CROSS-REFERENCE TO RELATED APPLICATION

[0001] This application claims the benefit of Indian Provisional Patent Application 20161 1039898 filed on November 22, 2016. The entire disclosure of the above application is incorporated herein by reference.

FIELD

[0002] The present disclosure relates generally to hydraulic lash adjusting tappets of the type having a roller follower for contacting a cam shaft in an internal combustion engine valve train.

BACKGROUND

[0003] Roller lifters can be used in an engine valvetrain to reduce friction and as a result provide increased fuel economy. In other advantages, a roller lifter can open a valve quicker and for a longer period of time than a flat tappet lifter. In this regard, airflow can be attained quicker and longer increasing the ability to create power.

[0004] The background description provided herein is for the purpose of generally presenting the context of the disclosure. Work of the presently named inventors, to the extent it is described in this background section, as well as aspects of the description that may not otherwise qualify as prior art at the time of filing, are neither expressly nor impliedly admitted as prior art against the present disclosure.

SUMMARY

[0005] An engine roller lifter for use in a valve train of an internal combustion engine includes a body, a groove, a connecting channel, an anti-rotation ring and a roller. The body has an outer peripheral surface configured for sliding movement in a bore provided in the engine. The bore is supplied by an oil passage communicating therewith. The body defines an axial pocket that receives a plunger therein and a transverse passage. The groove is formed in the body and inset from the outer peripheral surface. The groove has a central groove portion, an upper groove portion and a lower groove portion. The connecting channel is formed in the body and inset from the outer peripheral surface. The connecting channel is fluidly connecting the groove and the transverse passage. The anti-rotation ring is received at the groove and has an upper nose portion that is received at the upper groove portion and a lower nose portion that is received at the lower groove portion. The roller bearing is rotatably mounted to the body and is configured for rolling contact with an engine camshaft. Oil is received at the groove from the bore flows around the anti-rotation ring, along the connecting channel and into the transverse passage and onto the roller bearing. The groove can be offset from and out of alignment with the oil passage.

[0006] According to other features, the anti-rotation ring further includes an anti- rotation protrusion that extends across portions of the central ring body, the upper nose portion and the lower nose portion. The anti-rotation protrusion includes a central extension portion bound on opposite ends by lateral extension walls. The lateral extension walls have a first radius. The central extension portion has a second radius. The second radius is less than the first radius. The groove has a first height in an axial direction and the anti-rotation ring has a second height in the axial direction. The first height is greater than the second height.

[0007] In other features, the connecting channel is transverse to an axis of the transverse passage. The transverse passage extends entirely through the body. The body further defines an inset formed in the outer peripheral surface. An oil inlet hole is defined in the body that connects the inset with the axial pocket. The oil inlet hole is configured to communicate oil between the outer peripheral surface and the plunger. The anti-rotation ring is snap fit onto the groove of the body. The anti-rotation ring protrusion is configured to create a line contact with an opposing surface of a bore slot defined in the engine bore. The groove can extend along a groove depth into the peripheral surface. The connecting channel extends along a connecting channel depth into the peripheral surface. The groove depth is greater than the connection channel depth. The connecting channel extends axially along the peripheral surface in a direction transverse to the transverse passage.

[0008] An engine roller lifter for use in a valve train of an internal combustion engine according to another example of the present disclosure includes a body, a groove, a connecting channel, an anti-rotation ring and a roller. The body has an outer peripheral surface configured for sliding movement in a bore provided in the engine. The bore is supplied oil by an oil passage communicating therewith. The body defines a transverse passage. The groove is formed around the body and is inset from the outer peripheral surface. The connecting channel is formed in the body and is inset from the outer peripheral surface. The connecting channel fluidly connects the groove and the transverse passage. The anti-rotation ring is received at the groove. The anti-rotation ring has a central ring body, an upper nose portion and a lower nose portion. The anti- rotation protrusion includes a central extension portion is bound on opposite side by lateral extension walls. The lateral extension walls have a first radius and the central extension portion has a second radius. The second radius is less than the first radius. The roller bearing is rotatably mounted to the body and is configured for rolling contact with an engine camshaft. Oil is received at the groove from the bore flows along the connecting channel, into the transverse passage and onto the roller bearing.

[0009] According to other features, the anti-rotation ring is snap fit onto the groove of the body. The groove extends along a groove depth into the peripheral surface. The connecting channel extends along a connecting channel depth into the peripheral surface. The groove depth is greater than the connection channel depth. The connecting channel extends axially along the peripheral surface in a direction transverse to the transverse passage.

