JPS5819404Y2 - Bearing device for secondary 2-axis balancer - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a bearing device for a secondary two-shaft balancer for an internal combustion engine.

In general, secondary two-axis balancers require bearings at both ends of each balancer shaft, which has the disadvantage that the shape of the balancer housing tends to be complicated.

The present invention allows a rolling bearing to be used in a halved manner in the bearing structure of a secondary two-shaft balancer, and will be explained with reference to the drawings as follows.

The crankshaft 1 in Fig. 1 is supported at three points by main bearings 2 at both ends (one of which is not shown) and a main bearing 3 in the center. There are several crank parts (slow), and Figure 1 shows the first cylinder (center line 0).
1) and the crank throw of the portion corresponding to the second cylinder (center line 02).

4 and 5 are connecting rods for the first cylinder and the second cylinder, respectively.

The main bearings 2, 3 are both supported by the crankcase 6 and fixed thereto by bolts 7.8.

A flywheel 10 is fixed to the right end of the crankshaft 1 by a plurality of bolts 9.

11 is a cover, 12 is a bolt for fixing the cover, and 13 is an oil seal.

In the space 15 below the crankshaft 1 between the first and second cylinders and between the third and fourth cylinders (not shown), there is a secondary space parallel to the center line O of the crankshaft 1, respectively. A two-shaft balancer 16 is arranged, and the input balancer shaft 17 of each balancer 16 is provided with an input gear 18 on the crankshaft end side, and the input gear 18 is connected to the crank web 19 of the crankshaft 1.
It meshes with a ring-shaped drive gear 20 fixed to.

The angular position of the drive gear 20 with respect to the crank web 19 is fixed by meshing and shrink-fitting a notch 21 provided on the inner periphery with a radial positioning pin 22 on the crank web 19 side.

The angular position of the input gear 18 with respect to the balancer shaft 17 is fixed by a key 23, and the angular position of the input gear 18 with respect to the drive gear 20 is fixed.
/2 teeth, and the meshing position with the drive gear 20 is kept constant by alignment marks (not shown) or the like.

24 is a nut for fixing the input gear, and 25 is a balance weight integrated with the balancer shaft 1T.

Each balancer 16 has another driven balancer shaft 1 driven by an input gear 18 parallel to the input balancer shaft 1T.
7' (FIG. 2), which include a top-opening container-shaped bearing body 21 and bearing caps 28, 28, 28', 28',
The input gear 18 is rotatably supported by a split bearing cap type bearing consisting of a rolling bearing 29, and meshes with a gear 18' having the same number of teeth fixed to the other balancer shaft 17'.

The bearing body 21 is fastened to the lower surface of the crankcase 6 with bolts 31 using four brackets 30 provided at the lower end.

32 in Figure 1 is a spacer, 33°34 is a rolling bearing 29
35 and 36 are bolts for fixing the presser plate, 37 is an oil pan fixed to the lower side of the crankcase 6, and 38 is a bolt for fixing the oil pan.

Input balancer shaft 1T and the other driven balancer shaft 17'
The center lines 03, 03' are biased toward the input balancer shaft 17 so as to be higher, thereby preventing the gear 18' and the driving gear 20 from meshing with each other.

The upper surface 40, 40' of the bearing body 27 has a balancer shaft 1γ,
11' center line o3. It is formed of two horizontal planes including o3', and a bearing cap 28.2 of the same shape is placed above it.
8' are tightened with two bolts 41, respectively.

Instead of having the upper surface 40, 40' stepped, an inclined common surface 42 is provided which includes the center lines 03, 03' of both balancer shafts 17, 17', and the bearing caps 28, 28' are adapted to the common surface 42. It can also be transformed as follows.

In that case, machining of the bearing body 27 becomes easier.

When the common surface 42 is adopted, the center line of the insertion hole 43 of the bolt 41 and the screw hole 44 can be changed to be perpendicular to the surface 42 as shown in 04 in order to use the bearing cap 28, 28' as it is.

Both balancer shafts 17, 17' are located at the same distance left and right from the vertical plane A including the center lines 01, 02... of each cylinder as shown in Fig. 2, and the balance weights on both balancer shafts 17, 11' 25 have the same vertical phase, that is, when one balance weight 25 is at the top dead center, the other balance weight is also close to the top dead center, and when one balance weight 25 is at the bottom dead center, the other balance weight is also at the bottom dead center. The meshing position of both gears is and is' is set so that the gears are at the bottom dead center.

In addition, the balancer 16 on the right side and the balancer (not shown) on the left side of the main bearing 3 in FIG. The position, size, phase, etc. of the weights are determined.

During engine operation, the secondary two-shaft balancers 16 on both sides of the main bearing 3
are operated by receiving rotational force from the crankshaft 1, respectively, and perform a couple removal function.

That is, the rotation of the crankshaft 1 was fixed to the crank web 19.

It is transmitted from the drive gear 20 to the input balancer shaft 17 through the input gear 18, and the input balancer shaft 17 rotates at twice the speed of the crankshaft 1, and the other balancer shaft 17' rotates at a constant speed in the opposite direction to the balancer shaft 17. do.

Balance weight 25 on both balancer shafts 17.17'
rotates so that the top and bottom phases are equal.

The balancer 16 can be pre-assembled using the bearing body 2T and the bearing caps 28, 28' to form a unit at a separate location away from the engine assembly line.
When assembling, insert the balancer unit into the space 15 below the crankshaft through the opening at the lower end of the crankcase,
With the input gear 18 meshed with the drive gear 20, the four brackets 30 are each fastened to the crankcase 6 with bolts 31, and then the oil pan 37 is attached.

As explained above, according to the present invention, a half-split type bearing with a built-in rolling bearing is used, making it extremely easy to disassemble and assemble the balancer, and the balancer can be assembled as a unit on a separate line, making handling easier. It also becomes easier.

In particular, the secondary two-shaft balancer can be installed compactly below the crankshaft of a two-slot, one-crankshaft engine.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional view, and FIG. 2 is a sectional view including a vertical section of each main part perpendicular to the crankshaft. 1...Crankshaft, 15...Space, 1
6...Secondary 2-axis balancer 17, 17'...
...Balancer axis, i s, i a'...
...Gear 19...Crank web, 20.
... Drive gear 21 ... Bearing body, 2
8... Bearing cap, 29... Rolling bearing.

Claims (1)

[Scope of utility model registration request] A ring-shaped drive gear is fixed to the crank web of the crankshaft, and a secondary two-shaft balancer is placed parallel to the crankshaft in the space below the crankshaft, and both balancer shafts roll and split into a bearing cap with a built-in bearing. Supported by model type bearings,
An input gear with the number of teeth equal to 1/2 of the above drive gear is fixed to the input balancer shaft, and the input gear is directly meshed with the drive gear, and the input gear is meshed with a gear with the same number of teeth on the other balancer shaft that is biased downward. A bearing device for a secondary two-shaft balancer, which is characterized by the following: