JP6040548B2 - Multi-row combination angular contact ball bearing - Google Patents

Description

The present invention relates to a multi-row combination angular contact ball bearing, in particular, an application in which a thrust load larger than a radial load is applied, for example, a ball screw support rolling bearing for an electric injection molding machine, or a ball screw support rolling bearing for a die casting machine, The present invention relates to a multi-row combination angular contact ball bearing that is applied to applications that rotate under a large load in the axial direction, such as a ball screw support rolling bearing for an electric servo press machine.

As a method for producing a plastic product, a method by injection molding is common. In the case of injection molding, when the molding material is a thermoplastic resin such as polyamide (PA), polyphenylene sulfide (PPS), or polyether ether ketone (PEEK), injection is performed on plastic (usually 180 to 450 ° C) heated to a softening temperature. Apply pressure to fill the mold and mold. In this molding process, it is necessary to maintain the internal pressure of the mold until the plastic filled in the mold is solidified, which is called “clamping”.

  Clamping of a conventional injection molding machine has mainly been a cylinder driving system by hydraulic control as a method for giving a very large clamping force. However, recently, a ball screw drive system based on electric servo control using a high torque motor that does not use a large amount of oil and is environmentally friendly and excellent in energy saving has been developed and put into practical use.

  6 and 7 show an electric injection molding machine 101, which includes a mold clamping unit 102 and an injection unit 103. FIG. The mold clamping unit 102 includes a rear platen 104, a movable platen 105, and a fixed platen 106, and a mold clamping mechanism 108 in which a mold 107 disposed between the movable platen 105 and the fixed platen 106 is disposed between the rear platen 104 and the movable platen 105. To open / close and close the mold.

  The mold clamping mechanism 108 has a toggle structure, and when the mold clamping ball screw 110 pivotally supported on the rear platen 104 is driven and rotated by the mold clamping motor 109, the cross head 111 moves back and forth and expands and contracts. As a result, the movable platen 105 is moved back and forth. The mold clamping ball screw 110 is pivotally supported on the rear platen 104 by a support bearing 112.

  Further, the movable platen 105 is provided with a drive mechanism 141 that operates an ejector pin 140 for projecting a molded product from the mold 107. The drive mechanism 141 includes a motor and a ball screw, and moves the ejector pin 140 by rotating an ejector shaft 142 that forms a screw shaft of the ball screw. The ejector shaft ball screw is pivotally supported on the movable platen 105 by a support bearing (not shown).

  The injection unit 103 includes a rear plate 113, a movable plate 114, and a front plate 115. The base of the metering / injecting screw 117 disposed in the cylinder assembly 116 of the front plate 115 is the front surface of the movable plate 114 (on the mold clamping unit side). ) Through a support bearing 118 (screw sleeve). The metering / injecting screw 117 is driven and rotated by a metering motor (not shown) attached to the movable plate 114 when the resin for molding is weighed, melted and kneaded.

  As shown in FIG. 7, a ball nut 120 is fixed to the rear surface of the movable plate 114, and an injection ball screw 121 screwed to the movable nut 114 is pivotally supported by the rear plate 113, and the injection mechanism 122. Is configured. The injection ball screw 121 is pivotally supported on the rear plate 113 by a support bearing 123 and is driven by an injection motor 124 attached to the rear plate 113.

  When the injection motor 124 is driven in the forward direction, the injection ball screw 121 is rotated forward, the movable plate 114 moves forward, and the molten resin in the cylinder assembly 116 is injected into the mold 107 by the injection / metering screw 117. Is done. After the injection, the metering motor is driven, the injection / metering screw 117 is rotated, and the resin is newly metered and kneaded. At this time, the injection / metering screw 117 is pushed back by the pressure of the resin to be fed, but back pressure is applied by the injection motor 124 so that kneading and melting are sufficiently performed. At the stage where the metering is completed, in order to prevent leakage from the tip of the nozzle, the injection motor 124 is reversed, the injection / metering screw 117 is slightly retracted, and suck back is performed.

  Further, the injection unit 103 is provided with a nozzle touch mechanism 153 that rotates the ball screw 151 forward or backward by the driving motor 150 to move the cylinder assembly 116 forward and backward on the fixed platen 106. The nozzle touch mechanism 153 presses the tip nozzle 116a attached to the cylinder 116 against the mold 107 attached to the fixed platen 106 with a predetermined force. The nozzle touch ball screw 151 is pivotally supported by a support bearing (not shown).

