JP6478611B2 - Bearing cage - Google Patents

Description

  The present invention relates to a bearing cage that holds rolling elements of a rolling bearing.

  Conventionally, there have been proposed a bearing cage in which a large number of oil grooves are formed on the pocket surface holding the rolling elements, and a bearing cage in which a large number of minute dimples are formed on the pocket surface. This type of bearing cage can prevent oil film breakage at the sliding contact portion between the pocket surface and the rolling element by the oil retained in the oil groove or dimple (Patent Documents 1 and 2).

JP-A-8-184318 (especially abstract) Japanese Patent Laying-Open No. 2005-155696 (especially abstract)

  In recent years, transmissions have a tendency to reduce the setting of the oil level to a necessary minimum or to select an oil having a low kinematic viscosity as means for reducing oil agitation resistance for the purpose of improving fuel efficiency. As a lubrication method for rolling bearings in the transmission, oil splashing using gears, etc. is adopted. However, when the oil stirring resistance is lowered by the above-mentioned means, the amount of oil splashing is small and low for rolling bearings. Viscous oil will be used, resulting in a harsh lubricating environment. The pocket surface portion concentrically concentric with the pitch circle of the rolling element is far from the pocket opening, and when the amount of supplied oil is small, the oil is particularly difficult to reach. There is a need for a rolling bearing that is free from damage such as seizure due to oil film breakage even under such a severe lubrication environment and satisfies the required life.

  However, in the bearing cage disclosed in Patent Document 1, oil grooves that circulate around the pocket surface in the circumferential direction or spiral direction around the pocket central axis set in the radial direction of the cage are formed at a close interval. Or oil grooves that extend across the pocket surface in the radial direction of the cage on a virtual plane including the pocket central axis. In the former case, the oil cannot be held in the entire area of the pocket surface portion having the same diameter as the concentric diameter of the rolling element. On the other hand, in the latter case, the oil retained in each oil groove is easily discharged to the outer diameter side of the cage as the cage rotates. In any case, in a severe lubrication environment with a small amount of oil and a low viscosity, the oil cannot be satisfactorily held over the entire surface of the pocket surface where the oil is difficult to reach, and due to contact between the rolling element and the pocket surface. There is a risk that heat generation will increase, noise or torque will increase, and seizure will eventually occur.

  The bearing cage disclosed in Patent Document 2 has a large number of minute dimples formed on the entire surface of the pocket, but in a lubricating environment with a small amount of oil and a low viscosity, it is concentric with the pitch circle of the rolling element. Since it becomes difficult for oil to reach the dimples on the surface of the diameter pocket, there is a possibility that seizure will eventually occur.

  Therefore, the problem to be solved by the present invention is to prevent the bearing from being damaged early due to poor lubrication between the bearing cage and the rolling element in a severe lubricating environment with a small amount of oil supplied to the rolling bearing and low viscosity. It is to be.

In order to achieve the above object, the present invention provides a bearing retainer in which an oil groove is formed on a pocket surface for holding a rolling element, wherein the oil groove is positioned concentrically and concentrically with a pitch circle of the rolling element. The oil passage network is formed around the pocket surface, and an oil passage network communicating the radial end of the pocket surface and the oil groove is formed on the pocket surface.
According to this configuration, the oil supplied to the inside of the rolling bearing can easily reach the oil groove around the pocket surface portion concentric with the pitch circle of the rolling element through the oil passage network. For this reason, even in a harsh lubricating environment where the amount of oil supplied to the rolling bearing is small and the viscosity is low, the oil is easily supplied to the contact portion between the rolling element and the pocket surface, and lubrication between the bearing cage and the rolling element is facilitated. It is possible to prevent early damage to the bearing due to a defect.

