JPH11229888A - Support structure for intermediate gears in gear train - Google Patents

Abstract

(57) [Summary] [Problem] To increase the support rigidity of a support shaft of an intermediate gear,
Supporting the force acting on the intermediate gear of the first gear train transmitting the rotational force from the crankshaft to the first drive shaft, and supporting the intermediate gear of the second gear train transmitting the rotational force from the crankshaft to the second drive shaft The present invention provides a support structure for an intermediate gear in a gear train in which the shaft can be shared and deformation of the support shaft of the intermediate gear can be suppressed, and thus damage to the bearing portion is small and gear noise is small. Each intermediate gear is rotatably supported on a respective support shaft fixed to a main body of the internal combustion engine, and is further separated from and independent of a cover of a gear case for accommodating the gear train. And a connecting support plate that connects the distal end side of the support shaft that supports the intermediate gear of the second gear train and the distal end side of the support shaft that supports the intermediate gear of the second gear train.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a support structure for an intermediate gear (idle gear) in a gear train for transmitting a torque of a crankshaft disposed on a rear surface or a front surface of an internal combustion engine to a drive shaft. . More specifically, in an internal combustion engine having a PTO shaft (output take-out shaft) for taking out a part of the output of the internal combustion engine for use with an external device, this P
A first gear train for driving the TO shaft (first drive shaft);
A second gear train for driving a second drive shaft for an internal combustion engine such as a valve train mechanism, and a device for supporting an intermediate gear in the gear train when each gear train has an intermediate gear. It is.

[0002]

2. Description of the Related Art The internal combustion engine of a work vehicle is shown in FIGS.
As shown in FIG. 1, a PTO shaft (output extraction shaft) 15 for driving a working device, for example, an oil pump for driving a mixer of a mixer truck, etc., is provided. An output gear 16 is provided on the PTO shaft 15,
A gear train (hereinafter, referred to as a first gear train) including a plurality of intermediate gears (idle gears) 12 and 14 is provided between a crankshaft 21 having a crank gear 22. This gear train is generally provided on the rear side or the front side of the internal combustion engine.

[0003] Further, the internal combustion engine drives a device such as a fuel injection pump, an intake / exhaust valve, an air compressor, an oil pump, etc. for the internal combustion engine itself. A gear train having an intermediate gear (hereinafter referred to as a second gear)
Gear train). This second gear train is usually provided on the same side as the first gear train. This second gear train is, for example, as shown in FIG.
A crank gear 22 is fixed to a crankshaft 21 below 10, a cam gear 26 is fixed to an upper camshaft 25, and a third intermediate gear rotatably supported by a third support shaft 23 between these gears. 24 are provided. By the second gear train, the rotational force of the crankshaft 21 is transmitted to the camshaft 25 via the crank gear 22, the intermediate gear 24, and the cam gear 26. Although not shown, the rotational force of the crankshaft 21 is transmitted to the fuel injection pump gear, the air compressor gear, and the like via the third intermediate gear 24 and other intermediate gears not shown.

Generally, as shown in FIG. 7A, a support shaft (idle gear spindle) 2 of an intermediate gear of these gear trains is provided with a bolt 2a in a positioning hole 3 provided in a cylinder block 10 of the internal combustion engine. The intermediate gear 5 is rotatably supported around the non-rotating support shaft 2 via a bearing 2b or the like.

Since the support shaft 2 receives the force applied to the intermediate gear 5, the intermediate gear 5
When an external force F acts on the support shaft 2, since the support shaft 2 is fixedly supported at one end, a bending moment M for deforming acts as shown in FIG. 7B. That is, the force F applied to the intermediate gear 2 is opposed by the bending rigidity of the support shaft 2 (including the bolt 2a).

However, in recent years, the performance of the internal combustion engine has been improved, the output to the PTO shaft has been increased, and the rotational force transmitted to the accessories of the internal combustion engine has been increased. The load applied to gears is increasing.
Therefore, the amount of bending deformation of the support shaft increases with the increase in the load applied to the gear, and damage to the bearing of the bearing portion that supports the gear and partial contact of the tooth surface caused by a slight inclination of the shaft are caused. There has been a problem that the meshing noise of the gear, which is the cause, increases.

