JPH0314943A - Support structure for balancer shaft - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a support structure for a balancer shaft that eliminates engine vibration.

A balancer that cancels the vibrations of a strained engine has a balance weight attached to a balancer shaft installed parallel to the crankshaft, and the rotation of the crankshaft is transmitted to the rotation of the balancer shaft via a chain or gear to cause the piston to reciprocate. This attempts to offset vibrations by rotating the balance weight in synchronization with the vibrations.

First, the balancer shaft is supported by a bearing provided in the balancer case and is installed in advance.

Therefore, initial assembly is troublesome and removal is not easy, making maintenance management inconvenient.

Furthermore, it is difficult to provide a large-diameter starter clutch or the like to the balancer shaft, making it difficult to use the balancer shaft separately.

The present invention has been made in view of the above, and an object thereof is to provide a support structure for a balancer shaft that is easy to assemble and maintain.

That is, in the present invention, a balancer shaft having a balance weight and a clutch for a starting system provided on the shaft is housed in a balancer case with one side open through the same opening, and one end of the balancer shaft is supported by a bearing provided in the balancer case. This is a balancer shaft support structure in which the other end of the balancer shaft is supported by a bearing provided on a lid member that covers the opening of the eight balancer case.

A balancer shaft equipped with a balance weight and a starting clutch is inserted into the balancer case through its opening, one end of the balancer shaft is supported by a bearing provided in the balancer case, and then the lid member is inserted into the opening of the balancer case. By supporting the other end of the balancer shaft on a bearing provided on the cover member, the balancer shaft can be easily assembled to the balancer case.

The two bearings that support the balancer shaft are installed in separate balancer cases and lid members, so even if the balancer shaft is equipped with a large-diameter clutch, assembly is easy. There is no problem with disassembly, and small-diameter bearings can be used.

Furthermore, in the present invention, by detachably providing an AC generator driven by a balancer shaft on the outside of the lid member, the AC generator can be easily assembled and removed, and a compact design is possible. .

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment according to the present invention illustrated in FIGS. 1 to 3 will be described below.

FIG. 1 is a side sectional view of the engine according to the present embodiment, and FIG. 2 is an explanatory diagram combining various cross sections showing the structure of the drive transmission system from the crankshaft to the balancer shaft and the balancer shaft.

This engine 1 is an in-line four-cylinder engine, and includes a crankcase 3 below each cylinder 2, a transmission case 4 behind it, and a balancer case 5 diagonally above it.

A crankshaft 10 is supported within the crankcase 3 so as to be oriented in the left and right horizontal directions, and a primary drive gear 11 is formed on the crankshaft 10.

A front balancer is provided in front of the crankshaft 10, and a balancer shaft 12 is fixedly supported by the crankcase 3 in parallel with the crankshaft 10, and rotates in a cylinder through the balancer shaft 12 through two bearings l3 on the left and right. The body 14 is rotatably fitted, and the cylindrical rotating body ■
A haranth weight 15 is fixed to the outside of the end of the shaft 4, and a balancer drive gear 16 is fitted to the other end, and the balancer drive gear 16 meshes with the primary drive gear 11.

Primary drive gear 11 and balancer drive gear 1
The tooth number ratio of 6 is 2:1.

The balance weight 15 is located approximately at the center in the left-right direction of the engine, and rotates together with the cylindrical rotating body 14 via the primary drive gear 11 and balancer drive gear 16 as the crankshaft 10 rotates, and
Rotates in the opposite direction at twice the speed of 0.

On the other hand, in the transmission case 4 behind the crankshaft 10, a main shaft l7 and a countershaft 18 are supported in parallel with the crankshaft 10, and are fitted into the taratch outer 19a of the clutch 19 provided on the main shaft l7. Primary driven gear 2
0 is meshed with the brimary drive gear 11.

Therefore, the rotation of the crankshaft IO rotates the clutch outer 19a via the primary drive gear 11 and the primary driven gear 20, and the clutch outer 19a is rotated.
is transmitted to the main shaft 17 via.