[0010] An engine roller lifter for use in a valve train of an internal combustion engine according to another example of the present disclosure includes a body, a groove, a connecting channel, an anti-rotation ring and a roller. The body extends along a longitudinal axis and has an outer peripheral surface configured for sliding movement in a bore provided in the engine. The bore is supplied oil by an oil passage communicating therewith. The body defines an axial pocket that receives a plunger. The body further defines a transverse passage. The groove is formed around the body and is inset from the outer peripheral surface. The groove has an upper groove portion inset into the body above a central groove portion and a lower groove portion inset into the body below the central groove portion. The connecting channel is formed in the body along an axis generally parallel to the longitudinal axis of the body and is inset from the outer peripheral surface. The connecting channel fluidly connects the groove and the transverse passage. The anti-rotation ring is received at the groove. The anti- rotation ring has a central ring body, an upper nose portion and a lower nose portion. The anti-rotation protrusion includes a central extension portion is bound on opposite side by lateral extension walls. The lateral extension walls have a first radius and the central extension portion has a second radius. The second radius is less than the first radius. The roller bearing is rotatably mounted to the body and is configured for rolling contact with an engine camshaft. Oil received at the groove from the bore flows around the anti-rotation ring, along the connecting channel, into the transverse passage and onto the roller bearing.

[0011] According to additional features, the groove extends along a groove depth into the peripheral surface. The connecting channel extends along a connecting channel depth into the peripheral surface. The groove depth is greater than the connection channel depth. The transverse passage extends entirely through the body. The groove has a first height in an axial direction and the anti-rotation ring has a second height at the ring body in the axial direction. The first height is greater than the second height. The anti-rotation protrusion has a third height in the axial direction, the third height is greater than the second height.

BRIEF DESCRIPTION OF THE DRAWINGS

[0012] The present disclosure will become more fully understood from the detailed description and the accompanying drawings, wherein:

[0013] FIG. 1 is a roller lifter constructed in accordance to one example of the present disclosure and shown in an exemplary Type V valve train arrangement;

[0014] FIG. 2 is a first side perspective view of the roller lifter of FIG. 1 ;

[0015] FIG. 3 is a second side perspective view of the roller lifter of FIG. 2 and shown with an anti-rotation clip in exploded view;

[0016] FIG. 4 is cross-sectional view of the roller lifter taken along lines 4-4 of FIG. 2; [0017] FIG. 5 is a side view of the roller lifter shown received in an exemplary guide bore of a cylinder head of an internal combustion engine illustrating details of an exemplary oil feed circuit;

[0018] FIG. 5A is a detail view of an interface between an anti-rotation ring and an opposing bore slot in the cylinder head;

[0019] FIG. 6 is a cross-sectional view of the roller lifter taken along lines 6-6 of FIG.

2;

[0020] FIG. 6A is a detail view of area 6A of FIG. 6; and

[0021] FIG. 7 is a first side view of a roller lifter and anti-rotation ring constructed in accordance to additional features of the present disclosure;

[0022] FIG. 8 is a front perspective view of the anti-rotation ring of FIG. 7;

[0023] FIG. 9 is a front view of the roller lifter of FIG. 7 shown with the anti-rotation ring removed;

[0024] FIG. 10 is a side view of the roller lifter of FIG. 9;

[0025] FIG. 1 1 is a top perspective view of an exemplary bore slot in a cylinder head according to one example;

[0026] FIG. 12 is a side view of a roller lifter constructed in accordance to another example and received in an exemplary guide bore of a cylinder head of an internal combustion engine and shown in a lifted position where an exemplary oil feed circuit does not communicate oil to a groove in the roller lifter; and

[0027] FIG. 13 is a side view of the roller lifter of FIG. 12 and shown with the roller lifter moved downward in the guide bore relative to the position shown in FIG. 12.

DETAILED DESCRIPTION

[0028] With initial reference to FIG. 1 , a roller lifter constructed in accordance to one example of the present disclosure is shown and generally identified at reference number 10. The roller lifter 10 is shown as part of a Type V arrangement. It will be appreciated that while the roller lifter 10 is shown in a Type V arrangement, the roller lifter 10 may be used in other arrangements within the scope of the present disclosure. In this regard, the features described herein associated with the roller lifter 10 can be suitable to a wide variety of applications. A cam lobe 12 indirectly drives a first end of a rocker arm 14 with a push rod 16. It will be appreciated that in some configurations, such as an overhead cam, the roller lifter 10 may be a direct link between the cam lobe 12 and the rocker arm 14. A second end of the rocker arm 14 actuates a valve 20. As the cam lobe 12 rotates, the rocker arm 14 pivots about a fixed shaft 22.