In order to solve these problems, there is a method of increasing the diameter of a support shaft for supporting the intermediate gear and increasing the rigidity to cope with an increase in the force applied to the support shaft. However, there is a problem that the weight and size of the internal combustion engine become large, which leads to an increase in the weight of the internal combustion engine and an increase in manufacturing cost. As shown in FIG. 8, the support shafts 11, 13 of the intermediate gears 12, 14 are provided.
Are supported not only on the cylinder block 10 side but also on the gear case cover 51 side, and the support shafts 11 and 13
There is also a method to prevent bending deformation of this, but in this method, in order to center the intermediate gears 12 and 14, the positions of the bearing holes on the cover 51 side correspond exactly to the fixing holes on the cylinder block 10 side. And high precision processing technology is required. For this reason, there is a problem that capital investment is required for high precision processing equipment and the like, which leads to an increase in manufacturing cost.

In the structure in which the support shafts 11 and 13 are held by the gear case cover 51, the vibration of the intermediate gears 12 and 14 is transmitted through the support shafts 11 and 13 to cover the gear case.
Since this is transmitted to the 51 side, there is a problem that the cover 51 becomes a new noise source and engine noise increases. In particular, the gears 12, 14 of the first gear train for driving the PTO shaft 15
Since the driving force is transmitted twice or more to the gears 24 and 26 of the second gear train for driving auxiliary equipment such as cams and pumps, the intermediate gears of the first gear train 12, 14 support shafts
A large force in the bending direction acts on 11 and 13.

[0009] The magnitude of this force depends on the driving situation,
For example, the acting force on the camshaft 25 is 20 kg.
f (196 N), while the acting force on the PTO shaft 15 is 40 kg. f (392N). In particular, in the case of a diesel engine, since the torque fluctuation is large, the thrust vibration increases with the rotation fluctuation of the crankshaft, the external force F increases, and the engine noise increases.

For this reason, one of the inventors of the present invention disclosed in Japanese Utility Model Publication No. 58-51380, a plurality of intermediate gears 12 of the first gear train on the PTO shaft 15 side with the support plate 30 as shown in FIG. , 14 are connected and supported, and both ends of the support shafts 11 and 13 are supported to increase rigidity.
As shown in FIG. 5, a support device for an intermediate gear in which the support plate 30 is provided separately from the cover 50 of the gear case to prevent the propagation of vibration to the cover 50 of the gear case is proposed.

[0011]

However, in this intermediate gear supporting device, when the number of intermediate gears is plural, for example, two, as shown in FIG.
Since the crankshaft 21 receives a reaction force from the output gear 16 of the PTO shaft 15 when the 15 is driven, the forces T1 and T2 act on the support shafts 11 and 13 of the intermediate gears 12 and 14, respectively. Therefore, a rotational moment M1 (= T1 × AB) generated by the couple of T1 and T2 acts on the support plate 30.

Therefore, the distal ends of the two intermediate gears 12 and 14 of the same first gear train opposite to the cylinder block 10 of the support shafts 11 and 13 are connected to the support plate 30 by press fitting (press fitting). However, since the support plate 30 itself is rotationally displaced by the rotational moment M1, the ends of the support shafts 11, 13 cannot be completely fixed, and the support shafts 11, 13 are inclined. . The rotation moment M1 is generated when the number of support shafts of the intermediate gear connected by the support plate 30 is even.

When the number of intermediate gears is odd, for example, three, as shown in FIG. 10, the reaction forces U1, U2, U3 act on the support plate 31 via the support shafts 61, 63, 65. In addition, since this reaction becomes U1 + U3> U2,
The support plate 31 has a combined force U = U1 + U3-U in the directions of U1 and U3.
Then, it is displaced in response to 2. The generation of a force in this direction occurs when the number of support shafts of the intermediate gear connected by the support plate 31 is an odd number.