As a preferred embodiment, the oil passage network communicates only with the radial end on the cage inner diameter side, out of the radial end on the cage inner diameter side and the radial end on the cage outer diameter side of the pocket surface. Can be mentioned.
In this case, when a large centrifugal force is generated by the high speed rotation of the bearing cage, the oil retained in the oil groove or the oil passage network tends to move toward the outer diameter side of the cage, The pocket surface that does not penetrate is dammed by the meat at the end on the outer diameter side of the cage. For this reason, the situation where oil is discharged from the oil groove or the oil passage network can be prevented.

Moreover, as another preferable aspect, it is mentioned that the oil passage network is formed in an intermittent mesh shape in the cage radial direction.
In this case, when a large centrifugal force is generated by the high-speed rotation of the bearing cage, the oil retained in the oil groove or the oil passage network tends to move toward the outer diameter side of the cage. It is disturbed by the disconnection part. For this reason, it becomes difficult for oil to be discharged from the oil groove or the oil passage network.

  By adopting both of the above aspects together, it is possible to further prevent oil from being discharged due to centrifugal force.

  In the case of a resin cage formed of a synthetic resin, it is easy to form an oil groove or an oil passage network on the pocket surface.

For example, in this invention, it can be set as the cage for bearings formed with the polyamide resin, the polyether ether ketone resin, or the polyphenylene sulfide resin.
Polyamide resin (PA) is suitable when PA66, PA46, PA9T, and the like are properly used in consideration of the temperature environment and compatibility with oil.
Further, the polyether ether ketone resin (PEEK) is suitable for preventing damage to the cage surface in a high-speed rotation environment such as a motor support for an electric vehicle (EV) or a hybrid vehicle (HEV).
Polyphenylene sulfide resin (PPS) is suitable when the cage strength is required in a high temperature environment.

  The bearing cage according to the present invention is suitable for a ball bearing incorporated in a transmission. Ball bearings for this purpose are rotated at a high speed in a harsh lubricating environment where a small amount of low-viscosity oil is splashed. By applying the bearing cage according to the present invention, early bearing failure due to poor lubrication can be achieved. Can be prevented.

  By adopting the above configuration, the present invention makes it easy for oil to reach the oil groove around the pocket surface portion concentric with the pitch circle of the rolling element, and the delivered oil is held in the oil groove, so that it is supplied to the rolling bearing. In a severe lubrication environment with a small amount of oil and low viscosity, early bearing damage due to poor lubrication between the bearing cage and the rolling elements can be prevented.

The partial perspective view which shows the external appearance of the pocket of the bearing retainer which concerns on 1st Embodiment of this invention. The fragmentary sectional view which shows a rolling bearing provided with the cage for bearings of FIG. Sectional view showing a transmission incorporating the rolling bearing of FIG. The figure which unfolded and displayed a part of pocket surface of FIG. Enlarged view of the vicinity of the oil groove in FIG. The figure which expanded and displayed a part of pocket surface of 2nd Embodiment The figure which expanded and displayed a part of pocket surface of 3rd Embodiment The figure which expanded and displayed a part of pocket surface of 4th Embodiment

  1st Embodiment as an example of this invention is described based on an accompanying drawing. A rolling bearing 1 shown in FIGS. 1 and 2 is for bearings that maintain an inner ring 2, an outer ring 3, a predetermined number of rolling elements 4 interposed between the inner ring 2 and the outer ring 3, and a circumferential interval between the rolling elements 4. And a cage 5.

  The rolling bearing 1 is a ball bearing that is incorporated into the automobile transmission 10 shown in FIG. The transmission 10 is of a manual type, and an input shaft 12, an output shaft 13 and a pilot shaft 14 are arranged in series in a housing 11, and a counter shaft 15 and a reverse shaft 16 are arranged in parallel with the output shaft 13. It has a structure. Note that FIG. 3 is expanded and displayed for easy viewing of the drawing, and the reverse shaft 16 is also engaged with the output shaft 13. Each of the shafts 12 to 16 is provided with a large number of gear groups. By changing the meshing of these gear groups by a clutch hub 17 that is shifted by an external operation, the input shaft 12 is changed to the output shaft 13. The torque transmission path is appropriately selected. In this transmission 10, an input shaft 12, an output shaft 13, a pilot shaft 14, a counter shaft 15, and a gear member 18 attached to one end side of the counter shaft 15 are supported by the rolling bearing 1.

