JP2003090346A - Roller bearing - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a roller bearing which can restrain a lateral sliding phenomenon at a low cost without depending on the improvement of machining accuracy. SOLUTION: The bearing 1 has plural rollers 2 and a cylindrical-shaped outer ring 3. An axial center O1 of an outer ring raceway surface 5 is inclined by a certain angle θ relative to an axial center O0 of an outer diameter surface 6 of the outer ring, where the angle θ is a minute angle.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a roller bearing used in various devices such as connecting rods of engines, planetary gear speed reducers in robot arms, construction machines, pumps and the like.

[0002]

2. Description of the Related Art In a roller bearing, when the outer ring rotates, a unidirectional thrust force is generated due to the influence of the roller skew and the cage pocket inclination accuracy, which causes axial movement of the outer ring, so-called lateral running. Is inevitable. In particular, the phenomenon is remarkable in the high speed range. Due to this lateral running, the guide portion in the width direction with respect to the bearing in the bearing-installed device comes into contact with the outer ring width surface of the bearing, etc., causing heat generation and seizure damage. For this reason, the lateral running phenomenon has been conventionally prevented. Conventionally, in order to prevent the lateral running phenomenon, a method of improving the processing accuracy of the rollers and the cage has been adopted.

[0003]

However, in order to improve the processing accuracy, there is a limit in consideration of the processing technology and there is a problem of high processing cost. In recent years, the operating environment of bearings has become even faster and leaner,
For this reason, it is necessary to prevent heat generation and seizure due to the lateral running phenomenon of the bearing.

An object of the present invention is to provide a roller bearing which can suppress the lateral running phenomenon at a low cost without improving the machining accuracy.

[0005]

A roller bearing according to a first aspect of the present invention is a roller bearing having a plurality of rollers and a cylindrical outer ring for rolling the rollers, wherein the axis of the outer ring raceway surface is outside the outer ring. It is characterized in that it is inclined at a constant angle with respect to the axis of the radial surface. According to this structure, since the axis of the outer ring raceway surface is inclined with respect to the axis of the outer ring outer diameter surface, when a radial load is applied, a circle where the radial load acts between the outer ring and the inner ring equivalent member. Thrust force acts in the direction of inclination of the outer ring raceway surface at the circumferential position. In the case of the outer ring rotation, the inclination angle of the outer ring raceway surface at the circumferential position where the radial load acts changes depending on the rotation phase.
The tilt direction is reversed every 0 degree. Therefore, thrust forces in opposite directions act alternately. This alternating thrust force suppresses the lateral running phenomenon of the bearing.
The roller bearing according to the first aspect of the present invention is effective in suppressing the lateral running phenomenon, for example, when the roller bearing is installed at a large end portion of a connecting rod of an engine or at a supporting portion of a planetary gear in a planetary gear reduction device. Become.

A roller bearing according to a second aspect of the present invention has a plurality of rollers, a member corresponding to an outer ring having an inner diameter surface having a raceway surface for rolling the rollers, and an outer diameter surface having a raceway surface for rolling the rollers. In a roller bearing having an inner ring equivalent member,
It is characterized in that the axis of the raceway surface of the member corresponding to the outer ring is inclined by a certain angle with respect to the axis of the raceway surface of the member corresponding to the inner ring. Also in the case of this configuration, since the axial center of the raceway surface of the member equivalent to the outer ring is tilted, when a radial load is applied when the outer ring is used for rotation, thrust forces in opposite directions are alternately applied as in the first invention. Will work. This alternating thrust force suppresses the lateral running phenomenon of the bearing. In the roller bearing of the second invention, the member corresponding to the outer ring is, for example, a large end portion of a connecting rod of an engine or a gear, particularly a planetary gear in a planetary gear reduction device.

