JPH10299849A - Belt type speed change gear - Google Patents

Abstract

PROBLEM TO BE SOLVED: To lower friction and improve abrasion resistance by using a resin material wherein a thermosetting resin is blended with specific quantity of a lubricant consisting of molybdenum disulfide, graphite, etc., as to a material of a sliding surface of a cam on a cam mechanism to move movable sheaves on the driving side and the driven side in the axial direction. SOLUTION: A belt type speed change gear moves a speed changing belt in the radial; direction and changes a speed changing ratio as each of speed changing pulley units on the driving side and the driven side is constituted of a movable sheave and a fixed sheave and the movable sheave is moved in the axial direction through a resin made cylindrical cam 21. In this case, in the case of manufacturing the cylindrical cam 21, a cylindrical cam 21a is formed by using a steel material, a sliding surface 21c of the cam and its side surface are cut out by the thickness of a resin layer, thereafter, by using a resin material which is made by blending a thermosetting resin of 100 weight part with a 15-30 weight part of lubricant selected from molybdenum disulfide, graphite or fluororesin, a resin layer 21b is formed by injection molding, etc., in a cutout part.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a belt-type transmission, and more particularly, to a movable sheave of a drive-side and a driven-side transmission pulley which is connected by a cam mechanism for moving according to a load torque or a link connection. By operating lever,
The present invention relates to a belt-type transmission provided with a cam mechanism for moving a movable sheave.

[0002]

2. Description of the Related Art As a material for the above-mentioned cams, a method of polishing hardened steel or using cast iron having high wear resistance is generally employed. However, this method inevitably increases the cost due to the number of polishing steps, and sliding between metal materials generally causes wear and seizure.
There is a drawback that oil supply is always required and the coefficient of friction increases. For example, when the rotation of the cylindrical cam is entrusted to the lever operation, the operation force is increased, which causes a problem in work. In addition, in the case of the torque-responsive torque cam, the increase in the operating force reduces the sheave thrust of the movable sheave, resulting in a problem that the shift function is impaired and the belt slips.

[0003] This cylindrical cam is disclosed in
As described in JP-A-90158, as a pulley and a cam material, a metal, a thermosetting resin such as a phenolic resin, an epoxy resin, a polyimide resin, an unsaturated polyester resin, a diallyl phthalate resin, Discloses a method of forming a resin layer made of a thermoplastic resin such as polyethylene terephthalate resin, polyoxyphenylene oxide resin, polyoxymethylene resin, polyamide resin, polycarbonate resin, polyacetal resin, ABS resin, polyethylene resin, polyvinyl chloride resin, etc. Have been.

Japanese Patent Application Laid-Open No. 57-124151 discloses a method in which a carbon fiber reinforced epoxy resin is mounted on the working surface of a cam. As described above, the present invention relates to a belt-type transmission, for example, a cylindrical cam provided on a rotation shaft of a speed-change pulley, and another rotating cylinder which engages with the cam and separates and moves the movable cam described above in the axial direction. An object of the present invention is to improve a material of a cam surface which comes into sliding contact with each other in terms of performance of low friction and wear resistance.

[0005]

However, as a recent trend, the transmission horsepower has increased, and a large surface pressure has acted on the resin material on the cam surface. Use in an atmosphere of 200 ° C.) is becoming common.

[0006] This high temperature increases the coefficient of friction,
As a result, the amount of wear has also increased. In particular, when using a thermoplastic resin, even when a metal material is used for the reinforcing material, as well as the resin cam alone, the heat resistance of the resin material, that is, the strength when heated, the adhesive strength, and the abrasion resistance are improved. There was a problem. Even when a thermosetting resin is used, how to reduce the coefficient of friction and how to reduce the amount of wear thereof have not been elucidated in detail and have been left as problems.

In the method of mounting a carbon fiber reinforced type epoxy resin on a sliding portion of a cam, a sheet-like prepreg in which carbon fiber is impregnated with a resin is prepared in advance, laminated and heated with an epoxy adhesive. However, a complicated process of pressure bonding is required, and there is a problem in bonding strength.

[0008]

According to a first aspect of the present invention, there is provided a belt type transmission for transmitting rotation of a driving sheave to a driven sheave via a belt. 15-30 parts by weight of at least one lubricant selected from molybdenum disulfide, graphite, or a fluororesin is mixed with 100 parts by weight of a thermosetting resin in a sliding surface material of a cam used for a moving cam mechanism. The belt-type transmission is constituted by using the resin material thus obtained.