  As shown in FIGS. 1 and 2, the bearing cage 5 applied to the rolling bearing 1 is a crown-shaped resin cage that houses balls as rolling elements 4 in the respective pockets 6. The pocket 6 is a space that opens to the inner diameter side of the cage, the outer diameter side of the cage, and one side in the axial direction. Hereinafter, unless otherwise specified, the “axial direction” refers to a direction along the central axis of the bearing cage 5 (matches the central axis of the rolling bearing 1), and the “radial direction” refers to the axis. The direction perpendicular to the direction, that is, the cage radial direction.

  The pitch circle (Dpw) of the rolling elements 4 is the diameter of a circle including the centers of one row of the rolling elements 4 existing in the rolling bearing 1. The center of the pitch circle (Dpw) of the rolling element 4 is determined on the central axis of the bearing cage 5.

  The basic overall shape of the pocket surface 7 defining the pocket 6 is set on the basis of the radial pocket central axis passing through the position that bisects the pocket 6 in the axial direction and the circumferential direction around the cage central axis. Has been. The basic overall shape of the pocket surface 7 in the illustrated example is a spherical shape centered on the pitch circle (Dpw) of the rolling element 4.

  An oil groove 8 (in FIG. 1, the oil groove 8 is drawn with solid lines) is formed on the pocket surface 7. As shown in FIGS. 1, 4, and 5, the oil groove 8 is formed so as to go around the pocket surface 7 at a position concentric with the pitch circle (Dpw) of the rolling element 4. That is, when a virtual cylindrical surface that includes the pitch circle (Dpw) of the rolling element 4 and is concentric with the central axis of the bearing cage 5 is considered, the entire region of the pocket surface 7 that intersects the virtual cylindrical surface. The oil groove 8 is formed in a series over. In FIG. 4, the pocket surface 7 is developed and the vicinity of the center is displayed.

  An oil passage network (9 a, 9 b) that communicates the radial ends 7 a, 7 b of the pocket surface 7 with the oil groove 8 is formed in the pocket surface 7. The radial end 7 a of the pocket surface 7 is an end of the pocket surface 7 on the inner diameter side of the cage, and is an edge that intersects the inner diameter surface of the bearing cage 5. The radial end 7 b of the pocket surface 7 is an end of the pocket surface 7 on the outer diameter side of the cage, and is an edge that intersects the outer diameter surface of the bearing cage 5. The oil passage network (9a, 9b) is composed of a net-like recess that uniformly intersects the oil groove 8 and the radial end portions 7a, 7b.

  The oil passage network (9a, 9b) in the illustrated example is composed of one or more first oil passages 9a parallel to the oil groove 8, and one or more second oil passages 9b intersecting the first oil passage 9a. Has been.

  A plurality of first oil passages 9a are formed on the inner diameter side of the cage with the oil groove 8 as a boundary, and a plurality of first oil passages 9a are formed on the outer diameter side of the cage. On the inner diameter side of the cage, a first oil passage 9a passing through the radial end 7a and a first oil passage 9a passing through the radial middle between the radial end 7a and the oil groove 8 are formed. On the outer diameter side of the cage, a first oil passage 9a passing through the middle of the oil groove 8 and the radial end 7b and a first oil passage 9a passing through the radial end 7b are formed. The second oil passages 9b intersect the first oil passages 9a and the oil grooves 8 at equal intervals in the direction along the oil groove 8, and continuously cross the pocket surface 7 on a virtual plane including the pocket central axis. Yes.

