JPH03244832A - Clutch bearing - Google Patents

Abstract

PURPOSE:To load a thrust on the wide surface of a cage and reduce the extent of frictional resistance by setting up an rolling element on each raceway surface of raceway members of both conical inner and outer rings in a line contact manner, and positioning the cage housed with the rolling element in the axial direction with these inner and outer rings. CONSTITUTION:A rolling element 2 is tilted to the shaft center at three dimensions, and it is formed so as to roll on both raceways 15, 16 in line contact. The rolling element 2 is interposed between these raceways 15 and 16 of an outer ring 1 and an inner ring 3, and it is kept in a pocket hole 10 of a cage 7. At the inner side of a cage rib 17, there are provided with protrusions 8, 9, contacting with the vicinity of the axial center of an edge of the rolling element 2, while an outer side 18 of the cage 7 comes into contact with the raceway ring and is supported in the axial direction. When radial load 28 works on a clutch, it is proportionate to conical angle as a raceway is of conical surface, therefore thrust component forces 26, 27 are produced there, thus there are produced such forces 29, 30 as holding the cage 7 in between with ribs 4 and 5 for the inner ring 3 and the outer ring 1. Since the cage slide-contact surface 18 receiving the thrust load is being finished so as to secure a correct surface contact, low frictional resistance is ensured.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention interposes rolling elements between the raceway rings on the drive side and the driven side, and uses rotational force to automatically move the rolling elements between the raceway rings. It acts like a wedge so that the rotational force is transmitted only in one direction.If it rotates in the opposite direction, it will idle and function as a rolling bearing.If the inner and outer races are separated in the axial direction, the power will be transmitted. It also serves as a dog clutch that can be used to engage and disengage, while also providing a taratch.

Prior Art A conventional one-way clutch has a structure in which sprags are interposed between an inner raceway ring and an outer raceway ring, and the sprags are wedge-shaped and wedged radially between the races due to rotational force. This is called a sprag type clutch, and recently a conical cone bearing ring is used, and the rolling elements are wedged between the bearing rings by the load torque.
One-way clutches such as No. 092, No. 46-21126, and No. 7523-Sho. 42 have been devised, and are called rolling one-way clutches.

In a sprag clutch, if a lubricant with a strong oil film is present between the contact surface between the sprags arranged on the raceway circumference and the raceway ring, some of the sprags may slip and all the sprags will always maintain correct and even contact pressure. It becomes difficult to work as a wedge, and the disadvantage is that the calculated rated torque cannot be obtained. When the surface pressure varies, only some of the sprags exceed the allowable surface pressure and reverse due to the excessive load (referred to as rollover) and lose their function as a clutch. In addition, due to minute torque fluctuations or high-speed indexing, the sprags jump and do not engage, resulting in uncertain engagement (known as bobbing phenomenon) and causing fatigue breakage of the spring that controls the sprag position, preventing normal locking function. I had a problem losing it.

Furthermore, sprags always have a short lifespan due to repeated contact pressure at the same location, localized wear due to sliding friction, and fatigue peeling due to contact stress.

In addition, the spring that presses the sprag may be damaged due to fatigue due to repeated indexing, and due to the many factors that cause instability, the usage conditions of the clutch are extremely limited, and there are also problems with reliability.

Tokuko Sho 58, which solved the above-mentioned drawbacks of the sprag clutch.
-52092, 1972-21126, 1972-7523
However, in this one-way rolling clutch using a conical cone, the rolling elements are in line contact with the raceways of the inner and outer rings of the hyperboloid surface, and the rolling elements cannot be called perfect due to the following drawbacks. On the other hand, since the rollers are arranged at an angle (skew), a thrust force is generated on the rollers during idling (overrunning), and the corners of the end faces of the rollers slide into contact with the corners of the flange formed at the end of the bearing ring. , metal corners are in point contact with each other, and it is difficult to lubricate due to centrifugal force, making it difficult to form an oil film and causing high frictional resistance.The rollers also rotate at high speeds, causing heat generation, wear, and abnormal noise. There is.

