JPS6024327B2 - sliding spline joint - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement of a Numabuki spline joint used in a drive system of a vehicle, particularly an automobile.

In automobiles, this type of sliding spline joint consists of a sleeve with a spline shape and a spline shaft.
It is used in the drive system that transmits the power of the prime mover to the wheel axle, that is, the propeller shaft. When used in propeller shafts, sliding spline joints must have low frictional resistance against relative sliding in the axial direction, sufficient resistance to shock loads during torque transmission, and It is also required that there is little play between the sleeve and the spline shaft in the direction of rotation, and that no noise is generated during torque transmission.

Conventionally, in order to reduce the sliding friction resistance between the sleeve and the spline shaft, spline joints have been made by applying anti-friction surface treatment to the splines of the spline shaft.
As described in Japanese Patent Application No. 5-5 Ei No. 1, the splines of the spline joints in spline joints have been coated with a nylon thin film in order to reduce sliding friction resistance and absorb impact loads during torque transmission.

However, in the former method, even though the sliding friction resistance of the sliding spline joint is greatly reduced, it is difficult to absorb the impact load during torque transmission.・In order to reduce the looseness between the spline shaft and the sleeve, the spline shaft and spline sleeve must be machined with high precision, and the machining process is extremely difficult. The latter method is difficult, especially for spline sleeves that are broached, and the cutting load is high.
The superdynamic friction resistance of sliding spline joints is reduced, and
Even if the shock load during torque transmission is absorbed, because the nylon thin film is thicker than the metal coating, a relatively large steel clearance is required between the spline shaft and the spline sleeve. The radial and circumferential clearance between the spline shaft and the spline sleeve increases, and as a result, during torque transmission, even if the shock load in the rotational direction is absorbed, there is a looseness between the spline shaft and the spline sleeve. In particular, the large radial play between the spline shaft and the spline sleeve makes it difficult to smoothly reciprocate the sliding engagement between the spline shaft and the spline sleeve, and the large torque In transmission, long-term use was difficult.

As such, it has been difficult for all of these conventional methods to satisfy the requirements placed on the sliding spline joints mentioned above. The purpose of this invention is to reduce sliding friction resistance, sufficiently absorb shock loads during torque transmission, and to reduce sliding friction resistance in the drive system of automobiles, that is, propeller shafts. It reduces the play between the sleeve and the spline shaft, and in order to reduce the play, it facilitates cutting, especially finishing, with high precision, and as a result, noise is extremely reduced. To provide a sliding spline joint. In order to address these issues, the emotional spline joint of the present invention includes a spline shaft with a plurality of splines formed on the outside, and a plurality of spline grooves corresponding to the splines on the inside so that the spline bag can be telescopically received inside. A sleeve having a shape of It consists of a thin synthetic tree paper coating layer that covers the spline, and a thin low-friction metal layer that covers the top surfaces of the splines. Hereinafter, preferred specific examples of the sliding spline joint according to the present invention will be described with reference to the drawings.

Figures 1 and 2 show the truck's propeller shaft 301.
Specific example 1 of the sliding spline joint of the present invention to which this is applied
It shows 0.

The propeller shaft is connected to a transmission (not shown) connected to an engine (not shown) via a clutch (not shown), and a rear wheel (not shown) via a rear axle (not shown). ) for transmitting power to the sardine device (not shown)
A super-dynamic spline joint 10 is used to increase or decrease the distance between the transmission and the rear axle when the rear wheels start moving or when braking.
The sliding spline joint 10 is arranged on the transmission side.

Its sliding spline joint 10' and propeller shaft 3
It is integrally attached to the transmission side end of 0,
A sleeve having a spline shaft 11 formed with a large number of splines 13 on the outside and a large number of spline grooves 14 corresponding to the splines 13 formed on the inside so as to telescopically receive the spline shaft 11 inside in the axial direction. 12.

The sleeve 12 is integrally formed with a yoke 15 for a universal joint at the transmission side end.

Also, the oil seal and oil seal retainer of this spline joint 10' are omitted from illustration.

The spline shaft 11, which is one component of the sliding spline joint 10, has a thin film 18 made of nylon on the spline portion 17 so as to expose the top surface 16 of each spline 13.
is coated.

This can also be seen from FIG.
7 and integrally connected at both ends of each spline 13, in other words, at both ends of the spline portion 17,
In other words, they are continuous.

However, the connection portions that are integrally connected at both ends are not shown. Furthermore, the nylon thin film 18
The top surface 16 of each spline 13 exposed from the top surface constitutes one contact surface and is coated with a thin film 19 made of a low-friction metal.

In detail, the coating of the low friction metal film 19 is applied to the top surface 16 of the subline 13 by, for example, a conventional phosphate coating process.

