JP2011174554A - Planetary gear mechanism - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a planetary gear mechanism capable of suppressing movement of cages due to centrifugal force accompanying revolution of pinion gears. <P>SOLUTION: The planetary gear mechanism 1 includes: a sun gear 2 which is an external gear; a ring gear 3 which is an internal gear arranged on a concentric circle with the sun gear 2; and the plurality of pinion gears 5 arranged between the sun gear 2 and the ring gear 3. The pinion gears 5 are rotatably provided in a plurality of pinion shafts 4b provided in a carrier 4, respectively, and rolling bearings 6 each including a plurality of rolling elements 6a and the cage 6b having a holding part holding the rolling elements 6a are provided between the pinion gears 5 and the pinion shafts 4b. The cage 6b includes a projecting part 6c in which at least one end in the axial direction is protruded from an end of the pinion gear 5, and a ring member 8 wound around to bind the projecting parts 6c of the respective cages 6b is provided. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a three-element planetary gear mechanism including a sun gear, a ring gear, and a carrier that supports a pinion gear provided between the sun gear and the ring gear, and in particular, a pinion gear and a carrier support portion. The present invention relates to a planetary gear mechanism having a rolling bearing therebetween.

  A conventionally known planetary gear mechanism includes a sun gear, a ring gear, and a pinion gear that meshes with the sun gear and the ring gear. Since the pinion gear is supported by the pinion gear shaft of the carrier, it revolves relatively with the rotation of the carrier and meshes with the sun gear and the ring gear, so that it rotates with the revolution. Further, since the pinion gear is particularly required to rotate at a high speed, a needle roller mainly composed of a needle roller and a cage that holds the needle roller is interposed between the pinion gear and the pinion gear shaft. A bearing is provided.

  Further, as the pinion gear revolves, centrifugal force acts on the pinion gear. Therefore, especially in the case of the Ravigneaux type planetary gear mechanism, the axial width of the planetary gear becomes larger and the length of the pinion shaft becomes longer, so that the load of the pinion gear acts on the pinion shaft supporting the pinion gear. Therefore, the pinion shaft may be bent. In order to suppress deformation or bending of the pinion shaft, Patent Document 1 includes two needle roller bearings for one pinion gear, and a resin-made through-hole or pinion between the needle roller bearings. A planetary gear mechanism having a grooved spacer is described. Further, Patent Document 2 describes a planetary gear mechanism that reduces friction between the cage and the inner peripheral surface of the pinion gear by cutting the outer diameter guide surface of the cage.

JP 2008-303992 A JP 2009-204089 A

  The planetary gear mechanism described in Patent Document 1 described above can reduce the load applied to the pinion shaft due to centrifugal force by providing a lightweight spacer between the needle roller bearings, and the pinion gear and the pinion shaft. Can be maintained, and the smooth movement of the rollers can be ensured. However, due to the centrifugal force caused by the revolution of the pinion gear, the cage moves, and the inner peripheral surface of the pinion gear and the outer peripheral surface of the cage, or the outer peripheral surface of the pinion shaft and the inner peripheral surface of the cage are in contact. In contact, friction loss occurs. Moreover, the planetary gear mechanism described in Patent Document 2 can reduce friction between the outer peripheral surface of the cage and the inner peripheral surface of the pinion gear by cutting the outer peripheral surface of the cage. However, the invention described in Patent Document 2 reduces friction loss for surface roughness, and there is still room for improvement in terms of suppressing contact between the pinion gear and the cage.

  This invention was made paying attention to the technical subject mentioned above, Comprising: It aims at providing the planetary gear mechanism which can suppress the movement of the holder | retainer by the centrifugal force accompanying the revolution of a pinion gear. Is.

  In order to achieve the above object, the invention of claim 1 includes a sun gear of an external gear, a ring gear of an internal gear disposed concentrically with the sun gear, and the sun gear and the ring gear. A plurality of pinion gears, and each pinion gear is rotatably provided on a plurality of pinion shafts provided in the carrier, and a plurality of rolling elements between the pinion gears and the pinion shafts. And a planetary gear mechanism provided with a rolling bearing provided with a holder having a holding part for holding the rolling element, wherein the cage has at least one end in the axial direction extending from the end of the pinion gear. A ring member having a protruding portion that protrudes and wound so as to bind the protruding portions in each cage is provided.

