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Valve timing control apparatus for internal combustion engine

a timing control and internal combustion engine technology, applied in mechanical equipment, engines, machines/engines, etc., can solve problems such as inability to control the timing control apparatus, and achieve the effect of suppressing the deformation of the eccentric cam

Inactive Publication Date: 2013-08-15
HITACHI AUTOMOTIVE SYST LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Benefits of technology

The patent text describes a device that reduces the speed of rotation from an electric motor. It uses a speed reducer with an engagement portion to transmit the reduced rotational force to a follower rotation member. The device also integrates an eccentric cam with the motor output shaft to prevent plastic deformation. The technical effect of this innovation is to improve the precision and durability of the valve timing control apparatus.

Problems solved by technology

As a result, precision of the clearance between the respective balls and the ball recesses is deteriorated, thereby causing an unstable control condition of the valve timing control apparatus.

Method used

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  • Valve timing control apparatus for internal combustion engine
  • Valve timing control apparatus for internal combustion engine
  • Valve timing control apparatus for internal combustion engine

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second embodiment

[0141]Referring to FIG. 7 and FIG. 8, valve timing control apparatus 200 according to a second embodiment will be explained hereinafter. The second embodiment differs from the first embodiment in construction of large-diameter portion 13a of motor shaft 13 and omission of washer 55. As shown in FIG. 7 and FIG. 8, in valve timing control apparatus 200, large-diameter portion 13a of motor shaft 13 has radial thickness Q slightly larger than that of small-diameter portion 13b, and axial length L increased by a thickness of washer 55 of the first embodiment.

[0142]An inner peripheral side of tip end surface (i.e., rear end surface) 13f of large-diameter portion 13a is contacted with the front end surface of eccentric cam 39 in the axial direction. On the other hand, an outer peripheral side of tip end surface 13f is contacted with a front end surface of inner race 47a of intermediate-diameter ball bearing 47. Accordingly, tip end surface 13f of large-diameter portion 13a and snap ring 56...

third embodiment

[0145]Referring to FIG. 9, valve timing control apparatus 300 according to a third embodiment will be explained hereinafter. The third embodiment differs from the first and second embodiments in construction of needle bearing 38, large-diameter portion 13a of motor shaft 13, and eccentric cam 39. As shown in FIG. 9, in valve timing control apparatus 300, needle bearing 38 has an outer diameter larger than those of the first and second embodiments. Further, large-diameter portion 13a of motor shaft 13 includes annular cutout portion 13g formed in the inner peripheral surface of tip end portion 13e. A front side of needle bearing 38 is disposed in cutout portion 13g. Further, eccentric cam 39 has a thickness slightly smaller than that of the first embodiment.

[0146]With the construction of needle bearing 38 having the larger outer diameter, it is possible to enhance rigidity of needle bearing 38 supporting motor shaft 13 and eccentric cam 39 and thereby increase strength of coupling be...

fourth embodiment

[0148]Referring to FIG. 10, valve timing control apparatus 400 according to a fourth embodiment will be explained hereinafter. The fourth embodiment differs from the first embodiment in construction of needle bearing 38 and large-diameter portion 13a of motor shaft 13, and omission of washer 55. As shown in FIG. 10, in valve timing control apparatus 400, needle bearing 38 has an outer diameter larger than those of the first and second embodiments. Further, large-diameter portion 13a of motor shaft 13 has radial thickness Q slightly larger than that of small-diameter portion 13b, and axial length L increased by a thickness of washer 55 of the first embodiment, like in the second embodiment. In the fourth embodiment, washer 55 can be omitted, and rigidity of needle bearing 38 supporting motor shaft 13 and eccentric cam 39 can be enhanced.

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PUM

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Abstract

A valve timing control apparatus for an internal combustion engine, including a drive rotation member, a follower rotation member, an electric motor, and a speed reducer including an internal gear portion, an eccentric cam on an inner peripheral side of the internal gear portion, rollers disposed between the internal gear portion and the eccentric cam, and a cage rotatable relative to the internal gear portion by rotation of the eccentric cam. A motor output shaft is arranged in series relative to the eccentric cam in an axial direction thereof. A needle bearing is rollably disposed on a part of an outer peripheral surface of the follower rotation member. The eccentric cam and the motor output shaft are press-fitted onto an outer peripheral portion of the needle bearing. The needle bearing extends over both the eccentric cam and the motor output shaft.

Description

BACKGROUND OF THE INVENTION[0001]The present invention relates to a valve timing control apparatus for an internal combustion engine, which variably controls opening and closing timings of an engine valve, i.e., an intake valve and / or an exhaust valve.[0002]Recently, there has been proposed a valve timing control apparatus adapted to change a relative rotational phase between a crankshaft and a camshaft by transmitting a rotational force of an electric motor to the camshaft through a speed reducer and control opening and closing timings of an engine valve.[0003]As well known, alternating torque is generated in the camshaft of the internal combustion engine due to a spring force of a valve spring that biases the engine valve in a closing direction of the engine valve.[0004]For instance, Japanese Patent Application Unexamined Publication No. 2010-255543 discloses a valve timing control apparatus equipped with a speed reducer. The speed reducer includes an eccentric drive plate having ...

Claims

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Application Information

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Patent Type & Authority Applications(United States)
IPC IPC(8): F01L1/344
CPCF01L1/352F16C19/54F01L2820/032F01L2250/02
Inventor TADOKORO, RYOKOKUBO, NAOKIYAMANAKA, ATSUSHIKAWADA, SHINICHI
Owner HITACHI AUTOMOTIVE SYST LTD
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