JP2557688Y2 - Coupling structure of viscous coupling - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial application field) The present invention relates to a coupling structure of a viscous coupling.

(Conventional technology and problems to be solved) Four-wheel drive vehicles, in which driving force is applied to four front and rear wheels of a vehicle to improve running performance, are becoming widespread. There are two types of four-wheel drive vehicles: a four-wheel drive (full-time) system and a four-wheel drive (part-time) system as needed. Some have a viscous coupling unit (VCU) interposed between the shafts.

FIG. 4 shows an example of a viscous coupling unit (hereinafter, simply referred to as a “viscus coupling”). A viscous coupling 1 is externally fitted to a rear output shaft 3 rotatably fitted to a transfer drive shaft 2 and is splined. A fitted hollow inner shaft 4, a case 5 having a cylindrical shape, and through which the inner shaft 4 is rotatably and liquid-tightly penetrated through shaft holes at both ends via seal members, and a shaft hole is splined to the inner shaft 4. A large number of disc-shaped inner plates 6 coupled to each other, and a large number of annular outer plates 7 whose outer peripheral surfaces are spline-coupled to the inner peripheral surface of the case 5 and are alternately arranged with the respective inner plates 6.
Are filled between the inner plate 6 and the outer plate 7 by being filled in the case 5, and are constituted by a highly viscous silicone oil (not shown) or the like which couples the both.

The viscous coupling 1 is built in a casing 10 of a power transmission device, and has a rear output shaft 3.
Some are connected to a ring gear 9 of a planetary gear set 8 for transmitting power to the planetary gear unit 8. Conventionally, as a means for connecting the case 5 and the ring gear 9, a spline 5 a is provided at one end of the outer peripheral surface of the case 5 and at the inner surface of the open end of the ring gear 9.
And 9a, which are fitted to each other and spline-coupled.

However, in the structure in which the outer peripheral surface of the case 5 of the viscous coupling 1 and the inner peripheral surface of the ring gear 9 are connected by spline coupling, the ring gear 9 necessarily has a large diameter, and accordingly, the casing 10 of the power transmission device also has a large diameter. There is a problem that the diameter becomes a factor that hinders downsizing of the power transmission device.

The present invention has been made in view of the above points, and provides a coupling structure of a viscous coupling capable of reducing the outer diameter of a casing of a power transmission device of a type having a built-in viscous coupling and achieving compactness. The purpose is to do.

(Means for Solving the Problems) According to the present invention, in order to achieve the above object, in a coupling structure of a viscous coupling for connecting a viscous coupling case to a ring gear of a planetary gear device, the outer diameter of the ring gear is reduced. The case and the outer diameter are made substantially the same diameter so that they can be opposed to each other, and a plurality of grooves are fitted along one of the outer peripheral edge of the case and the end surface of the ring gear along the circumferential direction, and the other is fitted with each of the grooves. Are provided so that they can be mutually non-rotatably engaged.

(Operation) The viscous coupling is housed in the casing of the power transmission device, and the groove or the ridge formed on the peripheral edge of the case is
It is fitted with a ridge or groove formed on the end face of the ring gear of the planetary gear set incorporated in the casing. Thereby, the viscous coupling is non-rotatably engaged with the ring gear of the planetary gear device.

(Embodiment) An embodiment of the present invention will be described below in detail with reference to the accompanying drawings. The same members as those shown in FIG. 4 are denoted by the same reference numerals, and description thereof will be omitted.

1 to 3, the viscous coupling 1
And the planetary gear unit 8 are disposed in the casing 10 ′ so as to face each other. The ring gear 9 of the planetary gear unit 8 has an outer diameter set to be substantially the same as the outer diameter of the case 5 of the viscous coupling 1. Have been. The outer peripheral edge of the one end face 5b of the case 5 of the viscous coupling 1 and the end face 9b of the ring gear 9 of the planetary gear device 8 facing the outer peripheral edge of the end face 5b are respectively provided with convex ridges 5c, 5c '( (Fig. 2) and the ridge 9c (Fig. 3
Figure) is formed. As shown in FIG. 2, the outer peripheral edge of the end face 5b of the case 5 has a predetermined width at each end position on two diameter lines passing through the center of the end face 5b and orthogonal to each other, and on both sides of these diameter lines. Thus, the ridges 5c and 5c 'are formed to face each other. Each of the facing ridges 5c and 5c 'is formed with an engaging groove 5d.

