JPH04122811U - Crankshaft bearing structure - Google Patents

Abstract

(57) [Summary] [Purpose] To average the bearing loads for all bearings. [Configuration] The crankshaft 1 is not entirely connected to the web 3a.
Counterweights 5a to 5d are attached to one side of 3d. A bearing 6 adjacent to one side of the webs 3a to 3d to which the counterweights 5a to 5d are attached
a, 6c, and 6e, a sub-bearing 8 made of a material with lower rigidity than the bearing body 9, such as aluminum, and having an elliptical cross-section with the major axis in the vertical direction is located between the bearing body 9 and the crankshaft 1 (metal 7). is interposed in. [Effect] Since the auxiliary bearing 8 relieves the displacement of the crankshaft 1, the bearing load is evened out.

Description

[Detailed explanation of the idea]

0001

[Industrial application field]

The present invention relates to a bearing structure for a crankshaft.

0002

[Conventional technology]

An example of a conventional crankshaft bearing structure is the one shown in Fig. 4. (Refer to Utility Model Application Publication No. 157423/1983, Publication No. 28915/1988, etc.).

0003 The crankshaft 101 shown in FIG. 4 has counterweights on all webs 102. 103, a crank journal 104, a web 102, a crank pin The crank consisting of 105 has almost the same structure for each cylinder, and bearings with the same support rigidity. It is supported by 106.

0004

[Problem that the idea aims to solve]

In conventional crankshaft bearing structures, all bearings generally have the same structure. and have approximately the same support rigidity.

[0005] However, all crankshaft bearing structures are made of the same bearing. When used on a crankshaft that does not have a counterweight on the web, the counter The load on the bearing adjacent to the web with the weight becomes relatively large, causing the clamp to A moment is generated inside the shaft.

[0006] As a result, the crankshaft deforms due to a partial increase in bearing load, causing noise and vibration. There were problems in that the bearing metal was deteriorated and the durability of the bearing metal was also deteriorated.

[0007] This invention was developed by focusing on these conventional problems, and it solves all problems. Average bearing load sharing on crankshafts without counterweights To provide a crankshaft bearing structure that reduces local increases in bearing load. The purpose is to

[0008]

[Means to solve the problem]

Therefore, this invention consists of a crank journal, a web, and a crank pin. It has a crank with multiple cylinders, and a counterweight is attached to the limited web. In the bearing structure that supports the crankshaft, the counterweight is attached to the bearing structure. Between the crankshaft of the bearing part adjacent to the bearing part and the bearing body, there is a A secondary shaft that is made of material and has an elliptical cross-section with the major axis in the direction of the bearing body with higher rigidity. Uke was interposed.

[0009]

[Effect]

Crankshafts that do not have counterweights on all webs are centrifugal due to rotation. The force causes the bearing load at the journal position adjacent to the counterweight to be relatively high. Ru.

0010 Therefore, we installed a sub-bearing with lower rigidity than the bearing main body for the bearing in this area, and This allows the bearing load to be shared evenly across all bearings.

[0011]

【Example】

Hereinafter, the present invention will be explained based on the drawings. Figure 1 shows the present invention applied to a four-cylinder engine. It is a figure which shows one Example which applied.

0012 First, the configuration will be explained. Crankshaft 1 is inserted from the front side of the engine (left side in Figure 1). #1 journal 2a, #2 journal 2b, #3 journal 2 arranged in order c, #4 journal 2d, #5 journal 2e, and each journal 2a to 2e #1 web 3a, #2 web 3b, #3 web 3c, #4 web arranged between 3d, also #1 crank pin 4a, #2 crank pin 4b, #3 crank pin 4 c, the #4 crank pin 4d, and the #4 crank pin attached to one of the webs 3a to 3d. 1 counterweight 5a, #2 counterweight 5b, #3 counterweight It is composed of a weight 5c and a #4 counterweight 5d.