As described above, the intermediate gear 12 of the first gear train,
In the support plate 30 or 31 that only supports and supports the support shafts 11, 13 or 61, 63, 65 of 14 or 62, 64, 66, the reaction forces T1, T2, U
1, U2 and U3 displace due to the rotational moment M1 and the resultant force U, so that the support plate side 30 or 31 of the support shaft 11 of the intermediate gear 12... Becomes insufficient and the support shaft 11. It was found that it was not possible to completely prevent the inclination of.

The amount of rotational displacement and the amount of displacement are represented by P
Since it changes according to the reaction force received from the TO shaft 15, the support plate 30 vibrates with the fluctuation of the rotation force of the PTO shaft 15 and the rotation force of the crankshaft 21 that generate these reaction forces.
Alternatively, there is a problem that 31 itself causes noise. In other words, the intermediate gear (idle gear) of the first gear train having a large driving force receives a large load and vibration due to the forces on the crankshaft side and the PTO shaft side, so that the supporting rigidity of the intermediate gear is secured. Was a problem.

The present invention has been made in order to solve these problems, and an object of the present invention is to provide a first gear train for transmitting a rotational force from a crankshaft to a first drive shaft, and a second gear train.
A second gear train having a second gear train for transmitting a rotational force from a crankshaft to the drive shaft is provided. The support rigidity of the support shaft of the intermediate gear in the gear train is increased, and the force acting on the intermediate gear of the first gear train is increased by the second gear train.
The support shaft of the intermediate gear of the gear train can bear the load, and the deformation of the support shaft of the intermediate gear can be suppressed. Therefore, the damage of the bearing portion is small, and the support of the intermediate gear in the gear train with less gear noise is also possible. It is to provide a structure.

[0017]

According to a first aspect of the present invention, there is provided an intermediate gear supporting apparatus for transmitting a rotational force from a crankshaft of an internal combustion engine to a first drive shaft. A first gear train and a second gear train having an intermediate gear that transmits to the second drive shaft, and each of the intermediate gears is rotatably supported on each support shaft fixed to the main body of the internal combustion engine. And further, independently of a cover of a gear case accommodating the gear train, a tip end side of at least one support shaft of a support shaft supporting an intermediate gear of the first gear train and a second gear train. It is characterized in that a connecting support plate is provided that connects the front end side of at least one support shaft of the support shaft that supports the intermediate gear.

With this configuration, the support shaft of the intermediate gear of the first gear train of the first drive shaft such as the PTO shaft that receives a relatively large rotational load can be rotated only by a significantly lower rotational load than the first drive shaft. No support, that is, the cam drive with less vibration, the auxiliary shaft is fixedly supported via the connecting support plate by the support shaft of the intermediate gear of the second gear train of the second drive shaft for driving the auxiliary equipment, so the rigidity of the support shaft is increased, The inclination of the gears is prevented, and the vibration, noise, and wear of the bearings due to the gear train are reduced.

Further, the first gear train has two or more intermediate gears, and the connection supporting plate supports at least two first and second intermediate gears of the first gear train, respectively. , The front end side of the second support shaft and the front end side of the third support shaft that supports at least one third intermediate gear of the second gear train are connected. With this configuration, the two support shafts of the intermediate gear of the first gear train of the first drive shaft, such as a PTO shaft, which receives a relatively large rotational load, are combined with the support shaft of the intermediate gear of the second gear train having less vibration. Since the connection support plate is fixedly supported by the point support, the displacement and vibration of the connection support plate are significantly reduced, and the displacement of the tip side of each support shaft is also reduced, so that the inclination of the intermediate gear is prevented, and the vibration by the gear train, Noise and wear of the bearing portion are significantly reduced.

Further, a second distance between the meshing point and the third support shaft is larger than a first distance between a meshing point of the first intermediate gear and the second intermediate gear and the first support shaft. The distance is formed large. With this configuration, the second distance, which is a moment lever opposing the rotational moment, is greater than the first distance, which is a moment lever for the rotational moment about the meshing point generated between the first intermediate gear and the second intermediate gear. The force of the third support shaft against this rotational moment is smaller than the force acting on the first and second support shafts, and the displacement and swing of the connection support plate are easily suppressed.