  Here, in the injection molding machine by electric servo control, in the above-described ball screw support bearing 112 for clamping, ball screw support bearing for ejector shaft, ball screw support bearing 123 for injection, and ball screw support bearing for nozzle touch, In order to apply a large axial load during rotation support and mold clamping, special ball screw support bearings using large-diameter balls as shown in FIG. 8 have begun to be used.

  Further, in the ball screw device described in Patent Document 1, in a multi-row combination ball bearing that supports a screw shaft of a ball screw applied to an electric injection molding machine, a contact angle is set to 40 degrees or more and 65 degrees or less, and a thrust load is reduced. It is described that a large load capacity is secured.

JP 2008-101711 A

  By the way, in the ball screw support portion applied to each axis of the injection molding machine, a standard as shown in FIG. 8, which is mainly used for a headstock of a machine tool or a bed feeding mechanism for mounting a workpiece. An angular ball bearing 200 for supporting a ball screw is used. Such an angular ball bearing 200 has a specification in which the contact angle matches the load direction as much as possible so that the rolling life of the bearing can be satisfied even when an axial load of a ball screw generated by a cutting load during processing is applied. Usually, the contact angle is set to 60 degrees. In such a bearing, in the case of a parallel combination in which bearings having the same contact angle direction are used side by side, an extension line L of the normal line of the contact angle is included in the axial end plane 201 of the adjacent bearing 200. It was normal not to. For this reason, when a large thrust load is applied, an excessive load is applied to the groove portion of the bearing ring, which may cause problems such as cracking of the bearing ring.

  In other words, as hydraulic injection molding machines have been electrified in the past, there has been an application that applies a large thrust load that has not been envisaged with conventional ball screw support angular contact ball bearings. . For this reason, the possibility of raceway cracking due to a large thrust load has become apparent.

  In addition, in the application of an injection molding machine, in order to satisfy the fatigue life of a bearing with respect to a large load, a multi-row combination of 4 to 5 rows, which has been hardly adopted so far, is applied so that a load in one direction can be applied. In many cases, there are many places where malfunctions are expected.

The present invention has been made in view of the above-described problems, and the object thereof is to prevent problems such as breakage and cracking of the race ring even when a very large thrust load is applied. It is to provide a multi-row combination angular contact ball bearing.

The above object of the present invention can be achieved by the following constitution.
(1) In a multi-row combination angular ball bearing comprising at least two rows of ball bearings in parallel combination, the ball bearing being an angular ball bearing,
The outer ring and inner ring of each ball bearing of the parallel combination have a groove shoulder on the side through which an extension line of the contact angle passes with respect to the axial center of the ball bearing, than a groove shoulder on the opposite side to the axial center. Is also formed high,
Each of the ball bearings of the parallel combination has a width dimension that is larger than that of a standard bearing of the ISO standard by increasing the width dimension of the groove shoulder on the side through which the extension line of the contact angle passes in at least one of the outer ring and the inner ring. Lengthen the
Each ball bearing of the parallel combination, in at least one of the outer ring and the inner ring, by shortening the width dimension of the groove shoulder on the opposite side to the axial center, the total width dimension of the ball bearings, It corresponds to the total of ISO standard bearings,
Of the ball bearings of the parallel combination, the extension line of the contact angle of one of the ball bearings passes through the axial end plane of the other ball bearing adjacent to the one ball bearing, and the other A multi-row angular contact ball bearing characterized in that an extended line of a contact angle of the ball bearing passes through an axial end plane of the one ball bearing adjacent to the other ball bearing.
(2) At least three rows of the ball bearings are arranged in a parallel combination,
Among the ball bearings of the parallel combination, the ball bearing located in the middle in the axial direction is configured to increase the width dimension of the groove shoulder on the side through which the extension line of the contact angle passes in both the outer ring and the inner ring. Increasing the width of the ISO standard bearing
Extension of the contact angle of the ball bearing positioned on the axial middle, the multi-row duplex angular contact according to, characterized in that passing through the axial end plane of the ball bearing adjacent to each other in the axial direction on both sides (1) Ball bearing.

According to the multi-row combination angular contact ball bearing of the present invention, each of the parallel combination ball bearings, in at least one of the outer ring and the inner ring, by increasing the width dimension of the groove shoulder on the side through which the extension line of the contact angle passes, By increasing the width dimension relative to the ISO standard bearing, each ball bearing in parallel combination has a groove shoulder on the opposite side with respect to the center in the axial direction in at least one of the outer ring and the inner ring. The total width of each ball bearing corresponds to the total of ISO standard bearings, and the contact angle extension of one of the ball bearings in parallel combination is adjacent to one of the ball bearings. Passing through the axial end plane of the other ball bearing, the extension of the contact angle of the other ball bearing passes through the axial end plane of one ball bearing adjacent to the other ball bearing. With such a configuration, when a very large thrust load is applied to the bearing, the contact angle direction generated between the contact portions between the rolling elements and the raceway grooves of the inner and outer rings is not changed without changing the overall axial width. The load can be backed up by the inner and outer rings of adjacent bearings without being loaded only by the inner and outer rings of the bearing. As a result, the bending stress acting on the inner and outer rings of the bearing is greatly reduced, and it is possible to prevent problems such as breakage and cracking of the bearing ring. As a result, the load limit value as a multi-row combination angular contact ball bearing can be increased.

  Even in the conventional ball bearing as shown in FIG. 8, if the contact angle is not 60 degrees or more, for example, about 50 degrees or less, the extension direction of the contact angle of the ball bearing is the axial direction of the adjacent ball bearing. In this case, the axial load of the ball bearing is reduced, and the rolling fatigue life is reduced. On the other hand, by using the multi-row combination ball bearing of the present invention, it is possible to realize both the extension of the rolling fatigue life and the prevention of damage to the bearing rings.

It is sectional drawing of the multi-row combination ball bearing which concerns on 1st Embodiment of this invention. It is sectional drawing of the multi-row combination ball bearing which concerns on 2nd Embodiment of this invention. It is sectional drawing of the multi-row combination ball bearing which concerns on 3rd Embodiment of this invention. It is sectional drawing of the multi-row combination ball bearing which concerns on 4th Embodiment of this invention. It is sectional drawing which shows the modification of the multi-row combination ball bearing of this invention. It is a front view of a general electric injection molding machine. It is a principal part enlarged view of a general electric injection molding machine. It is sectional drawing of the conventional multi-row combination ball bearing.

  Hereinafter, a multi-row combination ball bearing according to each embodiment of the present invention will be described in detail with reference to the drawings. The multi-row combination ball bearings according to the embodiments include the ball screw support bearing for clamping, the ball screw support bearing for ejector shaft, the ball screw support bearing for injection, and the ball screw for nozzle touch described with reference to FIGS. Although it is assembled as a support bearing, only a multi-row combination ball bearing is illustrated and described here.

(First embodiment)
As shown in FIG. 1, in the multi-row combination ball bearing 10 of the present embodiment, three rows of angular ball bearings 11A, 11B, and 11C are arranged in combination, of which two rows of angular ball bearings 11A and 11B are arranged. Arranged in parallel, and two rows of angular ball bearings 11B and 11C are arranged in rear combination.

  Each of the angular ball bearings 11A, 11B, and 11C includes an outer ring 12 having an outer ring raceway groove 12a on an inner peripheral surface, an inner ring 13 having an inner ring raceway groove 13a on an outer peripheral surface, and an outer ring raceway groove 12a and an inner ring raceway groove 13a. Are provided with a ball 14 that is freely rollable with contact angles α1, α2 and a retainer 15 that holds the ball 14 (see FIG. 5, not shown in FIGS. 1 to 4).

  The groove shoulder 12b on one axial side of the outer ring 12 (right side in the figure) is the outer ring on the side through which the extension line L of the contact angles α1, α2 passes with respect to the axial center of the ball bearing, that is, the center of the ball 14. The track groove 12a is formed to be higher than the groove shoulder 12c on the other side in the axial direction (left side in the figure), which is the opposite side to the center of the ball 14, so that the track groove 12a becomes longer. Further, a counter that inclines so as to increase in diameter toward the other side in the axial direction at the groove shoulder 12c of the outer ring 12 on the opposite side to the side through which the extension lines L of the contact angles α1, α2 pass with respect to the center of the ball 14. A bore 12d is formed on the inner peripheral surface. The counter bore 12d has a shape necessary for inserting a ball during assembly of the bearing.

  On the other hand, in the groove shoulders 13 b and 13 c of the inner ring 13, the groove shoulder 13 b on one side in the axial direction is formed low so that the cage 15 having an inclined cross section is inserted between the inner and outer rings 12 and 13. Further, the groove shoulder 13c on the other axial side of the inner ring 13 is centered on the ball 14 so that the inner ring raceway groove 13a on the side through which the extension line L of the contact angles α1, α2 passes is longer than the center of the ball 14. It is formed higher than the groove shoulder 13b on the one side in the axial direction, which is the opposite side.

