WO2006030257A1 - An engine - Google Patents

Abstract

This invention relates to an engine with an improved main bearing cap. The surfaces, in contact with the engine block, of the main bearing cap-used in the engine produced to attain the objectives of this invention- are processed to be inclined. The slope of these surfaces are from outside to inside in an ascending manner towards the main bearing.

Description

Description AN ENGINE

[001] Technical field of the invention

[002] This invention relates to an engine with an improved main bearing cap.

[003] Background of the invention

[004] As known, in internal combustion engines the crankshaft rotates in a main bearing.

This main bearing consists of caps inside the engine block located on a channel with half-circle shaped cross-section and including a channel with half-circle shaped cross- section.

[005] In the current state of the art, the main bearing cap is attached to the engine block following the completion of the processing of the semi-circle shaped surfaces where the bearing and the main bearing pivots are positioned and bolt holes are opened on the surfaces that have contact with the block. The assembly process is completed by tightening the bolts of the caps.

[006] As explained in the previous technical applications concerning the main bearing caps like the European Patent Document EP0056347 and the United States Patent Documents US5509387, US6076971, US5456228, US4474148, US4458640, US4453509 the surfaces in contact with the engine block are processed to be flat

(Fig.l).

[007] However, while tightening the bolts that fix the main bearing cap to the engine block deflections occur at the sides of the cap facing the bearing. Furthermore, after the main bearing pivot and the crankshaft are placed to the bearing, it is observed that the diameter increases in the direction of the cylindrical axis and decreases in per¬ pendicular direction resulting in an oval shape of the cavity (Fig.2).

[008] This deformation of the shape decreases the life-span of both the bearing and the crankshaft by disturbing the lubrication regime of the main bearing. Besides, since the contact surface is reduced, causing a decrease in the load carrying capacity of the bearing, the engine fails earlier than expected.

[009] Summary of the invention

[010] The aim of this invention is to develop an engine comprising a cap that prevents the deflections occurring at the contact surfaces of the main bearing cap after it is mounted.

[011] Yet one other aim of this invention is to develop an engine comprising a cap that prevents the oval shape occurring at the main bearing after it is mounted.

[012] The surfaces of the main bearing cap used in the engine which is produced to attain the objectives of this invention, are in contact with the engine block and are processed to be inclined. The slope of these surfaces are from outside to inside in an ascending manner towards the main bearing.

[013] As a result of the inclined surfaces of the engine cap which sets the scope of this invention , deflections do not occur while tightening the bolts. In addition to that, these surfaces prevent the formation of an oval shape by changing the stress distribution inside the cap. As a result, the problems encountered in the prior art methods are solved.

[014] Detailed description of the invention

[015] The engine designed to fulfill the above mentioned aim of this invention is il¬ lustrated on the accompanying drawings where;

[016] Fig. 1 - is the side view of a main bearing cap existing in the prior art.

[017] Fig. 2 - is the cross-sectional view showing the deformation at the engine block and main bearing cap existing in the prior art.

[018] Fig. 3 - is the side view of the main bearing cap of the engine considered in the present invention.

[019] Fig. 4 - is the cross-sectional assembly view of the engine according to the present invention.

[020] Parts shown on figures are numbered as follows;

[021] 1. Engine

1. Engine Block

2. Main Bearing

3. Main Bearing Cap

4. Contact Surface

5. Inclination

6. Bolt [022] X: Cap axis

[023] The engine (1) of the present invention comprises an engine block (2) and at least one bearing cap that is fastened to the block with bolts (7). The crankshaft (not shown in figures) is assembled to the main bearing (3) which is between the main bearing cap(s) (4) and engine block (2).

[024] The surfaces (5) of the main bearing cap (4) of the present invention, which are in contact with the engine block, are processed to be inclined at a certain degree (6). These inclinations are in the outer direction from the both sides of cap axis. In other words, contact surfaces ascend from outside towards the bearing.

[025] This inclination (6) is between 0.1° and 1°. However, 0.2° - 0.4° inclinations are utilized in the preferred embodiment of the present invention.

[026] Industrial aplications of the present invention

[027] While mounting the main bearing cap (4) of the engine which sets the scope of the present invention to the engine block, the higher portions of the contact surfaces of the cap touches first. As the bolts (7) are tightened, the gap between the engine block and contact surface closes. However, due to the inclined shape of the surface, a de¬ formation in the bearing does not take place.

[028] In line with this main principle, it is possible to develop various applications of mechanism of the present invention although the invention is actually what is claimed and can not be limited to the examples explained here.

Claims

Claims

[001] An engine characterized by a main bearing cap (4) the surfaces (5) of which in contact with the engine block are processed with a certain inclination in the outer direction from the two sides (6)of the cap axis (X),including an engine block (2), at least one main bearing cap (4) fixed to this block with bolts (7), a crankshaft (not shown in the figures) assembled to the main bearing (3) between the engine block (2) and main bearing cap(s) (4).

[002] 2. An engine as defined in Claim 1, characterized by an inclination (6) between

0.1° and 1°.