, the gear guide portion 22 and the shaft guide portion 23 can be inserted into the gear mounting hole 6 and the shaft mounting hole 7 from below without excessive interference with the sealing members 12 and 13.

[0036] [Parts assembly process] Next, the temporary assembly 16 of the parts set on the temporary assembly stand 30 is placed into the case body 2a of the transfer case 2 set on the transfer assembly device 20, as shown in Figure 5. In this embodiment, the worker holds the upper end of the drive gear 3 and the upper end of the output shaft 4 by hand, lifts the temporary assembly 16 from the temporary assembly stand 30, and lowers it from above onto the case body 2a on the transfer assembly device 20.

[0037] At this time, the inner surface of the drive gear 3 is fitted to the outer surface of the gear guide portion 22, thereby centering the drive gear 3, that is, aligning the axis of the drive gear 3 with the axis of the gear mounting hole 6 of the case body 2a, and further aligning it with the axis of the seal member 12 fixed to the gear mounting hole 6. More specifically, first, the cylindrical surface 3c provided near the lower end of the inner surface of the drive gear 3 is fitted to the small-diameter cylindrical surface 22b provided near the upper end of the gear guide portion 22, thereby roughly centering the drive gear 3. After that, the drive gear 3 is lowered further, and the cylindrical surface 3c of the drive gear 3 is fitted to the large-diameter cylindrical surface 22a of the gear guide portion 22, thereby achieving high-precision centering of the drive gear 3. Finally, the tapered surface 3d provided on the inner surface of the drive gear 3 comes into contact with the tapered surface 22c on the outer surface of the gear guide portion 22, completing the setting of the drive gear 3.

[0038] In this case, during the guide raising process described above, the upper end of the large-diameter cylindrical surface 22a of the gear guide portion 22 is positioned above the seal member 12. Therefore, the cylindrical surface 3c of the drive gear 3 can be fitted to the large-diameter cylindrical surface 22a (fitting surface) of the gear guide portion 22 above the seal member 12 (i.e., before insertion into the inner circumference of the seal member 12), thereby centering the drive gear 3. In particular, in this embodiment, the entire area of ​​the cylindrical surface 3c provided near the lower end of the inner circumference of the drive gear 3 above the seal member 12 is fitted to the large-diameter cylindrical surface 22a of the gear guide portion 22. As a result, the portion of the drive gear 3 that is inserted into the inner circumference of the seal member 12 (the seal surface 3b and the area below it) is centered with high precision relative to the seal member 12.

[0039] Furthermore, by lowering the temporary assembly 16 of the parts from above the case body 2a and fitting the outer surface of the output shaft 4 to the inner surface of the cylindrical portion 23a of the shaft guide portion 23, the output shaft 4 is centered, that is, the axis of the output shaft 4 is centered with the axis of the shaft mounting hole 7 of the case body 2a, and further, with the sealing member 13 fixed to the shaft mounting hole 7. When the lower end of the output shaft 4 comes into contact with the bottom surface of the cylindrical portion 23a of the shaft guide portion 23, the setting of the output shaft 4 is completed.

[0040] In this case, during the guide raising process described above, the upper end of the cylindrical portion 23a of the shaft guide portion 23 is positioned above the seal member 13. Therefore, the output shaft 4 can be centered by fitting it onto the inner circumferential surface (fitting surface) of the cylindrical portion 23a of the shaft guide portion 23 above the seal member 13 (i.e., before inserting it into the inner circumference of the seal member 13). In particular, in this embodiment, a sealing surface 4b is provided near the lower end of the outer circumferential surface of the output shaft 4, and this sealing surface 4b is fitted onto the inner circumferential surface of the cylindrical portion 23a of the shaft guide portion 23. As a result, the portion of the output shaft 4 that is inserted into the inner circumference of the seal member 13 (the sealing surface 4b and the region below it) is centered with high precision relative to the seal member 13.

[0041] [Parts assembly process] Next, the drive unit 25 is driven to lower the lifting platform 24, gear guide section 22, shaft guide section 23, and temporary assembly of parts 16 together (see Figure 6). This inserts the lower end of the drive gear 3 into the inner circumference of the seal member 12. At this time, the cylindrical surface 3c provided near the lower end of the drive gear 3 is fitted with the large-diameter cylindrical surface 22a of the gear guide section 22, so that the lower end of the drive gear 3 (specifically, the seal surface 3b and the area below it) is centered with respect to the seal member 12. In this state, by lowering the drive gear 3 and the gear guide section 22 together and inserting the lower end of the drive gear 3 into the inner circumference of the seal member 12, interference between the drive gear 3 and the seal member 12 can be prevented.

[0042] Simultaneously, the outer surface of the rolling bearing 9 attached to the drive gear 3 is fitted into the inner surface of the gear mounting hole 6 of the case body 2a. When the lower end surface of the rolling bearing 9 contacts the shoulder surface of the gear mounting hole 6, the downward movement of the drive gear 3 is restricted. Subsequently, by further lowering the gear guide portion 22, the gear guide portion 22 is separated from the drive gear 3, as shown in Figure 7.

[0043] Furthermore, by lowering the lifting platform 24, gear guide section 22, shaft guide section 23, and temporary assembly of parts 16 together, the lower end of the output shaft 4 is inserted into the inner circumference of the sealing member 13. At this time, the area near the lower end of the outer surface of the output shaft 4 (seal surface 4b) is fitted with the inner surface of the cylindrical section 23a of the shaft guide section 23, so that the lower end of the output shaft 4 (specifically, the seal surface 4b and the area below it) is centered with respect to the sealing member 13. In this state, by lowering the output shaft 4 and the shaft guide section 23 together and inserting the lower end of the output shaft 4 into the inner circumference of the sealing member 13, interference between the output shaft 4 and the sealing member 13 can be prevented. In particular, in this embodiment, since the lower end of the output shaft 4 is inserted into the inner circumference of the sealing member 13 while being covered from the outer circumference by the cylindrical section 23a of the shaft guide section 23, the output shaft 4 and the sealing member 13 do not slide directly against each other. This ensures that the lower end of the output shout 4 does not interfere with the sealing member 13, preventing the sealing lip from peeling off.

