JPH0747980B2 - Gear train switching device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention is mainly used for switching the traveling direction and speed of a small-sized agricultural tractor, so that the crawler belt is switched in both forward and reverse directions, or is driven with variable speed. The present invention relates to a gear train switching actuating device for use in, particularly to a friction clutch actuating device for selectively actuating one of two gear trains having different rotation directions or different speeds.

[Conventional technology]

Generally, in this type of gear switching mechanism, as shown in FIG. 9, two clutches 4a symmetrically provided on one surface and the other surface with a flange 7a connected to the transmission shaft interposed therebetween,
Of the two clutches 4a, 4b by projecting the projecting arms 7f, 7f outward from the pressing plates 7d, 7d of 4b and connecting the tip portions of the projecting arms 7f, 7f with three bolts B arranged at equal intervals. While 4b
It is considered that the other clutch 4a is operated by being antagonized by the hydraulic piston 8b provided in the.

[Problems to be Solved by the Invention]

However, in this way, the bolt B is pressed between the pressing plates 7d and 7d.
In the structure in which the clutch B is fastened by bolts, the work of assembling the clutch is troublesome, and the amount of protrusion of the protruding arm protruding outward from the outer ring 7 of the clutch becomes large. Alternatively, since the heavy bolt B is arranged outside the rotating body, there is a problem that the entire apparatus becomes large and it is not suitable for use in severe acceleration and deceleration or for use in a high-speed rotating shaft.

[Means for Solving the Problems]

SUMMARY OF THE INVENTION The present invention aims to solve the above problems, to provide a gear switching device which is easy to assemble, has a small external shape, and can withstand severe operating conditions. A clutch is provided on a transmission shaft via a flange. Of the outer ring is fixed, a pressure receiving plate is provided inside the outer ring, a pressing plate that advances and retracts toward the pressure receiving plate is provided between the flange and the pressure receiving plate, and a friction plate is provided between the pressure receiving plate and the pressing plate. Two friction clutches interposing the above are arranged on both sides of the flange, one of the friction clutches is a normally open type that is engaged by a piston, and the other is a normally closed type that is always engaged by a spring. While disposing a plurality of connecting members on the outer surface of the outer ring, a plurality of projecting arms that project outward from the outer circumferences of the pressing plates of both friction clutches through the outer ring are provided, and these projecting arms and the connecting member are provided as shafts. The direction is fixed and the front Outer periphery separation preventing ring of the connecting member is characterized in that fixed by fitting the.

[Action]

The clutch pressing plates arranged on the left and right sides of the flange are connected by a thin arc-shaped connecting member attached to the outer surface of the outer ring, and interlock with each other as in the conventional case. The connecting member is formed by combining a plurality of arc-shaped plate members into a circular shape, and a separation preventing ring is fitted on the outer periphery of the plate members to prevent the plate members from separating, and prevents the pressing plate from sliding smoothly. Further, the separation prevention ring has a small axial length and does not increase the mass of the rotating portion.

〔Example〕

First, the structure of the conventional gear change device shown in FIG. 9 will be outlined. In the figure, 1 is a transmission case, which includes a drive shaft 2
And the driven shaft 3 is arranged on the extension thereof and is supported.
Both shafts 2 and 3 form a transmission shaft and are directly connected via a direct coupling clutch 4a of the clutch mechanism 4, or are connected via a reduction clutch 4b and an auxiliary shaft 6 having gear trains 5 and 5.

The direct coupling clutch 4a and the left reduction clutch 4b are configured as a normally open type in which one is engaged only when pressed by the hydraulic piston 8b, and the other is a normally closed type in which the disc spring 9 constantly engages them. At the same time, when one of them is engaged, the other is operated so that the other is released. That is, when the direct coupling clutch 4a is engaged, the deceleration clutch 4b is released, the drive shaft 2 and the driven shaft 3 are directly coupled, and the driven shaft 3 is rotated at the same speed in the same direction as the drive shaft 2. Further, when the deceleration clutch 4b is engaged, the direct coupling clutch 4a is released, the reduction shaft 6 having the reduction gear trains 5, 5 is interposed between the drive shaft 2 and the driven shaft 3, and the driven shaft 3 is A decelerated rotation in the same direction as the drive shaft 2 is provided.