In the present invention, both in the case of the first invention and in the case of the second invention, the above-mentioned constant angle for inclining the axial center of the outer ring raceway surface and the above-mentioned constant angle for inclining the axial center of the raceway surface of the member equivalent to the outer ring. The angles are all minute angles. This constant angle is, for example, 0.0005 to 0.004ra
d. If this angle is smaller than 0.0005 rad., The thrust force acting alternately is small, and the effect of suppressing the lateral running phenomenon cannot be obtained. The above angle is 0.004ra
If it is larger than d., the behavior in which the thrust force acts alternately becomes unstable. As a result, the friction of the bearing increases.

In the present invention, the outer ring or the member corresponding to the outer ring may be a press-formed product. If it is a press-formed product, an outer ring or a member equivalent to the outer ring whose raceway surface is inclined at a constant angle can be easily manufactured. The outer ring or the member equivalent to the outer ring may be, for example, a cut product, a grind product, a cast product, a forged product, or a sintered product, in addition to the press-formed product.

[0009]

1 is a block diagram of a first embodiment of the present invention.
3 to FIG. This roller bearing 1 has a plurality of rollers 2 and a cylindrical outer ring 3 that rolls the rollers 2. The axis O ₁ of the outer ring raceway surface 5 is the axis O _{0 of the} outer ring outer diameter surface 6.
Is inclined by a constant angle θ with respect to. Around 2
Are held in pockets 4a provided at a plurality of positions in the circumferential direction of the cage 4. Although the angle θ is emphasized in the drawing, it is a minute angle, and 0.0005 to 0.0
The range of 04 rad. Is preferable. The outer ring 3 has flanges 3a and 3b on both sides. The outer ring 3 is a press-formed product of a steel plate and is hardened by heat treatment, and is a so-called shell type. The outer ring 3
Can be machined, ground, cast, forged, or sintered.

As shown in FIG. 3, the roller bearing 1 having this structure is installed so that the rollers 2 roll around the outer periphery of a member 7 corresponding to an inner ring such as a shaft or a bearing inner ring. In the case where the outer ring 3 is used for rotation, the axial center O ₁ (FIG. 1) of the outer ring raceway surface 5 is inclined with respect to the axial center O ₀ of the outer ring outer diameter surface 6, so that when the radial load A acts, the outer ring 3 A thrust force a in the inclination direction of the outer ring raceway surface 5 acts on the outer ring 3 between the inner ring member 3 and the member 7 corresponding to the inner ring at the circumferential position where the radial load A acts. In the case of outer ring rotation, the inclination angle of the outer ring raceway surface 5 at the circumferential position where the radial load acts gradually changes depending on the rotation phase, and the inclination direction is reversed every 180 degrees. Therefore, thrust forces a and b in opposite directions act alternately.

That is, in FIG. 3, the outer ring is actually rotated, but considering that the outer ring 3 is relatively fixed and the member 7 corresponding to the inner ring is rotated, when the radial load A acts,
When the thrust force a acts on the outer ring 3 and the radial load B acts in the opposite direction to the radial load A, the thrust force b acts in the opposite direction to the thrust force a. In the outer ring rotation, since the radial loads A and B act alternately, thrust forces a and b in opposite directions act alternately.

Due to the thrust forces a and b acting in opposite directions to each other, the lateral running phenomenon of the bearing is suppressed. If the constant angle θ that tilts the outer ring raceway surface 5 is too small, the thrust forces a and b that act alternately are small, and the effect of suppressing the lateral running phenomenon cannot be obtained. If it is too large, the behavior in which the thrust forces a and b act alternately becomes unstable. As a result, the friction of the bearing increases. Therefore, the angle θ is
The range of 0.0005 to 0.004 rad. Is preferable, and in this range, the effect of suppressing the lateral running phenomenon can be obtained without causing unstable behavior.

In this roller bearing 1, since the outer ring raceway surface 5 is inclined in this manner, the lateral running phenomenon can be suppressed without increasing the machining accuracy, and the lateral running phenomenon can be suppressed by suppressing the increase of the machining cost. it can. Since the lateral running phenomenon is suppressed, it is possible to reduce the contact between the roller bearing 1 and the width-direction guide portion in the bearing-installed device to prevent heat generation and seizure, and it is possible to further speed up and use under lean lubrication. Become.

FIG. 4 shows a roller bearing 1 according to the above embodiment.
Shows a connecting rod using. This connecting rod is used for connecting a piston and a crankshaft (neither is shown) in a reciprocating engine. The connecting rod 10 has a large end 12 and a small end 1 at both ends of the rod 11.
3, and cylindrical through holes 14 and 15 are provided in the large end 12 and the small end 13. These through holes 1
The roller bearing 1 according to the first embodiment is fixed to the rollers 4 and 15 by press fitting or the like. However, the roller bearings 1 press-fitted into the large end portion 12 and the small end portion 13 have different dimensions, and the roller bearing 1 on the large end portion 12 side having a large dimension is used. The connecting rod 1 and the roller bearings 1, 1 at both ends constitute a connecting rod with bearings.

As described above, when the roller bearing 1 according to this embodiment is used for the connecting rod 10, the roller bearing 1 of the connecting rod 10 is liable to roll due to the lateral running phenomenon, such as the adjacent crank portion of the crankshaft and the inner wall of the piston. The contact of the outer ring 3 of the roller bearing 1 with the widthwise guide portion for the bearing 1 is reduced. Therefore, it is possible to prevent heat generation and seizure, further speed up, and use under diluted lubrication becomes possible. This can be expected to improve engine performance.

In this embodiment, the roller bearing 1 of the above embodiment is provided on both the large end 12 and the small end 13 of the connecting rod 10.
However, the roller bearing 1 of the above-described embodiment is used for either one of the large end 12 and the small end 13, for example, the large end 12, and the other is a normal roller bearing, that is, the outer ring raceway surface. Non-tilted roller bearings may be used.

FIG. 5 shows an embodiment corresponding to the second invention. The connecting rod 10A has a large end portion 12A and a small end portion 13A at both ends of the rod 11A, and inner diameter surfaces of the large end portion 12A and the small end portion 13A roll the rollers 2 in the roller bearings 1A and 1B. These are surfaces 5A and 5B. The large end portion 12A and the small end portion 13A are respectively provided in the roller bearing 1
It becomes a member corresponding to the outer ring in A and 1B. Each roller bearing 1
The rollers 2 of A and 1B are respectively held by a cage 4, and the roller 2 and the cage 4 constitute a roller with a cage.

The roller bearing 1A of the large end portion 12A has a raceway surface 8 which is an outer peripheral surface of an inner ring equivalent member 7A which is a crankshaft.
To roll. In the roller bearing 1A of the large end portion 12A, the axial center O _1A of the raceway surface 5A of the large end portion 12A which is the outer ring equivalent member is fixed at a constant angle θ with respect to the axial center O _0A of the raceway surface 8 of the inner ring equivalent member 7A. Only _A is tilted. This angle θ _A has a size in the same range as the minute angle θ of the above embodiment. Although the roller bearing 1B of the small end portion 13A is a normal roller bearing in which the raceway surface is not inclined, this roller bearing 1B also has a large end portion 1A.
The raceway surface may be inclined similarly to the 2A roller bearing 1A.

As described above, even when the inner diameter portion of the connecting rod 10A is directly formed into the raceway surfaces 5A and 5B, the inclination angle θ is given to the axis O ₁ of the raceway surface 5A of the large end portion 12A thereof. As in the above embodiment, thrust forces in opposite directions are alternately applied to prevent the lateral running phenomenon. Even when the roller bearing 1A raceway surface 5A is directly formed on the connecting rod 10A, the connecting rod 10A
A may be a press-formed product.

FIG. 6 shows another embodiment corresponding to the second invention of the present invention. This roller bearing 1C has a plurality of rollers 2
A roller bearing having an outer ring equivalent member 3C having a raceway surface 5C for rolling the rollers 2 on the inner diameter surface and an inner ring equivalent member 7C having a raceway surface 8C for rolling the rollers 2 on the outer diameter surface, The axis O _1C of the raceway surface 5C of the outer ring equivalent member 3C is tilted by a constant angle θ _{C with} respect to the axis O _0C of the raceway surface 8C of the inner ring equivalent member 7C. The angle θ _C has a size in the same range as the angle θ in the first embodiment. The plurality of rollers 2 are held in pockets 4 a provided at a plurality of circumferential positions of the cage 4.