  Here, in two rows of angular contact ball bearings 11A and 11B in parallel combination, the extension line L of the contact angle α1 of the left ball bearing 11A is the outer ring of the right ball bearing 11B adjacent to the ball bearing 11A on one side in the axial direction. It passes through 12 axial end planes 12e. Further, the extension line L of the contact angle α1 of the right ball bearing 11B passes through the axial end plane 13e of the inner ring 13 of the left ball bearing 11A.

  In this embodiment, in order to satisfy these requirements, the angular ball bearing 11A increases the width dimension of the groove shoulder 12b on one side in the axial direction of the outer ring 12 by Δ, and the width dimension B of the ISO standard bearing. In contrast, the width dimension is increased by Δ. In the angular ball bearing 11B, the width dimension of the groove shoulder 13c on the other axial side of the inner ring 13 is increased by Δ, and the width dimension is increased by Δ relative to the width dimension B of the ISO standard bearing.

  Further, the angular ball bearing 11A shortens the width dimension of the groove shoulder 13b on one side in the axial direction of the inner ring 13 by Δ, and the angular ball bearing 11B reduces the width dimension of the groove shoulder 12c on the other side in the axial direction of the outer ring 12 by Δ. Only shortened. Therefore, when the angular ball bearings 11A and 11B are combined in parallel, the total width dimension of the ball bearings 11A and 11B becomes the total width dimension 2B of the ISO standard bearing, and without changing the overall axial width, The above requirements can be satisfied.

  Specifically, in the present embodiment, in the ball bearings 11A and 11B having a bearing inner diameter d of 25 mm to 120 mm, the contact angle α is 40 ° to 60 °, preferably 45 ° to 60 °, and the inclination angle β of the counter bore 12d. Is set to 0 ° to 20 °, and the ball diameter Da is set to 8.7 mm to 39 mm. The ratio Da / H between the ball diameter Da and the radial thickness H (= (bearing outer diameter−bearing inner diameter) / 2) is 0.5 to 0.7 (preferably 0.60 to 0.70). Set to

  For example, as shown in FIG. 1, the angular ball bearing 11C has an inner diameter d of 50 mm, an outer diameter D of 110 mm, a width B of 27 mm, a contact angle α of 60 °, and a ball diameter Da of 20.638 mm. While the ball bearing 7310 is used as it is, in the angular ball bearings 11A and 11B, the width dimensions of the outer ring 12 and the inner ring 13 are changed as described above with respect to the ball bearing of the reference number 7310. Thereby, the extension line L of the contact angle α1 of the left ball bearing 11A passes through the axial end plane 12e of the outer ring 12 of the right ball bearing 11B adjacent to the ball bearing 11A on the one axial side. Similarly, in the groove shoulder 13b on one axial side of the inner ring 13, the extension line L of the contact angle α1 of the right ball bearing 11B passes through the axial end plane 13e of the inner ring 13 of the left ball bearing 11A. To do.

  By satisfying the above requirements as described above, when a very large thrust load is applied to the multi-row combination ball bearing 10, it occurs between the contact portions between the balls 14 and the raceway grooves 12 a and 13 a of the inner and outer rings 12 and 13. The load in the contact angle direction can be backed up by the inner and outer rings 12 and 13 of the adjacent ball bearings 11A and 11B without being loaded only by the inner and outer rings 12 and 13 of the ball bearings 11A and 11B. As a result, the bending stress acting on the inner and outer rings of the ball bearings 11A and 11B is greatly reduced, and it is possible to prevent problems such as breakage and cracking of the bearing rings. As a result, the load load limit value as a multi-row combination ball bearing can be increased.

Further, the width of the groove shoulders 12b and 13c on the side through which the extended line of the contact angle α1 of the outer ring 12 and the inner ring 13 passes, that is, the thickness of the outer ring 12 and the inner ring 13 on the side where the rolling element load is applied is increased. The axial bending strength against the load of the outer ring 12 and the inner ring 13 can be increased.
In this embodiment, the counter bore is provided on the outer ring side, but the counter bore may be provided on the inner ring side.

(Second Embodiment)
FIG. 2 shows three rows of angular ball bearings 11A, 11B, and 11C according to the second embodiment of the present invention. Note that the same or equivalent parts as those of the first embodiment are denoted by the same reference numerals, and description thereof is omitted or simplified.

In the first embodiment, the sum of the width dimensions of the ball bearings 11A, 11B, and 11C is 3B, which is not different from the width dimension when three ISO standard bearings are combined, but the three ball bearings 11A, 11B, Each configuration of 11C is different. On the other hand, in this embodiment, the inner ring spacer 16 having a width dimension Δ is arranged between the inner rings 13 and 13 of the ball bearings 11B and 11C to be combined on the back surface, and the ball bearings 11A and 11B to be combined in parallel are shared. I am trying. In this case, the sum of the width dimensions of the ball bearings 11A, 11B, and 11C is 3B + 3Δ. Further, the preload clearances of the ball bearings 11A, 11B, and 11C can be easily adjusted by adjusting the width of the inner ring spacer 16.
Other configurations and operations are the same as those in the first embodiment.