The rotation of the main shaft 7 is transmitted to the countershaft 18 at a variable speed due to the meshing of various speed change gears 21 between the main shaft 17 and the countershaft 18. Although not shown, the end of the countershaft 18 protrudes outward from the transmission case 4. The rear wheel can be driven by rotating the dry sprocket fitted to the rear wheel via a chain that is spanned between the driven sprocket and the driven sprocket installed on the rear wheel.

In addition, a balancer shaft 2 is located inside the balancer case 5 of the NOYAHA Lancer, which is located diagonally above the main shaft 17.
5 is supported, and a balancer drive gear 26 fitted on the balancer shaft 25 meshes with the brilliance driven gear 20.

Brima drive gear 11 (crankshaft 10
) rotates the balancer drive gear 26 via the primary driven gear 20, and the ratio of the number of teeth between the ply 7 redrive gear 11 and the balancer drive gear 26 is 2:1, so the balancer shaft 25 rotates the balancer drive gear 26 through the primary driven gear 20.
Rotates in the same direction at twice the speed of 0.

As described above, the engine according to this embodiment has a two-shaft secondary balancer in which balancers are provided before and after the cylinder 2, respectively.

Each balancer shaft 12. In FIG. 1, if the line drawn in the reciprocating direction of the piston through the center of the crankshaft 10 is the cylinder centerline Y-Y, the position of 25 is a line that is perpendicular to the cylinder centerline YY and passes through the center of the crankshaft 10. Both balancer shafts from X-X10. The distance a to each balancer shaft 10.25 is equal and from the cylinder centerline Y-Y.
For the distance b, C to 25, c / b = 1.0 ~
It has a relationship of 2.5.

Next, the structure of the rear balancer will be explained based on FIG. 2.

The balancer case 5 extending from the crank case 3 and the transformer case 4 has a substantially cylindrical shape with a bottom, and has a bottom wall 5b on the right side of a cylindrical side wall 5a oriented in the left-right horizontal direction, and a bottom wall 5b on the left side. It's open.

A circular hole is formed in the bottom wall of the balancer case 5, and a bearing 27 is fitted into the circular hole.

A lid member 28 is placed over the opening of the balancer case 5.

The lid member 28 has a cylindrical shape with a shallow bottom wall 28b, and a flange 28c is formed at the edge of the cylindrical side wall 28a.
When placed inside, the side wall 28 of the balancer case 5
The outer circumferential surface of the side wall 28a of the lid member 28 is in contact with the inner circumferential surface of the a, and the flange 28c of the lid member 28 is in contact with the opening edge of the balancer case 5.

When the cover member 28 is placed on the balancer case 5 in this way, both bottom walls 5b and 28 of the balancer case 5 and the cover member 28
There is a space 29 between the cover member 28 and the cover member 28, and a recess 30 formed by the cover member 28 is formed on the left side of the cover member 28.

A circular hole is formed in the center of the bottom wall 28b of the lid member 28, and a bearing 31 is fitted into the circular hole.
Both bearings 27 correspond to the bearing 27 fitted to the bottom wall 5b of the
．． 31 rotatably supports the balancer shaft 25.

The balancer shaft 25 has a cylindrical shape with an oil passage 25a inside, and has two flanges 25b and 25C formed in the center.

The rotating body 32 that is positioned and fitted to one flange 25c has a cylindrical part 32a in the center that fits into the balancer shaft 25, and a disk part 32b extends in the centrifugal direction from the left end of the cylindrical part 32a. , a shallow cylindrical part 32 with a slightly smaller diameter than the disc part 32b from the left side of the disc part 32b.
c is shaped to the left.

A one-way clutch 33 for a starting system is provided on the right side surface of the disk portion 32b of the rotating body 32, and its tarlatch outer 3
3a is screwed onto the rotating body 32 with a bolt 34.

A gear 35 having approximately the same diameter as the rotating body 32 is fitted into the clutch inner 33b.