The two first gear trains of the first gear train
First and second fitting portions are provided only on the support shaft and the second support shaft, respectively, and third and fourth fitting portions that respectively fit into the first and second fitting portions are connected to the connection support. The first support shaft and the second support shaft are provided on a plate and pressed and fixed to the connection support plate. The first and second fitting portions are formed, for example, in a concave shape, and the third and fourth fitting portions are formed in a convex shape, and these are fixed by press fitting, that is, press fitting. This allows
Since the first and second support shafts that exert a large force are firmly fixed to the connecting support plate without any gap, it is possible to suppress the occurrence of relative displacement between the support shafts on the side where the vibration is large.

In addition, since the third support shaft on which the force acting from the connecting support plate is small is not pressed, but a bolt is inserted into the loose hole and fixed by bolting, the three support shafts are fixed by pressing. In comparison, only a portion requiring high-precision positioning is located between two points, so that a high-precision processing technique is not required. In other words, there is a very advanced position accuracy technology to keep the distance between three points of three holes with high precision, but it is relatively easy to keep only the distance between two points of two holes with high precision. Therefore, in consideration of manufacturing difficulty, the fixing between the first and second support shafts having a large acting force is more firmly performed.

Further, the connection support plate is fixedly supported on the main body side of the internal combustion engine, that is, the connection support plate is directly fixed to the cylinder block by bolting or the like, so that the connection support plate is more effectively connected. Displacement and vibration on the tip side of the support plate and the support shaft are reduced.

[0024]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, an embodiment of a support structure for an intermediate gear in a gear train according to the present invention will be described with reference to FIGS. The internal combustion engine of work vehicles such as mixer trucks, aerial work vehicles, and UNIC vehicles is equipped with a cylinder block 10
A PTO shaft (output take-out shaft) 15 for taking out a part of the output of the internal combustion engine to drive a working device, for example, an oil pump for driving a mixer of a mixer truck, is provided on the rear side or the front side. A crank gear of a crankshaft 21 for outputting a driving force of an internal combustion engine to drive a PTO shaft 15 which is a first drive shaft having the output gear 16
Between the first and second intermediate gears (idle gears) 12, 14
And a first gear train including a plurality of intermediate gears.

In the embodiment shown in FIGS. 1 to 4, a cam gear 26 for driving the cam shaft 25, a third intermediate gear 24, and a crank gear 22 are provided as a second gear train. The torque of the crankshaft 21 is transmitted to the camshaft 25 by the second gear train. The rotational force of the crankshaft 21 is transmitted through the third intermediate gear 24 and other intermediate gears (not shown).
It is configured to be transmitted to a fuel injection pump gear, an air compressor gear, and the like (not shown).

The first, second, and third intermediate gears 12, 14, and 24 include first, second, and third intermediate gears as shown in FIG.
It is rotatably supported around support shafts (spindles) 11, 13, and 23 through bearings 11b, 13b, and 23b. Also, these support shafts 11, 13, and 23 are bolts 11a,
Cylinder block 13a, 23a on the main body side of the internal combustion engine
Fixed to 10.

Then, as shown in FIG. 2, a connecting support plate (type plate) 40 is provided separately and independently from a cover 50 of a gear case for housing a gear train. With this connection support plate,
As shown in the first embodiment of FIG. 1, the front end sides of support shafts 11, 13 supporting first and second intermediate gears 12, 14 of a first gear train and a third intermediate gear of a second gear train. The support shaft 23 and the distal end side of the support shaft 23 are connected and fixed. The front ends of the support shafts 11, 13, and 23 are opposite to the cylinder block 10 side.

That is, the intermediate gear 12 of the first gear train is separated and independent of the cover 50 of the gear case that houses the gear train.
A connecting support plate 40 for connecting and supporting the support shafts 11, (13) of (14) and the support shaft 23 of the intermediate gear 24 of the second gear train is provided. Support shaft 11, (13)
Is supported by the support shaft 23 of the intermediate gear 24 of another second gear train having a small acting force.

