JPH0444922Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Field of Application] The present invention relates to a differential mechanism which is primarily mounted on agricultural tractors such as lawn tractors and has a differential case configured as a split case.

[Conventional technology]

Conventionally, in this type of differential mechanism, the differential case is configured into two split case members, left and right, each formed in a different shape, and all the pinion gears and side gears are housed in one case member. A radially protruding flange portion is formed on one side of the case member, a mounting seat for the input rotating body is formed on the flange portion formed on the other case member, and the flange portion is connected to the input rotating body as a joint surface. They were connected by a member, and each axle extended from both differential case members.
Publication No. 76744).

[The problem that the idea attempts to solve]

However, in this case, a mold with a different shape is required for each of the two split case members, which increases the amount of equipment required for manufacturing, leading to a rise in equipment costs and increasing the number of parts that must be manufactured. As a result, production efficiency decreased.

Furthermore, although a flange is formed on the other case and the input rotating body is attached to the flange, the input rotating body is attached at a position offset from the left-right center of the differential case. Moreover, each case member bears a different share of the load applied to the input rotating body, and a large biased force and twisting force are applied to the other case member.

Therefore, it is necessary to improve the strength of the other case, and since the axle is tilted, it is necessary to devise a pivot structure for the axle with respect to the case.

The purpose of this invention is to reduce manufacturing equipment costs and reduce production efficiency by devising the shape of each of the two split case members. The object of the present invention is to provide a vehicle that can appropriately distribute the load and avoid inconveniences such as tilting of the axle with a simple structure.

[Means to solve the problem]

The characteristic structure according to the present invention is that two differential case members of the same shape, each having a convex part and a concave part, are arranged point-symmetrically to each other with respect to the center of the joint surface on which the flange part extending in the radial direction is formed. With the joint surfaces facing each other, and so that the convex portion and the concave portion fit into the concave portion and the convex portion of the mating mold, respectively,
One differential case member is integrally attached and connected by a connecting member with the installation phase shifted by a certain angle, and an axle is provided protruding from each of the two differential case members, and the input rotating body is attached to the outer surface of the flange of the other differential case member. The input rotating body is fitted onto the mounting seat and is integrally connected to the flange portion of the differential case via the mounting connection member, and its functions and effects are as follows. be.

[Effect]

That is, by making the split case members of the same shape, only one mold is required. Then,
Compared to conventional configurations, the number of equipment and parts can be reduced.

Furthermore, since the joint surfaces of the case members are each provided with a convex portion and a concave portion, both case members can be integrally connected with the convex portions and concave portions fitting into the concave portions and convex portions of the other side. Therefore, the protrusion and the recess can be used as a positioning mechanism, there is no need for commonly used dowel pins, etc., and the protrusion and the recess can be integrally molded with the case member, reducing the number of parts. Production efficiency can be improved through reduction.

Furthermore, since the convex part and the concave part are provided in point-symmetrical positions with respect to the center of the joint surface, simply by shifting the mounting phase of one case member to the other case member, the convex part and the concave part can be separated. Since the mating position can be taken (for example, if the convex part and the concave part are formed in 180° symmetrical positions, it is only necessary to invert one case member by 180° with respect to the other case member), so assembly is easy and , it is possible to effectively utilize the fact that both case members have the same shape and the uneven portions are integrally formed.

By forming a flange part on the joint surface of both case members, this flange part can function as a reinforcing member for the case member, and since both case members have a symmetrical structure, the flange part can be used as a reinforcing member for the differential case. Since it is located at the center of the left and right sides, the load acting on the input rotating body is distributed almost equally to both case members, reducing the degree of torsional stress acting on the differential case itself, and reducing the inclination of the axle, etc. This can be suppressed by a simple shaft support structure (such as a bearing with a small load capacity) for the case member of the axle.

Moreover, the attachment connecting member used to connect the case members can also be used as the attachment member for attaching the input rotating body.

[Effect of idea]

As a result, by making both case members the same shape and providing uneven parts and mounting seats thereon, the number of molding molds and parts can be reduced, resulting in a reduction in manufacturing equipment. It was also possible to improve production efficiency and reduce manufacturing costs.

By making both case members the same shape, the mounting position of the input rotating body can be set at an appropriate position for the differential case, and as the torsional stress increases, the case member becomes stronger and the axle support structure becomes larger. It never invites.

〔Example〕

As shown in FIG. 8, an engine 2 and a fuel tank 3 are provided in the front gas bonnet 1, and a control section 7 with a control handle 4, a driver's seat 5, and a flat deck 6 on the left and right sides is formed at the rear. The machine body is supported by the front and rear wheels 8 and 9 so that it can move while mowing, and a mower 1 is installed at an intermediate position between the front and rear wheels 8 and 9.
0, a grass collection duct 11 and a grass collector 12 located between the left and right rear wheels 9, 9 and extending rearward from the mower 10, and a lawn tractor is constructed.

