JP2011033142A - Cam follower - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a cam follower capable of reducing cost of product by reducing cost of machining a cam follower stud. <P>SOLUTION: This cam follower is composed of the stud 21 and a bearing assembly 22 asssembled rotatably on the stud 21. The stud 21 includes a bearing supporting part 23 in its one end part and a mounting part 24 in the other end part. The stud 21 is in a primary product state formed by cold forging or cutting, and such stud that is heat-treated and finished is used as an inner ring 31 of the bearing assembly 22 pressed-in and fixed in the bearing supporting part 23. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a cam follower, and more particularly to a reduction in the processing cost of a cam follower stud.

  Cam followers are widely used, such as an indexing mechanism of an indexing device, a cam mechanism of a machine tool, and a paper feeding mechanism of a printing press. As a specific example, the operation part of many general equipments, such as a conveyor part of a general goods lifting and conveyance apparatus, a conveyance guide of a press machine, a slide part of an automatic door, a fork contraction part, such as a forklift, is guided. In a printing machine, it is used for a movement mechanism of a paper pressing claw shaft of a paper feeding mechanism, an ink kneading roller, a cam mechanism unit, and the like.

  Generally, a cam follower is a cam follower stud (hereinafter simply referred to as a “stud”) that is rotatably fitted with a thick outer ring via a rolling element. An outer ring supported in a cantilever manner by the stud rolls on a track. Also called a track roller (Patent Document 1).

  As shown in FIG. 5, the conventional cam follower includes a stud 1 and a bearing assembly 2 that is rotatably assembled to one end of the stud 1. The stud 1 is provided with a bearing support portion 3 in which a bearing assembly 2 is rotatably fitted at one end portion, and an attachment portion 4 at the other end portion. A stud collar portion 5 is provided at an end portion of the bearing support portion 3 opposite to the mounting portion 4, that is, an outer end portion, and an end portion of the bearing support portion 3 on the mounting portion 4 side, that is, an inner end portion. A press-fit portion 7 having a small diameter by the step portion 6 is provided in the portion. The mounting portion 4 having a slightly smaller diameter is provided adjacent to the press-fit portion 7 in the axial direction. A screw portion 8 is provided at the tip of the attachment portion 4. A lubricant supply hole 10 is provided in the stud 1.

  In the bearing assembly 2, an outer ring 12 is rotatably fitted via rollers 9 held by a cage 11 with the outer diameter surface of the bearing support portion 3 as a raceway surface. An annular inner plate 13 is press-fitted and fixed to the press-fitting portion 7. The inner plate 13 has the same outer diameter as the stud collar 5.

  On both end faces of the outer ring 12, annular recesses 14 and 15 are provided concentrically, and the stud collar 5 is fitted into one recess 14 with a slight gap in the radial direction and the axial direction. The inner plate 13 is also inserted into the recess 15 with a slight gap in the radial direction and the axial direction. The stud collar 5 and the inner plate 13 restrict the axial movement of the bearing assembly 2.

  Further, seal grooves 16 and 17 are provided in the respective recesses 14 and 15, and seal members 18 and 19 are attached to the seal grooves 16 and 17. The lips of the seal members 18 and 19 are in contact with the outer diameter surfaces of the stud collar 5 and the inner plate 13, respectively.

  The stud 1 is formed by, for example, cutting a steel material to form a stud collar portion 5, a bearing support portion 3, a press-fit portion 7, and a mounting portion 4, and further, threading of a screw portion 8 and supply of a lubricant. After performing primary processing such as drilling of the holes 10, heat treatment and grinding processing for the bearing support portion 3 are performed and completed.

  In place of the seal members 18 and 19, a washer is interposed between the axially facing surfaces of the outer ring 12 and the stud collar 5 and the outer ring 12 and the inner plate 13, and both the washer and the seal member are used. The thing with which it mounted | wore is also known (patent document 2).

Japanese Patent Laid-Open No. 7-42809 JITTO No.2513158

  In the cam followers disclosed in Patent Documents 1 and 2, as shown in FIG. 5, the bearing support portion 3 of the stud 1 becomes a raceway surface on which the rollers 9 roll. For this reason, in order to give predetermined hardness and intensity | strength, it is indispensable to heat-process as a secondary process, after primary-processing each part of the stud 1 by cutting.

  Further, in order to smoothly finish the raceway surface, it is indispensable to finish the bearing support portion 3 such as grinding after the heat treatment. However, since these secondary processing and finishing are necessary, the processing cost of the stud 1 becomes a factor.

  Accordingly, a first object of the present invention is to contribute to the cost reduction of a product by reducing the cost of processing a stud in a cam follower.

  Further, in the conventional cam follower, when the stud 1 is not heat-treated, when the retainer 11 is swung in the axial direction, the tip thereof contacts the inner surface of the stud collar 5 or the inner surface of the inner plate 13. Thus, there is a problem that these inner surfaces are damaged and the smooth rotation of the cage 11 is hindered.

  As for the problem that the cage 11 contacts the inner surface of the stud collar 5 or the inner surface of the inner plate 13, as disclosed in Patent Document 2, both ends of the cage 11, the stud collar 5 and the inner plate. It is an effective measure to interpose washers between 13. However, since the sealability is insufficient only with the washer, it is necessary to add a separate seal member. After all, in addition to the sealing member in the case of FIG. 5, a washer is required, and there is a problem that causes an increase in the number of parts and thus an increase in product cost.

  Accordingly, a second object of the present invention is to combine the washer function without increasing the number of parts while maintaining the sealing function, in addition to the first problem.

  In order to solve the first problem, a cam follower according to the present invention includes a stud and a bearing assembly rotatably assembled to the stud, and the stud is provided at one end of the bearing assembly. A bearing support portion in which the bearing support portion is rotatably fitted, an attachment portion is provided at the other end portion, and the bearing assembly includes an outer end restriction portion and an inner end restriction portion provided at both axial end portions of the bearing support portion. In the cam follower that is restricted in the axial direction by the seal ring between the outer ring of the bearing assembly and each restricting portion, the stud is subjected to cold forging, cutting, or the like to form each portion as the stud. As a member constituting the raceway surface of the bearing assembly and the stud collar portion, an inner ring with a flange subjected to heat treatment and grinding is used, and the inner ring is press-fitted and fixed to the bearing support portion. It is.

  Further, in order to solve the second problem, the cam follower according to the present invention has a sliding property and elasticity as each seal member in the cam follower having the above-described configuration that solves the first problem. The washer / seal member has an annular portion covered on the inner surface facing the restricting portion, and a bent portion is formed on the outer peripheral edge of the annular portion.

  As described above, in the present invention, as the stud, heat treatment and grinding are performed by using a stud that is in a state of a primary processed product before being subjected to heat treatment and grinding usually performed after cold forging or cutting. Since it becomes unnecessary, the processing cost can be reduced. The disadvantage of not performing heat treatment and grinding on the stud is eliminated by press-fitting and fixing the flanged inner ring subjected to these treatments to the bearing support portion of the stud.

  Also, because the stud collar is not heat-treated, a washer is required, but instead of the conventional seal member, the washer and seal member that performs the function of the washer and the seal function as one member is used. As a result, the product cost can be reduced.

  The raceway surface can also be configured by using both the inner ring and the side plate without using the inner ring with the collar. Since the inner ring and the side plate can use general-purpose products, the increase in the number of parts has little effect on the product cost.

  Further, by forming the stud by cold forging, the fiber flow of the metal bar is not cut, so that a strength higher than that formed by cutting is obtained.

Cross-sectional view of the cam follower of the first embodiment Sectional drawing which shows a part of cam follower of 2nd embodiment Sectional drawing which shows a part of cam follower of 3rd embodiment. Sectional drawing which shows a part of cam follower of 4th embodiment Cross-sectional view of a conventional cam follower

  Embodiments of the present invention will be described below with reference to the accompanying drawings.

[First embodiment]
The cam follower according to the first embodiment shown in FIGS. 1A and 1B includes a stud 21 and a bearing assembly 22 rotatably assembled to the stud 21 as in the conventional case.

  The stud 21 is provided with a bearing support portion 23 in which the bearing assembly 22 is rotatably fitted at one end portion, and an attachment portion 24 at the other end portion. A stud collar portion 25 serving as an inner end regulating portion is integrally provided at a boundary portion between the bearing support portion 23 and the mounting portion 24, that is, an inner end portion of the bearing support portion 23. A screw portion 26 is provided at the distal end portion of the attachment portion 24.

  Further, a lubricant supply hole 27 bent in an L shape at the tip is provided from the end surface on the screw portion 26 side to the center of the stud 21, and the L-shaped bent portion at the tip is provided around the outer peripheral surface. The oil supply groove 28 is communicated. A wrench hole 29 is provided at the center of the end face on the bearing support portion 23 side.

  The stud 21 is a primary work obtained by cold forging a steel metal rod with a die and a punch having a molding surface corresponding to the outer shape of the stud 21, and then processing the lubricant supply hole 27. Formed by goods. The wrench hole 29 can be processed simultaneously during cold forging.

  Thus, when the stud 21 is formed by cold forging, since the fiber flow of the metal rod of the material is formed in a continuous state without being cut, a material having higher strength than that obtained by cutting is obtained.

  In the conventional case, in order to give hardness and strength as secondary processing after the primary processing, the entire stud 1 (see FIG. 5) is subjected to heat treatment, and the bearing support 3 is finished smoothly. Finishing such as grinding was performed.

  However, as described above, the stud 21 of the present invention is in a state of a primary processed product before being subjected to heat treatment and finishing without being subjected to heat treatment and finishing.

  The bearing assembly 22 includes an inner ring 31 and an outer ring 32, rollers 33 interposed between the raceways 31a and 32a facing each other (see FIG. 1A) at a constant interval in the circumferential direction, A cage 34 that guides each roller 33 and a washer / seal member 36 attached to both ends of the outer ring 32 are configured.

  The inner ring 31 is integrally provided with an inner ring collar portion 37 which is an outer end regulating portion at an outer end portion thereof. By pressing the inner ring 31 into the bearing support portion 23, the bearing assembly 22 is attached to the stud 21. In order to prevent the bearing assembly 22 from coming off, caulking is applied to the inner periphery of the inner ring collar portion 37 at the end face of the stud 21. Reference numeral 42 indicates the caulking portion.

  The inner ring 31 is provided with a hole 40, and the hole 40 matches the oil supply groove 28. For this reason, when the inner ring 31 is press-fitted into the bearing support portion 23, the circumferential direction is not limited. When the hole 40 matches the oil supply groove 28, the interior of the bearing assembly 22 is communicated with the lubricant supply hole 27.

  Concentric annular recesses 38 are provided on both end surfaces of the outer ring 32 on the raceway surface 32a side, and the washer / seal member 36 is mounted in each recess 38. As a material of each washer / seal member 36, a material excellent in wear resistance, slipperiness, and sealability, for example, engineering plastics such as PEEK, POM, and PA can be used. Other than this, there is no particular limitation on the material as long as a predetermined function can be achieved.

  The inner ring 31 and the outer ring 32 are made of ordinary steel, heat-treated, and the raceway surfaces 31a and 32a are ground.

  As shown in FIG. 1B, the washer and seal member 36 has a shape having a bent portion 41 provided in an inverted L shape on the outer peripheral edge of the annular portion 39, and the bent portion 41 is a concave portion of the outer ring 32. It is pressed against the inner surface of 38. The annular portion 39 has a width that covers the inner surfaces of the stud collar portion 25 and the inner ring collar portion 37, and is sandwiched in the axial direction between the collar portions 25, 37 and the radial end surface of the recess 38. The The annular portion 39 provides a seal between the outer ring 32 and the flange portions 25 and 37. At the same time, it acts as a washer that reduces friction between both ends of the cage 34 and the inner surfaces of the flange portions 25 and 37, thereby contributing to smooth rotation of the outer ring 32.

  The cam follower according to the first embodiment is as described above. As in the conventional case, the screw assembly 26 is fixed to a part of the mechanical device to support the bearing assembly 22 in a cantilever manner. The outer ring 32 of the bearing assembly 22 is brought into contact with the track and rotated. With rotation, the roller 33 rolls on the raceway surface 31a of the inner ring 31 and the raceway surface 32a of the outer ring 32. Since these raceway surfaces 31a and 32a are heat-treated, they have sufficient durability.

  Further, since the annular portion 39 of the washer / seal member 36 is interposed between the flange portions 25 and 37 opposed to the respective concave portions 38 in the concave portions 38 at both ends of the outer ring 32, the outer ring 32 is smoothly formed. It rotates and seals at the same time. Further, since the inner surfaces of both collar portions 25 and 37 facing both end portions of the retainer 34 are covered with the annular portion 39 of the washer and seal member 36, even if the end portions of the retainer 34 come into contact with each other, Can be rotated. Further, there is no fear of scratching the stud collar portion 25 that has not been heat-treated.

[Second Embodiment]
Next, the second embodiment shown in FIG. 2 is different from the above case in the structure of the inner ring 31. That is, the inner ring 31 in this case is a cylindrical body, and a separate annular outer plate 44 that forms the outer end restricting portion is press-fitted into the outer diameter surface of the distal end portion of the stud 21 and is caulked along the inner peripheral portion thereof. A portion 42 is provided. The outer plate 44 is formed to have the same diameter as that of the stud collar portion 25, and a required gap is provided in the concave portion 38 on the outer end side of the outer ring 32 in the same manner as the inner ring collar portion 37 (see FIG. 1A). Inserted. Further, a washer / seal member 36 is mounted on the inner surface thereof.

  Since the inner surface of the outer plate 44 is covered with the washer / seal member 36 as described above, it is possible to use a plate without heat treatment.

[Third embodiment]
In the third embodiment shown in FIG. 3, the stud collar portion 25 of the second embodiment (see FIG. 2) is omitted, and instead of the stud 21, an independent annular inner plate 46 is supported by bearings. The inner ring 31 and the outer plate 44 of the bearing assembly 22 are press-fitted, respectively, until they hit the stepped portion 47 at the inner end of the portion 23.

  In this case, since both the inner plate 46 and the outer plate 44 are heat-treated, a washer for protecting the inner surface is not necessary. Therefore, a normal seal member 48 having a sealing function is mounted in the seal groove 49 of the recess 38 of the outer ring 32 so that the lip portions are in contact with the outer diameter surfaces of the outer plate 44 and the inner plate 46, respectively.

  In the case of the third embodiment described above, since the stud collar portion 25 is unnecessary, the stud 21 is straightened and is easy to form by cold forging in terms of shape, which can contribute to further reduction in product cost.

[Fourth embodiment]
In the modification shown in FIG. 4, the roller 33 is a full-roller type in the configuration of the third embodiment (see FIG. 3). In this case, since the retainer 34 is not used, the end portion of the roller 33 may come into contact with the inner surface of the outer plate 44 and the stud collar portion 25, and so-called galling may occur.

  For this reason, in this embodiment, the recessed part 45 (so-called Nusumi) is formed between the outer side plate 44 and the stud collar part 25 by forming the outer peripheral part of the both end surfaces of the cylindrical inner ring 31 into an R shape. I am doing so. The recessed portion 45 can be formed by a simple process of making the outer peripheral portions of both end faces of the inner ring 31 into an R shape. Due to the presence of the recessed portion 45, voids are generated in the respective corners between the inner ring 31 and the outer plate 44 and the inner plate 46, thereby preventing the roller end portion from being squeezed.

  In the first to fourth embodiments, the material and heat treatment method are not particularly limited, and any material or heat treatment method may be used as long as it has a predetermined function.

DESCRIPTION OF SYMBOLS 1 Stud 2 Bearing assembly 3 Bearing support part 4 Mounting part 5 Stud collar part 6 Step part 7 Press-fit part 8 Screw part 9 Roller 10 Lubricant supply hole 11 Cage 12 Outer ring 13 Inner plate 14, 15 Recess 16, 16 Seal groove 18, 19 Seal member
21 Stud 22 Bearing assembly 23 Bearing support portion 24 Mounting portion 25 Stud collar portion 26 Screw portion 27 Lubricant supply hole 28 Oil supply groove 29 Wrench hole 31 Inner ring 31a Raceway surface 32 Outer ring 32a Raceway surface 33 Roller 34 Cage 36 Washer and seal Member 37 Inner ring collar
38 concave portion 39 annular portion 40 hole 41 bent portion 42 caulking portion 44 outer plate 45 concave portion 46 inner plate 47 step portion 48 seal member 49 seal groove

Claims (7)

The stud includes a stud and a bearing assembly rotatably assembled to the stud. The stud has a bearing support portion in which the bearing assembly is rotatably fitted at one end thereof, and an attachment portion at the other end. The bearing assembly is axially restricted by an outer end restricting portion and an inner end restricting portion provided at both axial ends of the bearing support portion, and the outer ring of the bearing rotating body and the restricting portions In a cam follower in which a seal member is interposed between
As the stud, a primary work product in which each part is formed by performing cold forging, cutting, or the like is used, and the inner ring of the bearing assembly is subjected to heat treatment and grinding, and the inner ring is used as the bearing support part. Cam follower characterized by being press-fitted and fixed to.   2. The cam follower according to claim 1, wherein the inner end restricting portion is a stud collar portion integrally provided on an outer diameter surface of the stud.   As each of the sealing members, a washer / seal member having both an slidability and an elasticity, having an annular portion covering the opposing inner surface of each regulating portion, and forming a bent portion on the outer peripheral edge of the annular portion is used. The cam follower according to claim 1 or 2, characterized by the above.   The cam follower according to any one of claims 1 to 3, wherein the outer end restricting portion is an inner ring flange portion integrally provided at an outer end portion of the inner ring.   The outer end restricting portion is formed by an independent annular outer plate separate from the inner ring, and is press-fitted and fixed to the tip end portion of the bearing support portion in a state where the outer plate is pressed against the outer end surface of the inner ring. The cam follower according to any one of claims 1 to 3, wherein the cam follower is provided.   The inner restricting portion is formed by an independent annular inner plate and press-fitted and fixed to the inner end portion of the bearing support portion, the outer end restricting portion is formed by an independent annular outer plate, and the outer plate is formed by the inner ring. The cam follower according to claim 1, wherein the cam follower is press-fitted and fixed to an outer end portion of the bearing support portion in a state of being pressed against an outer end surface.   Inner peripheral portions of both end portions of the inner ring are formed in an R shape, a recessed portion is formed between the outer plate and the inner plate that are in contact with both end portions of the inner ring, and the rolling elements of the bearing assembly are full rollers. It is a type | mold, The cam follower of Claim 6 characterized by the above-mentioned.