In other words, the one-side fixed state of each of the support shafts 11, (13), and 23 is fixedly supported at both ends by the connecting support plate 40, so that the rigidity of each of the support shafts 11, (13), and 23 is enhanced. The force acting on the intermediate gears 12, (14), 24 is received by the connection support plate,
It is configured such that the combined force of the acting forces can be shared and supported by the support shafts 11, (13), and 23. The connecting support plate 40 shown in FIG.
Then, the support shaft 1 of the intermediate gears 12 and 14 of the first gear train to be supported
Although the number of 1 and 13 has been described as two, if there is only one intermediate gear, one support shaft may be used. May be selected. When there are a large number of intermediate gears, they may be selected from all or all of them, and the number of support shafts of the first gear train may be three or more. May be two or more.

With this configuration, the intermediate drive gears 12 and (14) of the first gear train of the first drive shaft 15, such as a PTO shaft, which are subjected to a relatively large rotational load, are supported by the first drive shafts 11 and (13). Axis 15
The second drive shaft 25 for the cam drive and the auxiliary machine drive with less vibration.
Since the support shaft 23 of the intermediate gear 24 of the gear train is fixedly supported via the connection support plate 40, the force applied to the support shafts 11, (13), and 23 can be dispersed, and the respective support shafts 11, (13), and 23 Since both ends are supported, rigidity is increased, inclination deformation of the shaft can be prevented, and vibration, noise, and bearings 11b, (13
b), the wear of 23b can be reduced.

The first and second drive shafts 15, 25
Since the support shafts of the first gear train and the second gear train having different directions and magnitudes of the reaction force received from them are connected by the connecting support plate 40, the forces acting on the support shafts 11, (13) and 23 are once combined. Then, since the resultant rotational moment and the resultant force are shared and supported by the respective support shafts, it is possible to prevent the support shaft of the first gear train from being largely deformed. Further, since some of the forces acting on each of the support shafts 11, (13), and 23 cancel each other out, the support can be performed efficiently.

Further, the support shafts 11, 13 of the two intermediate gears 12, 14 of the first gear train of the first drive shaft 15 are connected and supported by the support shaft 23 of the intermediate gear 24 of the second gear train having less vibration. When the plate 40 is fixedly supported, the connection support plate 40 is fixed at three points, so that the connection support plate 40 can be fixed stably and firmly, so that the displacement and vibration of the connection support plate 40 can be significantly reduced. Board 40
Noise due to noise.

At the same time, the displacement on the tip side of each of the support shafts 11, 13, and 23 can be reduced by fixing at three points, so that the support shafts 11, 13, and 23 and the intermediate gears 12, 14, and 24 are inclined. Vibration, noise and bearings 11
Wear of b, 13b and 23b can be significantly reduced.
Furthermore, the first distance PA between the mesh point P of the first intermediate gear 12 and the second intermediate gear 14 to the first support shaft 11 is larger than the second distance PA between the mesh point P and the third support shaft 23. The distance PC is formed to be large.

With this configuration, the intermediate gear 1 of the first gear train
The force T3 of the third support shaft 23 for countering the rotational moment M1 as shown in FIG. 1, which occurs when there are a plurality of, for example, two, 14, can be reduced. That is, when the crankshaft 21 is driven, it receives the reaction force from the output gear 16 of the PTO output shaft 15 and the support shafts 11 and 13 of the intermediate gears 12 and 14.
Respectively, the couple of T1 and T2 (= T1) acts to generate a rotational moment M1 (= T1 × AB).
The second distance PC, which is a moment lever opposing the rotational moment M1, is formed to be larger than the first distance PA, which is a moment lever for the rotational moment M1 around the meshing point P between the intermediate gear 12 and the second intermediate gear 14. I do.

Thus, the force T3 of the third support shaft 23 against the rotational moment M1 is T3 = T1 × AB / PC (usually, PA = PB, so that T3 = 2 × T1 × P
A / PC) can be made smaller than the acting forces T1 and T2, so that the displacement and swing of the connecting support plate 40 can be more easily suppressed. As a second embodiment, as shown in FIGS. 2 and 3, only two first support shafts 11 and second support shafts 13 are provided with concave first and second fitting portions 11c and 13c.
c, and the first and second fitting portions 11
c, 13c, the third and fourth fitting portions having a convex shape, respectively.
The connection support plate 41 is provided with 41a and 41b, and the first support shaft 11 and the second support shaft 13 are pressed and fixed to the connection support plate 41, that is, press-fitted. Also, bolts 11a, 13a are provided on the cylinder block 10 side.
And tighten with bolts.