[0029] With additional reference now to FIGS. 2-5, the roller lifter 10 will be described in greater detail. The roller lifter 10 generally includes a body 30, a leakdown assembly 32 received within the body 30, a roller bearing 34 rotatably mounted to the body 30 and an anti-rotation ring 40. The body 30 includes an outer peripheral surface 42 configured for sliding movement in a bore 48 provided in a cylinder head 50 of an internal combustion engine 52 (FIG. 5).

[0030] The body 30 can define an axial pocket 60 that receives the leakdown assembly 32. The leakdown assembly 32 can include a plunger 62, a check ball 64, a first biasing member 66, a cage 70 and a second biasing member 72. An inset 76 can be provided in the body 30 at the outer peripheral surface 42. An oil inlet hole 80 (FIG. 4) can be defined in the body 30 that connects the inset 76 with the axial pocket 60. The oil inlet hole 80 can be configured to communicate oil between the outer peripheral surface 42 and the plunger 62 of the leakdown assembly 32.

[0031] With continued reference to FIGS. 1 -5 and additional reference to FIG. 6, additional features of the body 30 will be described. The body 30 can define a transverse passage 84. The transverse passage 84 can extend entirely through the body 30 along an axis generally transverse to a longitudinal axis 88 of the body 30. A pair of clips 90 are nestingly received in corresponding grooves 92 formed on the body 30 for capturing an axle 94 of the roller bearing 34 in the roller lifter 10. As identified above, the roller bearing 34 can be configured for rolling contact with the engine camshaft 12.

[0032] The body 30 includes a groove 100 formed therein and inset from the outer peripheral surface 42. The groove 100 has a groove width 102 (FIG. 3) and a groove depth 104 (FIG. 4). The groove 100 is configured to receive the anti-rotation ring 40 thereat (FIGS. 2 and 3).

[0033] With particular reference to FIG. 3, the anti-rotation ring 40 will be further described. The anti-rotation ring 40 generally includes a ring body 1 10 having an anti- rotation protrusion 1 12 extending therefrom. The anti-rotation protrusion 112 extends radially beyond the outer peripheral surface 42 of the body 30 in an installed position. The anti-rotation protrusion 1 12 is configured to locate or key in a corresponding bore slot 1 16 in the cylinder head 50 for inhibiting rotation of the roller lifter 10 about the axis 88 during operation. The anti-rotation ring 40 can be snap fit into the groove 100. The anti-rotation ring 40 has a first height 120 (FIG. 3) at the ring body 1 10 and a second height 122 (FIG. 5) at the anti-rotation protrusion 1 12. In one example the second height 122 is greater than the first height 120. In one advantage, the snap fit relationship of the anti-rotation ring 40 and the groove 100 allows for far looser tolerances as compared to a conventional pin press-fit into a hole. In this regard, the configuration can be less costly and provide greater surface area contact (line contact along the second height 122 of the anti-rotation protrusion 112 with the surface of the bore slot 1 16) rather than a conventional point contact offered by a round headed pin with the cylinder head 50. See also FIG. 5A. The anti-rotation ring 40 reduces stress and thus wear on the bore slot 1 16 and the anti-rotation protrusion 1 12.

[0034] The body 30 includes a connecting channel 130 formed therein. The connecting channel 130 can be inset a connecting channel depth 134 from the outer peripheral surface 42. In one example the connecting channel depth 134 is less than the groove depth 104. The connecting channel 130 fluidly connects the groove 100 with the transverse passage 84.

[0035] During operation, oil received at the groove 100 from an oil passage 140 (FIG. 5) defined in the cylinder head 50 of the engine 52 flows around the anti-rotation ring 40, along (down) the connecting channel 130, into the transverse passage 84 and onto the roller bearing 34. Explained further, oil is permitted to flow around the ring body 1 10 of the anti-rotation ring 40 within the groove 100. In one example, the ring height 120 is less than the groove width 102 allowing a predetermined rate of oil to pass between the ring body 1 10 and the body 30 of the roller lifter 10. The groove 100 is therefore dual-purpose allowing for receipt of the anti-rotation clip 40 and providing an oil pathway to communicate oil to the roller bearing 34. Furthermore, because the connecting channel 130 is inset or recessed into the outer peripheral surface 42 of the body, a predetermined amount of oil is permitted to flow from the groove 100 to the transverse passage 84. See also FIG. 6A. In the example shown, the connecting channel depth 134 is minimal so as to control the rate of oil flow to a predetermined value. In one configuration, the connecting channel 130 can extend along an axis that is parallel to the longitudinal axis 88.