On the other hand, a damper coupling 36 is interposed within the left cylindrical portion 32c of the rotating body 32 and connected to the balancer shaft 25.

Therefore, the balancer shaft 25 is left alone with the rotating body 32 assembled in advance, and the fitting of the cylindrical portion 32a of the rotating body 32 to the balancer shaft 25 allows relative rotation between the two, and the transmission of rotation is This is done via a damper coupling 36.

A balance weight 3 is provided externally to the cylindrical portion 32c of the rotating body 32.
7 is fixed.

A coupling support member 38 is spline-fitted to the left end of the balancer shaft 25 and fixed with a nut 40 via a washer 39. The right cylindrical portion 38a is supported by the bearing 31 of the lid member 28.

On the other hand, the driving side of the damper coupling 4l is provided inside the left cylindrical portion 38b.

An AC generator 42 is attached to the opening side of the lid member 28, the flange 43a of the casing 43 of the AC generator 42 is brought into contact with the flange 28c of the lid member 28, and the bolt 44 is inserted between both flanges 43a. 28c and is screwed into the end edge of the cylindrical side wall 5a of the balancer case 5 to integrally fix the lid member 28 and the AC generator 42 to the balancer case 5.

A rotor shaft 45 in the AC generator 42 is supported by a casing 43 via a bearing 46, and is located coaxially with the balancer shaft 25, with its tip end face leaving a slight gap with the left end face of the balancer shaft 25. They are facing each other.

A coupling support member 47 is spline-fitted to the end of the rotor shaft 45 and fixed with a nut 49 via a washer 48, and the driven side of the damper coupling 41 is provided on the coupling support member 47. .

An oil passage 45a is formed in the rotor shaft 45, and the oil passage 45a passing through the central axis and the balancer shaft 2
The joint pipe 50 communicates with the oil passage 25a inside the joint pipe 50.

On the other hand, the balancer drive gear 26 is spline-fitted to the end of the balancer shaft 25 protruding rightward from the balancer case 5, and the nut 52 is fitted through a washer 51.
The rotation of the primary driven gear 20 that meshes with the balancer drive gear 26 is transmitted to the balancer shaft 25.

A cylindrical gigoint member 53 has its left half inserted into the oil passage 25a at the end of the balancer shaft 25, and its right half protrudes and is fixed with a fastener 54.

Note that an O-ring 55 is interposed at the fitting portion between the balancer shaft 25 and the joint member 53 to shut off water.

The protrusion of the jig pin member 53 penetrates into an oil seal 57 provided in a holder 56 separate from the balancer case 5.

The holder 56 also serves as a lubricating oil supply path, and as shown in FIG. The tip of the member 53 communicates with the circular hole into which the member is inserted.

There is another arm portion 56d extending from the support portion of the holder 56, and the end portion of the arm portion 56d is screwed onto the balancer case 5 by a bolt 58.

When the holder 56, which is separate from the balancer case 5, is attached to the balancer case 5 and rotatably supports the tip of the joint member 53, the oil passages 4c of the four crankcases and the oil passage 56c of the holder 56 side are connected. are in communication with each other, and their mating surfaces are water-tightened by an O-ring 59.

Therefore, the lubricating oil is in the oil passage 4c on the crankcase 4 side.
from the support part 5 through the oil passage 56c on the holder 56 side.
6a, the oil is then supplied to the oil passage 25a of the balancer shaft 25 via the joint member 53, and further to the AC generator 42 via the joint pipe 50.
The oil passage 45a of the rotor shaft 45 is supplied with oil.

Main oil passage 25a of balancer shaft 25 and rotor shaft 45. 45a passes through the center of rotation, and the balancer shaft 25 and rotor shaft 45 are provided with small holes at required locations to supply oil to the bearings and the like and to cool the generator 42.