In other words, in a rolling element that rolls in a skewed manner, an axial component force on the outer raceway due to traction and an axial component force in the opposite direction on the inner raceway are generated in proportion to the angle of inclination with respect to the axis. Although they are offset to some extent, thrust generated by the difference in surface pressure between the inner ring raceway and outer ring raceway and thrust generated by centrifugal force are generated, and due to this thrust, the corners of the rolling elements and the corners of the collar of the raceway are When the rolling elements rub against each other at high speed, especially when the diameter of the rolling elements is smaller than the diameter of the raceway, the rotational speed of the rolling elements reaches opposite rotation, and at the same time, when a radial load is applied to the clutch, the traction thrust generated on the rolling elements is further magnified, which not only creates a large frictional resistance but also causes noise burn-in if they rub against each other at high speed in point contact.

In addition, in the conventional technology, the rolling elements are only positioned in one direction by the collar provided on one side of the bearing ring.
If the rolling elements are used under acceleration conditions such as gravity or centrifugal force that causes them to come out of the bearing ring, for example when used on a vertical axis, a preload is always applied to generate thrust on the rolling elements due to the axial component of traction. If this was not done, the rolling elements would fall out of the raceway.

Also, when a torque is applied and the lock state is entered, the inner ring raceway is sucked in the axial direction by the traction caused by the rolling contact of the rolling elements to the outer ring raceway and is locked, but the uneven contact of the rolling elements due to misalignment between the two raceways can occur. , or if there is a large frictional resistance during the axial movement of the inner raceway relative to the outer raceway that causes resistance to the suction operation, or there is an obstacle such as catching, there is a problem in which the locking function is lost, or the rolling elements Since the wheels roll at an angle to the axis, there is a rolling contact with slippage, and there is a risk that the raceway will wear out as if it were constantly lapping due to foreign matter getting into the lubricant, and this wear could cause the raceway to deteriorate. If the geometry of the rolling elements changes, the force with which the outer ring sucks in the inner ring during traction due to a torque load will decrease, making locking uncertain.

Increasing the inclination angle (skew angle) of the rolling elements with respect to the axis will reduce the suction force, but the contact pressure of the rolling elements will decrease, so the torque capacity will increase. Conversely, decreasing the skew angle will increase the As the surface pressure increases, the suction force increases, but the torque capacity decreases. However, from the standpoint of functionality as a rolling bearing, the skew angle should be kept as small as possible to reduce frictional resistance and heat generation. Although this is important for achieving greater accuracy, it is a conflicting issue with torque capacity, and since the skew angle is selected based on the priority of both, it has been difficult to achieve both functions simultaneously.

The problem to be solved by the invention is to eliminate the frictional resistance, heat generation, and wear that occur when the end faces of the rolling elements and the corners of the collar of the raceway rub against each other at high speed in the aforementioned one-way rolling clutch, and to eliminate the frictional resistance, heat generation, and wear caused by the rolling elements In order to eliminate the problem of the outer raceway pulling out of the raceway due to axial acceleration, etc., and to increase reliability when locking, the force by which the outer raceway draws in the inner raceway is increased, and the torque capacity of the clutch is increased.

Means for Solving the Problems The present invention utilizes the axial component of traction generated on the rolling elements when the rolling clutch is idling as described above, by connecting the ends of the rolling elements to the rib portion of the window for holding the rolling elements of the cage. The thrust bearing of the retainer has a convex portion formed on the surface so as to make point contact in order to reduce the amount of slippage, and the convex portion is placed so that it can receive the thrust load by applying it to the inside of the roller. By arranging them close to the center so that they are in contact with each other, it is possible to almost eliminate friction, and by making the flat surface provided on the outer side of the cage touch the side surface of the inner and outer raceway rings, each rolling element can be connected to this surface. This supports the sum of thrust component forces due to traction, and completely solves the conventional problem of the corners of the rolling elements and the collar of the raceway rubbing directly against each other.