  As described above, the oil passage network (9a, 9b) is uniformly formed in the direction along the oil groove 8 between the oil groove 8 and the radial end portions 7a, 7b of the pocket surface 7. For this reason, the oil that has reached the radial end portions 7a and 7b of the pocket surface 7 reaches the entire area of the oil groove 8 via the oil passage network (9a and 9b).

  The depth of the oil passage network (9a, 9b) and the oil groove 8 is set such that the core pin for forming the pocket surface 7 can be forcibly removed when the bearing retainer 5 is integrally formed by synthetic resin injection molding. ing.

  Examples of the synthetic resin include polyamide resin (PA), polyether ether ketone resin (PEEK), and polyphenylene sulfide resin (PPS). The bearing cage 5 formed of PA such as PA66, PA46, and PA9T can be used properly in accordance with the compatibility with the temperature environment and the oil among the usage environment of the rolling bearing 1.

  Moreover, the bearing cage 5 formed of PEEK can prevent damage to the cage surface in a high-speed rotation environment such as a motor support for an electric vehicle (EV) or a hybrid vehicle (HEV). .

  Further, the bearing cage 5 formed of PPS can improve the strength of the cage in a high temperature environment as compared with those made of PA or PEEK.

  The bearing cage 5 is as described above, and the oil supplied to the inside of the rolling bearing 1 is concentric with the pitch circle (Dpw) of the rolling element 4 through the oil passage network (9a, 9b). It becomes easy to reach the oil groove 8 around the diameter portion. For this reason, oil is supplied from the oil groove 8 to the contact portion between the rolling element 4 and the pocket surface 7 even in a harsh lubricating environment like the transmission 10 with a small amount of oil supplied to the rolling bearing 1 and a low viscosity. It becomes easy to be done. Therefore, the bearing cage 5 can prevent the rolling bearing 1 from being damaged early due to poor lubrication between the pocket surface 7 of the bearing cage 5 and the rolling elements 4.

  During high-speed rotation of the bearing cage 5, oil is supplied to the oil groove 8 from the cage inner diameter side mainly by the action of centrifugal force. Therefore, the oil passage network (9a, 9b) may be formed at least in the range from the radial end 7a on the inner diameter side of the cage to the oil groove 8. It is not essential to form an oil passage network in the pocket surface portion between the oil groove 8 and the radial end 7b on the outer diameter side of the cage, and it is appropriately determined according to the overall lubrication environment in the pocket 6. An oil passage network may be formed.

  A second embodiment as an example thereof will be described with reference to FIG. 6 is an expanded display similar to FIG. Hereinafter, only differences from the first embodiment will be described. As shown in FIG. 6, the oil passage network (9a, 9b) of the second embodiment includes a radial end 7a on the cage inner diameter side of the pocket surface 7 and a radial end 7b on the cage outer diameter side. , It communicates only with the radial end 7a on the inner diameter side of the cage. Neither the first oil passage 9a nor the second oil passage 9b is formed at the radial end 7b on the cage outer diameter side, and the oil passage network (9a, 9b) has a diameter on the cage outer diameter side of the pocket surface. It does not penetrate the direction end 7b. Therefore, a meat portion corresponding to the depth of the first oil passage 9a is disposed between the first oil passage 9a located closest to the outer diameter of the cage and the radial end 7b on the outer diameter side of the cage. 7c is continuous.

  When a large centrifugal force is generated by the high-speed rotation of the bearing cage, the oil retained in the oil grooves 8 and the oil passage networks (9a, 9b) tends to move toward the outer diameter of the cage due to the centrifugal force. Is blocked by the meat portion 7c. For this reason, 2nd Embodiment can prevent the situation where oil is discharged | emitted from the oil groove 8 or the oil channel | path network (9a, 9b).

