JP2006105327A - Constant-velocity joint - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a constant-velocity joint with excellent constant-velocity property which requires no grease lubrication and hardly undergoes usage restrictions. <P>SOLUTION: An annular space 5 which opens in an outer ring 1 at its one end is formed and three track grooves 6, 7 are respectively formed in an outer peripheral surface and an inner peripheral surface of the annular space 5 in such a manner that they extend in the axial direction. A pocket 12 is formed in a cage 10 incorporated in the annular space 5, and a ball 20 is incorporated in the pocket 12, the ball 20 being capable of rolling along the track grooves 6, 7. The outer ring 1 is formed as a molded product of synthetic resin so that the grease lubrication is not required. An annular leaf spring 32 is attached to the outer periphery of the outer ring 1. The outer ring 1 is clamped by the leaf spring 32 so as to be elastically deformed inwardly. A preload is applied to the contact portions between the ball 10 and the track grooves 6, 7 to eliminate the circumferential looseness, thereby improving the constant-velocity property. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a constant velocity joint that connects two shafts, a drive shaft and a driven shaft, and transmits the power of the drive shaft to the driven shaft.

  Conventionally, a constant velocity joint has been known as a component for transmitting rotational torque of a drive shaft of an automobile to an axle.

  The constant velocity joint is a member that allows the angular displacement of both shafts while maintaining constant velocity between the drive shaft and the driven shaft, and is therefore frequently used in various industrial machines other than automobiles.

  The constant velocity joint includes a fixed type constant velocity joint that allows only angular displacement and a sliding type constant velocity joint that allows both angular displacement and axial displacement. 1 is known.

In the constant velocity joint described in Patent Document 1, an inner member is provided on the inner axial center of the outer ring to form an annular space, and extends in the axial direction on at least one of the outer wall surface and the inner wall surface of the annular space. Two track grooves are provided at intervals of 120 ° in the circumferential direction, and a pocket is formed at a position corresponding to the track groove in the cage incorporated in the annular space, and the balls incorporated in the pockets Rotating torque is transmitted between the outer ring and the cage through the balls so as to be freely rollable along the track grooves.
Japanese Patent Publication No. 52-34699

  By the way, in the constant velocity joint described in the above-mentioned Patent Document 1, since various parts of the outer ring, the inner member, the cage and the ball are made of metal such as steel, the strength is high, but it is heavy and requires grease lubrication. There was a problem that the operation sound was loud, and there was a restriction on the place of use. For example, there have been problems in use for office machines, audio equipment, medical equipment, household appliances, and the like.

  In addition, when used in food production equipment, food is contaminated by the leakage of grease, so it is necessary to take measures to prevent grease leakage by attaching boots, etc., which increases the number of parts and costs. There was a problem of increasing the size.

  An object of the present invention is to provide a constant-velocity joint that can eliminate the need for grease lubrication, is small in size, has a small operation sound, and is not subject to restrictions on use and excellent in constant-velocity performance.

  In order to solve the above problems, in the first aspect of the invention, there is an annular space having one end opened, and three track grooves extending in the axial direction are provided around at least one of an outer wall surface and an inner wall surface of the annular space. An outer ring formed at an interval of 120 ° in the direction, a cage incorporated in the annular space of the outer ring and having a second shaft at the end located on the opening end side of the outer ring, and held in the cage In the constant velocity joint comprising a ball that can roll along the track groove formed on the outer ring, the outer ring is a molded product of synthetic resin, and the outer ring is preloaded at the contact portion between the ball and the track groove. The structure provided with the preload provision means to provide was employ | adopted.

  In the constant velocity joint according to the first aspect of the invention, the preload applying means attaches an inner annular leaf spring having an axial disconnection portion to the outer periphery of the outer ring, and elastically deforms the outer ring radially inward by the leaf spring. Alternatively, a plurality of annular grooves may be formed on the outer periphery of the outer ring at intervals in the axial direction, and an elastic ring may be fitted into each annular groove in an expanded state. The outer ring may be elastically deformed radially inward by tightening.

  Here, if a separation portion extending in the axial direction from the opening end is formed on the outer wall of the annular space, the outer ring is easily elastically deformed, and a preload can be reliably applied to the ball.