  According to a second aspect of the present invention, in the first aspect of the present invention, the retainer is provided with a protruding member protruding in an outer peripheral direction of the retainer, and the ring member has a hole for fitting with the protruding member. A planetary gear mechanism characterized by being provided.

  The invention of claim 3 is characterized in that, in the invention of claim 1, teeth are formed on the outer peripheral surface of the cage, and other teeth that mesh with the teeth are formed on the inner peripheral surface of the ring member. Planetary gear mechanism.

  According to a fourth aspect of the present invention, in the second aspect of the present invention, the plurality of protruding members are integrated into a predetermined connecting member attached to the retainer at a predetermined interval and modularized. This is a featured planetary gear mechanism.

  According to the first aspect of the present invention, the retainer has a projecting portion projecting from the pinion gear in the axial direction, and the ring is wound so as to bind the projecting portions of the retainers. Therefore, even when the cage receives a force to the outside of the normal direction of the revolution track due to the centrifugal force generated by the revolution of the pinion gear, the ring member acts in a direction opposite to the force, so the inner circumference of the pinion gear The contact between the surface and the outer peripheral surface of the cage, or the outer peripheral surface of the pinion shaft and the inner peripheral surface of the cage can be suppressed or prevented. Therefore, friction loss due to contact can be reduced or avoided.

  According to the invention of claim 2 and claim 3, the retainer is provided with a projecting member or tooth projecting in the outer peripheral direction of the retainer, and the hole or tooth that fits into the projecting member or tooth is provided. It is provided on the inner peripheral surface of the ring member. Therefore, when the revolving speed of the pinion gear changes abruptly, it is possible to suppress or prevent slippage on the contact surface or contact surface between the cage and the ring member, thereby reducing sliding friction loss due to the slippage. can do.

  Furthermore, according to the invention of claim 4, since the plurality of projecting members are integrated with a certain interval, the assembly of the projecting member and the cage is easy, and the assembling cost is reduced. Can do.

It is sectional drawing which shows the structural example of the planetary gear mechanism which concerns on this invention. It is a figure which shows the arrow A in FIG. It is an enlarged view of the B section in FIG. It is sectional drawing which shows the other structural example of the planetary gear mechanism which concerns on this invention. It is a figure which shows the arrow A in FIG. It is an enlarged view of the B section in FIG. It is a perspective view which shows a rivet module. It is sectional drawing which shows an example of the method of attaching a rivet module. It is a front view which shows the other assembly method. It is sectional drawing which shows the further another structural example of the planetary gear mechanism which concerns on this invention. It is a figure which shows the arrow A in FIG.

  Next, the present invention will be described with reference to the drawings. 1 and 2 show an example of a planetary gear mechanism 1 according to the present invention. A planetary gear mechanism 1 shown in this figure is a single pinion type planetary gear mechanism 1, and includes a sun gear 2 as an external gear, a ring gear 3 as an internal gear, a carrier 4, and a pinion gear 5. Yes. First, the sun gear 2 that is an external gear and the ring gear 3 that is an internal gear are arranged concentrically, and the pinion gear 5 is rotatable and revolved so as to mesh with the sun gear 2 and the ring gear 3. 4 is supported.

  Here, the structure of the carrier 4 will be described. The carrier 4 is composed of two side plate portions 4a facing each other, and pinion shafts 4b arranged with both ends supported by the respective side plate portions 4a. In the example shown, four pinion shafts 4b are provided by 90 °. This pinion shaft 4b is for supporting and revolving the pinion gear 5 so that rotation is possible. Further, the pinion shaft 4b and the two side plate portions 4a facing each other are “crimped” and fixed.

