JPH0731012Y2 - Differential mechanism - Google Patents

Description

[Detailed Description of the Invention] [Industrial field of application] The present invention relates to a differential mechanism (hereinafter referred to as a differential mechanism) in which a ring gear is bolted to a differential case, and more specifically, between the differential case and the ring gear. The present invention relates to a diff mechanism capable of holding a high slip torque.

[Prior art]

The mesh case of the agricultural tractor is provided with a pair of left and right diff shafts. The inner shaft ends of the left and right diff shafts facing each other are connected by a diff mechanism as a differential gear mechanism. A ring gear (spiral gear) fastened with a bolt is driven by a differential pinion of a drive shaft.

[Problems to be solved by the invention]

However, the ring gear is fastened to the mounting surface of the differential case with bolts, but because the differential mechanism itself is placed in the lubricating oil, the oil penetrates the fastening surface of the ring gear and becomes an oil film contact surface, which causes metal There is a problem that the slip resistance is reduced as compared with the contact surface between them and the slip torque between the ring gear and the mounting surface of the differential case is reduced.

Therefore, the high torque acting on the axle of the agricultural tractor causes play between the ring gear mounting hole and the bolt screwed into the differential case, resulting in loosening of the bolt, breakage of the bolt, or damage to the ring gear. There was a problem such as doing.

Therefore, the present invention has been made in view of the above-mentioned conventional circumstances to solve the problem, and provides a differential mechanism capable of holding high slip resistance on the fastening surface between the ring gear and the differential case. It is to be implemented for the purpose.

[Means for solving problems]

The present invention for achieving the above object is a diff mechanism in which a ring gear mounting portion is directly fastened to a mounting portion of a diff case with a mounting bolt, and an annular recess is formed in at least one of the diff case and the ring gear mounting portion. In addition, by arranging the concave portion so as to surround the fastening surface where both mounting portions are fastened, and by filling the concave portion with a sealing material, it is possible to prevent oil from penetrating between the fastening surfaces. It is characterized by that.

[Action]

The present invention is configured as described above, and at least one of the attachment portion of the differential case or the ring gear is formed with a recess surrounding the fastening surface, the recess is filled with a sealing material, and oil permeates between the fastening surfaces. Since it is possible to prevent the fastening surface from becoming an oil film contact surface, it is possible to increase the sliding resistance between the metal surfaces and to secure a high sliding torque.

〔Example〕

Hereinafter, the drawings showing the present invention as an embodiment will be described.

As shown in FIG. 3, an agricultural tractor (not shown) is provided with a mission case 1 which constitutes the rear part of the monocoque machine body. This mesh case 1 is provided with a pair of left and right rear axles 2 whose inner shaft ends are axially supported by respective bearings provided on both side walls of the case 1 and which project to the left and right sides beyond the width of the case 1. Has been. After this axle 2
Each of the final gears 3 fixed to the outside of the case 1 is meshed with a small-diameter gear 5 which is integrally formed with a pair of left and right differential shafts 4.

The respective differential shafts 4 are rotatably supported by respective bearings provided on the side wall of the transmission case 1 at approximately middle portions in the lengthwise direction, and the small diameter gears 5 are formed outside the transmission case 1. The brake case 6 is fixed to the left and right sides of the mesh case 1 by a plurality of mounting bolts.

An intermediate side wall 7 is integrally formed on each of the brake cases 6, and a bearing provided on the intermediate side wall 7 rotatably supports the outside of the small diameter gear of the differential shaft 4 so that the differential shaft 4 can be rotated. A wet disk brake 9 configured to operate on both braking surfaces of the outer surface of the intermediate side wall 7 and the inner surface of the brake case 6 is attached to the shaft ends projecting outward from the intermediate side wall 7.

The inner shaft ends of the left and right paired differential shafts 4 facing each other are connected by a differential gear mechanism 10 as a differential gear mechanism disposed substantially in the center of the transmission case 1, and the ring gear of the differential gear mechanism 10 is connected. Def pinion 12 meshing with 11
Is integrally formed at the rear end of the drive shaft 13 which is passed through a transmission mechanism from an engine (not shown). The diff mechanism 10 is adapted to be interlocked with the sliding movement of the shift fork 35 to switch between a locked state and a unlocked state.

Both ends of the differential case 14 constituting the differential mechanism 10 are supported by bearings 15 fixed to both side walls of the case 1, respectively, and inside the differential case 14, a shaft 16 fixed to the differential case 14 is rotatable. Defpinion 17, 19
And the diff gears 20 and 21 that mesh with the diff pinions 17 and 19.
And are provided. Of the diff gears 20 and 21, one diff gear 20 is spline fitted to the diff shaft 4 on the right side,
The other differential gear 21 is spline-fitted to the left differential shaft 4. Although the example in which the differential mechanism 10 is provided in the power transmission path of the rear axle 2 has been described above, the diff mechanism 10 may be provided in the power transmission path of the front wheels.