Further, the clutch mechanism 4 is provided inside the outer ring 7 fixed to the drive shaft 2 via the flange 7a. That is, the pressure receiving plates 7c and 7c, which are prevented from retreating by the circlip 7b and 7b, are provided on the inner peripheral portion of the outer ring 7, and the pressing plate retreating against the pressure receiving plates 7c and 7c.
7d, 7d are provided facing each other, and a plurality of friction plates are provided between them.
7e and 7e are installed. Pressure receiving plates 7c, 7c and pressure plates 7d, 7d
Both are engaged with axial notches provided on the outer ring 7 at their outer peripheral portions, as is well known, and are movable only in the axial direction. The friction plates 7e, 7e interposed between the pressure receiving plates 7c, 7c and the pressing plates 7d, 7d are the reduction gear train 5,
5 is spline-engaged with a shaft portion protruding from the gear 5 in the axial direction or a shaft portion extending from the driven shaft 3, and the pressing plate 7d,
When 7d advances toward the pressure receiving plates 7c, 7c, it is pinched and drives them at the same speed as the outer ring 7.

The pushing plates 7d, 7d are moved back and forth by a hydraulic mechanism 8 provided on one side of the flange 7a and a plurality of leaf spring groups 9 provided on the other side. That is, the hydraulic mechanism 8 includes a cylinder 8a formed on the inner surface of the outer ring 7 and a slidable piston 8b fitted therein, and a predetermined pressure oil is supplied to the hydraulic chamber 8c on one side of the piston 8b. When the piston 8b moves to the left, the pressing plate 7d is advanced to the pressure receiving plate 7c side to engage the deceleration clutch 4b, and the direct coupling clutch 4a is pressed against the elastic force of the leaf spring group 9 via the bolt B. The plate 7d is separated from the pressure receiving plate 7c to open the direct coupling clutch 4a.

Next, the structure of the present invention will be described with reference to the first embodiment shown in FIGS. 1 to 4 and the second embodiment shown in FIGS. The same structures as those of the above-mentioned conventional device in the embodiments are designated by the same reference numerals and names, and detailed description thereof will be omitted.

In both embodiments, the pressing plates 7d, 7d of the direct coupling clutch 4a and the deceleration clutch 4b are connected by a connecting member 10 made of an arc-shaped plate material wound so as to cover the outer periphery of the outer ring 7 as follows. ing. That is, the outer peripheral surface of the outer ring 7 is wound with four divided arc-shaped connecting members 10 formed in a curved surface having substantially the same diameter as the outer diameter of the outer ring 7, and the separation preventing ring 9a is provided outside both ends thereof. The pressing plates 7d and 7d of the direct coupling clutch 4a and the deceleration clutch 4b are held by the coupling member 10 so as not to be separated from each other, and can be disassembled.

In the first embodiment shown in FIGS. 1 to 4, the separation prevention ring 9a is formed by winding a piano wire or other hard wire in a circular shape and forming locking portions 9c and 9c at both ends. , 7d
A plurality of projecting arms 7f extending radially from the outer ring 7 and the connecting member 10 to the two small holes 9b provided in the locking arms 9c,
9c is inserted and locked. The separation prevention ring 9a, which is in the shape of a truncated circle, is made smaller in diameter than the outer diameter of the outer ring 7, and its end is bent in the axial direction and inserted into the small hole 9b as shown in FIG. That is, in the through hole 10A of the connecting member 10 through which the protruding arm 7f penetrates, one surface 10a is formed at right angles to the axis and the other surface 10b is formed in a chevron shape, and the separation prevention ring 9a wound around it. Is a slope 1 formed by the other surface 10b
When the clutch mechanism 4 rotates at a high speed by generating a component force in the direction of the small hole 9b due to the elasticity of 0c and the diameter reduction tendency, the separation preventing ring 9a does not expand due to centrifugal force and the end does not come off from the small hole 9b. I am doing it.

In the second embodiment, the separation prevention ring 9a also serves as the pressure receiving plate 7c. That is, the separation prevention ring 9a is shown in FIGS.
As shown in the figure, the steel plate is press-formed into a substantially annular shape,
Four fan-shaped through holes 9d are formed and then heat-treated to cure. Then, the connecting member 10 that engages with the through hole 9d
A relatively large end face groove 10B is provided on both end faces of the above, and the remaining portions are inserted into the through holes 9d and locked to each other.
In addition to the connecting member 10, a projection 7h formed at the end of the outer ring 7 is also inserted and locked in the through hole 9d, and a circlip 9e is locked in the projection 7h for separation. The prevention ring 9a is prevented from coming off in the axial direction. Therefore, the separation prevention ring 9a, the connecting member 10, and the outer ring 7 rotate integrally, and only the connecting member 10 is attached to the outer peripheral surface of the outer ring 7 so as to be slidable in the axial direction.

