Cam follower roller device

Abstract

A cam follower roller device having a tappet extending along a longitudinal axis and including a cylindrical tappet body defining a bore. The device further having a rolling assembly arranged within the bore, and including a support body with a base and flanges, a pin and a roller. Each of the flanges of the support body is provided with an outwardly protruding portion that extends transversally from the flange towards the tappet body. The tappet body includes a support diametrically opposed and having each a transverse surface that cooperates with the protruding portion of the support body to longitudinally block the support body.

Claims

1. A cam follower roller device comprising: a tappet extending along a longitudinal axis and including a cylindrical tappet body defining a bore, a rolling assembly arranged within the bore, and having: a support body including a base and two longitudinal flanges that are diametrically opposed and that extend longitudinally from the base in the bore of the cylindrical tappet body, a pin centered on a transverse axis and including two opposite ends, each adapted to be supported by the two longitudinal flanges of the support body, and a roller rotatably mounted on the pin around the transverse axis, wherein each of the two longitudinal flanges of the support body is provided with an outwardly protruding portion that extends transversally from each of the two longitudinal flanges towards the cylindrical tappet body, and wherein the cylindrical tappet body provides a support diametrically opposed and having each a transverse surface that cooperates with the outwardly protruding portion of the support body to longitudinally block the support body.

2. The cam follower roller device according to claim 1, wherein the outwardly protruding portion of each of the two longitudinal flanges comprises an upper sloped surface, to ease the insertion of the outwardly protruding portion in the bore of the tappet body.

3. The cam follower roller device according to claim 1, wherein the bore of the tappet body comprises recesses each having a transverse surface that cooperates with the outwardly protruding portion of one of the two longitudinal flanges.

4. The cam follower roller device according to claim 3, wherein the recesses consist in openings provided through the cylindrical tappet body.

5. The cam follower roller device according to claim 4, wherein the second longitudinal retention means cooperate with an end of pin or with a flange of support body supporting the end of pin.

6. The cam follower roller device according to claim 1, wherein the cylindrical tappet body comprises a second longitudinal retention means for the rolling assembly.

7. The cam follower roller device according to claim 6, wherein the second longitudinal retention means of the cylindrical tappet body comprises at least one transverse portion extending from the cylindrical tappet body towards an interior of the tappet body.

8. The cam follower roller device according to claim 1, wherein the support body is integral, the outwardly protruding portions being formed by material deformation of the two longitudinal flanges.

9. The cam follower roller device according to claim 1, wherein the outwardly protruding portion of each of the two longitudinal flanges is in the transverse extension of the base.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The invention will now be explained in correspondence with the annexed figures, as illustrative examples, without restricting the object of the invention. In the annexed figures:

(2) FIG. 1 is a perspective top view of a cam follower roller device according to a first embodiment of the invention;

(3) FIG. 2 is a perspective bottom view of the cam follower roller device;

(4) FIG. 3 is a sectional view along line I-I of the cam follower roller device;

(5) FIG. 4 is a sectional view along line II-II of the cam follower roller device; and

(6) FIG. 5 is a perspective view of a support body dedicated to be arranged within the cam follower device.

DETAILED DESCRIPTION

(7) The cam follower roller device 1 represented on FIGS. 1 to 4 is adapted to equip an injection pump for a motor vehicle, preferably for a gasoline car, not shown.

(8) The device 1 comprises a tappet 2 and a rolling assembly 3 including a support body 4, a pin 5 and a roller 6. Pin 5 and roller 6 are centered on a transverse axis X5, while tappet 2 is centered along a longitudinal axis X2. Axis X2 and X5 are perpendicular.

(9) Hereinafter, to facilitate the special identification of the device 1 for these figures and for the following ones, the adjectives longitudinal and transverse and the adverbs longitudinally and transversally are defined relative to the axis X2 and X5, respectively. Thus, a longitudinal portion or part is parallel to the axis X2, whilst a transverse portion or part is perpendicular to the axis X2 and parallel to the axis X5.

(10) Tappet 2 comprises a cylindrical tappet body 7 centered on axis X2 and extending between an upper edge 8 and a lower edge 9. Tappet body 7 defines a cylindrical outer surface 10a and a cylindrical inner bore 10b delimiting a cavity 11 inside tappet 2. The cavity 11 is adapted to receive the rolling assembly 3. Tappet 2 is movable back and forth along axis X2, in a non-represented bore belonging to the injection pump or motor with surface 10a sliding in this bore. The surface 10a comprises anti-rotation means 10c, here a protruding portion dedicated to slide in an adapted groove provided in the bore, to prevent any rotation of the tappet 2 in this bore. Tappet 2 can be made of synthetic material, by example polyamide 6.6 (PA) or polyether-ether-ketone (PEEK), or made of metal, by example steel. Material of tappet 2 is chosen resistant to oil and its additives and temperature variations.