  A third embodiment will be described with reference to FIG. 7 is an expanded display similar to FIG. As shown in FIG. 7, the oil passage network (9a, 9b1 to 9b4) of the third embodiment is formed in an intermittent mesh shape in the radial direction. In the illustrated example, the positions where the second oil passages 9b1 to 9b4 pass between the oil groove 8 and the first oil passage 9a are shifted in the circumferential direction around the cage center axis.

  When centrifugal force is applied by the rotation of the bearing cage, the oil flowing out from the second oil passage 9b1 intersecting the first oil passage 9a passing through the radial end 7a on the cage inner diameter side is the next first oil. When reaching the passage 9a, it hits the thick cut-off portion 7d1 corresponding to the depth of the oil groove 8, enters the second oil passage 9b2 so as to bypass the cut-off portion 7d1, and enters the oil groove 8 from the second oil passage 9b2. When it reaches, it hits the thick cut-off portion 7d2 corresponding to the depth of the oil groove 8, enters the second oil passage 9b3 so as to bypass the cut-off portion 7d2, and from the second oil passage 9b3 to the next first oil passage 9a. The second oil passage 9b4 so as to bypass the discontinuity 7d3, and hit the outer diameter side of the cage from the second oil passage 9b4. To the first oil passage 7a passing through the radial end 7b.

  Thus, when a large centrifugal force is generated by the high-speed rotation of the bearing cage, the oil retained in the oil grooves 8 and the oil passage networks (9a, 9b1 to 9b4) is directed toward the cage outer diameter side. I'm going to be disturbed by the break (7d1-7d3). For this reason, compared with 1st Embodiment, 3rd Embodiment becomes difficult to discharge | emit oil from the oil groove 8 or the oil channel | path network (9a, 9b1-9b4).

  A fourth embodiment will be described with reference to FIG. FIG. 8 is an expanded display similar to FIG. As shown in FIG. 8, the fourth embodiment is a combination of the second embodiment and the third embodiment. That is, when the centrifugal force is applied by the rotation of the bearing cage, the oil that has entered the second oil passage 9b3 so as to bypass the disconnecting portion 7d2 from the oil groove 8 is blocked by the meat portion 7c, and the third embodiment It cannot escape from the 2nd oil passage 9b4 to the radial direction edge part 7b by the side of a cage outer diameter like a form. For this reason, in the fourth embodiment, as compared with the second and third embodiments, when a large centrifugal force is generated by the high-speed rotation of the bearing cage, the oil is transferred to the oil groove 8 or the oil passage network (9a). , 9b1 to 9b3) can be further prevented.

  The technical scope of the present invention is not limited to the above-described embodiments, and includes all modifications within the scope of the technical idea based on the description of the scope of claims.

DESCRIPTION OF SYMBOLS 1 Rolling bearing 4 Rolling element 5 Bearing cage 6 Pocket 7 Pocket surface 8 Oil groove 9a First oil passage (oil passage network)
9b Second oil passage (oil passage network)
10 Transmission

Claims (4)

In the bearing cage in which the oil groove is formed on the pocket surface holding the rolling element,
The oil groove is formed to circulate around the pocket surface at a position concentric with the pitch circle of the rolling element;
An oil passage network communicating the radial end of the pocket surface and the oil groove is formed on the pocket surface ;
Said oil passage network, among the radial end portion of the radial end portion and the cage outer diametric side of the cage inner diameter side of said pocket surface, and Turkey through communicating only in the radial direction end portion of the cage inner diameter side A bearing retainer characterized. The oil passage network is composed of one or more first oil passages parallel to the oil groove and one or more second oil passages intersecting the first oil passage, and toward the outer diameter side of the cage. 2. The structure according to claim 1, wherein the oil to be directed flows out of the second oil passage and reaches the first oil passage or the oil groove so as to hit the break and bypass the break . Bearing cage. The cage for bearings according to claim 1 or 2 formed with polyamide resin, polyetheretherketone resin, or polyphenylene sulfide resin. The bearing retainer according to any one of claims 1 to 3 , which is applied to a ball bearing incorporated into a transmission.

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