The third support shaft 23, which has a small acting force, is not press-fitted, but the bolt 23a is inserted into the loose hole and fixed by bolting, whereby the first acting force and vibration are large. Since the second support shafts 11 and 13 can be firmly fixed to the connection support plate 41 without any gap, the occurrence of relative displacement between the two support shafts 11 and 13 can be suppressed.

When the three support shafts 11, 13, and 23 are fixed by pressing, the distances AB, AC,
Since it is difficult to maintain the CB with high precision, a very advanced processing technique is required. In contrast, in the third embodiment, only the two support shafts 11 and 13 are fixed by pressing. Only the distance AB between the two points of the two holes 11c and 13c needs to be maintained with high accuracy, and it is not necessary to use advanced processing technology.

Then, as a third embodiment,
As shown in FIG. 4, a connection support plate 42 is fixedly supported by bolts 70 on the body (cylinder block) 10 side of the internal combustion engine. In other words, by directly fixing the connection support plate 42 to the cylinder block 10 with a bolt 70 or the like, the support shafts 11, 13,
The support shaft of the intermediate gears 12, 14, and 24 supported by the continuous support plate 42 and the connection support plate 42 more effectively by increasing the rigidity of the
Displacement and vibration on the tip side of 11, 13, and 23 can be reduced.

[0039]

According to the support structure of the intermediate gear of the gear train of the present invention, the following effects can be obtained. First, a second supporting plate, which receives a relatively small force, receives a connection supporting plate that supports a supporting shaft of an intermediate gear of a first gear train such as a PTO shaft on which a large force acts to output a large driving force. Since it was connected to the third support shaft of the intermediate gear in the gear train,
The force acting on the support shaft of the first gear train can be shared by the support shaft of the second gear train via the connection support plate.

Therefore, each support shaft is supported at both ends by the connecting support plate to increase the rigidity of each support shaft and reduce the displacement and vibration of the connecting support plate itself, and particularly to the deformation of the support shaft of the first gear train. In addition, displacement and vibration can be reduced, and damage to bearings of each intermediate gear and gear noise can be reduced. And
Since this connection support plate is provided separately and independently from the cover of the gear case, without vibrating the cover,
Since the noise generated from the connecting support plate can be reduced by the cover, the noise of the internal combustion engine can be further reduced.

Second, the first moment lever which is the first distance between the first intermediate gear and the second intermediate gear, which is the first distance between the first intermediate gear and the first intermediate gear, makes the engagement point, the third support shaft and The second moment lever, which is a second distance between the first and second intermediate gears, is made large so that the force acting on the third support shaft by the rotational moment due to the couple force generated in the first and second intermediate gears is increased. The force acting on the shaft can be made smaller, and the swinging of the connecting support plate in the rotational moment direction can be suppressed with this small supporting force.

Third, the first and second support shafts, which have large acting forces and are easily deformed, are mounted on the connecting support plate by press fitting, and are mounted on the cylinder block side by bolting. It is necessary to increase the support rigidity by eliminating the relative displacement between the first and second support shafts, which have large acting force, by mounting the cylinder block side with bolts through the loose hole of the connection support plate, while increasing the positional accuracy. Since a certain distance is limited to two points instead of three points, processing becomes relatively easy, and an increase in manufacturing cost can be suppressed.

In addition, fourth, by directly fixing the connecting support plate to the cylinder block by bolting or the like, the displacement and vibration of the connecting support plate can be significantly reduced, and the connection support plate is supported by this connecting support plate. Deformation and vibration of the support shaft of each intermediate gear can be prevented. Therefore, according to the support structure of the intermediate gears in the gear train of the present invention as described above, the deformation and vibration of the support shaft of each intermediate gear can be prevented, and the vibration of the connecting support plate can be prevented. Damage to the bearings and gear noise caused by bending deformation can be reduced, the durability of the gear train can be improved, and gear noise can be reduced.