That is, a saturated solution of ferrous phosphate with manganese dioxide added thereto is heated to about 95°C, the spline shaft 11 coated with the nylon thin film 18 is placed in the solution, and the top surface 16 of the spline 13 is coated with phosphoric acid. A coating of iron and manganese phosphate is produced, thus coating the top surface 16 of the spline 13 with a thin film of iron and manganese phosphate. In this way, the tooth surfaces and tooth bottoms of the spline shaft 11 are coated with the nylon thin film 18, so that
The phosphate coating treatment only on the top surface of the spline 13 on the spline shaft 11 becomes extremely simple.

In addition, since the spline 13 is coated with the nylon thin film 18 and the iron phosphate-manganese phosphate thin film 19, the spline 13 can fit into the spline groove 14 in the gap, especially in the radial direction. The top surface 16 of the spline 13 provides a radial backlash surface for the spline groove 14, which is machined to reduce the mating gap.

In addition, the sleeve 12, which is the other component of the Sakazen spline joint 10, has the bottom surface 20 of each spline groove 14 as the other contact surface, and the bottom surface 20 of each spline groove 14 is complementary to the top surface 16 of each spline 13. It is configured as follows.

Furthermore, the bottom surface 20 of each spline groove 14 is smoothly broached with high precision, making the gap between the bottom surface 20 and the top surface 16 of the corresponding spline 13 extremely small. Furthermore, the bottom surface 20 of each spline groove 14 is broached with a pair of relief grooves 21 on both sides, so that the processing accuracy of the bottom surface itself can be increased. In this way, since the relief grooves 21 are formed in advance on both sides of the bottom surface 20, the cutting load is greatly reduced during broaching, making pressurization easier and improving finishing accuracy.

As a result, the bottom surface 20 of the spline groove 14 has a radial backlash against the spline 13 so as to reduce the iron gap between the top surface 16 of the spline 13 and the bottom surface 20 of the spline groove 14. provide a face. Since the Sakekin spline joint 10 is configured as described above, when used in a truck, the nylon thin film, that is, the thin nylon coating layer 18 reduces the sliding frictional resistance between the spline shaft 11 and the sleeve 12. , the spline shaft 11 and the sleeve 12 in the rotational direction during torque transmission.
It absorbs the impact load between it and suppresses the generation of noise.

Furthermore, the bottom surface 20 of the spline groove 14 is smoothly broached with high precision, and the top surface 16 of the spline 13 is coated with a low-friction metal thin film, that is, a thin low-friction metal layer 19, so that the spline The dynamic frictional resistance between the shaft 11 and the sleeve 12 is reduced, and the gap between the spline shaft 11 and the sleeve 12 becomes extremely small in all directions of the shaft, thereby suppressing the generation of noise. According to the above invention, in the spline shaft, a thin synthetic resin coating layer covers the spline portion so as to cover the top surface of the spline, and a thin low-friction metal layer covers the top surface of the spline. On the other hand, in a sleeve with a spline groove, a pair of relief grooves are formed on both sides of the bottom surface of the spline groove in the length direction of the spline groove, and the bottom surface of the spline groove is broached. Compared to the spline joints that have been proposed and used, the frictional resistance between the spline shaft and the sleeve is reduced, and the impact load between the spline and the sleeve in the rotational direction is effectively reduced during torque transmission. Furthermore, since a pair of escape grooves are formed in advance on both sides of the bottom of the spline groove and the bottom is broached, the cutting load is reduced during broaching. The top surface of the spline and the bottom surface of the spline groove cooperate with each other to provide a contact surface that greatly reduces the broaching and improves the finishing accuracy, so that the radial In other words, the gap between the spline shaft and the sleeve becomes extremely small, preventing rattling between the spline shaft and the sleeve in the direction of rotation and in the direction of rotation. When a large torque is transmitted, the top surface of the spline and the bottom surface of the spline groove, which provide a contact surface for the backlash, prevent the spline shaft and the spline sleeve from shifting, and as a result, the large torque is transmitted. Even when a large torque is transmitted, smooth reciprocating sliding is achieved between the spline shaft and the sleeve. Damage to the synthetic resin coating layer and low-friction metal layer is prevented, allowing long-term use in large torque transmission.

[Brief explanation of the drawing]

FIG. 1 is a split perspective view of a propeller shaft for a truck using a sliding spline joint according to the present invention, and FIG. 2 is a partial sectional view taken along line 2--2 in FIG. 1. 10... Sliding spline joint, 11...
・Spline shaft, 12...Sleeve, 13...Spline, 14...Spline groove, 16...
Top surface, 17...Spline part, 18...
...No. 19... Thin film made of low friction metal, 20... Bottom surface, 21... Relief groove. Fudenozu diagram 2

Claims (1)

[Scope of Claims] 1. A spline shaft having a plurality of splines formed on the outside; a sleeve having a plurality of spline grooves corresponding to the splines formed inside so as to telescopically receive the spline shaft therein; A pair of relief grooves formed on both sides of the bottom of each spline groove in the length direction of the spline groove, and a thin synthetic resin covering the spline portion of the spline shaft so as to expose the top surface of the spline. A coating layer and a thin low-friction metal layer covering the top surface of each spline. and sliding spline fittings.