[0013] In addition, the bearing body includes #1 bearing 6a, #1 bearing 6a, and #1 bearing 6a from the front side, corresponding to the crankshaft 1. 2 bearing 6b, #3 bearing 6c, #4 bearing 6d, and #5 bearing 6e are installed in order, and the metal The crankshaft 1 is supported via a lever 7.

[0014] #1 bearing 6a and #3 bearing 6 adjacent to counterweights 5a to 5d c. The #5 bearing 6e is made of a material with lower rigidity than the bearing body and has a vertical Sub bearings 8 each having an elliptical cross section with a long diameter in the right direction are connected to the crankshaft 1 (metal 7) and the shaft. It is interposed between the receivers 6a, 6c, and 6e.

[0015] FIG. 2 shows a #1 bearing 6a, a #3 bearing 6c, and a #5 bearing in which a secondary bearing 8 is interposed. 6e is shown for the #1 bearing.

The sub-bearing 8 is made of a material with lower rigidity than the bearing main body 9, for example, the bearing main body 9 is made of cast iron E=12000 kg/mm ² and the sub-bearing 8 is made of aluminum E=7200 kg/mm ² . . Further, the sub-bearing 8 is formed into an ellipse with a major axis l ₁ in the direction of high rigidity of the bearing main body, that is, a vertical direction, and a minor axis l ₂ in the horizontal direction.

[0017] Next, the operation will be explained with reference to FIG. Centrifugal force due to rotation causes each counter to Journals located adjacent to weights 5a, 5b, 5c, and 5d, that is, #1 The relative loads on journal 2a, #3 journal 2c, and #5 journal 2e The journal that is higher and located between these, i.e. #2 journal 2b , an internal moment occurs in #4 journal 2d.

[0018] For this reason, in a conventional bearing structure where all bearings have approximately the same bearing support rigidity, , as shown by the chain line in Figure 3, the bearing load varies greatly depending on the location, and the #1 bearing , #3 bearing, and #5 bearing were larger.

[0019] In contrast, in the device of the present invention, the bearing portion with a large bearing load, that is, The #1 bearing 6a, the #3 bearing 6c, and the #5 bearing 6e are fitted with a bearing body 9 made of aluminum or the like. The secondary bearing 8 has low rigidity and has an elliptical cross section with a long axis in the vertical direction. There is.

[0020] Therefore, in #1 bearing 6a, #3 bearing 6c, and #5 bearing 6e, crankshaft 1 is easily displaced, and is rigidly supported in the intermediate #2 bearing 6b and #4 bearing 6d. Moreover, the rigidity of the bearing in the horizontal direction, where the rigidity is originally low, does not decrease further.

[0021] Therefore, as shown in FIG. 3, the bearing load distribution of each bearing 6a to 6e is indicated by a solid line. The vertical load shown in the figure and the horizontal load shown by the dashed line are also averaged.

[0022]

[Effect of the idea]

Since the structure is as explained above, according to the present invention, the bearing load can be distributed. Since the load is evened out, sound and vibration performance is improved, and the durability of the bearing metal is also improved. can do.

[Brief explanation of drawings]

FIG. 1 is a longitudinal sectional view showing an embodiment of the present invention.

FIG. 2 is a cross-sectional view showing a bearing in which a sub-bearing of another embodiment is interposed.

FIG. 3 is a diagram showing bearing loads at each bearing position in comparison with a conventional example.

FIG. 4 is a sectional view showing a conventional example.

[Explanation of symbols]

1...Crankshaft 5a, 5b, 5c, 5d...Counterweight 6a, 6b, 6c, 6d, 6e...Bearing 8…Secondary bearing 9...Bearing body

Claims (1)

[Scope of utility model registration request] Claim 1: In a bearing structure that supports a crankshaft, which has a multi-cylinder crank consisting of a crank journal, a web, and a crank pin, and a counterweight is attached to a limited web, the counterweight is attached. A sub-bearing is interposed between the crankshaft of the bearing part adjacent to the bearing web and the bearing body, and is made of a material with lower rigidity than the bearing body and has an elliptical cross-section with a longer diameter in the direction of the bearing body's higher rigidity. The crankshaft bearing structure is characterized by: