JP2005121195A - Self-aligning roller bearing - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a self-aligning roller bearing restricted in the generation of torque to reduce self-heating and capable of rotating at higher speed than a current one. <P>SOLUTION: Two inside polymer forming bodies 5 and 5 formed from a polymer (polymer lubricant) containing a lubricant and having a ring-like base body (a ring part 5a) and a plurality of branch parts 5b, 5b... projecting from the ring part 5a in the axial direction are arranged in each of a right and a left roller raceways provided in both sides of a plane crossing the axis at the axial center position of a bearing so that an end surface of each of the ring parts 5a faces to each other with a clearance in a space of an annular space formed between an outer ring 1 and the inner ring 2 on a side close to the inner ring 2 than holders 4a and 4b. With this structure, rotating torque of the bearing can be reduced, and self-heating is restricted to prevent melting and breakdown of a lubricant containing polymer forming body 5 itself and deterioration of the basic oil due to oxidization. Consequently, this automatic centering roller bearing can be rotated at higher speed than a current self-aligning roller bearing. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a polymer lubricant-enclosed self-aligning roller bearing in which a polymer mixed with a lubricant or grease is accommodated between an outer ring and an inner ring.

  In rolling bearings, in order to improve the lubricity between the inner ring raceway surface and the rolling element or between the outer ring raceway surface and the rolling element, lubricating oil is generally supplied to the annular space formed between the inner ring and the outer ring. Or, grease is sealed. In order to supply or seal such lubricating oil or grease into the space between the inner ring and the outer ring, or to prevent water or foreign matter from entering the space from the outside, the inner ring and the outer ring are usually used. In order to seal or partition the space between and the outside, contact type seals, labyrinth seals, and the like are attached to both ends of the annular space in the axial direction.

  However, a double-row self-aligning roller bearing in which two rows of raceway surfaces are formed on the outer periphery of the inner ring and one raceway surface formed of a concave spherical surface is formed on the inner periphery of the outer ring is used under certain conditions. The rolling element may protrude from the outer ring raceway surface and rotate. In such a self-aligning roller bearing, if the normal lubrication method as described above is used, lubricating oil or grease may flow out of the bearing. There is.

  As one of the countermeasures in such a case, conventionally, a mixture of polymer and lubricating oil or grease is heated and melted in a space formed between the inner ring and the outer ring, and then cooled and solidified. A method of enclosing a so-called polymer lubricant is known. According to this self-aligning roller bearing filled with polymer lubricant, the lubricating oil or grease contained in the polymer is gradually released by the rotation of the bearing and spreads between the raceway surfaces of the inner and outer rings and the rolling elements. It is possible to maintain a good lubrication state over a long period of time.

FIG. 6 is a cross-sectional view showing an example of the structure of a conventional double row spherical roller bearing.
This self-aligning roller bearing includes an outer ring 1 having a concave spherical outer ring side raceway surface 1a on an inner peripheral surface, an inner ring 2 having two rows of arc-shaped inner ring side raceway surfaces 2a and 2b on the outer peripheral surface, and these The main body is composed of two rows of barrel rollers 3, 3,... Disposed between the outer ring side raceway surface 1a and the inner ring side raceway surfaces 2a, 2b. Between the outer ring 1 and the inner ring 2, two retainers 4a and 4b that hold the two rows of rollers 3 so as to freely roll, and a guide wheel 10 that separates the rollers 3 are disposed. .

  A polymer lubricant 11 is filled in an annular space formed between the outer ring 1 and the inner ring 2. The polymer lubricant 11 used here is usually a solidified mixture of ultra-high molecular weight polyethylene resin and lubricating oil or grease. When sealing between the inner and outer rings of the bearing, the above-mentioned mixture is used. A method of cooling and solidifying after filling the space between the inner and outer rings and rolling elements of the assembled bearing in a heated and melted state is used (see, for example, Patent Document 1 or Patent Document 2). ).

  In addition, the present applicants do not inject and solidify the polymer lubricant between the inner ring and the outer ring of the assembled bearing in a molten state, but preliminarily apply the polymer lubricant with a jig that simulates the assembled bearing. After being molded and divided into multiple pieces in the circumferential direction, using the structural features of double-row spherical roller bearings, they are fitted between the outer ring and cage of assembled spherical roller bearings. Have proposed a method for stably producing a self-aligning roller bearing having a small rotational torque (see Patent Document 3).

JP 2002-339993 A JP 2002-349589 A JP 2002-349586 A

  By the way, in the above-described self-aligning roller bearing with a polymer lubricant enclosed type, the polymer lubricant is tightly filled in the gap between the inner ring and the outer ring except for the rollers and the cage. There has been a problem that the rotational torque is increased due to sliding frictional resistance caused by the contact of the polymer lubricant with the rollers or the inner and outer rings during rotation.

  In addition, the contact with the polymer lubricant or the inner and outer rings may cause self-heating of the bearing, and this self-heating may cause melting or breakage of the polymer lubricant or oxidative deterioration of the base oil as the lubricant. Therefore, there is a problem that the rotation speed must be limited and cannot be used at high speed.

  The present invention has been made in view of such circumstances, and an object of the present invention is to provide a self-aligning roller bearing capable of rotating at a higher speed than a conventional product with low torque and less self-heating.

  In order to achieve the above-mentioned object, the invention according to claim 1 includes an outer ring having a concave spherical outer ring side raceway surface on the inner periphery, and an inner ring having two rows of arc-shaped inner ring side raceway surfaces on the outer periphery. In a self-aligning roller bearing comprising: two left and right axial rollers arranged between the raceway surfaces of the inner and outer rings, and two cages that hold these roller rows in a freely rollable manner. Of the annular space formed between the outer ring and the inner ring, the inner ring side of the cage is made of a polymer containing a lubricant and fits in a space between adjacent rollers and the inner ring. Two inner diameter side polymer moldings having branch portions that are jammed and annular portions that connect these branch portions in the circumferential direction on the center side in the axial direction are arranged such that the end surfaces of the annular portions face each other with a gap therebetween. At the center position in the axial direction of the bearing with a plane perpendicular to the axis Characterized in that it is arranged, one for track.

  The present invention relates to a self-aligning roller bearing, in place of a polymer lubricant injected into an annular space between an inner ring and an outer ring of the bearing, and a ring-shaped base body (annular portion) and an axial direction from the annular portion. A lubricant-containing polymer molded body is separately formed which has a branch portion that protrudes into a space and has a substantially trapezoidal cross section formed between the rollers, and this polymer molded body is used as one of the bearing parts. By trying to interpose between the rollers of each track, the intended purpose is achieved.

  That is, according to the first aspect of the present invention, in the annular space formed by the inner ring and the outer ring, lubrication is performed only on the inner diameter side of the cage, that is, only between the cage and each roller and the inner ring. By arranging the polymer molded body containing the agent, the outer diameter side of the cage becomes a void. Therefore, compared with the case where the polymer lubricant is densely filled in the annular space between the inner ring and the outer ring, the frictional resistance is reduced as much as the contact area with each element of the bearing becomes smaller.

  Further, the polymer molded body arranged on each of the left and right tracks in the axial direction is formed in a shape along the annular space of the bearing without dividing the annular portion connecting the branch portions in the circumferential direction, Its rotational accuracy is high. In addition, since each is an independent body and is arranged with a gap in the axial direction, each has a feature that it can freely rotate.

  Therefore, the self-aligning roller bearing of the present invention can be rotated at a high speed with low torque and less self-heating as compared with the conventional self-aligning roller bearing.

  Here, the inner diameter side polymer molded body preferably has a shape having a predetermined gap with respect to the roller and the inner ring. (Claim 2)

  According to the second aspect of the present invention, the rotational torque of the bearing can be further reduced by this gap, and even when the polymer molded body itself undergoes volume expansion due to heat generated during the operation of the bearing, the polymer molded body is It is possible to prevent sliding contact with the rollers and the inner ring.

  In addition, although it differs somewhat depending on the size of the bearing, it is generally desirable that the clearance between these rollers and the inner ring and the polymer molded body be about 100 μm to 300 μm. If the thickness is less than 100 μm, contact due to thermal expansion may occur. If the gap exceeds 300 μm, the lubricant exuded from the polymer molded article may not be sufficiently distributed, and the oil film may not be sufficiently formed. .

  Next, in the invention according to claim 3, in addition to the inner diameter side polymer molded body, in the annular space formed between the outer ring and the inner ring, the outer ring side of the retainer is lubricated. 2 which has a branch portion which is made of a polymer containing an agent and fits into a space between adjacent rollers and an outer ring, and an annular portion which connects these branch portions in the circumferential direction on the center side in the axial direction. Two outer diameter side polymer moldings, one on each of the left and right tracks, sandwiching a plane orthogonal to the axis at the axial center position of the bearing so that the end faces of the annular portions face each other with a gap therebetween It is arranged.

  According to the third aspect of the present invention, in the annular space formed between the outer ring and the inner ring, the outer side of the outer ring side of the retainer has the same shape as the inner diameter side polymer molded body. By disposing the diameter side polymer molded body, it is possible to improve the lubricity outside the cage while maintaining low torque and low heat generation of the bearing.

  Further, the outer diameter side polymer molded body preferably has a shape having a predetermined gap with respect to the roller and the outer ring. (Claim 4)

  According to the invention of claim 4, similar to the inner diameter side polymer molded body, even when the polymer molded body itself undergoes volume expansion due to heat generated during the operation of the bearing, the outer diameter side polymer molded body is It is possible to prevent sliding contact with the rollers and the outer ring.

  As described above, according to the self-aligning roller bearing of the present invention, the rotational torque of the bearing can be reduced, self-heating is suppressed, and the lubricant-containing polymer molded body itself melts and breaks. Oxidative deterioration of the can be prevented. Therefore, it can be rotated at a higher speed than a conventional self-aligning roller bearing.

Embodiments of the present invention will be described below with reference to the drawings.
FIG. 1 is a partial cross-sectional perspective view illustrating the configuration of a self-aligning roller bearing according to an embodiment of the present invention. 2 is a cross-sectional view showing the structure of this self-aligning roller bearing, and FIG. 3 is an arrow cut in the circumferential direction along the end surface (XX line) of one of the roller rows in FIG. FIG. In addition, the same code | symbol is attached | subjected to the structural member which has the same function as a prior art example.

  The basic configuration of the self-aligning roller bearing in this embodiment is the same as that of the conventional self-aligning roller bearing, and includes an outer ring 1 having a concave spherical outer ring side raceway surface 1a and two rows of arc-shaped inner rings. Mainly the inner ring 2 having the side raceway surfaces 2a, 2b and the two rows of barrel rollers 3, 3,... Arranged between the outer race side raceway surface 1a and the inner ring side raceway surfaces 2a, 2b. It is configured. Further, between the outer ring 1 and the inner ring 2, two cages 4a and 4b that hold the two rows of rollers 3 in a freely rollable manner are arranged.

  The self-aligning roller bearing according to the present embodiment is characterized by a ring-shaped base (ring) in an annular space formed between the outer ring 1 and the inner ring 2 in a space closer to the inner ring 2 than the cages 4a and 4b. .., And two inner diameter side polymer molded bodies 5 and 5 each including a plurality of branch portions 5b, 5b,... Protruding in the axial direction from the annular portion 5a. These polymer molded bodies 5 are formed using a polymer containing a lubricant (polymer lubricant), and as shown in FIG. 2, the end faces of the respective annular portions 5a face each other with a gap therebetween. In this manner, the bearings are arranged one by one on the left and right roller raceways across a plane (axial center axis) perpendicular to the axis at the axial center position of the bearing.

  Further, the branch portions 5b, 5b of the polymer molded body 5 are formed in a shape (see FIG. 3) that fits in a substantially trapezoidal space formed between the adjacent rollers 3 and the inner ring 2. Between the branch portions 5b and 3 and the branch portion 5b and the inner ring 2, there are provided gaps for preventing sliding contact of the polymer molded body 5 during rotation of the bearing.