To explain the transmission mechanism in detail, output pulleys 14 and 15 are fitted in two stages, upper and lower, to the downward output shaft 13 of the engine 2, and the lower output pulley 15 and the mower 1
A working device transmission mechanism is constructed by connecting an input pulley 16 fitted to the zero input shaft with a belt 17.
On the other hand, an input pulley 20 of a transmission case 19 is connected to belts 21 and 22 via a continuously variable belt transmission 18 to the upper output pulley 14, and rear wheels 9 and 9 pivotally supported on the lower end of the transmission case 19 are connected to the upper output pulley 14. A traveling transmission system is configured to be drivable.

As shown in FIGS. 4 and 5, the continuously variable transmission 18 is explained in detail. The continuously variable transmission 18 is supported by a flat plate base 23 which is pivotally supported on the fuselage frame so as to be swingable about the vertical axis P. A movable boss 24 is supported, and a tension pulley 25 is attached to this boss 24.
arm 26 and main clutch pedal 27
A swing arm 28, which is interlocked with the swing arm 28, is integrally fixed. On the lower surface side of this flat plate base 23, there is an upper output pulley 14 provided on the engine output side 13, an upper pulley part 29A to which the belt 21 is transmitted, an input pulley 16 on the transmission case side, and a lower pulley part 29B to which the belt 22 is transmitted. A relay pulley 29 having
and is provided. A Soroban spherical member 29C, which is a common part to the upper and lower pulley parts 29A and 29B, is pivotally supported on the relay pulley 29 so as to be slidable in the axial direction of the pivot shaft 29a. Engine output is applied to the tension pulley 25 on the belt 21 stretched between the pulley 14 and the upper pool portion 29A, and the belt 21 is applied to the biasing force of the biasing spring 30 in the direction of action by depressing the main clutch pedal 27. The main clutch mechanism 31 is configured such that the action on the main clutch mechanism 31 is released. The extended end of the flat plate base 23 and the main clutch pedal 27 are connected to a variable speed pedal 32 installed in parallel with the main clutch pedal 27 by a linking mechanism (not shown), and by depressing the pedal 32, the constant speed state shown in FIG. 6 is achieved. By swinging the flat plate base 23 against the urging force of the spring 33, the belt 21 is moved to the large diameter side of the upper pulley portion 29A, and the belt 22 is moved to the small diameter side of the lower pulley portion 29B. As the belt moves, the member 29C also moves upward and enters a deceleration state.

The mission case 19 will be explained in detail. An input shaft 34 with an input pulley 20 fitted thereon is supported in a protruding manner on the upper surface of the transmission case 19.
A second transmission shaft 37, an intermediate shaft 38, and a rear wheel shaft 39 are arranged on the lower side of the first transmission shaft 36. First transmission shaft 37, intermediate shaft 38, rear wheel shaft 3
9 is placed. A drive sprocket 40 integrally formed with the shaft and a large and small two-stage gear 41 are spline-fitted to the first transmission shaft 36, and a second
A large and small two-stage gear 42, which is slidable in the axial direction and also serves as a clutch sleeve, is spline-fitted to the transmission shaft 37, and a passive sprocket 43 is loosely fitted thereto, and a drive sprocket 44 is spline-fitted thereto.
By sliding the large and small two-stage gear 42 in conjunction with the switching operation of the speed change lever 45 and switching the engagement with the large and small two-stage gear 41, a forward high speed F ₂ , a neutral position N, a forward low speed F ₁ , a neutral position N, It is possible to switch to the reverse position R, and when traveling in reverse, an engagement pin 46 protruding from the large and small two-stage gear 42 toward the passive sprocket 43 and engagement holes 43a provided at multiple locations in the circumferential direction of the passive sprocket 43. Reverse transmission is possible by fitting and engaging the two. The engagement hole 43a is formed into a long hole elongated in the circumferential direction, and is designed to smoothly engage with the pin 46.
The output shifted by the above configuration is transmitted to a large diameter passive sprocket 47 which is integrally formed with the drive sprocket 44 and the intermediate shaft 38, and which is integrally fitted into a small diameter drive sprocket 48 which is integrally formed with the intermediate shaft 38 and a differential case 49. The power is transmitted to the rear wheel shaft 39 through a chain 51 that is connected to an input sprocket 50, which is one of the input rotating bodies.