The outer ring-corresponding member 3C is a gear and has a tooth portion 17 on its outer periphery. More specifically, the outer ring equivalent member 3C is, for example, a planetary gear in a planetary gear speed reducer.
The inner ring equivalent member 7C is a shaft, for example, a gear support shaft provided on a carrier in a planetary gear speed reducer. In the illustrated example, the inner ring equivalent member 7C is an eccentric shaft portion of the shaft 18.

Also in this structure, since the raceway surface 8C of the outer ring equivalent member 3C has the inclination angle θ _C , thrust forces in opposite directions are alternately applied to prevent the lateral running phenomenon. Therefore, it is possible to prevent the outer ring-corresponding member 3C such as a gear from interfering with adjacent components in the width direction and increasing friction.

7 and 8 show an example of a planetary gear speed reducer to which the roller bearing of the present invention is applied. This device is used as a drive unit for an arm of a robot. This planetary gear reduction device includes an internal gear ring gear 21, a carrier 22 serving as a rotation output portion, and a crankshaft 23 having a plurality of eccentric shaft portions 23a and 23b rotatably supported by the carrier 22 and adjacent to each other. , Each eccentric shaft portion 23 of the crankshaft 23
It has a plurality of planetary gears 24 and 25 that are rotatably installed on a and 23b and mesh with the ring gear 21, and a rotation input unit 26 that inputs rotation to the crankshaft 23. The ring gear 21 is fixed to the housing 27, and the carrier 22 is installed in the housing 27 via a bearing 28 (FIG. 8) so as to be rotatable concentrically with the ring gear 21. The ring gear 21 serves as an internal sun gear. Rotation input unit 26
Is composed of an input shaft 29 that is concentric with the ring gear 21, and a transmission gear 30 that is provided on each crankshaft 23 and that meshes with the gear portion of the input shaft 29. The crankshaft 23 is provided at a plurality of positions (for example, three positions) in the circumferential direction of the carrier 22. As shown in FIG. 8, the planetary gears 24 and 25 are arranged such that the eccentric shaft portion 23 of the crankshaft 23 is interposed via roller bearings 31.
a, 23b. For this roller bearing 31, the roller bearing of the present invention, for example, the roller bearing 1C of the embodiment shown in FIG. 6 is used. In that case, the planetary gears 24 and 25 and the eccentric shaft portions 23a and 23b become the outer ring equivalent member 3C and the inner ring equivalent member 7C in the example of FIG. 6, respectively.

The operation of this planetary gear speed reducer will be described.
When the central input shaft 29 is rotated, the three crankshafts 23 rotate via the transmission gear 30 in synchronization with each other. Here, the first stage deceleration is performed. The crankshaft 23 and the planetary gears 24, 25 are connected via a roller bearing 31, and the whirling of the crankshaft 23 is controlled by the planetary gears 24, 2
5 synchronizes with the combined motion of the revolution and the rotation when the inner ring 5 rotates inside the ring gear 21. The two planetary gears 24, 25 aligned in the axial direction revolve around the inner circumference of the internal gear ring gear 21 in a state of being 180 ° out of phase with each other. Therefore, the inertial forces due to the whirling of the two planetary gears 24 and 25 cancel each other out. The internal ring gear 21 is fixed, and the planetary gear 2
Reference numerals 4 and 25 rotate around the inner circumference of the inner ring gear 21. The three crankshafts 23 are sandwiched between the two disk portions 22a and 22b of the carrier 22 which serves as an output member. Therefore, the revolutions of the planetary gears 24 and 25 reach the carrier 22 through the revolutions of the crankshaft 23, and a decelerated rotational movement is obtained.