On the other hand, a starter motor 65 is provided along the cylindrical side wall 5a of the balancer case 5, and a drive shaft 66 of the starter motor 65 and its bearing portion are located in a bulged portion 5d where a right side portion of the side wall 5a of the balancer case 5 is bulged. 67 is fitted, and a bracket 68a protruding from the casing 68 of the starter motor 65 is screwed onto the balancer case 5 and fixedly supported.

The balancer shaft 2 is attached to the bulging portion 5d of the balancer case 5.
A support shaft 69 is provided between the drive shaft 66 of the starter motor 65 and the drive shaft 66 of the starter motor 65, and a support shaft 69 is rotatably supported on the shaft 69. The large-diameter glue reduction gear 70 meshes with teeth formed on the drive shaft 66 of the starter motor 65, and the small-diameter glue reduction gear 71 meshes with the gear 35 fitted to the clutch inner 33b of the one-way clutch 33. .

Therefore, the rotation of the drive shaft 66 of the starter motor 65 is decelerated through the reduction gears 70 and 71, and the gear 35 is decelerated.
transmitted to.

The structure of the balancer according to this embodiment is as described above, and to explain its driving state, the rotation of the crankshaft 10 is caused by rotating the primary drive gear 11 integrally and via the balancer drive gear 16 meshing with the primary drive gear 11. It rotates the front balancer shaft l2 and the balance weight 15, and the rotation of the primary drive gear 11 is transmitted to the balancer drive gear 26 via the primary driven gear 20 that meshes with this, and the rotation of the primary drive gear 11 is transmitted to the balancer drive gear 26,
Rotate 5.

The rotation of the balancer shaft 25 is controlled by the damper coupling 36.
The signal is transmitted to the rotating body 32 via the rotating body 32, and rotates a balance weight 37 that is integrated with the rotating body 32.

With respect to the rotation of the crankshaft 10, the front balance weight 15 rotates at twice the speed in the opposite direction, and the rear balance weight 37 rotates at twice the speed in the same direction as the crankshaft 10.
It rotates at twice the speed and uses a two-axis secondary balancer to create a low-vibration engine.

Since the balance weight is provided via the damper coupling, it is possible to achieve low noise and improved durability.

On the other hand, the rotation of the balancer shaft 25, which rotates at twice the speed of the crankshaft 10, connects the rotor shaft 45 of the AC generator 42, which is coaxial with the balancer shaft 25, to the damper coupling 4.
1, it can be rotated at high speed and efficiently generate electricity.

Since the drive is transmitted by gear drive, parts such as chains and tensioners are not required, and the number of parts can be reduced.

Note that the rotation of the rotating body 32 rotated via the damper coupling 36 is controlled by the gear 35 by the one-way clutch 33.
And it is not transmitted to the starter motor 65 side.

Conversely, during startup, the rotation of the drive shaft 66 of the starter motor 65 is decelerated through the reduction gears 70, 71 and transmitted to the gear 35, which rotates the balancer shaft 25 through the one-way clutch 33 and damper coupling 36. The rotation of the balancer shaft 25 is transmitted from the balancer drive gear 26 to the primary drive gear l1 via the briny driven gear 20, which rotates the crankshaft 10 and starts the engine.

As described above, the balancer shaft 25, which also serves to transmit drive to the AC generator 42 and the starter motor 65, is located opposite to the front balancer shaft 12 with respect to the cylinder centerline Y-Y, and is The distance c is the distance b of the balancer shaft l2.
Since the AC generator 42 can be arranged coaxially with the balancer shaft 25 on the C dimension side, a compact design can be achieved by providing the one-way clutch 33 of the starting system on the balancer shaft 25.

Furthermore, the fact that the bearings 27 and 31 that support the balancer shaft 25 are provided in the separate balancer case 5 and lid member 28 respectively increases the degree of freedom in designing the position of the balancer shaft 25 and enables a compact design. .