As shown in FIGS. 3 and 4, the second power transmission shaft 3
A brake device 52 is provided at one end of the brake lever 7, and a brake operating arm 53 is connected to the main clutch pedal 2 via a relay ring 54 and a release wire 55.
7, and an elongated hole 54a is provided at the attachment site between the relay ring 54 and the wire 55 attachment fitting 55a, so that when the main clutch is further depressed after actuation, the brake device 52 will continue to actuate.

protruding from both ends of the mission case 19,
A pair of left and right axles 39a, 39b of a rear wheel axle 39 with rear wheels 9, 9 fitted and held on the protruding ends are held within the differential case 49, with one axle 39a fitted and held within the thickness of the other so as to be relatively rotatable. There is a differential case 4
Four bevel gears 56 having the same specifications are rotatably held within the gear 9. Its holding form is differential case 4
9 Insertion part 4 that holds each bevel gear 56 on the inner surface
9a is provided, and each bevel gear 5 is provided in this fitting portion 49a.
6 is held in metal contact state and is lubricated by oil supply from an oil hole 49b communicating with the inner space of the case 49.

The differential case 49 is divided into two parts,
The left and right differential case members 49A, 49A are made of the same shape, and one differential case member 49
The joint configuration is made with A reversed by 180°. That is, for two of the four mounting holes 49d formed in the joint surface 49c of the differential case member 49A, which are located at 180° symmetrical positions, the convex portion 57 and the concave portion 58 are respectively attached.
and is set in a shape that allows them to be fitted and engaged. For one differential case member 49A in which such concave and convex portions 57 and 58 are formed one by one,
With the other differential case member 49A reversed by 180°, the convex portion 57 is made to correspond to the concave portion 58, and the concave portion 58 is made to correspond to the convex portion 57, and the two are integrally assembled using the positioning action of both 57 and 58. It is configured to be connected with a bolt 59. A mounting seat 49e having a rectangular cross section that can fit and hold a sprocket 50 as an input rotating body is provided on the outside of the joint surface 49c, and the input sprocket 50, which is integrally fitted and held on the mounting seat 49e, is attached to the differential case members 49A, 49A.
They are configured to be connected and fixed to the differential case 49 using bolts 59 that connect them.

Bevel gear 5 fitted and held in differential case 49
Of the 6 sprockets, two symmetrically positioned splines are externally fitted onto the axles 39a and 39b, respectively, so that the input from the input sprocket 50 is transmitted to the rear wheels.

The differential case 49 is a left and right differential case member 49.
A and 49A are configured with the same specifications, and
Fitting holding portion 49a of bevel gear 56 and uneven portion 5
7, 58 and input sprocket mounting seat 49
e is integrally molded with a mold, which is advantageous in terms of manufacturing costs.

[Another embodiment] A plurality of uneven portions 57 and 58 may be provided,
One case member 49A corresponds to the number of pieces.
All you have to do is set the inversion angle of .

The input rotating body 50 may be a gear.

[Brief explanation of the drawing]

The drawings show an embodiment of the differential mechanism according to the present invention,
Figure 1 is an exploded vertical side view of the differential case, Figure 2 is an assembled side view of the differential mechanism, Figure 3 is a vertical side view of the transmission case, Figure 4 is a side view showing the main clutch mechanism, and Figure 5 is a side view of the transmission case. Fig. 6 is a plan view showing the main clutch mechanism, Fig. 6 is a longitudinal sectional view showing the continuously variable transmission mechanism, Fig. 7
The figure is a longitudinal side view of the transmission case, and FIG. 8 is a side view of the lawn tractor. 39a, 39b...Axle, 49...Differential case, 49A...Case member, 49c...Joint surface,
49e...Mounting seat, 50...Input rotating body, 5
7... Convex portion, 58... Concave portion, 59... Connection member.

Claims (1)

[Scope of utility model registration request] At positions point symmetrical to each other with respect to the center of the joint surface 49c forming a flange portion extending in the radial direction,
Two differential case members 49A, 49A having the same shape each having a convex portion 57 and a concave portion 58 are placed in a state in which the joint surfaces 49c are facing each other, and the convex portion 57 and the concave portion 58 are on the other side. One differential case member 49A is integrally connected by an attachment connecting member 59 with the attachment phase of one differential case member 49A shifted by a certain angle so as to fit into the concave portion 58 and the convex portion 57, respectively, and the two differential case members 49c, 49c are
axles 39a and 39b are respectively provided protrudingly, and a mounting seat 49e for the input rotating body 50 is formed on the outer surface of the flange portion of one differential case member 49A;
The differential mechanism is integrally connected to the flange portion of the differential case 49 via the attachment connecting member 59 with the input rotating body 50 fitted onto the attachment seat 49e.