[0036] With initial reference to FIGS. 7-1 1 , a roller lifter constructed in accordance to another example of the present disclosure is shown and generally identified at reference number 210. The roller lifter 210 may be used as part of a Type V arrangement discussed above with respect to FIG. 1. It will be appreciated that while the roller lifter 210 is shown in a Type V arrangement, the roller lifter 210 may be used in other arrangements within the scope of the present disclosure. The roller lifter 210 generally includes a body 230, a leakdown assembly 232 received within the body 230 and an anti-rotation ring 240. It will be appreciated that the roller lifter 210 can also include a roller bearing such as roller bearing 34 (FIG. 2) rotatably mounted to the body 230. The body 230 includes an outer peripheral surface 242 configured for sliding movement in a bore 248 (FIG. 11 ) provided in a cylinder head 250 of an internal combustion engine.

[0037] The body 230 can define an axial pocket 260 that receives the leakdown assembly 232 and a plunger 262. The leakdown assembly 232 can include similar components as discussed above and shown in FIG. 4 such as the check ball 64, the first biasing member 66, the cage 70 and the second biasing member 72. Other components and configurations are contemplated. An inset 276 (FIG. 10) can be provided in the body 230 at the outer peripheral surface 242. An oil inlet hole 280 (FIG. 10) can be defined in the body 230 that connects the inset 276 with the axial pocket 260. The oil inlet hole 280 can be configured to communicate oil between the outer peripheral surface 242 and the plunger 262 of the leakdown assembly 232.

[0038] With particular reference to FIGS. 9 and 10, additional features of the body 230 will be described. The body 230 can define a transverse passage 284. The transverse passage 284 can extend entirely through the body 230 along an axis generally transverse to a longitudinal axis 288 of the body 230.

[0039] The body 230 includes a groove 300 formed therein and inset from the outer peripheral surface 242. The groove 300 has a central groove portion 302, an upper groove portion 304 and a lower groove portion 306. In the example shown, the upper groove portion 304 is inset into the body 230 generally above the central groove portion 302 while the lower groove portion 306 is inset into the body 230 generally below the central groove portion 302. The central groove portion 302 includes a groove width 312 (FIG. 9) and a groove depth 314 (FIG. 10). The groove 300 is configured to receive the anti-rotation ring 240 thereat as will be discussed below. The upper groove portion 304 is configured to receive the upper nose portion 312 of the anti-rotation ring 240. The lower groove portion 306 is configured to receive the lower nose portion 314 of the anti- rotation ring 240.

[0040] With particular reference to FIG. 8, the anti-rotation ring 240 will be further described. The anti-rotation ring 240 generally includes a central ring body 310, an upper nose portion 312 and a lower nose portion 314. The anti-rotation ring 240 further includes an extended nose or anti-rotation protrusion 332 extending therefrom. In the example shown, the anti-rotation protrusion 332 extends across portions of all of the central ring body 310, the upper nose portion 312 and the lower nose portion 314. The anti-rotation protrusion 332 generally includes a central extension portion 334 bound on opposite ends by lateral extension walls 336. The lateral extension walls 336 can take a similar radius as the central ring body 310 while the central extension portion 334 has a smaller radius.

[0041] Shown in FIG.8, the lateral extension walls 336 have a radius R1 , the central ring body 310 has a radius R2 and the central extension portion 334 has a radius R3. The lateral extension walls 336 can provide a smooth structural transition from the central ring body 310 to the central extension portion 334. In this regard, the lateral extension walls 336 can provide a relatively widely distributed surface contact onto the body 230 of the roller lifter 210. The lateral extension walls 336 can improve the structural integrity of the anti-rotation ring 240 as a whole.

[0042] The anti-rotation protrusion 332 extends radially beyond the outer peripheral surface 242 of the body 230 in an installed position. The anti-rotation protrusion 332 is configured to locate or key in the corresponding bore slot 248 of a bore 249 in the cylinder head 250 for inhibiting rotation of the roller lifter 210 about the axis 288 during operation. The anti-rotation ring 240 can be snap fit into the groove 300. The anti- rotation ring 240 has a first height 340 (FIG. 8) at the central ring body 310 and a second height 342 (FIG. 5) at the anti-rotation protrusion 332. The second height 122 is greater than the first height 120. In one advantage, the snap fit relationship of the anti- rotation ring 240 and the groove 300 allows for far looser tolerances as compared to a conventional pin press-fit into a hole. In this regard, the configuration can be less costly and provide greater surface area contact (line contact along the second height 342 of the anti-rotation protrusion 332 with the surface of the bore slot 248) rather than a conventional point contact offered by a round headed pin with the cylinder head 250. The anti-rotation ring 240 reduces stress and thus wear on the bore slot 248 and the anti-rotation protrusion 332.