(11) Rolling assembly 3 is arranged within the cavity 11 of tappet body 7. Rolling assembly 3 comprises support body 4 forming a support element for pin 5 and roller 6. Support body 4 comprises a base 13 centered on transverse axis X5. Two lateral flanges 14, 15 are opposite each other relative to the base 13 and longitudinally extend from the base 13 towards the upper side of the device 1.

(12) Lateral flanges 14, 15 each comprises support means 16, 17 for the pin 5. The pin 5 is cylindrical and extends along the transverse axis X5. In the embodiment shown in FIG. 4, the support means 16, 17 of the lateral flanges 14, 15 each comprises a concave portion of semicircular profile and opened to the upper side of the device 1. The portions 16, 17 are adapted to receive ends 18, 19 of the pin 5. The profile of the concave portions 16, 17 fit the cylindrical ends 18, 19 of the pin 5. As an alternate not shown, the support means of the lateral flanges 14, 15 may comprise each a cylindrical bore wherein is inserted an end of the pin. As an embodiment not illustrated, at least one end 18 or 19 may be secured to the corresponding support means 16 or 17, respectively.

(13) Rolling assembly 3 further comprises roller 6 rotatably mounted on pin 5 by a roller bearing 20 with needles arranged between the pin 5 and roller 6. Alternatively, the roller bearing may be replaced by a sliding bushing. Roller 6 longitudinally extends from the upper edge 8 of tappet 2 so as to collaborate with a cam synchronized with the internal combustion engine camshaft, not shown.

(14) According to the invention, the rolling assembly 3 is longitudinally retained in the tappet 2 by means of protruding portions 21, 22.

(15) The flanges 14, 15 of the support body 4 are each provided with an outwardly protruding portion 21, 22 that extends transversally from the flange 14, 15 respectively, towards the bore 10b of the tappet body 7.

(16) The outwardly protruding portions 21, 22 define each a lower transverse surface 23, 24, respectively.

(17) The outwardly protruding portions 21, 22 comprise each an upper sloped surface 25, 26, respectively.

(18) The outwardly protruding portions 21, 22 are advantageously formed by material deformation of the flanges 14, 15.

(19) As an alternate embodiment not shown, the flanges may comprise bulges, in particular of semi-spherical shape or of truncated cone.

(20) According to the invention, the inner bore 10b of tappet body 7 comprises support means 27, 28 being diametrically opposed and having each a transverse surface 29, 30 respectively, that cooperates with the protruding portions 21, 22 respectively, of the support body 4.

(21) In the present embodiment of FIG. 4, the support means of tappet body 7 consist in inwardly protruding portions 27, 28 extending from the inner surface of bore 10b and directed towards the flanges 14, 15 respectively, of the support body 4. The inwardly protruding portions 27, 28 define each an upper transverse surface 29, 30, and a lower transverse surface 31, 32 respectively.

(22) The inwardly protruding portions 27, 28 are each topped by an opening 33, 34 provided through the thickness of tappet body 7, the lower edges of the openings defining the the upper transverse surfaces 29, 30. As an alternate embodiment not shown, the openings may be replaced by recesses.

(23) The lower transverse surfaces 23, 24 of the protruding portions 21, 22 extending from the support body are longitudinally supported by the upper transverse surfaces 29, 30 provided in the bore 10b of the tappet body 7.

(24) The pin 5, the roller bearing 20 and the roller 6 are first assembled together, and then installed on the support means 16, 17 provided to the flanges 14, 15 of the support body so as to form the rolling assembly 3. The assembly 3 is then longitudinally inserted in the cavity 11 defined by the bore 10b of the tappet body 7, from the lower edge 9 towards the upper edge 8. The flanges 14, 15 are pushed in the cavity 11 and then the sloped surfaces 25, 26 of the protruding portions of the support body come into abutment against the lower surfaces 31, 32 of the support means 27, 28 in the cavity 11. The assembly 3 is pushed so that the sloped surfaces 25, 26 slide against the support means 27, 28. The tappet body 7 is then locally deformed. The protruding portions 21, 22 then pass the support means 27, 28, the lower transverse surfaces 23, 24 resting against the upper transverse surfaces 29, 30 of the support means 27, 28. The support body 4, hence the rolling assembly 3, is then longitudinally blocked in the tappet body 7 in one direction.

(25) Tappet body 7 further comprises second longitudinal retention means 36, 37 for maintaining rolling assembly 3 within tappet 2. Second longitudinal retention means comprise each a transverse portion 36, 37 extending from the upper edge 8 of tappet body 7 directed towards the inner side of tappet body 7. Transverse portions 36, 37 are opposite each other towards the axis X2.

(26) The transverse portions 36, 37 longitudinally cover ends 18, 19 of pin 5 so as to prevent any dismounting of the pin 5, hence rolling assembly 3, from the upper side of tappet body 7.

(27) Rolling assembly 3 is then longitudinally maintained on one side by the cooperation between the outwardly protruding portions 21, 22 of support body 4 with inwardly protruding portions 27, 28 of tappet body 7, and on the other side by the second fixation means 36, 37 of tappet body 7.