According to a second aspect of the present invention, an epoxy resin or a phenolic resin is used as the thermosetting resin of the first aspect.

[0010]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. In FIG. 5, the belt-type transmission 1 according to the present invention includes a drive-side transmission pulley unit 10, a driven-side transmission pulley unit 20, and a transmission belt 3 wound around the pulley. Fixed sheaves 16 and 26 are arranged in the shift pulley units 10 and 20 of the belt type transmission 1 at axial positions facing the movable sheaves 15 and 25, respectively, and the movable sheave moves in the axial direction. By doing so, the speed change belt moves in the radial direction, and as a result, the effective pitch diameter changes. The above is the outline of the transmission mechanism and the device.

In the driven-side transmission pulley unit 20 shown in FIG. 5, a movable sheave 25 is fitted on a driven shaft, is movable in an axial direction, and is rotatable in a rotational direction within a range of a cam rotation angle. A fixed sheave 26 is fixed integrally with the driven shaft so as to face the movable sheave 25, and the pair of sheaves forms a V-groove shape. The pair of sheaves is always pressurized by the coil pulling 24 in a direction in which the V-groove shape becomes the narrowest. This spring force is applied to a pair of cylindrical cams, that is, the resin cylindrical cam 2 according to the present invention.
1, 21 'and a metal cylindrical cam 22 are provided between the fixed sheave 26 and the movable sheave 25.

Next, the resin cams 21 and 21 'according to the present invention.
Will be described with reference to FIG. 1 and FIG. Resin cam 2
1, 21 'are the resin layers 21 on the reinforcing members 21a, 21a'.
b, 21b '. Here, FIG. 3 shows a plan view of the resin cams 21 and 21 ′, and FIG. 4 is a developed view showing a cam displacement curved surface of the resin cams 21 and 21 ′. 3 and FIG.
D, E, F, G, and H are symbols indicating positions corresponding to each other, and the hatched portions in the drawing are the cam sliding surfaces 21c,
21c 'is shown.

The inclination direction of the cam is provided so as to decrease when the load torque of the driven shaft increases and to increase when the load decreases. Therefore, the torque cam repeatedly slides with the load fluctuation at all times. In addition, resin cam 2
Numerals 1 and 21 'are always in pressure contact with a metal cylindrical cam 22 (not shown) and the cam sliding surfaces 21c and 21c' of the inclined portions.

Hereinafter, embodiments will be described in detail. In the embodiment shown in FIG. 1, a resin layer is provided only on the sliding surface of the cam, and the details are as follows. First, the reinforcing steel S2
The cylindrical cam 2a is formed using 5C, and the sliding surface 2c and the side surface of the cam are cut out by the thickness of the resin layer.
Thereafter, the notch is formed by using a resin material in which 15 to 30 parts by weight of at least one lubricant selected from molybdenum disulfide, graphite, or a fluororesin is blended with respect to 100 parts by weight of the thermosetting resin. The part is made by compression molding or injection molding, and inserted and fitted into the notch of the reinforcing material.

The modified embodiment of FIG. 2 further improves the reinforcing effect, and does not have a notch as shown in FIG. 1, and the above resin is laminated on the entire surface of the reinforcing material by compression molding or injection molding. It was done. By this method, the adhesive force between the resin layer and the reinforcing material becomes stronger, and the weight can be reduced. In addition, it is possible to arbitrarily increase the bonding strength by roughening or knurling the finishing surface of the reinforcing material. In addition to the above-mentioned reinforcing materials, aluminum alloy, magnesium alloy, other alloys Timber,
Alternatively, a ceramic material can be used.

Next, the results of experiments conducted by the present inventors will be described in detail with reference to Table 1 below. For the thermosetting resin of the examples, epoxy resin and phenol resin are used, and in order to reduce the friction coefficient, 15 parts by weight or 20 parts by weight of any of molybdenum disulfide, graphite or a fluorine-based resin as a lubricant is used. The mixture was used, and 30 parts by weight of carbon short fibers and 30 parts by weight of aramid short fibers were used as a reinforcing material for the resin layer.

As a comparative example, a material containing 10 parts by weight of molybdenum disulfide, graphite or a fluorine resin was used. It is well known that the compounding exceeding 30 parts by weight significantly reduces the basic performance as a resin, that is, the strength and the abrasion resistance. As other comparative examples, polyetheretherketone, polyamide,
A resin made of polyamideimide was used.