  Each pinion shaft 4b is fitted with a pinion gear 5, and a needle roller bearing 6 is fitted between the pinion gear 5 and the pinion shaft 4b. The needle roller bearing 6 is for smoothly rotating the pinion gear 5, and is composed of a needle roller 6a and a cage 6b that holds the needle roller 6a. That is, in the needle roller bearing 6, a plurality of holding portions separated by grooves are formed in the circumferential direction of the cage 6b, and the needle rollers 6a are held in the respective holding portions. Accordingly, needle rollers 6a are arranged between the pinion gear 5 and the pinion shaft 4b, and even if the pinion gear 5 rotates, the inner peripheral surface of the pinion gear 5 and the outer peripheral surface of the pinion shaft 4b Since they do not come into contact with each other, the pinion gear 5 can rotate smoothly. Further, a bag hole 4c is formed in the axial center portion of the pinion shaft 4b from the right side to the center in the drawing, and from the left end of the bag hole 4c to the outer peripheral direction of the planetary gear, that is, in the direction of the ring gear 3. A bag hole 4c is formed so as to face. The bag hole 4c is for supplying lubricating oil to the needle roller bearing 6, and the lubricating oil is injected from the opening of the bag hole 4c.

  Washers 7 are respectively provided on the left and right of the retainer 6b and the pinion gear 5 in the drawing, that is, at positions adjacent to the carrier 4, so that the back and forth play or gaps of the retainer 6b and the pinion gear 5 are eliminated. This is to prevent the sliding friction from occurring due to the movement of the respective members 6b and 5 to the left and right to reduce the transmission efficiency and durability.

  In the planetary gear mechanism 1 configured as described above, centrifugal force acts on the pinion gear 5 and the needle roller bearing 6 as the carrier 4 rotates. That is, the pinion gear 5 and the needle roller bearing 6 receive a force on the outside in the normal direction of the revolution track of the pinion gear 5, that is, on the ring gear 3 side. And especially the cage 6b of the needle roller bearing 6 moves in the outer peripheral direction. Therefore, the outer circumferential surface of the cage 6b and the inner circumferential surface of the pinion gear 5 or the inner circumferential surface of the cage 6b and the outer circumferential surface of the pinion shaft 4b come into contact with each other, and friction is generated.

  Therefore, the planetary gear mechanism 1 according to the present invention also has a function for suppressing or preventing movement of the cage 6b in the outer circumferential direction. FIG. 3 shows an enlarged view of a portion B in FIG. As shown in the drawing, the cage 6b is larger than the pinion gear 5 in the left-right direction, and a ring 8 is provided on the outer peripheral side of the protruding portion 6c protruding left and right. The ring 8 is disposed so as to surround or bind all the protrusions 6c of the cage 6b provided in the planetary gear mechanism 1. That is, in the example shown in the figure, since four pinion gears 5 are provided, the rings 8 are provided so as to integrally surround the holding portions 6b provided in the respective pinion gears 5. Therefore, even when the carrier 4 rotates and each retainer 6b receives a centrifugal force in the outer peripheral direction, the ring 8 biases each retainer 6b, so that the retainer 6b moves in the outer peripheral direction. This can be suppressed or prevented. In addition, since a plurality of pinion gears 5 are provided, the centrifugal force of one cage 6b and the cage 6b provided on the opposite side centering on the rotation axis of the carrier 4 is balanced. Can also be suppressed or prevented. That is, by providing the ring 8 that suppresses the movement of the cage 6b in the outer peripheral direction, the contact between the cage 6b and the pinion gear 5 or the pinion shaft 4b can be suppressed or prevented. Since there is no friction on the contact surface, the durability of the cage 6b is improved and the size can be reduced. Further, polishing and surface treatment of the inner and outer peripheral surfaces of the cage 6b are not required.

  Next, another configuration example of the present invention will be described. 4 to 6 are diagrams showing examples thereof. This configuration example is an improvement of the above-described configuration example. In this configuration example, for example, when the carrier 4 is stopped from a state where the planetary gear mechanism 1 is operating, a sudden revolution speed or a change in direction causes a slip on the contact surface between the ring 8 and the cage 6b. This is to suppress or prevent the occurrence of friction loss. Therefore, in the example given here, the holding portion 6b is provided with a rivet 9 projecting toward the outer peripheral direction, and the ring 8 is provided with a hole 10 for fitting with the rivet 9. The hole 10 may be a through-hole that protrudes from the inner periphery to the outer periphery of the ring 8, or may be a groove or a recess that does not penetrate. Therefore, since the ring 8 and the holding portion 6b are connected via the rivets 9 and the holes 10, even if there is a sudden revolution speed or direction change as described above, It can operate without sliding friction loss. In this configuration example, the rivet 9 is provided in the retainer 6b, and the hole 10 to be fitted with the rivet 9 is provided in the ring 8. In short, the slip is caused by the contact surface between the retainer 6b and the ring 8. In order not to occur, a protruding member such as a rivet 9 may be provided on one side, and a hole 10 fitted to the protrusion may be provided on the other side.