When applying a large radial load, the thrust component acting on the cage also increases, so in order to protect the sliding friction surface between the cage and the raceway, rolling elements are inserted between the cage and the raceway to form a rolling bearing. It's okay.

Furthermore, the above-mentioned axial clearance between the rolling element, cage, and raceway becomes the axial clearance of the bearing when used as a bearing, while backlash occurs when used as a clutch, so a smaller one is preferable. This occurs due to the accumulation of manufacturing errors, so during assembly, it is possible to adjust the gap between the cage and raceway to an appropriate value by selecting and combining the thickness of the thrust spacer provided on the inner or outer ring. It is also possible to install a spring that biases the device in the axial direction to constantly press the rolling elements against the raceway and eliminate any gaps.

In addition, because the outer ring raceway generated by the traction of the rolling elements due to the torque load during locking assists the force that sucks the inner ring raceway,
By fitting one of the bearing rings to the housing or the shaft via a helical spline or a cam, the torque is converted into a component force in the axial direction, thereby providing means for assisting the suction force.

When torque is applied in the direction of locking, the rolling elements are sandwiched between the inner and outer rings in proportion to the torque and bite into a wedge, transmitting torque. When torque is applied in the direction of slipping, the rolling elements The moving body rolls between the inner raceway ring and the outer raceway ring like a bearing, and the thrust component of the axial traction generated on the rolling body is first applied to a point between the end face of the rotating rolling body and the window of the cage. The force is received in a state of contact, and the force is further transmitted to the cage and is in contact with the flat side surfaces of the cage and the wide sides of the inner and outer race rings, resulting in a stable oil film or low friction on the rolling elements. The thrust force of traction can be supported by resistance.

In the case of locking, the load torque is converted into thrust force by the helical spline or cam provided on the housing of the bearing ring or the fitting part with the shaft, and the force generated by the traction caused by the skew angle of the rolling elements to suck the bearing ring. By adding thrust, the lock operation is made more reliable.

EXAMPLE An example will be explained below with reference to the drawings. Figure 1 shows the entire structure of the conventional product, and Figure 5 shows the contact situation between the corner of the rolling element and the collar of the raceway in the conventional product. In other words, the corner 19 of the rolling element is in contact with the edge 20 of the rib 6 of the bearing ring, and the arrows indicate the traction thrust generated at the skew angle 21 of the rolling element. The component force 22 is shown, and 23 is an arrow showing the direction of movement of the rolling element during idling. Therefore, regardless of whether the rolling element is a tapered roller, a model, or a cylindrical roller, or whatever the generatrix shape is, it is sufficient that the opposing raceway surface also maintains line contact and transfers. FIG. 2 shows a cross section of the structure of the present invention, in which rolling elements 2 are interposed between the raceways 15 and 16 of the outer ring 1 and the inner ring 3, and the rolling elements are formed in pocket holes provided in the cage 7. A convex portion 8.9 is provided on the inside of the rib 17 of the retainer, and the convex portion 8.9 is held within the 10 of the retainer so as to contact the vicinity of the axial center of the end of the rolling element. The outer surface 18 contacts the bearing ring and is supported in the axial direction.As a method of supporting the cage in the axial direction, it is also possible to provide flanges 11 and 12 on the cage as shown in FIG. , Figure 8 shows the shape of the convex part of the cage during press molding,
Figure 7 shows the shape of a plastic cage.The function of the bearing during idling is that the rolling elements sandwiched between the two raceways roll with a skew angle between the outer raceway and the inner raceway. Since the direction of the thrust component force of the traction generated on the rolling elements is mostly canceled out because the direction 25 of the inner ring and the direction 24 of the outer ring shown in Fig. 3 are compatible, the thrust load actually generated is Although it is small, when a radial load 28 acts on the clutch as shown in FIG. 4, since the raceway is a conical surface, a thrust component 26.27 is generated in proportion to the cone angle, and the ribs 4. 5 generates a force of 29.30 in the direction of pinching the retainer.

