JP5160745B2 - Tripod type constant velocity joint - Google Patents

Description

  The present invention relates to a tripod 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 the constant velocity of the drive shaft and the driven shaft, and is therefore widely 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.

  The constant velocity joint described in Patent Document 1 is referred to as a tripod type constant velocity joint, and three track grooves extending in the axial direction are formed on the inner periphery of the outer ring at intervals of 120 ° in the circumferential direction. The tripod member built inside the outer ring has three radial leg shafts that are inserted into the track grooves, and is a spherical roller that can roll along the track grooves outside the leg shafts. Are rotatably fitted, and rotational torque is transmitted between the outer ring and the tripod member via the spherical roller.

Japanese Patent Publication No. 3-1528

  By the way, in the tripod type constant velocity joint described in the above-mentioned patent document 1, since various parts of the outer ring, tripod member and spherical roller are made of metal such as steel, grease lubrication is required, and mounting is performed by tightening the boot band. It is necessary to close the open end of the outer ring with the boots to prevent leakage of grease.

  For this reason, when assembling and disassembling the tripod type constant velocity joint, complicated work of mounting and removing the boot is required. Input side parts for inputting power to the tripod type constant velocity joint and tripod type constant velocity joint There is a problem that it takes a lot of time to replace the output side parts that are rotationally driven by the output from the power source.

  In addition, the conventional metal tripod type constant velocity joint has high strength, but it is heavy, has a large operating noise, and there is a risk of grease leakage. Therefore, office machines, acoustic equipment, medical equipment, food production machines However, there are problems in use for household appliances, and there are many cases where the use location is restricted.

  An object of the present invention is to provide a tripod type constant velocity joint that can be easily assembled and disassembled, eliminates the need for grease lubrication, is light in weight, small in size, has low operating noise, and is less subject to restrictions on use. is there.

In order to solve the above-mentioned problems, in the present invention, tripods are formed on the inner circumference of the outer ring by forming three track grooves extending in the axial direction on the inner circumference of the outer ring at intervals of 120 ° in the circumferential direction. In a tripod type constant velocity joint, in which the member is slidable in each track groove and provided with three projecting portions for transmitting torque between the outer ring and the tripod member, between adjacent track grooves of the outer ring At the tip of the formed bulging portion, a pair of tapered surfaces are formed which are inclined in a direction opposite to the circumferential direction to form a top portion at the center of the circumferential width of the bulging portion, and the outer ring of the protruding portion A pair of tapered surfaces that incline toward both sides from the center in the width direction of the projecting portion and form a top portion in the center in the width direction of the projecting portion on the front side portion that is the leading side when the joint is inserted through the opening end to assemble the joint. Set up A tripod type is formed by inserting a tripod member from the opening end of the outer ring and guiding the projection to the inside from the tip opening of the track groove by guiding the projection with a tapered surface formed at the tip of the bulge. the assembly of the constant velocity joint, by pulling the tripod member from the outer ring, and the decomposition of the tripod type constant velocity joint, the rotation driven by the output from the input-side component and constant velocity joints for power is input to the constant velocity joint The configuration that facilitates the replacement of the output side parts is adopted.

Here, at the tip of the bulging portion formed between the adjacent track grooves of the outer ring, a tapered surface that is inclined to enter the outer ring from the outer diameter side toward the inner diameter side is provided.
When assembling the joint to insert the tripod member from the outer ring opening end, the taper surface of the protrusion is contact-guided by the taper surface formed at the tip of the bulge even if the axial center of the outer ring and the tripod member is misaligned. Since the protrusion is guided to the opening at the end of the track groove, the tripod constant velocity joint can be assembled more easily.

Further, if each of the outer ring and the tripod member is made of a crystalline synthetic resin, it is possible to eliminate the lubrication of the tripod type constant velocity joint and to reduce the operation noise and reduce the weight during torque transmission.

  Here, when a synthetic resin that can be injection-molded is employed as the synthetic resin, the outer ring and the tripod member can be easily molded. In addition, when the lubricating resin is used, the contact portion between the track groove and the protruding portion can be effectively lubricated, so that a tripod type constant velocity joint with smaller operation noise can be obtained.