[Brief description of the drawings]

FIG. 1 is a front view showing a support structure of an intermediate gear in a gear train according to the present invention.

FIG. 2 is a side sectional view showing a support structure of an intermediate gear in a gear train according to the present invention.

FIG. 3 is a front view showing a support structure of an intermediate gear in a gear train according to the present invention in which two support shafts are pressed and fitted to a connection support plate.

FIG. 4 is a front view showing a support structure of an intermediate gear in a gear train according to the present invention in which a connection support plate is fixed to a cylinder block.

FIG. 5 is a front view showing a support structure of an intermediate gear in a gear train of the related art.

FIG. 6 is a side sectional view showing a support structure of an intermediate gear in a gear train of the related art.

FIGS. 7A and 7B are partial side sectional views showing a supporting structure of an intermediate gear in a gear train according to the related art, in which FIG. 7A is a diagram showing a force acting on the gear, and FIG. It is a figure which shows typically.

FIG. 8 is a side sectional view showing a supporting structure of an intermediate gear in another conventional gear train.

FIG. 9 is a front view showing a support structure for two intermediate gears in a gear train of the improved technology.

FIG. 10 is a front view showing a support structure for three intermediate gears in a gear train of the improved technology.

[Explanation of symbols]

10 Cylinder block 11, 13, 23, 61, 6
3, 65 Support shafts 11a, 13a, 23a, 61a, 63a, 65a Bolts 11b, 13b, 23b, 61b, 63b, 65b Bearing Bearing 11c First fitting portion 13c Second fitting portion 12, 14, 24, 62, 64, 66 Intermediate gear (idle gear) 15 PTO shaft (first drive shaft) 16 Output gear 21 Crank shaft 22 Crank gear 25 Cam shaft (second drive shaft) 26 Cam gear 30, 31 Support plate 40, 41, 42 Connection Support plate 41ac Third fitting portion 42a Second fitting portion 50 Gear case cover 61b, 63b, 65b
Bearing bearing 70 bolt

 ──────────────────────────────────────────────────続 き Continuing from the front page (72) Inventor Kenichi Yanagihara 3-25-1, Tonomachi, Kawasaki-ku, Kawasaki-shi, Kanagawa Prefecture Isuzu Motors Corporation Kawasaki Plant

Claims (5)

[Claims] 1. A first gear train having an intermediate gear for transmitting a torque from a crankshaft of an internal combustion engine to a first drive shaft, and a second gear train.
A second gear train having an intermediate gear for transmitting to a drive shaft, wherein each intermediate gear is rotatably supported on each support shaft fixed to the main body of the internal combustion engine, and further, the gear train is further provided. Separately and independently of the cover of the gear case to be housed, the distal end side of at least one support shaft of the support shaft supporting the intermediate gear of the first gear train and the support shaft supporting the intermediate gear of the second gear train. A support structure for an intermediate gear in a gear train, comprising a connection support plate connecting at least one support shaft to a distal end side. 2. The first gear train has two or more intermediate gears, and the connection support plate supports at least two first and second intermediate gears of the first gear train, respectively. The gear train according to claim 1, wherein a distal end side of the second support shaft is connected to a distal end side of a third support shaft that supports at least one third intermediate gear of the second gear train. Support structure for intermediate gears inside. 3. A first distance between a meshing point of the first intermediate gear and the second intermediate gear to the first support shaft,
The supporting device for an intermediate gear in a gear train according to claim 2, wherein a second distance between the meshing point and the third support shaft is formed large. 4. A first and a second fitting portion are provided only on two of the first support shaft and the second support shaft of the first gear train, and the first and second fitting portions are provided on the first and second fitting portions. Third and fourth fitting portions to be fitted respectively are provided on the connection support plate,
4. The intermediate gear supporting device in a gear train according to claim 2, wherein a supporting shaft and the second supporting shaft are pressed and fixed to the connection supporting plate. 5. The supporting device for an intermediate gear in a gear train according to claim 1, wherein said connecting support plate is fixedly supported on a main body side of said internal combustion engine.