Next, a method for producing the polymer molded body 5 will be described.
4A and 4B are explanatory views showing an outline of a method for producing a polymer molded body, in which FIG. 4A shows a state before the injection of the polymer material, and FIG. 4B shows a state after the injection of the polymer material. In addition, the manufacture of the polymer molded body in the present embodiment was performed in accordance with the method described in Patent Document 2.

  First, one of the above-described cages (4a or 4b) has substantially the same inner peripheral shape as the state in which each roller 3 is held, has no radial through-holes, and has a plurality in the circumferential direction. An outer jig 21 that can be divided into two parts, and an inner jig 22 having substantially the same outer peripheral shape as the inner ring side raceway surface (2a or 2b) are prepared.

  The outer jig 21 is preferably combined with the cage and each roller, and the one corresponding to the outer ring 1 of the bearing. In this example, the outer ring 1 of the actual bearing is the axial center axis. For an equally divided member, the outer diameter side of the retainer 4a is hardened in advance by using an assembly in which a roller having a slightly larger diameter than the roller 3 actually used is held by the retainer 4a. It can be easily manufactured by filling with a resin or the like.

  In addition, the outer side jig | tool 21 in FIG. 4 is displayed as the thing after integrating this assembly already. The reason why the roller used here has a larger diameter than that actually used is that when the polymer molded body 5 after molding is incorporated in a bearing, the required clearance between the polymer molded body 5 and 3 is set. This is to ensure.

  Further, as the inner jig 22, the inner ring 2 of the actual bearing equally divided by the central axis in the axial direction may be used as it is. However, for the same reason as the outer jig 21, the outer peripheral surface is actually It is desirable to form a slightly larger diameter than the inner ring side raceway surface of the bearing.

  Then, these jigs 21 and 22 are arranged concentrically, and a lubricant is contained in the annular space in a state where both end sides in the axial direction of the formed annular space are closed by side plates 23a, 23b and the like. The polymer raw material to be injected is injected and solidified. Thereafter, by removing these jigs, a large number of branch portions 5b that fit into the space between the adjacent rollers 3 and the inner ring 2, and an annular portion 5a that connects these branch portions 5b in the circumferential direction. An inner diameter side polymer molded body 5 can be obtained. In addition, these inner diameter side polymer molded bodies 5 and 5 are manufactured as a pair which becomes a symmetrical shape for roller arrays on the left and right sides of the bearing.

  A suitable composition of the polymer molded body 5 in this embodiment is 18.3 to 79.6% by weight of urethane prepolymer, 20 to 80% by weight of lithium soap-based grease, and 0.1 to 6.7% by weight. An aromatic polyamine curing agent. Moreover, you may add additives, such as antioxidant, a rust preventive agent, and an extreme pressure agent, to these raw materials as needed. The mixture of the resin and the lubricating component is cured by adding a curing agent and leaving the mixture at a temperature of room temperature to 170 ° C. for about several minutes to 24 hours in a state of being filled in a jig arranged in a ring shape. Is done.

  With the above configuration, this self-aligning roller bearing can reduce the rotational torque of the bearing compared to the conventional self-aligning roller bearing in which the annular space between the inner ring and the outer ring is densely filled with a polymer lubricant. In addition, it is possible to suppress self-heating and prevent melting and breakage of the lubricant-containing polymer molded body itself and oxidative deterioration of the base oil. Therefore, the self-aligning roller bearing in the present embodiment can be rotated at a higher speed than the conventional self-aligning roller bearing.

  In addition, the self-aligning roller bearing has an effect of reducing bearing parts because the polymer molded bodies 5 and 5 guide the cages 4a and 4b instead of the guide wheels 10 in the conventional example (see FIG. 6). be able to.

  In the above embodiment, the example in which the inner diameter side polymer molded body 5 containing the lubricant is arranged only on the inner ring 2 side from the cages 4a and 4b is shown, but the self-aligning roller bearing of the present invention is As shown in the cross-sectional view of FIG. 5, the outer diameter side polymer molded bodies 6 and 6 having the same shape as the inner diameter side polymer molded bodies 5 and 5 may be arranged between the cages 4 a and 4 b and the outer ring 1. good.