  In this case, since the outer ring can be elastically deformed in the circumferential direction by forming a separation portion extending in the axial direction from the opening end of the outer ring on the outer peripheral wall of the track groove, the preload against the contact portion between the track groove and the protruding portion Can be easily provided, and it is not necessary to strictly manage the width dimension of the track groove, so that the outer ring can be easily manufactured.

  When the outer ring is a synthetic resin molded product, preload can be applied to the contact portion between the track groove and the protruding portion by the elasticity of the outer ring. By applying the preload, it is possible to obtain a tripod type constant velocity joint that is free from rattling in the circumferential direction and excellent in constant velocity.

As described above, a pair of ridges formed in the center of the circumferential width of the bulging portion are inclined in the direction opposite to the circumferential direction at the tip of the bulging portion formed between adjacent track grooves of the outer ring . In addition to forming a tapered surface, the projecting portion is inclined toward the front side portion, which is a leading side when the tripod member is inserted from the outer ring opening end, toward the both sides from the center in the width direction of the projecting portion. By providing a pair of tapered surfaces that form the top at the center in the width direction, even when the phase of the track groove and the projecting part is shifted in the circumferential direction when the joint is assembled to insert the tripod member from the outer ring opening end, the projecting part The part is guided and guided by the tapered surface formed at the tip of the bulge and guided to the opening of the tip of the track groove, so there is no need to align the phase of the track groove and the protrusion, and a tripod constant velocity joint is used. It can be assembled Te easy fit.

  Moreover, grease lubrication can be dispensed with by making each of the outer ring and tripod member a synthetic resin molded product. Therefore, it is possible to obtain a tripod type constant velocity joint that is light in weight, has a low operating noise during torque transmission, and has very little torque transmission loss, without requiring measures for preventing grease leakage by attaching a boot.

  Therefore, it can be used for various devices such as office machines, audio equipment, household appliances, etc. that have been difficult to use until now, and the degree of freedom in designing these devices is increased. Therefore, it is possible to reduce the size and the cost.

  Further, since a boot is unnecessary, a tripod constant velocity joint that can be easily assembled and disassembled can be obtained.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. As shown in FIGS. 1 to 3, the tripod constant velocity joint includes an outer ring 1 and a tripod member 11 incorporated inside the outer ring 1.

  The outer ring 1 has a configuration in which a first shaft 3 is provided at the closed end of the cup portion 2 whose one end is open, and three track grooves 4 extending in the axial direction from the opening end are provided on the inner periphery of the cup portion 2. Are formed at intervals of 120 ° in the circumferential direction. A pair of side surfaces 5 facing each other in the circumferential direction of each track groove 4 are flat surfaces parallel to each other.

  The tripod member 11 has a second shaft 12. The tripod member 11 is integrally provided with three projecting portions 13 that are inserted into the track grooves 4 of the outer ring 1.

  Each protrusion 13 is slidable in the track groove 4, and both sides of the track groove 4 facing the side surface 5 are cylindrical surfaces 14 and are curved in the circumferential direction of the protrusion 13. Instead of the cylindrical surface 14, it may be a spherical surface that bends in two directions, the circumferential direction and the axial direction.

  When the rotational torque is input to one of the first shaft 3 and the second shaft 12, the protruding portion 13 is engaged with the one side surface 5 of the track groove 4 on one side of the track groove 4. Rotational torque is transmitted between the 1 and the tripod member 11.

  When the first shaft 3 and the second shaft 12 transmit torque at an angle, the projecting portion 13 slides along the track groove 4 in the axial direction of the outer ring 1. At this time, since the contact between the protruding portion 13 and the side surface 5 of the track groove 4 is a line contact, the sliding resistance is small, and the protruding portion 13 slides smoothly along the track groove 4.

  A pair of tapered surfaces 7 are formed at the tip of the bulging portion 6 formed between the adjacent track grooves 4 of the outer ring 1. The pair of tapered surfaces 7 are inclined so as to enter the outer ring from the outer diameter side toward the inner diameter side, and incline in opposite directions in the circumferential direction, and are apexes at the center of the circumferential width of the bulging portion 6. 8 is formed.

  Here, the tapered surface 7 may be a flat surface or a convex curved surface.

  In addition, three tapered surfaces 9 having both ends at the center of the circumferential width of the bulging portion 6 are formed on the outer peripheral portion of the opening end surface of the outer ring 1, and each tapered surface 9 is directed from the outer diameter portion toward the inner diameter portion. Inclined to enter the outer ring.