In the planetary gear speed reducer having this structure, the roller bearing 3 interposed between the planetary gears 24 and 25 and the crankshaft 23 is used.
On the other hand, a large radial load is applied to the first roller, a lateral running phenomenon occurs in the conventional roller bearing, and sliding contact occurs between the width surfaces of the adjacent eccentric planetary gears 24 and 25. However, when the roller bearing 1C of the above-described embodiment is used, lateral running is prevented, the above-mentioned sliding contact is avoided, and even if sliding contact occurs, the contact pressure can be small, and there is a problem of increased frictional resistance and wear. Does not happen.

[0026]

According to the roller bearing of the present invention, the shaft center of the raceway surface of the outer ring or the member equivalent to the outer ring is inclined by a certain angle.
When a radial load is applied when using with outer ring rotation,
Thrust loads in opposite directions will act alternately,
Lateral running is suppressed. Therefore, the lateral running phenomenon can be suppressed without increasing the processing accuracy, and the lateral running phenomenon can be suppressed while suppressing an increase in the processing cost. Since the lateral running phenomenon is suppressed, contact with the width-direction guide portion of the bearing is reduced, heat generation and seizure are prevented, and further speeding up and use under lean lubrication are possible. The constant angle is 0.0005
When it is 0.004 rad., The effect of suppressing the lateral running phenomenon due to the alternately acting thrust load can be stably obtained without causing unstable behavior. When the outer ring or the outer ring-equivalent member is a press-molded product, the outer ring or the outer ring-equivalent member whose raceway surface is inclined at a constant angle can be easily manufactured.

[Brief description of drawings]

FIG. 1 is a sectional view of a roller bearing according to an embodiment of the present invention.

FIG. 2 is a sectional view of a cage of the bearing.

FIG. 3 is an explanatory view of the operation of the bearing.

FIG. 4 is a sectional view of a connecting rod using the bearing.

FIG. 5 is a cutaway side view of a connecting rod provided with a roller bearing according to another embodiment of the present invention.

FIG. 6 is a sectional view of a planetary gear including a roller bearing according to still another embodiment of the present invention.

FIG. 7 is a schematic view of an example of a planetary gear speed reducer using the roller bearing of the same embodiment.

FIG. 8 is a partially cutaway side view of the planetary gear reduction device.

[Explanation of symbols]

1, 1C ... Roller bearing 2 ... Roller 3 ... Outer ring 3C ... Outer ring equivalent member 4 ... Retainer 5, 5A, 5C ... Raceway surface 6 ... Outer ring inner diameter surface 7, 7C ... Inner ring equivalent member 10, 10A ... Connecting rod 12A ... Large end part (outer ring member) 21 ... ring gear 22 ... carrier 23 ... crankshaft 23a, 23b ... eccentric shaft portion 24, 25 ... planet gear 31 ... roller bearing _{O 0, O 0A ,, O 0C} ... outer ring outer diameter surface of the shaft Centers O ₁ , O _1A ,, O _1C ... Axes of outer ring raceway surfaces θ, θ _A , θ _C … constant angles

   ─────────────────────────────────────────────────── ─── Continued front page    F term (reference) 3J033 AA04 AA05 EA10 EB10                 3J101 AA13 AA24 AA32 AA42 AA52                       AA62 AA72 BA55 DA09 FA33                       GA11 GA22 GA32 GA51

Claims (4)

[Claims] 1. A roller bearing having a plurality of rollers and a cylindrical outer ring for rolling the rollers, wherein the axis of the outer ring raceway surface is inclined at a constant angle with respect to the axis of the outer ring outer diameter surface. Characteristic roller bearing. 2. A roller bearing having a plurality of rollers, an outer ring equivalent member having an inner diameter surface having a raceway surface for rolling the rollers, and an inner ring equivalent member having an outer diameter surface having a raceway surface for rolling the rollers, A roller bearing, wherein the axis of the raceway surface of the member equivalent to the outer ring is inclined at a constant angle with respect to the axis of the raceway surface of the member equivalent to the inner ring. 3. The constant angle is defined as 0.0005 to 0.
The roller bearing according to claim 1 or claim 2, which has a diameter of 004 rad. 4. The roller bearing according to claim 1, wherein the outer ring or the member equivalent to the outer ring is a press-molded product.