JPH04307144A - Connecting structure for crankshaft and torque converter - Google Patents

Abstract

PURPOSE:To slenderize a crankshaft as well as to make it lighter in weight by forming a hole in a terminal of the crankshaft, while connecting an interval between the terminal of the crankshaft and a pilot shaft of a torque converter by means of a bearing being slidable along an inner circumferential surface where the hole is curved. CONSTITUTION:In a connecting structure of a crankshaft 20 and a pilot shaft 33 for a torque converter, a hole 22 with an inner diameter D2 larger than an outer diameter D1 of the pilot shaft 33 is formed in a member attached to a terminal of the crankshaft 20, namely, the turning center part of a flywheel 21. In addition, an inner circumferential surface 22a being curved along the axial direction is formed in this hole 22. Moreover, an interval between the flywheel 21 and the pilot shaft 33 is connected to each other by an outer race 23 slidable along a curve 22a, an inner race 24 attached to an outer circumferential surface 33a of the pilot shaft 33, and a ball 25 interposed between them. With this constitution, such a bearing as being free of shaft connecting angles is constituted, through which bending force and deflection force in a connecting part are absorbed.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a connecting structure between an engine and an automatic transmission, and more particularly to a connecting structure between a crankshaft and a torque converter.

0002

[Prior Art] As a technique for reducing torsional vibration of a crankshaft, the present applicant has previously proposed a connection structure in which a damper is interposed between a crankshaft and a torque converter (Utility Model Application No. 58-144146). (see official bulletin). According to this technology, as shown in FIG.
The rotational motion R of 0 is caused by the flywheel 11 and the damper 1.
2 to the case 13 of the torque converter, and the damper 12 can reduce vibration components in the rotational direction and torsional vibration of the crankshaft.

0003

However, in such a conventional connection structure, a recess 11a is formed in the center of rotation of the flywheel 11, and the pilot shaft of the torque converter (also referred to as the pilot converter portion) is formed in the recess 11a. ) 13a, so
As the torque converter swings around (see arrow L in the figure), bending (and swinging) force acts on the connecting portion between the recess 11a and the pilot shaft 13a, and in order to counteract this bending force, the crankshaft 10 is made thicker. (Therefore, it is heavy), and as a result, the engine load increases, resulting in a decrease in fuel efficiency.

[0004] Incidentally, the swing of the torque converter is
The main cause is an unbalanced couple in the torque converter caused by errors in processing accuracy and assembly accuracy of the torque converter. Therefore, an object of the present invention is to make the crankshaft thinner (therefore lighter) by devising the connection structure between the crankshaft and the torque converter, thereby reducing the engine load and improving fuel efficiency.

[0005]

[Means for Solving the Problems] In order to achieve the above object, the present invention provides a hole having an inner diameter larger than the outer diameter of the pilot shaft of a torque converter at the end of the crankshaft or a member attached to the end. an end of the crankshaft or a member attached to the end by means of a bearing having an inner circumferential surface curved along the axial direction in the hole and an outer circumferential surface capable of sliding along the curved surface; and the pilot shaft of the torque converter.

[0006]

[Operation] In the present invention, a bearing is formed between the crankshaft and the torque converter, and the shaft connection angle can be adjusted freely, and the above-mentioned bending (and wobbling) force is absorbed by this bearing. Therefore, the sound vibration performance of the crankshaft can be improved, and the crankshaft can be made thinner (lighter).

[0007]

Embodiments Hereinafter, embodiments of the present invention will be explained based on the drawings. FIG. 1 is a diagram showing an embodiment of a connection structure between a crankshaft and a torque converter according to the present invention. In FIG. 1, 20 is a crankshaft of an engine, 21 is a flywheel as a member fixed to the end of the crankshaft 20, 30 is a housing of an automatic transmission, and 31 is a cover of a torque converter. A plate 32 that faces the flywheel 21 and is relatively rotatable is fixed to the cover 31, and the plate 32 and the flywheel 21 are connected by a damper 40 that exerts an elastic force in the direction of rotation. There is.

The key point of this embodiment is the connection structure between the crankshaft 20 and the pilot shaft (also referred to as the pilot converter portion) 33 of the torque converter. That is, the hole 22 having an inner diameter D2 larger than the outer diameter D1 of the pilot shaft 33 is formed in a member attached to the end of the crankshaft 20, that is, in the rotational center portion of the flywheel 21, and a hole 22 is formed in the center of rotation of the flywheel 21 along the axial direction. An outer race 23 that forms a curved inner circumferential surface 22a and is slidable along this curved surface (inner circumferential surface 22a), an inner race 24 attached to an outer circumferential surface 33a of a pilot shaft 33, and The ball 25 between the outer race 23 and the inner race 24 connects the member attached to the end of the crankshaft 20, that is, the flywheel 21, and the pilot shaft 33 of the torque converter. Note that the hole 22 is
It may also be formed at the end portion of the crankshaft 20. The inner race 24, outer race 23, and ball 25 function as a bearing having an outer peripheral surface that is slidable along the curved surface of the hole 22.

In such a configuration, if the torque converter oscillates (see arrow L in the figure) due to an unbalanced couple of the torque converter due to processing accuracy errors or assembly accuracy errors, this excitation force acts as a bending (and swinging) force on the connecting portion between the crankshaft and the torque converter, but in this embodiment, the connecting portion can be bent freely in the direction of the excitation force, thereby reducing vibration transmission to the crankshaft 20. It can be avoided.

That is, the torque converter cover 31
When tilts in the direction of arrow L in the figure, the pilot shaft 33, inner race 24, and outer race 23
However, since the outer race 23 and the hole 22 of the flywheel 21 are in sliding contact with each other on a curved surface, the tilting movement is absorbed between the outer race 23 and the hole 22 of the flywheel 21. , or more (crankshaft 2
0 side) is not transmitted.

[0011] Therefore, the crankshaft 2 suffers from bending and runout vibrations generated using the torque converter side as an excitation source.
Transmission to the zero side can be avoided, sound vibration performance can be improved, and the crankshaft 20 can be designed to be thinner (lighter), reducing engine load and improving fuel efficiency. In the above embodiment, a ball bearing with an outer race having a curved outer circumferential surface was used as the bearing.
It may also be a plain bearing whose outer peripheral surface is simply curved.

0012

According to the present invention, since the connection structure between the crankshaft and the torque converter is devised, the crankshaft can be made thinner (and therefore lighter), reducing engine load and improving fuel efficiency.

[Brief explanation of drawings]

FIG. 1 is a sectional view of a main part of an embodiment.

FIG. 2 is a sectional view of a main part of a conventional example.

[Explanation of symbols]

20: Crankshaft 21: Flywheel (member) 22: Hole 22a: Inner peripheral surface 23: Outer lace 24: Inner lace 25 balls 33: Pilot axis 33a outer peripheral surface

Claims (1)

[Claims] Claim 1: A hole having an inner diameter larger than the outer diameter of a pilot shaft of a torque converter is formed in the end of the crankshaft or a member attached to the end, and an inner periphery curved along the axial direction of the hole is provided. A bearing that forms a surface and has an outer circumferential surface that can slide along the curved surface connects the end of the crankshaft or a member attached to the end and the pilot shaft of the torque converter. A connecting structure between the crankshaft and torque converter.