The balancer shaft 25 is supported by left and right bearings 27, 31, has a balancer drive gear 26 for human power at the end that protrudes outward to the right from the right bearing 27, and has an end that protrudes outward to the left from the left bearing 3l. AC generator 4
A damper coupling 41 that engages with the rotor shaft 45 of No. 2 is provided, and a rotating body 32, a balance weight 37, and a one-way clutch 33 are provided between both bearings 27 and 31, so that the starter motor 65 and the reduction gear 7
The overall horizontal center of gravity position including 0.71 can be matched to the engine's center of gravity position, and an engine with well-balanced left and right weight can be realized.

The balance weight 37 is provided on a rotating body 32 that is engaged with the balancer shaft 25 via a damper coupling 36, and a one-way clutch 3 is connected to the rotating body 32.
3, the rotating body 32 is provided with a balance weight 37, a driven side of the damper coupling 36, and a tarlatch outer 33a of the one-way clutch 33.
can be integrally formed into an oval shape, thereby reducing costs.

Note that the rotating body 32 to which the balance weight 37 is fixed is driven via the damper coupling 36, resulting in low noise.

Since the drive transmission system from the starter motor 65 to the crankshaft 10 at the time of starting has a damper coupling 36 interposed therebetween, it is advantageous in terms of gear strength even against excessive torque such as locking.

In the case of the present invention, it is easy to provide the bearing of the balancer shaft 25 in the horizontal direction substantially equal to the bearing of the main shaft 17 in the transmission case 4, and also in this embodiment, the bearing 27 of the balancer shaft 25 and the bearing of the main shaft 17 It is located at approximately the same left-right position as the bearing 80, and can maintain high rigidity in the bearing portion.

As shown in FIG. 2, the balancer shaft 25 is supported by a bearing 27 provided on the balancer case 5 and a bearing 31 provided on a lid member 28 separate from the balancer case 5. Excellent in sex.

That is, the procedure for assembling the balancer shaft 25 and the AC generator 42 is to first attach the balance weight 37 and damper coupling 36 on the shaft via the rotating body 32.
, the one-way clutch 33, and the gear 35 are inserted into the balancer shaft 25 from the left side opening of the balancer case 5, and the right end of the balancer shaft 25 is supported through the circular hole in the bottom wall 5b of the balancer case 5 through the bearing 27. Then, the gear 35 is meshed with the reduction gear 71, and then the lid member 28 fitted with the coupling support member 3 is placed over the opening of the balancer case 5 via the bearing 31, and the cup is attached to the left end of the balancer shaft 25. The cylindrical portion 38a of the ring support member 38 is spline-fitted, and the nut 40 is screwed and fixed to the tip of the balancer shaft 25 via the washer 39.

Note that the lid member, coupling support member, etc. may be assembled into the balancer shaft in advance before the balancer shaft is assembled into the case. Next, the AC generator 42 with the coupling support member 47 fitted to the rotor shaft 45 is attached to the left side opening of the lid member 28, and at this time, the giraffe intipe 50 is interposed between the balancer shaft 25 and the rotor shaft 45. ,
and the damper coupling 41 is engaged, and A
The casing 43 of the C generator 42 is screwed together with the lid member 28 by the port 44.

Balance weight 37, one-way clutch 33. The damper coupling 36 is located in the space 29 between the balancer case 5 and the lid member 28, and the damper coupling 41 is located in the space 29 between the balancer case 5 and the lid member 28.
8 and the AC generator 42. A balancer drive gear 2 is attached to a balancer shaft 25 that protrudes to the right from a bearing 27 provided in the balancer case 5.
6 is fitted so as to mesh with the primary driven gear 20, and is fitted with a nut 52 via a washer 51.

After assembling the joint member 53 to the balancer shaft 25, the holder 56 with the oil seal 57 assembled is brought into contact with a desired position on the right side of the balancer case 5, and an oil passage is established between the joint member 53 and the shaft 25. Observe formal precepts. Note that the holder 56 itself is screwed onto the balancer case 5 with bolts.

The balancer shaft 25, lid member 28, and AC generator 42, each of which is assembled into one, are sequentially installed from the left side opening of the balancer case 5, making it easy to assemble and easy to assemble, and conversely easy to remove. It is also convenient for maintenance management.

