Camshaft phaser and assembly method therefor

Abstract

The present disclosure relates to a camshaft phaser and assembling method thereof. The camshaft phaser includes an outer front cover, an inner front cover, a spring, a rotor, and a stator. The spring retainer of the outer front cover is substantially cup-shaped and includes a protrusion protruding radially outward from its peripheral wall. The inner front cover includes an inner front cover recess, and the rotor includes a rotor recess. The inner front cover and the rotor are configured so that when viewed axially, a part of the rotor recess is covered by the inner front cover. After the spring retainer is inserted axially into the inner front cover and rotor, the outer front cover rotates under the torque of the spring so that the protrusion of the spring retainer is stopped axially by the inner periphery of the inner front cover.

1 . A camshaft phaser comprising:
 an outer front cover having a spring retainer, the spring retainer having a protrusion extending radially outward from a peripheral wall of the spring retainer,   a rotor having a rotor recess extending radially outward,   a stator configured to surround the rotor,   an inner front cover fixed to the stator, the inner front cover having an inner front cover recess extending radially outward,   a spring, and   the inner front cover and the rotor are configured so that a part of the rotor recess is covered by the inner front cover, and   the outer front cover is configured to be rotated via the spring so that the protrusion of the spring retainer is stopped axially by an inner periphery of the inner front cover.   
     
     
         2 . The camshaft phaser according to  claim 1 , wherein the inner front cover includes a central hole through which the peripheral wall of the spring retainer passes, and the inner front cover recess is recessed radially outward from the central hole. 
     
     
         3 . The camshaft phaser according to  claim 1 , wherein the outer front cover is configured to be rotated by the spring so that the protrusion of the spring retainer abuts with a stop arranged on the rotor. 
     
     
         4 . The camshaft phaser according to  claim 1 , wherein a circumferential length of the inner front cover recess is greater than a circumferential length of the protrusion, and the circumferential length of the rotor recess is greater than the circumferential length of the inner front cover recess. 
     
     
         5 . The camshaft phaser according to  claim 1 , wherein a depth of the rotor recess on a top side of the rotor recess is greater than a depth of the rotor recess on a bottom side of the rotor recess. 
     
     
         6 . The camshaft phaser according to  claim 1 , wherein the protrusion includes an opening. 
     
     
         7 . The camshaft phaser according to  claim 6 , wherein the opening extends to the peripheral wall of the spring retainer on both circumferential sides of the protrusion. 
     
     
         8 . The camshaft phaser according to  claim 6 , wherein an axial ridge is formed by punching the peripheral wall of the spring retainer, and the opening and the protrusion are formed by removing a part of the axial ridge. 
     
     
         9 . The camshaft phaser according to  claim 1 , wherein the spring retainer includes two or more protrusions arranged circumferentially. 
     
     
         10 . The camshaft phaser according to  claim 1 , wherein the rotor includes a recessed portion for receiving a bottom of the spring retainer, and the rotor recess is recessed radially outward from the recessed portion. 
     
     
         11 . The camshaft phaser according to  claim 10 , wherein a top side of the recessed portion has a greater diameter than a bottom side of the recessed portion. 
     
     
         12 . The camshaft phaser according to  claim 3 , wherein the stop is a side wall of the rotor recess, the protrusion configured to abut with the side wall. 
     
     
         13 . The camshaft phaser according to  claim 1 , wherein the outer front cover is cup-shaped and surrounds three sides of the spring, the spring arranged between the outer front cover and the inner front cover. 
     
     
         14 . The camshaft phaser according to  claim 6 , wherein the opening defines a first portion of the protrusion and a second portion of the protrusion, the first portion arranged below the inner front cover, and the second portion arranged above the inner front cover. 
     
     
         15 . A method for assembling a camshaft phaser, the method comprising:
 providing a rotor, a stator, an inner front cover, and an outer front cover; the stator configured to surround the rotor;   mounting the inner front cover to the stator;   aligning a protrusion of the outer front cover to: i) an inner front cover recess, and ii) a rotor recess;   moving the outer front cover axially so that the protrusion passes through the inner front cover recess and is received by the rotor recess; and,   rotating the outer front cover so that: i) the protrusion and the inner front cover recess are circumferentially misaligned; ii) the outer front cover abuts with a rotational stop; and, iii) the protrusion is stopped axially by the inner front cover.   
     
     
         16 . The method of  claim 15 , wherein at least a portion of the protrusion is arranged between the inner front cover and a recessed portion of the rotor after rotating the outer front cover. 
     
     
         17 . The method of  claim 15 , wherein the rotating the outer front cover is accomplished via a spring that is installed on the outer front cover before the outer front cover is moved axially. 
     
     
         18 . The method of  claim 15 , wherein the protrusion is configured with an opening, the opening defining a first portion and a second portion of the protrusion, the first portion arranged between the inner front cover and a recessed portion of the rotor, and the second portion arranged between the inner front cover and a body of the outer front cover. 
     
     
         19 . The method of  claim 15 , wherein the inner front cover recess extends radially outward and the rotor recess extends radially outward. 
     
     
         20 . The method of  claim 15 , wherein a circumferential length of the inner front cover recess is greater than a circumferential length of the protrusion, and the circumferential length of the rotor recess is greater than the circumferential length of the inner front cover recess.