(Third embodiment)
FIG. 3 shows three rows of angular ball bearings 11A, 11B, and 11C according to a third embodiment of the present invention. Note that the same or equivalent parts as those in the second embodiment are denoted by the same reference numerals, and description thereof is omitted or simplified.

In the present embodiment, the ball bearing 11C has the same configuration as the ball bearings 11A and 11B of the second embodiment. In this case, the width dimension is provided between the inner rings 13 and 13 of the ball bearings 11B and 11C to be combined on the back surface. A 2Δ inner ring spacer 16a is disposed. In this case, the sum of the width dimensions of the ball bearings 11A, 11B, and 11C is 3B + 5Δ. Further, the preload clearances of the ball bearings 11A, 11B, and 11C can be easily adjusted by adjusting the width of the inner ring spacer 16a.
Other configurations and operations are the same as those of the second embodiment.

(Fourth embodiment)
FIG. 4 shows three rows of angular ball bearings 11A, 11B, and 11C according to a fourth embodiment of the present invention. Note that the same or equivalent parts as those of the first embodiment are denoted by the same reference numerals, and description thereof is omitted or simplified.

In the present embodiment, the angular ball bearing 11C has the same effects as the first embodiment by reducing the ball diameter and the width dimension with respect to the ball bearing 11C of the first embodiment. The width dimension of the bearing can be reduced. That is, in this embodiment, the angular diameter of the angular ball bearing 11C is smaller than the diameter of the other angular ball bearings 11A and 11B, φDa1, and the width dimension is Δ2 from the width dimension B of the ISO standard bearing. It is small.
Other configurations and operations are the same as those in the first embodiment.

In addition, this invention is not limited to embodiment mentioned above, A deformation | transformation, improvement, etc. are possible suitably.
For example, the multi-row combination ball bearing 10 of the present invention is also applicable to a multi-row combination of 4-5 rows of ball bearings 11A to 11E as shown in FIG. 5 so that a large load in one direction can be applied. Can do. In FIG. 5, four rows of the parallel combination ball bearings of the second embodiment are arranged, but the ball bearings of other embodiments may be arranged.

10 Multi-row combination ball bearings 11A, 11B Ball bearing 12 Outer ring 12b, 12c Groove shoulder 12d Counter bore 12e Axial end plane 13 Inner ring 13b, 13c Groove shoulder 13e Axial end plane 14 Ball 15 Cage α1 Contact angle L Extension line

Claims (2)

In a multi-row combination angular contact ball bearing comprising at least two rows of parallel combination ball bearings, the ball bearing being an angular contact ball bearing,
The outer ring and inner ring of each ball bearing of the parallel combination have a groove shoulder on the side through which an extension line of the contact angle passes with respect to the axial center of the ball bearing, than a groove shoulder on the opposite side to the axial center. Is also formed high,
Each of the ball bearings of the parallel combination has a width dimension that is larger than that of a standard bearing of the ISO standard by increasing the width dimension of the groove shoulder on the side through which the extension line of the contact angle passes in at least one of the outer ring and the inner ring. Lengthen the
Each ball bearing of the parallel combination, in at least one of the outer ring and the inner ring, by shortening the width dimension of the groove shoulder on the opposite side to the axial center, the total width dimension of the ball bearings, It corresponds to the total of ISO standard bearings,
Of the ball bearings of the parallel combination, the extension line of the contact angle of one of the ball bearings passes through the axial end plane of the other ball bearing adjacent to the one ball bearing, and the other A multi-row angular contact ball bearing characterized in that an extended line of a contact angle of the ball bearing passes through an axial end plane of the one ball bearing adjacent to the other ball bearing. At least three rows of the ball bearings are arranged in a parallel combination;
Among the ball bearings of the parallel combination, the ball bearing located in the middle in the axial direction is configured to increase the width dimension of the groove shoulder on the side through which the extension line of the contact angle passes in both the outer ring and the inner ring. Increasing the width of the ISO standard bearing
2. The multi-row combination angular contact member according to claim 1, wherein an extension line of a contact angle of the ball bearing located in the middle in the axial direction passes through an axial end plane of each ball bearing adjacent on both sides in the axial direction. Ball bearing.

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