  In order to solve the above-mentioned problem, in the second invention, there is an annular space having one end opened, and three track grooves extending in the axial direction are provided on at least one of an outer wall surface and an inner wall surface of the annular space. An outer ring formed at an interval of 120 ° in the circumferential direction, a cage incorporated in the annular space of the outer ring and having a second shaft at an end located on the opening end side of the outer ring, and the cage In a constant velocity joint comprising a ball that is held and can roll along the track groove formed on the outer ring, the outer ring and the cage are formed of a synthetic resin, and the contact portion between the ball and the pocket portion is formed on the cage. A configuration in which a preload applying means for applying a preload is provided is adopted.

  In the constant velocity joint according to the second aspect of the present invention, the preload applying means is formed with a pair of radially extending windows between the pockets for holding the balls formed in the cage, and a pair of pockets on both sides of the cage in the circumferential direction. An arc-shaped wall may be provided, and the ball may be elastically held by the pair of arc-shaped walls. Alternatively, the ball holding pocket provided in the cage may be centered on the outer periphery of the cage. An annular groove may be formed, and an inner wall of the annular groove may be elastically deformed inward by an elastic ring incorporated in the annular groove so as to be in elastic contact with the ball.

  In the constant velocity joints according to the first and second inventions, the constant velocity joint can be further reduced in weight by simultaneously forming the second shaft when the cage is formed.

  In the constant velocity joints according to the first and second inventions, it is preferable to use a resin that can be injection-molded as a synthetic resin or a lubricating resin.

  As in the first invention and the second invention, by forming the outer ring and the cage as a synthetic resin molded article, it is possible to obtain a constant velocity joint that is light in weight and has a small operation sound during torque transmission, Since grease lubrication can be dispensed with, the boot can be dispensed with and a small constant velocity joint with a simple structure can be obtained.

  For this reason, it can be used for office machines, audio equipment, medical equipment, household appliances, etc., which have been difficult to use, with few restrictions on use. The degree can be increased, and the size and cost can be reduced.

  Also, as in the first invention, preload applying means is provided on the outer ring, or as in the second invention, preload applying means is provided in the cage and preload is applied to the ball, so that the operation sound during torque transmission is obtained. Thus, a constant velocity joint having a small torque transmission loss and an excellent constant velocity characteristic can be obtained.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. 1 (I) and (II) show a first embodiment of a constant velocity joint according to the present invention. As shown, the constant velocity joint includes an outer ring 1, a cage 10 and a ball 20.

  The outer ring 1 has a cup portion 2 that is open at one end, and a first shaft 3 is integrally provided at the closed end of the cup portion 2. Further, a guide shaft 4 is provided on the central axis in the cup portion 2, an annular space 5 is formed between the guide shaft 4 and the cup portion 2, and the cup portion 2 that forms the outer wall surface of the annular space 5 is formed. Three track grooves 6 and 7 extending in the axial direction are provided on the outer peripheral surface of the guide shaft 4 that forms the inner peripheral surface and the inner wall surface of the annular space 5 at intervals of 120 ° in the circumferential direction.

  In the embodiment, the track grooves 6 and 7 are formed on the outer wall surface and the inner wall surface of the annular space 5, respectively, but the track groove may be provided on one of the outer wall surface and the inner wall surface.

  The cage 10 is incorporated in the annular space 5 of the outer ring 1, and the second shaft 11 is integrally provided at an end portion of the cage 10 located on the opening end side of the annular space 5.

  The cage 10 is formed with pockets 12 corresponding to the three track grooves 6 and 7 of the outer ring 1, and the balls 20 are incorporated in the pockets 12. Each of the balls 20 can roll along the track grooves 6 and 7.

  The cage 10 is retained by a retaining ring 8 attached to the inner periphery of the open end of the cup portion 2.

  The outer ring 1 and the cage 10 are formed of a synthetic resin molded product. A suitable synthetic resin is selected according to the use conditions of the constant velocity joint, and a synthetic resin that can be injection-molded is desirable. Any resin that can be injection-molded may be a thermoplastic resin or a thermosetting resin.

  There are two types of resin that can be injection-molded: crystalline resin and non-crystalline resin. Either resin can be used, but non-crystalline resin has low toughness and breaks rapidly when torque exceeds the allowable amount. Therefore, it is preferable to use a crystalline resin.

  Preferred synthetic resins include synthetic resins with high lubricating properties, such as polyacetal resins (POM), nylon resins, fluoroplastics such as PFA, FEP, and ETFE, injection moldable polyimide resins, and polyphenylene sulfide resins (PPS). , Wholly aromatic polyester resins, polyether ether ketone resins (PEEK), polyamideimide resins, and the like.