In the evaluation of the resin material, the magnitude of the coefficient of friction, the amount of wear in an atmosphere at normal temperature of 25 ° C., and the amount of wear in an atmosphere of 90 ° C. when heated were measured.
For this wear test, a Takachiho friction wear tester (pin-on-disk method) was used, and the test condition was a load of 60 kgf.
/ Cm ² , and the sliding speed was 0.6 m / sec.

[0019]

[Table 1]

In Table 1, Comparative Examples 1, 2, and 3 each use 100 parts by weight of an epoxy resin or a phenol resin, which is a thermosetting resin, and all of them use molybdenum disulfide, graphite, or Since the compounding weight of the fluororesin was 10 parts by weight, the friction coefficient was 0.4
As a result, the sliding resistance of the cam surface could not be reduced. In addition, the wear amount was 2.8 (g × 10 ⁻³ ) or more in both cases of 25 ° C. at normal temperature and 90 ° C. when hot, and the durability performance could not be improved.

In Examples 1, 2, 3, 4, 5, and 6, the compounding weight of molybdenum disulfide, graphite or fluororesin is 15 to 20 parts by weight, and the coefficient of friction is Was improved to 0.28 to 0.32, and the wear amount was improved to 0.4 to 1.5 (g × 10 ⁻³ ).

Further, Comparative Examples 4, 5, and 6 using thermoplastic resins composed of polyetheretherketone, polyamide and polyamideimide were used in which 15 parts by weight of molybdenum disulfide, graphite or a fluorine-based resin was blended. However, the coefficient of friction was 0.30 to 0.38, and the amount of wear at ordinary temperature was 0.9 to 1.6 (g × 10 ⁻³ ), and relatively good results were obtained. However, the amount of wear when heated is 2.
2 to 2.9 (g × 10 ⁻³ ), and the durability under heat could not be improved.

From the above results, it can be seen that the addition of 15 to 30 parts by weight of molybdenum disulfide, graphite or a fluorine-based resin to 100 parts by weight of the thermosetting resin has a remarkable effect of reducing the coefficient of friction. It was also found that there was an effect of reducing the amount of wear regardless of whether it was hot.

[0024]

According to the first aspect of the present invention, the sliding surface material of the cam is molybdenum disulfide with respect to 100 parts by weight of the thermosetting resin.
By blending 15 to 30 parts by weight of at least one lubricant selected from graphite or fluorine-based resin, it becomes possible to provide a resin material having low friction and excellent abrasion resistance, thereby reducing the sheave thrust. It was possible to reduce the operating force without impairing it, and at the same time, it was possible to improve the heat and abrasion resistance at normal temperature and hot time. As a result, it has become possible to provide a belt type transmission having excellent durability.

According to a second aspect of the present invention, by using a general-purpose epoxy resin or a phenolic resin as the thermosetting resin of the first aspect, an extremely inexpensive and stable physical property, which is an advantage of a general-purpose material, can be obtained. It became possible to obtain resin materials having

[Brief description of the drawings]

FIG. 1 is a perspective view showing a resin cam according to the present invention.

FIG. 2 is a partial cross-sectional perspective view showing another embodiment according to the present invention.

FIG. 3 is a plan view showing a resin cam according to the present invention.

FIG. 4 is a development view of the resin cam according to the present invention.

FIG. 5 is a sectional view showing a belt-type transmission according to the present invention.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 belt-type transmission 3 transmission belt 8 cam fixing lever 9 cam rotation lever 10 drive-side transmission unit 20 driven-side transmission unit 11 metal cam 12 cam follower roller 15, 25 movable sheave 16, 26 fixed sheave 21, 21 'resin Cam 21a, 21a 'Reinforcing material 21b, 21b' Resin layer 21c, 21c 'Cam sliding surface 22 Metal cam 24 Coil spring

Claims (2)

[Claims] 1. A belt-type transmission for transmitting the rotation of a driving sheave to a driven sheave via a belt, comprising a cam used for a cam mechanism for moving the driving and driven movable sheaves in an axial direction. The sliding surface material is thermosetting resin 10
A belt-type transmission device comprising 15 to 30 parts by weight of at least one lubricant selected from molybdenum disulfide, graphite, or a fluororesin per 0 parts by weight. 2. The belt-type transmission according to claim 1, wherein the thermosetting resin is an epoxy resin or a phenol resin.