  On the other hand, each protruding portion 13 of the tripod member 11 is formed with a pair of tapered surfaces 15 on the front side portion which becomes the leading side when the joint is assembled to insert the tripod member 11 from the opening end of the outer ring 1.

  The pair of tapered surfaces 15 are inclined toward the both sides from the center in the width direction of the protruding portion 13 to form a top portion 16 at the center in the width direction of the protruding portion 13.

  The material for forming the outer ring 1 and the tripod member 11 may be any of metal, ceramics, and synthetic resin. Forming with a synthetic resin is preferable because weight reduction and grease-less can be achieved.

  An appropriate synthetic resin is selected according to the use conditions of the tripod type 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 fat.

  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. POM, nylon resin, and PPS are excellent in heat resistance and lubricity, and are relatively inexpensive. Therefore, a tripod constant velocity joint with excellent cost performance can be obtained.

  As shown in the embodiment, the center of the circumferential width of the bulging portion 6 is inclined at the tip of the bulging portion 6 formed between adjacent track grooves 4 of the outer ring 1 in a direction opposite to the circumferential direction. A pair of tapered surfaces 7 that form the top portion 8 are formed on the front side portion of the projection portion 13 that is the leading side when the tripod member 11 is inserted from the opening end of the outer ring 1, and the width direction of the projection portion 13 When a joint is assembled to insert the tripod member 11 from the opening end of the outer ring 1 by providing a pair of tapered surfaces 15 which are inclined toward the both sides from the center of the outer ring 1 and form the apex 16 at the center in the width direction of the protrusion 13. Even when the phase of the track groove 4 and the protruding portion 13 is shifted in the circumferential direction, the protruding portion 13 is guided and guided by the tapered surface 7 formed at the distal end portion of the bulging portion 6 and guided to the opening at the distal end of the track groove. Will be.

  For this reason, it is not necessary to perform phase alignment between the track groove 4 and the protrusion 13 at the time of joint assembly, and each protrusion 13 of the tripod member 11 is inserted into the track groove 4 by pushing the tripod member 11 into the opening end of the outer ring 1. The tripod type constant velocity joint can be assembled very easily.

  Further, the tripod type constant velocity joint can be disassembled by pulling out the tripod member 11 from the outer ring 1.

  Therefore, a constant velocity joint that can be easily assembled and disassembled can be obtained, and replacement of the input side component that inputs power to the constant velocity joint and the output side component that is rotationally driven by the output from the constant velocity joint are replaced. Can be easily performed.

  Further, by forming the outer ring 1 and the tripod member 11 as a synthetic resin molded product, it is possible to obtain a tripod type constant velocity joint that is light in weight 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 a boot, and a small tripod type constant velocity joint having a simple structure with a small number of parts can be obtained. Moreover, PEEK is excellent in mechanical strength and lubricity even if it does not contain a reinforcing material or a lubricant, so that a highly functional tripod type constant velocity joint 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.

  When using a tripod type constant velocity joint for a medical device or a food manufacturing machine, it is preferable to use a white synthetic resin in order to give a hygienic impression. POM is optimal because it is white and has high lubricity and can be made grease-free.

  In the embodiment, the tripod member 11, the second shaft 12, and the protruding portion 13 are integrally formed of synthetic resin. However, the tripod member 11 and the protruding portion 13 are formed of synthetic resin, and the second shaft 12 is formed of ceramics, steel, stainless steel, or the like. You may form with metals, such as steel and an aluminum alloy.

  In addition, when the 2nd axis | shaft 12 is comparatively long, in order to prevent a torque loss, it is preferable to form the 2nd axis | shaft 12 with ceramics or a metal.

  In the outer ring 1, the cup portion 2 and the first shaft 3 are integrally formed of synthetic resin. However, the first shaft 3 is formed of ceramics, steel, stainless steel, aluminum alloy, or the like, and is coupled to the cup portion 2. You may make it do.