  Each of these resins may be used alone or a polymer alloy in which two or more kinds are mixed. Or the polymer alloy which mix | blended said synthetic resin with the synthetic resin with low lubrication characteristics other than the above may be sufficient.

  Moreover, even a synthetic resin having low lubricating properties can be used by enhancing the lubricating properties by adding a solid lubricant or lubricating oil. Examples of the solid lubricant include polytetrafluoroethylene, graphite, and molybdenum disulfide.

  Further, glass fiber, carbon fiber, various mineral fibers (whiskers) may be added to the synthetic resin to increase the strength, or may be used in combination with a solid lubricant or the like.

  The most suitable materials for use in the present invention are POM, nylon resin, PPS, and PEEK. The nylon resin may be nylon 6, nylon 66, nylon 610, nylon 612, nylon 11, nylon 12, nylon 46, semi-aromatic nylon having an aromatic ring in the molecular chain, or the like. Since POM, nylon resin, and PPS are excellent in heat resistance and lubricity and relatively inexpensive, a constant velocity joint with excellent cost performance can be obtained.

  Moreover, PEEK is excellent in mechanical strength and lubricity even if a reinforcing material and a lubricant are not blended, so that a high-performance constant velocity joint can be obtained.

  As described above, by forming the outer ring 1 and the cage 10 as a molded product of synthetic resin, it is possible to obtain a constant velocity joint that is lightweight and has a low operating noise during torque transmission, and does not require grease lubrication. be able to. Further, since it is not necessary to lubricate the grease, it is not necessary to attach the boot, and a small constant velocity joint having a simple structure with a small number of parts can be obtained.

  For this reason, there are few restrictions on use, and it can be used for various kinds of equipment such as food production equipment.

  As the ball 20, a ball made of bearing steel, stainless steel, ceramics, synthetic resin or the like can be used. When the constant velocity joint is used for a medical device or a food manufacturing machine, it is preferable to use a ball 20 made of stainless steel or ceramics because environmental concerns are eliminated. By using the ball 20 as a synthetic resin, it is possible to obtain a constant velocity joint that is further excellent in weight reduction and noise reduction. In order to give a hygienic impression, it is preferable to use a white resin as the synthetic resin forming the outer ring and the like. POM is optimal because it is white and has high lubricity and can be made grease-free.

  In the first embodiment, the cage 10 and the second shaft 11 are integrally formed of synthetic resin. However, the cage 10 and the second shaft 11 may be integrally formed of metal such as steel, stainless steel, and aluminum alloy. May be formed separately and combined. For example, the second shaft 11 may be formed of a metal such as ceramics, steel, stainless steel, or aluminum alloy, and may be coupled to the cage 10 formed of a synthetic resin by a coupling means such as a bolt. In addition, it is desirable that the cage 10 and the second shaft 11 are integrally formed of synthetic resin, which is further excellent in weight reduction and noise reduction, easy to manufacture, and superior in price.

  In addition, when the 2nd axis | shaft 11 is longer than the full length of a constant velocity joint, in order to prevent a torque loss, it is preferable to form the 2nd axis | shaft 11 with ceramics or a metal.

  In the outer ring 1, the cup portion 2 and the guide shaft 4 are integrally formed of synthetic resin. However, the guide shaft 4 is formed of ceramics, steel, stainless steel, aluminum alloy or the like so as to be coupled to the cup portion 2. It may be.

  As shown in the first embodiment, the cup portion 2 and the guide shaft 4 and the cage 10 and the second shaft 11 are integrally formed of synthetic resin, whereby the constant velocity joint can be further reduced in weight.

  As described above, when the outer ring 1 is formed of a synthetic resin, the outer ring 1 can be elastically deformed. Therefore, in the first embodiment, the outer ring 1 is provided with a preload applying means 30, and the preload applying means 30 elastically deforms the outer ring 1 radially inward to the contact portion between the ball 20 and the track grooves 6 and 7. A preload is applied.

Here, the preload imparting means 30 is provided with a spring fitting recess 31 on the outer periphery of the outer ring 1, and an annular leaf spring 32 having an axial separation portion is fitted in the spring fitting recess 31 in an expanded state. The outer ring 1 is tightened by the restoring elasticity that the leaf spring 32 tends to reduce in diameter, and a preload is applied to the contact portion between the ball 20 and the track grooves 6 and 7 by elastic deformation of the outer ring 1 inward.
The plate spring 32 may be any spring, such as a metal spring, a rubber spring, a resin spring, or the like, as long as it has a restoring elasticity to reduce the diameter.