Therefore, the contact surface 18 with the bearing ring that carries the thrust load of the cage receives the load with a relative sliding speed that is half that of the rotating train, so oil grooves etc. are provided to form an oil film to ensure proper surface contact. Finishing accuracy is required to ensure that Furthermore, a rolling element is inserted into the contact surface 18 to form a rolling bearing to cope with a large radial load, and a thrust spring is inserted and biased to move the rolling element 2 on the orbit 15.16 via the retainer 7. This eliminates axial clearance when used as a radial bearing, and also eliminates backlash when locking.

As shown in Fig. 6, a helical spline is provided on the outer periphery of the outer ring as a means of reinforcing the force of the outer ring sucking in the inner ring during locking. Configure so that force is generated.

A cam (not shown) may be used instead of the helical spline, and it is even better if the frictional resistance is reduced through a nylon-coated spline or pole (not shown).The key is to efficiently convert torque into axial component force and improve efficiency. Any device that returns well is fine.

Effects of the Invention With the implementation described above, the rolling elements as sprags do not bear the sliding friction of the trochoidal curve with the collar of the bearing ring at the corners of the rolling elements, as in the conventional scheme, but instead Because the thrust is applied over a wide surface, even though the rolling elements have a skew angle, they can rotate smoothly at high speed with low frictional resistance, just like a rolling bearing, and therefore not only function as a one-way clutch, It can also function satisfactorily as a high-performance bearing that can carry radial loads.

In other words, in the case of a tapered roller bearing, the large end surface of the roller contacts the inner ring flange in a trochoid curve, and if there is an excessive thrust load or insufficient lubrication at the contact area, seizing may occur, but in the present invention, The load is received by a sufficiently wide and highly accurate surface of the device, and when a thrust load is applied, the thrust component of traction generated on the raceway is canceled out, and only an extremely small thrust load is generated on the rolling elements. Bearings with better performance than existing tapered roller bearings can also achieve a neutral state in which no power is transmitted by separating the inner and outer raceways until they are no longer in contact. By combining two clutches on the same shaft and moving the bearing rings in the axial direction, it can be used as a fully synchronized dog clutch for power interruption or in place of a multi-disc clutch. It provides a clutch.

[Brief explanation of drawings]

Fig. 1 is a sectional view of the existing invention, Fig. 2 is an explanatory sectional view of the application,
Figure 3 is a sectional view of an applied example of the cage, Figure 4 is an applied example and an explanatory diagram of the direction of load action, Figure 5 is a diagram of the traction of the rolling elements, and Figure 6 is the torque applied to the outer raceway. FIG. 7 shows the shape of a plastic cage, and FIG. 8 shows an applied example of a cage press-molded from a metal plate. Symbols and names in the diagram: 1. Outer ring, 2. Rolling element, 3. Inner ring, 4. Outer ring rib (spacer) 5. Inner ring rib 8.9. Convex part, 10. Cage. Pocket window, 11.12... Flange, 15.16... Raceway surface 17... Cage rib, 18... Cage contact surface, 19...
Corner of rolling element, 20... Elan of bearing ring rib, 21...
Skew angle 22... Axial component of traction, 23... Rotational component of traction, 24.25...
Axial component of traction on raceway surface, 26.27... Direction of thrust component force generated by radial load, 28... Direction of radial load, 29.30... Thrust load acting on retainer, Figure 1 5. Figure 2 20 Figure 5 Figure 6

Claims (1)

[Claims] 1) The rolling elements are rolled onto the raceway surfaces of the conical inner ring raceway member and outer ring raceway member at an angle so that the extension line of the rotation axis of the rolling element is not parallel to and does not intersect with the axis of the raceway. A one-way rolling clutch in which moving bodies are arranged so as to be in line contact, and a one-way rolling clutch is characterized in that a retainer containing rolling elements is positioned in the axial direction using an inner ring member and an outer ring member. 2) A rolling one-way clutch, characterized in that the one-way clutch is provided with means for generating an axial component force on the bearing ring in proportion to the load torque to assist the suction force.