Thus, the clutch mechanism 4 includes the pressing force of the hydraulic mechanism 8 acting on the pressing plate 7d of the reduction clutch 4b and the pressing plate of the direct coupling clutch 4a.
The elastic force of the leaf spring group 9 acting on 7d interacts with each other via the connecting member 10, and the two pressing plates 7d are interlocked so as to operate in opposition.

It should be noted that it is not essential to divide the connecting member 10 into four in the axial direction in the configuration of the invention, and three or five may of course be formed if a plurality of members are assembled to form a circular shape as a whole. Is. Further, although the example in which the clutch mechanism is used in the gear transmission has been shown, the invention is not limited to this, and the invention can be applied to the one used in the gear forward / reverse rotation mechanism.

〔The invention's effect〕

As described above, according to the present invention, the pressing plates 7d of the two clutches, the direct coupling clutch 4a and the reduction clutch 4b, which are coaxially arranged, are provided.
Since they are connected to each other via the connecting member 10, both clutches can be antagonized and disengaged in the same manner as the conventional bolt B. Also, the connecting member 10
However, since it is used in place of the conventional bolt B, the labor for screwing the bolt and the nut each time when assembling is eliminated, the assembly is facilitated, and the outer diameter of the rotating portion can be made smaller, It has the effect of enabling safe high-speed operation.

[Brief description of drawings]

The drawings show an embodiment of the invention. 1 to 4 show a first embodiment, FIG. 1 is a sectional view taken along the line I--I in FIG. 2, FIG. 2 is a front view of an essential part, and FIG. 3 is a ring which is an essential part.
9b is a front view (a) and a side view (b), and FIG. 4 is a front view (a) and a side view (b) of the auxiliary cylinder member 11 which is also a main part. 5 to 8 show the second embodiment,
FIG. 5 is a front view of the main part corresponding to FIG. 2, and FIG. 6 is its arrow view.
FIG. VI is a sectional view taken along line VII-VII of FIG. 7, and FIG. 8 is a front view (a) and a side view (b) corresponding to FIG. FIG. 9 is a sectional view showing a conventional actuating device. 1 ... transmission case, 2 ... drive shaft, 3 ... driven shaft, 4 ...
… Clutch mechanism, 4a …… Direct coupling clutch, 4b …… Deceleration clutch, 5 …… Gear train, 6 …… Auxiliary shaft, 7 …… Outer ring, 7a…
… Flange, 7b …… Circlip, 7c …… Pressure plate, 7d…
… Pressing plate, 7e …… Multiple friction plates, 7f …… Multiple protruding arms, 7h
...... Projection, 8 ... Hydraulic mechanism, 8a ... Cylinder, 8b ... Piston, 8c ... Hydraulic chamber, 9 ... Leaf spring group, 9a ... Separation prevention ring, 9b ... Two small holes, 9c ... Locking part, 9d ... Through hole, 9e ... Circlip, 10 ... Connecting member, 10A ... Through hole, 10B ... End face groove, 10a ... One surface, 10b ... Other surface , 1
0c ... slope, B ... bolt,

Claims (1)

[Claims] 1. An outer ring of a clutch is fixedly mounted on a transmission shaft via a flange, a pressure receiving plate is provided inside the outer ring, and a pressing plate is provided between the flange and the pressure receiving plate to move back and forth toward the pressure receiving plate. , Two friction clutches in which a friction plate is interposed between the pressure receiving plate and the pressing plate are arranged on both sides of the flange, and one of the friction clutches is a normally open type in which a piston engages the other. Is always closed by a spring, and a plurality of connecting members are arranged on the outer surface of the outer ring, while a plurality of projecting arms projecting outward from the outer periphery of the pressing plates of both friction clutches through the outer ring. A gear train switching actuating device provided with the projecting arms and the connecting member which are immovably engaged with each other in the axial direction, and a separation preventing ring fitted and fixed to the outer periphery of the connecting member.