  As described above, by applying a preload to the contact portion between the ball 20 and the track grooves 6 and 7, the play in the circumferential direction can be eliminated, so that the operating noise during torque transmission is small and the torque transmission loss is extremely small. A constant velocity joint excellent in constant velocity can be obtained.

2 (I) and 2 (II) show a second embodiment of the constant velocity joint according to the present invention. This embodiment is different from the first embodiment in that a plurality of separating portions 33 extending in the axial direction from the opening end of the cup portion 2 are formed between the track grooves 6 formed in the cup portion 2 of the outer ring 1. is doing.
For this reason, the same components as those in the first embodiment are denoted by the same reference numerals and description thereof is omitted.

  As shown in FIGS. 2 (I) and 2 (II), by forming the separating portion 33 in the cup portion 2 of the outer ring 1, the cup portion 2 is easily elastically deformed and attached to the spring fitting recess 31 of the outer ring 1. By tightening the leaf spring 32, a preload can be reliably applied to the contact portion between the ball 20 and the track grooves 6 and 7.

  3 (I) and 3 (II) show a third embodiment of the constant velocity joint according to the present invention. The preload applying means 30 is different between the third embodiment and the first embodiment described above. For this reason, the same components as those in the first embodiment are denoted by the same reference numerals and description thereof is omitted.

In the preload applying means 30 shown in the third embodiment, a plurality of annular grooves 34 are provided on the outer periphery of the cup portion 2 of the outer ring 1 at intervals in the axial direction, and an elastic ring 35 is expanded in each annular groove 34. The cup portion 2 is reduced in diameter by tightening each elastic ring 35 to apply a preload to the contact portion between the ball 20 and the track grooves 6 and 7.
The elastic ring 35 may be a C-shaped metal ring, a resin ring, or an O-ring that is partially cut away.

  In the constant velocity joint shown in the third embodiment, the cup portion 2 of the outer ring 1 may be provided with an axial disconnection portion in the same manner as the constant velocity joint shown in FIG.

4 (I) to (III) show a fourth embodiment of the constant velocity joint according to the present invention. The fourth embodiment is different from the first embodiment described above in that a preload applying means 40 is provided in the cage 10 to apply a preload between the pocket 12 and the ball 20. .
For this reason, the same components as those in the first embodiment are denoted by the same reference numerals and description thereof is omitted.

In the preload applying means 40 shown in FIGS. 4 (I) to (III), a window 41 penetrating in the radial direction between adjacent pockets 12 is formed by making the inner diameter of the pocket 12 formed in the cage 10 smaller than the diameter of the ball 20. And a pair of arc-shaped walls 42 are provided on both sides of each pocket 12 in the circumferential direction of the cage, and the balls 20 are elastically held by the pair of arc-shaped walls 42.
In this case, when the driving torque is larger than the allowable strength of the cage, the allowable strength of the cage can be kept high by arranging a spacer in each window 41.

  As described above, by providing the cage 10 with the preload applying means 40 and applying the preload between the ball 20 and the pocket 12, the operation sound at the time of torque transmission is small and the torque transmission loss is extremely small and excellent in constant velocity. A constant velocity joint can be obtained.

FIG. 5 shows a fifth embodiment of the constant velocity joint according to the present invention. This fifth embodiment is different from the fourth embodiment described above only in the configuration of the preload applying means 40 that applies a preload between the ball 20 and the pocket 12.
For this reason, the same components as those in the fourth embodiment are denoted by the same reference numerals, and description thereof is omitted.

In the preload applying means 40 according to the fifth embodiment, an annular groove 43 centering on each pocket 12 is formed on the outer periphery of the cage 10, and an elastic ring 44 is incorporated in each annular groove 43. The thin inner wall 45 of the groove 43 is elastically deformed inward to be brought into elastic contact with the ball 20.
The elastic ring 44 may be a C-shaped metal ring, a resin ring, or an O-ring that is partially cut away.

  In the fifth embodiment as well, since a preload can be applied between the ball 20 and the pocket 12, a constant velocity joint with low operation noise during torque transmission and excellent constant velocity performance with small torque transmission loss. Can be obtained.