On the other hand, the ridges (teeth) 9c of the ring gear 9 are formed at respective locations facing the respective grooves 5d formed in the case 5 as shown in FIG. Each of these ridges 9c can be fitted into each of the opposed grooves 5d from the axial direction. As shown in FIG. 1, each end face of each of the ridges 5c, 5c 'and 9c of the case 5 and the ring gear 9 has a slight gap δ between the end faces facing each other in a state of being engaged with each other. It is set to such a height.

This viscous coupling 1 is incorporated in a casing 10 'of a power transmission device as shown in FIG. 1, and is provided in each groove 5d between each of the ridges 5c, 5c' of the case 5 to form a ring gear 9 of a planetary gear device 8. The opposing ridges 9c are fitted in the axial direction and are mutually non-rotatably engaged. In this engaged state, the end face of each ridge 9c of the ring gear 9 and the groove of the case 5
5d, between the opposing end faces of 5d, and each convex ridge 5c, 5 of the case 5.
A slight gap δ is provided between the end face c ′ and the opposite end face of the ring gear 9. In this way, the outer peripheral edge of the end face of the case 5 and the end face of the ring gear 9 are engaged with the clutch teeth. Thereby, the case 5 and the ring gear 9
The transmission of the axial force between them is interrupted.

In the above embodiment, the viscous coupling 1
A groove 5d is formed on the end surface of the case 5 and a ridge (teeth) 9c is formed on the end surface of the ring gear 9. On the contrary, the viscous coupling 1 is formed.
A convex ridge (teeth) may be formed in the case 5 and a groove may be formed in the end face of the ring gear 9. Further, it is sufficient that two or more grooves and ridges are formed, and the number is not limited to four as in the embodiment.

(Effects of the Invention) As described above, according to the present invention, in the coupling structure of the viscous coupling that connects the viscous coupling case to the ring gear of the planetary gear device, the outer diameter of the ring gear is equal to the outer diameter of the case. A plurality of grooves are provided along the circumferential direction on one of the end surface outer peripheral edge of the case and the end surface of the ring gear, and a convex ridge is provided on one of the other surfaces so as to be fitted to each of the grooves. By engaging these two members so that they cannot rotate with each other, the outer diameter of the casing of the power transmission device incorporating the planetary gear device and the viscous coupling can be reduced, and compactness can be achieved. effective.

[Brief description of the drawings]

FIG. 1 is an enlarged sectional view of a main part of a power transmission device to which a coupling structure of a viscous coupling according to the present invention is applied, FIG. 2 is an end view in the direction of arrows II-II in FIG. 1, and FIG. Arrow II in the figure
FIG. 4 is an enlarged sectional view of a main part of a power transmission device incorporating a conventional viscous coupling. DESCRIPTION OF SYMBOLS 1 ... Viscous coupling, 2 ... Transfer drive shaft, 3 ... Rear output shaft, 4 ... Inner shaft, 5 ... Case, 6 ... Inner plate, 7 ... Outer plate, 8 ... Planetary gear, 9 ... Ring gear, 5c,
5c ', 5d ... groove, 9c ... ridge, 10, 10' ... casing.

Claims (1)

(57) [Scope of request for utility model registration] 1. A viscous coupling coupling structure for coupling a viscous coupling case to a ring gear of a planetary gear device, wherein an outer diameter of the ring gear is substantially equal to an outer diameter of the case, and the ring gear can face each other. A plurality of grooves are provided along the circumferential direction on one of the outer peripheral edge of the end surface of the ring gear and the end surface of the ring gear, and a convex ridge is provided on one of the other surfaces so as to fit into each of the grooves. A coupling structure for a viscous coupling.