[0044] Simultaneously, the outer circumferential surface of the rolling bearing 11 attached to the output shaft 4 is fitted into the inner circumferential surface of the shaft mounting hole 7 of the case body 2a. When the lower end face of the rolling bearing 11 contacts the shoulder surface of the shaft mounting hole 7, the downward movement of the output shaft 4 is restricted. Subsequently, by further lowering the shaft guide portion 23, the shaft guide portion 23 is separated from the output shaft 4, as shown in Figure 7. More specifically, after the rolling bearing 11 attached to the output shaft 4 contacts the shoulder surface of the shaft mounting hole 7 and the downward movement of the output shaft 4 stops, the shaft guide portion 23 further descends while the outer circumferential surface of the cylindrical portion 23a of the shaft guide portion 23 slides against the seal member 13. At this time, since the shaft guide portion 23 is centered with respect to the seal member 13, peeling of the seal lip is prevented.

[0045] After that, the assembly of the transfer case 1 is completed by attaching the cover from above the case body 2a.

[0046] The present invention is not limited to the embodiments described above. Other embodiments of the present invention will be described below, but redundant explanations of points similar to those described above will be omitted.

[0047] For example, the gear guide portion 22 and the shaft guide portion 23 may be fixed, and the case support portion 21 may be raised and lowered. Alternatively, the gear guide portion 22 and the shaft guide portion 23 may be fixed without being raised and lowered relative to the case support portion 21. In this case, the case body 2a is set and positioned on the case support portion 21, and at the same time, the gear guide portion 22 and the shaft guide portion 23 are inserted into the inner circumference of the gear mounting hole 6 and the shaft mounting hole 7, and the upper ends of their fitting surfaces are positioned above the seal members 12 and 13. Then, the cylindrical surface 3c of the drive gear 3 and the seal surface 4b of the output shaft 4 are inserted into the inner circumference of the seal members 12 and 13 while sliding against the fitting surface of the gear guide portion 22 (large diameter cylindrical surface 22a) and the fitting surface of the shaft guide portion 22 (inner circumferential surface of the cylindrical portion 23a).

[0048] Furthermore, during the guide raising process, the upper end of the fitting surface (large diameter cylindrical surface 22a) of the gear guide portion 22 may be positioned above the seal member 12, while the upper end of the fitting surface (inner circumferential surface of the cylindrical portion 23a) of the shaft guide portion 23 may be positioned at the same height as or below the seal member 13. Conversely, the upper end of the fitting surface of the shaft guide portion 23 may be positioned above the seal member 13, while the fitting surface of the gear guide portion 22 may be positioned at the same height as or below the seal member 12.

[0049] Furthermore, the transfer of the temporary parts assembly 16 from the temporary parts assembly stand 30 to the case body 2a can be performed by the worker holding the upper ends of the drive gear 3 and output shaft 4 by hand, or it can be done using a jig to hold the temporary parts assembly 16. [Explanation of Symbols]

[0050] 1 Transfer 2 Transfer Cases 2a Case body 3 Drive gear 3a sprocket 3b Sealing surface 3c cylindrical surface 3D tapered surface 4 Output shaft 4a sprocket 4b Sealing surface 5 chains 6 gear mounting holes 7. Shaft mounting holes 12, 13 Sealing members 14 Gear Unit 15 Shaft Unit 16-part temporary assembly 20 Transfer Assembly Machine 21 Case support section 22 Gear guide section 22a Large diameter cylindrical surface (fitting surface) 23 Shaft guide section 23a Cylindrical section 24 Elevating platform 25 Drive unit 30 Component Temporary Assembly Stand 31 Gear insertion hole 32 shaft insertion holes

Claims

1. A method for assembling a drive gear and output shaft, on which a chain is stretched, into gear mounting holes and shaft mounting holes provided in a transfer case, from one axial side, The process involves inserting a gear guide portion into the gear mounting hole of the transfer case from the other axial side, and positioning at least a portion of the fitting surface provided on the gear guide portion to one axial side of the sealing member attached to the gear mounting hole, The process involves fitting the drive gear onto the fitting surface of the gear guide portion from one axial side, A method for assembling a transfer case, comprising the steps of inserting the drive gear into the inner circumference of the sealing member while the drive gear and the fitting surface of the gear guide portion are fitted together.

2. The method for assembling a transfer according to claim 1, wherein the fitting surface of the gear guide portion fits with the vicinity of the other end of the drive gear on the axial side.

3. The method for assembling a transfer according to claim 1, wherein the gear guide portion is movable relative to the transfer case in the axial direction.

4. A method for assembling a drive gear and output shaft, on which a chain is stretched, into gear mounting holes and shaft mounting holes provided in a transfer case, from one axial side, The steps include inserting the shaft guide portion into the shaft mounting hole of the transfer case from the other axial side, and positioning at least a portion of the fitting surface provided on the shaft guide portion to one axial side of the sealing member attached to the shaft mounting hole, The process of fitting the output shaft into the fitting surface of the shaft guide portion from one axial side, A method for assembling a transfer, comprising the steps of inserting the output shaft into the inner circumference of the sealing member while the output shaft and the fitting surface of the shaft guide portion are fitted together.

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