In particular, since the AC generator 42 is removably attached to the lid member 28, it is extremely convenient to replace it.

The large diameter one-way clutch 33 is connected to the balancer shaft 25
Even if the small-diameter bearings 27 are installed in the center of the
, 31 are separate balancer case 5 and lid member 28, respectively.
Each is provided in a combination structure, so it is easy to assemble. There is no problem in disassembling the bearing, and the bearing is small in diameter.27.
31, the engine speed can be increased.

In this embodiment, a holder 56 separate from the crankcase 4 in which the oil passage 56c is formed can be attached later, and the balancer shaft 25 and the rotor shaft 45 of the AC generator 42 are connected to each other via the joint member 53. Since lubricating oil is supplied to the center of the shaft, a sufficient amount of oil can be secured even during high-speed rotation.

Since the joint member 53 is interposed between the holder 56 and the balancer shaft 25, high-pressure oil can be supplied, and durability can be increased by stable oil supply. The present invention has a structure in which the balancer shaft, on which the balance weight and the clutch of the starting system are provided, and the lid member are sequentially assembled into the balancer case. It is also easy to remove, making it easy to maintain.

The two bearings that support the balancer shaft are provided in separate balancer cases and lid members, so even if the balancer shaft is equipped with a large-diameter clutch, assembly and disassembly will not be hindered, and the bearings Since a small-diameter type can also be used, it can also handle high-speed rotation. A clutch is provided on the balancer shaft, allowing the starting system to be installed nearby, allowing for a more compact engine design.

In addition, by providing the AC generator on the outside of the lid member in a detachable manner, it is possible to easily assemble and remove the AC generator, making it easy to replace and improve assembly and maintenance. It can also contribute to downsizing.

[Brief explanation of the drawing]

FIG. 1 is a side sectional view of an engine according to an embodiment of the present invention;
FIG. 2 is an explanatory cross-sectional view of the drive transmission system and balancer structure, and FIG. 3 is a cross-sectional view of the holder at the end of the balancer shaft. 1... Engine, 2... Cylinder, 3... Crank case, 4... Transmission case, 5...
- Balancer case, 10... Crankshaft, 11... Primary drive gear, 12... Balancer shaft, 13...
Bearing, 14... Cylindrical rotating body, 15... Balance weight, 16... Balancer drive gear, l7... Main shaft, 18... Counter shaft, 19...
·clutch. , 20...Primary drip gear, 2
l...Transmission gear, 25... Balancer shaft, 26... Balancer drive gear, 27... Bearing, 28... Lid member, 29...
...Space, 30...Recess, 31...Bearing, 32...
・Rotating body, 33...One-way clutch, 34...
Bolt, 35... Gear, 36... Damper coupling, 37... Balance weight, 38... Coupling support member, 39... Washer, 40... Nut, 4l... Damper cup Ring, 42... AC generator, 43... Casing, 44... Bolt,
45... Rotor shaft, 46... Bearing, 47...
・Coupling support member, 48... washer, 49・
...Nut, 50...Joint pipe, 51...
Washer, 52... Nut, 53... Joint member, 55... O-ring, 56... Holder, 57...
...Oil seal, 58...Bolt, 59...O ring, 65...Starter motor, 66...Drive shaft,
67...Bearing part, 68...Casing, 69...
Support shaft, 70... Reduction gear, 7l... Reduction gear, 80... Bearing.

Claims (2)

[Claims] (1) A balancer shaft with a balance weight and a clutch for the starting system mounted on the shaft is housed in a balancer case with an opening on one side through the same opening, and one end of the balancer shaft is supported by a bearing provided in the balancer case. A balancer shaft support structure, characterized in that the other end of the balancer shaft is supported by a bearing provided on a lid member that covers an opening of a balancer case. (2) The balancer shaft support structure according to claim 1, wherein an AC generator driven by the balancer shaft is detachably provided on the outside of the lid member.