  Further, since the rivet 9 can be formed of resin or the like, a plurality of rivets 9 can be formed integrally. An example of the integrally formed rivet 9 is shown in FIG. The integrally formed rivet 9 shown in the drawing, that is, the rivet module 9a, is formed by arranging a plurality of rivets 9 at equal intervals or at predetermined intervals in a band-shaped portion. The method for attaching the rivet module 9a to the holding portion 6b is, for example, as shown in FIG. 8, in which a through hole 10 that penetrates from the inner periphery to the outer periphery is formed in the holding portion 6b, and the rivet 9 passes through the through hole 10. In addition, as shown in FIG. 9, a groove is formed from the end surface of the cage 6b, that is, the left side surface in FIG. 9, to the right as shown in FIG. 9, and the rivet 9 is placed in the groove. There is a method of assembling to insert by sliding.

  Furthermore, another configuration example for suppressing or preventing slippage of the contact surface between the ring 8 and the cage 6b will be described. An example of the configuration is shown in FIGS. In this configuration example, teeth are provided on the inner peripheral surface of the ring 8 and the outer peripheral surface of the cage 6b, and slipping on the contact surface is suppressed or prevented by meshing each tooth. Similar to the configuration example using the rivet 9 described above, the operation by this configuration can operate without any sliding friction loss on the contact surface even when there is a sudden revolution speed or direction change.

  The configuration example described above is the single pinion type planetary gear mechanism 1, but the present invention is not limited to this and may be a double pinion type planetary gear mechanism 1. The pinion shaft 4b may be supported at both ends as described above, or the pinion shaft 4b and the carrier 4 are integrally formed by casting or the like, and the pinion shaft 4b is provided with a mechanism or shape for preventing the pinion gear 5 from coming off. One-end support may be used. In short, the present invention is only required to be provided with a ring member 8 around which each cage 6b is wound so as to bind the cage 6b of the rolling bearing 6 provided between the pinion gear 5 and the pinion shaft 4b. .

  DESCRIPTION OF SYMBOLS 1 ... Planetary gear mechanism, 2 ... Sun gear, 3 ... Ring gear, 4 ... Carrier, 4a ... Side plate part, 4b ... Pinion shaft, 4c ... Bag hole, 5 ... Pinion gear, 6 ... Needle roller bearing, 6a ... Roller, 6b ... Cage, 6c ... Projection, 7 ... Washer, 8 ... Ring, 9 ... Rivet, 9a ... Rivet module, 10 ... Hole.

Claims (4)

With external gear sun gear,
A ring gear of an internal gear arranged concentrically with the sun gear;
A plurality of pinion gears disposed between the sun gear and the ring gear;
Each pinion gear is rotatably provided on a plurality of pinion shafts provided in the carrier,
In a planetary gear mechanism provided with a rolling bearing provided with a plurality of rolling elements and a holder having a holding part for holding the rolling elements between the pinion gear and the pinion shaft,
The cage has a protruding portion in which at least one end portion in the axial direction protrudes from an end portion of the pinion gear;
A planetary gear mechanism, characterized in that a ring member wound so as to bind the protrusions in each cage is provided. The retainer is provided with a protruding member protruding in the outer peripheral direction of the retainer,
The planetary gear mechanism according to claim 1, wherein the ring member is provided with a hole for fitting with the protruding member. Teeth are formed on the outer peripheral surface of the cage,
The planetary gear mechanism according to claim 1, wherein other teeth that mesh with the teeth are formed on an inner peripheral surface of the ring member.   The planetary gear mechanism according to claim 2, wherein the plurality of projecting members are integrated with a predetermined connecting member attached to the retainer at a predetermined interval and modularized.

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