  The resin used for the polymer molded body of the present invention is not limited to the above example, and may be either a thermoplastic resin or a thermosetting resin. Examples of the thermoplastic resin include polyolefin resin, polyamide resin, polyamideimide resin, polyacetal resin, polyether ether ketone resin, polycarbonate resin, and the like. As examples of thermosetting resins, polyester resins, urea resins, melamine resins, urethane resins, phenol resins, polyimide resins, silicone resins, and the like can be used.

  These resins may be used alone or in combination, and various additives such as antioxidants, anti-aging agents, antiwear agents, curing agents, and fillers may be added as necessary. good.

  The lubricating components used in the polymer molded body of the present invention include synthetic hydrocarbon oil, mineral oil, ether oil such as diphenyl ale, ester oil such as phthalate ester and phosphate ester, silicone oil, fluorine oil. These lubricants can be used alone or in a mixed form. In addition, mineral oil grease, diester grease, silicone grease, fluorine grease, metal soap-type grease, non-metal soap-type grease, or the like can also be used.

It is a partial cross section perspective view explaining the structure of the self-aligning roller bearing in embodiment of this invention. It is sectional drawing which shows the structure of the self-aligning roller bearing in embodiment of this invention. It is sectional drawing which cut | disconnected the self-aligning roller bearing in embodiment of this invention in the circumferential direction along the XX line in FIG. It is explanatory drawing which shows the outline of the method of manufacturing the polymer molded object 5, (A) is before the injection | pouring of a polymer raw material, (B) is a figure showing after injection | pouring of a polymer raw material. It is sectional drawing which shows another structural example of the self-aligning roller bearing in embodiment of this invention. It is sectional drawing which shows the structure of the conventional double row self-aligning roller bearing.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Outer ring 1a Outer ring side track 2 Inner ring 2a, 2b Inner ring side track 3 Rollers 4a, 4b Cage 5 Inner diameter side polymer molded body 5a Ring portion 5b Branch portion 6 Outer diameter side polymer molded body 6a Ring portion 6b Branch portion 10 Guide Wheel 11 Polymer lubricant 21 Outer jig 22 Inner jig 23a, 23b Side plate

Claims (4)

An outer ring having a concave spherical outer ring side raceway surface on the inner periphery, an inner ring having two rows of arc-shaped inner ring side raceway surfaces on the outer periphery, and two axial left and right rows arranged between the raceway surfaces of these inner and outer rings In a self-aligning roller bearing comprising a roller and two cages each holding these roller rows in a freely rollable manner,
Of the annular space formed between the outer ring and the inner ring, the inner ring side of the cage is made of a polymer containing a lubricant and fits in a space between adjacent rollers and the inner ring. Two inner diameter side polymer moldings having branch portions that are jammed and annular portions that connect these branch portions in the circumferential direction on the center side in the axial direction are arranged such that the end surfaces of the annular portions face each other with a gap therebetween. In addition, the self-aligning roller bearing is characterized by being arranged one by one on the left and right raceways across a plane orthogonal to the shaft at the axial center position of the bearing.   2. The self-aligning roller bearing according to claim 1, wherein the inner diameter side polymer molded body is formed in a shape having a predetermined gap with respect to the roller and the inner ring.   Of the annular space formed between the outer ring and the inner ring, the outer ring side of the cage is made of a polymer containing a lubricant, and is a space between adjacent rollers and the outer ring. Two outer-diameter-side polymer molded bodies having branch portions to be fitted and annular portions that connect the branch portions in the circumferential direction on the center side in the axial direction. 3. The automatic adjustment according to claim 1, wherein the bearings are arranged one by one on left and right tracks so as to face each other across a plane orthogonal to the shaft at the axial center position of the bearing. Center roller bearing.   The self-aligning roller bearing according to claim 3, wherein the outer diameter side polymer molded body is formed in a shape having a predetermined gap with respect to the roller and the outer ring.