  Although the first and second inventions described above may be used alone, the first invention in which the preload applying means is provided on the outer ring and the second invention provided in the cage may be used in combination. The constant velocity joint combining the first invention and the second invention gives a preload to both the contact portion between the ball and the track groove and between the ball and the pocket, so that the operating noise during torque transmission is small. Thus, it is possible to obtain a constant velocity joint that is extremely excellent in constant velocity characteristics with a very small torque transmission loss.

(I) is a longitudinal front view showing the first embodiment of the constant velocity joint according to the present invention, (II) is a cross-sectional view taken along the line II of (I) (I) is a longitudinal front view showing a second embodiment of the constant velocity joint according to the present invention, and (II) is a cross-sectional view along the roll line of (I). (I) is a longitudinal front view showing a third embodiment of the constant velocity joint according to the present invention, and (II) is a cross-sectional view taken along the ha-ha line of (I). (I) is a longitudinal front view showing a fourth embodiment of the constant velocity joint according to the present invention, (II) is a sectional view taken along the knee line of (I), and (III) is a front view of the cage. (I) is a longitudinal front view showing a fifth embodiment of the constant velocity joint according to the present invention, (II) is a sectional view taken along the hoe line of (I), and (III) is a front view of the cage.

Explanation of symbols

1 outer ring 4 guide shaft 5 annular space 6, 7 track groove 10 cage 11 second shaft 12 pocket 20 ball 30 preload applying means 32 leaf spring 33 separating portion 34 annular groove 35 elastic ring 40 preload applying means 41 window 42 arcuate wall 43 Annular groove 44 Elastic ring

Claims (10)

  An outer ring having an annular space having one end open, and three track grooves extending in the axial direction on at least one of an outer wall surface and an inner wall surface of the annular space and spaced by 120 ° in the circumferential direction, and the outer ring Can be rolled along the track groove formed in the outer ring and held in the cage. The cage is incorporated in the annular space of the outer ring and has a second shaft at the end located on the opening end side of the outer ring. A constant velocity joint comprising: a constant velocity joint composed of a simple ball, wherein the outer ring is a molded product of a synthetic resin, and the outer ring is provided with a preload applying means for applying a preload to a contact portion between the ball and the track groove. .   The preload applying means comprises a configuration in which an annular leaf spring having an axial separation portion is attached to the outer periphery of the outer ring, and the outer ring is elastically deformed radially inward by the leaf spring. Constant velocity joint as described.   The preload imparting means forms a plurality of annular grooves on the outer periphery of the outer ring at intervals in the axial direction, and an elastic ring is fitted in each annular groove in an expanded state, and the outer ring is tightened by tightening the elastic ring. The constant velocity joint according to claim 1, wherein the constant velocity joint is configured to be elastically deformed radially inward.   The constant velocity joint according to any one of claims 1 to 3, wherein a separation portion extending in an axial direction from the opening end is formed on an outer wall of the annular space.   An outer ring having an annular space having one end open, and three track grooves extending in the axial direction on at least one of an outer wall surface and an inner wall surface of the annular space and spaced by 120 ° in the circumferential direction, and the outer ring Can be rolled along the track groove formed in the outer ring and held in the cage. The cage is incorporated in the annular space of the outer ring and has a second shaft at the end located on the opening end side of the outer ring. In the constant velocity joint composed of a simple ball, the outer ring and the cage are formed of a synthetic resin, and the cage is provided with a preload applying means for applying a preload to the contact portion between the ball and the pocket portion. Fast joint.   The preload imparting means forms a window penetrating in the radial direction between the ball holding pockets formed in the cage, and provides a pair of arc-shaped walls on both sides in the cage circumferential direction of each pocket. 6. The constant velocity joint according to claim 5, wherein the ball is elastically held by an arcuate wall.   The preload applying means forms an annular groove around a cage for holding a ball provided in the cage on the outer periphery of the cage, and the inner wall of the annular groove is inwardly formed by an elastic ring incorporated in the annular groove. The constant velocity joint according to claim 5, wherein the constant velocity joint is configured to be elastically deformed to be brought into elastic contact with the ball.   The constant velocity joint according to claim 1, wherein the second shaft is integrated with a cage.   The constant velocity joint according to any one of claims 1 to 8, wherein the synthetic resin is made of injection-moldable synthetic resin.   The constant velocity joint according to any one of claims 1 to 9, wherein the synthetic resin is a lubricating resin.

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