  As shown in the embodiment, by using the outer ring 1 as a synthetic resin molded product, preload can be applied to the contact portion between the side surface 5 of the track groove 4 and the protruding portion 13 by utilizing the elasticity of the outer ring 1. it can. Specifically, by making the dimension between both side surfaces 5 of the track groove 4 smaller than the dimension between the cylindrical surfaces 14 on both sides of the projecting portion 13, preload is applied to the contact portion between the both side surfaces 5 of the track groove 4 and the projecting portion 13. Can be granted.

  Further, even when the outer ring 1 is formed of ceramics or metal instead of synthetic resin, the elasticity of the protruding portion 13 is utilized by making the tripod member 11 including the protruding portion 13 a synthetic resin molded product. Thus, a preload can be applied to the contact portion between the side surface 5 of the track groove 4 and the protruding portion 13. Specifically, by making the dimension between the cylindrical surfaces 14 on both sides of the projecting portion 13 larger than the dimension between the both side surfaces of the track groove 4, preload is applied to the contact portion between the both side surfaces 5 of the track groove 4 and the projecting portion 13. can do.

  As described above, by applying a preload between the contact surface of the side surface 5 of the track groove 4 and the protruding portion 13, a tripod type constant velocity joint having no backlash in the circumferential direction and excellent in constant velocity can be obtained.

  Here, as shown in FIG. 4 and FIG. 5, when the separation part 20 extending in the axial direction from the opening end of the cup part 2 is formed on the outer peripheral wall part of the track groove 4 formed in the cup part 2, the cup part 2 is formed. Since it can be elastically deformed in the circumferential direction, it is easy to apply a preload to the protruding portion 13, and it is not necessary to strictly manage the width dimension of the track groove 4, so that the outer ring 1 can be easily manufactured. Can do.

  In the embodiment, the outer ring 1 and the tripod member 11 as a whole are molded products of synthetic resin, but only the protruding portion 13 of the tripod member 11 or only the outer ring 1 may be molded products of synthetic resin.

A longitudinal front view showing an embodiment of a tripod type constant velocity joint according to the present invention Right side view of FIG. Exploded perspective view showing outer ring and tripod member Longitudinal front view showing another embodiment of the tripod type constant velocity joint according to the present invention Right side view of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Outer ring 4 Track groove 5 Side surface 6 Expanding part 7 Tapered surface 8 Top part 11 Tripod member 13 Protruding part 15 Tapered surface 16 Top part 20 Separation part

Claims (5)

Three track grooves extending in the axial direction on the inner circumference of the outer ring are formed at intervals of 120 ° in the circumferential direction, and a tripod member incorporated inside the outer ring is slidable in each track groove, In a tripod type constant velocity joint provided with three protrusions that transmit torque between the outer ring and the tripod member,
On the outer peripheral wall of the track groove, a separation portion extending in the axial direction from the opening end of the outer ring is formed, and a preload is applied to the contact portion between the track groove and the protruding portion,
A pair of tapered surfaces are formed at the tip of the bulging portion formed between adjacent track grooves of the outer ring, and incline in a direction opposite to the circumferential direction to form a peak at the center of the circumferential width of the bulging portion. In addition, the front portion of the protruding portion, which is the leading side when the tripod member is inserted from the opening end of the outer ring, is inclined toward the both sides from the center in the width direction of the protruding portion to the center in the width direction of the protruding portion. A pair of tapered surfaces that form the top of
A tripod member is inserted from the opening end of the outer ring, and the protruding portion is guided to the inside from the opening of the track groove by contacting and guiding the protruding portion with a tapered surface formed at the leading end of the bulging portion. Assembling a fast joint,
By pulling out the tripod member from the outer ring, as a decomposition of the tripod constant velocity joint,
A tripod type constant velocity joint that facilitates replacement of an input side component that inputs power to the constant velocity joint and an output side component that is rotationally driven by the output from the constant velocity joint.   The tripod type according to claim 1, wherein a tapered surface that is inclined so as to enter the inside of the outer ring from the outer diameter side toward the inner diameter side is provided at a tip portion of a bulging portion formed between adjacent track grooves of the outer ring. Fast joint.   The tripod constant velocity joint according to claim 1 or 2, wherein each of the outer ring and the tripod member is a molded product of a crystalline synthetic resin.   The tripod constant velocity joint according to claim 3, wherein the synthetic resin is made of an injection-moldable synthetic resin.   The tripod type constant velocity joint according to claim 3 or 4, wherein the synthetic resin is a lubricating resin.

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