[0043] The body 230 includes a connecting channel 330 formed therein. The connecting channel 330 can be inset a connecting channel depth (see connecting channel depth 134 identified in FIG. 6A) from the outer peripheral surface 242. In one example, the connecting channel depth is less than the groove depth 314. The connecting channel 330 fluidly connects the groove 300 with the transverse passage 284.

[0044] During operation, oil received at the groove 300 from an oil passage (see 140 FIG. 5) defined in the cylinder head 250 of the engine flows around the anti-rotation ring 240, along (down) the connecting channel 330, into the transverse passage 284 and onto the roller bearing. Explained further, oil is permitted to flow around the ring body 310 of the anti-rotation ring 240 within the groove 300. In one example, the ring height 340 is less than the groove width 312 allowing a predetermined rate of oil to pass between the ring body 310 and the body 230 of the roller lifter 210. The groove 300 is therefore dual-purpose allowing for receipt of the anti-rotation clip 240 and providing an oil pathway to communicate oil to the roller bearing. Furthermore, because the connecting channel 330 is inset or recessed into the outer peripheral surface 242 of the body 230, a predetermined amount of oil is permitted to flow from the groove 300 to the transverse passage 284. In the example shown, the connecting channel depth is minimal so as to control the rate of oil flow to a predetermined value. In one configuration, the connecting channel 330 can extend along an axis that is parallel to the longitudinal axis 288. [0045] The anti-rotation protrusion 332 inhibits relative rotation between concentric sliding cylinders (the body 230 of the roller lifter 210 and the bore 249 of the cylinder block 250). The anti-rotation protrusion 332 creates an additional moment which counters moments generated by side loads. This counter bending moment reduces the bending stresses on the anti-rotation clip 240. The low bending stresses improve the ultimate strength and fatigue strength of the anti-rotation clip 240.

[0046] Turning now to FIGS. 12 and 13, a roller lifter constructed in accordance to another example of the present disclosure is shown and generally identified at reference numeral 310. Unless otherwise described herein, the roller lifter 310 is constructed similarly to the roller lifter 10 described above where like components are referred to with like reference numerals increased by 300. The roller lifter 310 generally includes a body 330, a leakdown assembly 332 received within the body 330, a roller bearing 334 rotatably mounted to the body 330 and an anti-rotation ring 340. The body 330 includes an outer peripheral surface 342 configured for sliding movement in a bore 348 provided in a cylinder head 350 of an internal combustion engine 352.

[0047] The leakdown assembly 332 can be constructed similarly to the leakdown assembly 32 described above and will not be repeated here. The body 330 can define a transverse passage 384. The transverse passage 384 can extend entirely through the body 330 along an axis generally transverse to a longitudinal axis 388 of the body 330. A pair of clips are nestingly received in corresponding grooves formed on the body 330 for capturing an axle 394 of the roller bearing 334 in the roller lifter 310. As identified above, the roller bearing 334 can be configured for rolling contact with the engine camshaft (see camshaft 12, FIG. 1 ).

[0048] The body 330 includes a groove 400 formed therein and inset from the outer peripheral surface 342. The groove 400 has a groove width and a groove depth similar to the width 102 and depth 104 shown in FIG. 4. The groove 400 is configured to receive the anti-rotation ring 340 thereat. The groove 400 however is configured differently on the body 330 as compared to the groove 100 of the body 30. In this regard, the groove 400 is defined in the body 330 closer to the roller bearing 334 as compared to the groove 100. As a result, the groove 400 does not directly align with the oil passage (rifle groove) 440 when the roller lifter 310 is in an uppermost position in the bore 348 (FIG. 12). Similarly, the groove 400 will not align with the oil passage 440 in a lowermost position in the bore 348 (FIG. 13). Explained further, the groove 400 will not align with the oil passage 440 throughout motion of the roller lifter 310. Instead, oil around the outer peripheral surface 342 provides sufficient lubrication. In other words, the groove 400 is scavenging sufficient oil from the outer peripheral surface 342 without ever communicating directly with the oil passage 440. The oil therefore makes it way from the outer peripheral surface 340, to the groove 400, along (down) the connecting channel 430, into the transverse passage 384 and onto the roller bearing 334.

[0049] The foregoing description of the examples has been provided for purposes of illustration and description. It is not intended to be exhaustive or to limit the disclosure. Individual elements or features of a particular example are generally not limited to that particular example, but, where applicable, are interchangeable and can be used in a selected example, even if not specifically shown or described. The same may also be varied in many ways. Such variations are not to be regarded as a departure from the disclosure, and all such modifications are intended to be included within the scope of the disclosure.