Next, FIG. 1 showing an enlarged differential mechanism will be described.

In FIG. 1, a collar-shaped mounting portion 22 protruding to one side of the outer periphery of the differential case 14 is provided with a plurality of mounting holes, and a mounting portion 11a of one ring gear 11 has a plurality of mounting holes corresponding to the mounting holes. There are screw holes at these points, and this ring gear
11 is fastened to the mounting portion 22 with a mounting bolt 23 that penetrates the mounting hole of the mounting portion 22 and has a threaded portion screwed into the screw hole of the mounting portion 11a. A small diameter O-ring 29 and a large diameter O-ring 30 that prevent oil from penetrating are provided between the differential ring 14 and the mounting surface 25 of the differential case 14.
It is designed to prevent oil from penetrating into the fastening surface by 29 and 30. That is, the annular recesses 41, 42 are formed in the mounting surface 24 of the mounting portion 11a of the ring gear 11, and the recessed portions 41, 42 are provided with mounting surfaces (fastening surfaces) 24, 25 to which both mounting portions 11a, 22 are fastened. The recesses 41 and 42 are arranged so as to be sandwiched and enclosed, and O-rings (sealing materials) 29 and 30 are filled in the recesses 41 and 42 to prevent oil from penetrating from the outside between the mounting surfaces 24 and 25. The recesses 41, 42 may be provided on the mounting surface 25 of the mounting portion 22 of the differential case 14, and may be formed on at least one of the ring gear 11 and the mounting portions 11a, 22 of the differential case 14.

In this case, the mounting surface 24 of the ring gear 11 and the mounting surface 25 of the differential case 14 are in metal-to-metal contact, and the O-rings 29, 30
Since oil does not permeate into the respective fastening surfaces, the fastening torque of the mounting bolt shown by reference symbol R in FIG. 2 can be obtained. Therefore, as shown by reference symbol O in FIG. However, it is possible to solve the problem that the fastening torque is reduced and the play is generated between the mounting hole of the ring gear 11 and the mounting bolt 23 screwed to the differential case 14.

Also, as shown in FIG. 4, the ring gear 11 and the differential case
End portions of both axial mounting surfaces 33, 34 in which 14 and 14 are in contact with each other,
And ring-shaped recessed grooves 31 and 32 extending over the mounting surfaces 24 and 25, which are orthogonal to the axial direction.
By filling and sealing the oil-repellent coating material on 1, 32, for example, epoxy system (two-component type) or silicone system, the oil penetrates between both mounting surfaces 24, 25 and the fastening torque It is possible to solve the problem that the value decreases.

[Effect of device]

As described above, the present invention is a diff mechanism in which a ring gear mounting portion is directly fastened to a mounting portion of a diff case with a mounting bolt, and an annular recess is formed in at least one of the diff case and the ring gear mounting portion. At the same time, the concave portion is arranged so as to surround the fastening surface where both mounting portions are fastened, and the concave portion is filled with a sealing material so that oil can be prevented from permeating between the fastening surfaces. It is possible to prevent the fastening surface from becoming an oil film contact surface and increase the sliding resistance between the metal surfaces. Therefore, it becomes possible to secure a high sliding torque, prevent the looseness of the tightened mounting bolt from occurring, and effectively prevent the bolt from loosening or breaking, or the ring gear from being damaged. In particular, it is extremely effective for agricultural tractors and the like in which high torque acts on the axle.

Further, since it is only necessary to fill the recess with the sealing material, the configuration is extremely simple and the cost does not increase.

[Brief description of drawings]

FIG. 1 shows an embodiment of the present invention. FIG. 1 is a vertical sectional front view of a differential mechanism showing a state in which an O-ring (sealing material) is used, and FIG. FIG. 3 is a plan view showing a power transmission path of the agricultural tractor, FIG. 4 shows another example of the present invention, and an enlarged view of a main part of the diff mechanism showing a state in which a coating material (sealing material) is filled. FIG. 10 ... Differential mechanism, 11 ... Ring gear, 11a ... Ring gear mounting portion, 14 ... Differential case, 22 ... Differential case mounting portion, 23 ...
Mounting bolts, 24 and 25… Mounting surface (fastening surface), 29,30…
O-ring (sealing material), 31, 32 ... Recessed groove (recess), 41, 42 ...
Recess.

Claims (1)

[Scope of utility model registration request] 1. A diff mechanism in which an attachment portion of a ring gear is directly fastened to an attachment portion of a diff case with an attachment bolt, and an annular recess is formed in at least one of the diff case and the attachment portion of the ring gear. A diff mechanism having a configuration in which a recess is arranged so as to surround a fastening surface to which both mounting portions are fastened, and the recess is filled with a sealing material to prevent oil from penetrating between the fastening surfaces.