JP2009120094A5

JP2009120094A5 -

Info

Publication number: JP2009120094A5
Application number: JP2007297874A
Authority: JP
Filing date: 2007-11-16
Publication date: 2011-03-10
Anticipated expiration: 2027-11-16

Claims

A power steering device for transmitting a steering force of a steering wheel to a steered system while adding a steering assist force generated by a steering assist force generating means,
A housing;
An input shaft that is rotatably supported by the housing and receives a steering force from the handle;
A pinion shaft rotatably supported by the housing in a state of being coaxially connected to the input shaft;
A speed reduction mechanism for transmitting a steering assist force from the steering assist force generating means to the pinion shaft;
A rack shaft that converts the rotational motion of the pinion shaft into a linear motion and transmits the linear motion to the steered system ;
A first ball bearing for pivotally supporting the pinion shaft on the housing at a lower portion thereof;
A second ball bearing for pivotally supporting the pinion shaft on the housing at an upper portion thereof;
With
The housing includes a gear case that supports the speed reduction mechanism; a gear box that is adjacent to the gear case and accommodates the rack shaft and the pinion portion of the pinion shaft that meshes with the rack shaft; and the gear box that is adjacent to the gear box and the input A stub case that houses the shaft,
The gear box is provided with a pinion shaft housing chamber that penetrates the gear box in the insertion direction of the pinion shaft and has a substantially oval cross-sectional shape in a direction orthogonal to the insertion direction.
The pinion shaft is provided with an annular relief recess for temporarily retracting the second ball bearing at the time of assembly at the upper portion of the pinion shaft above the pinion portion.
The rack shaft is provided with a group of rack teeth and a relief portion at one end of the rack tooth group for temporarily avoiding interference with the pinion shaft during assembly. A featured power steering device.

It is a manufacturing method of the power steering device according to claim 1,
The coaxial coupling of the input shaft and the pinion shaft, by the pinion shaft is operatively connected to the speed reduction mechanism with attached rotatably to the gear case with the first ball bearing, primary assembly A first step of constructing the body;
The gear box is arranged so that the pinion shaft of the primary assembly is relatively offset toward one end in the major axis direction of the pinion shaft accommodating chamber having a substantially oval cross-sectional shape. A second step of inserting the primary assembly and inserting the rack shaft into the pinion shaft accommodating chamber of the gear box in the offset arrangement state;
By adjusting the position of the gearbox with the pinion portion of the pinion shaft facing the clearance portion of the rack shaft, the pinion shaft of the primary assembly is positioned at a specified position in the pinion shaft housing chamber. and, third constitution with the pinion shaft with said second ball bearing rotatably mounted to the gear box, by coupling the gearbox to the gear case, a second assembly Process,
And a fourth step of pivotally mounting the input shaft of the secondary assembly to the stub case using a third ball bearing and connecting the stub case to the gear box. A method for manufacturing a power steering apparatus.