JP2001027220A - Power transmission shaft - Google Patents

Abstract

PROBLEM TO BE SOLVED: To attain weight reduction, high rigidity and cost reduction of a power transmission shaft used as a drive shaft or the like for an automobile. SOLUTION: A fiber reinforced resin layer 0.01 mm to 10 mm in wall thickness with the large modulus of flexural elasticity is fitted to the outer peripheral part of a metal shaft 10 to form a composite shaft with sufficient flexural rigidity as a power transmission shaft. A countermeasure to vibration is thereby taken at a low cost in a space-saving manner without using a dynamic damper.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a power transmission shaft, and more particularly, to a power transmission shaft which is lightweight and has improved bending rigidity. Can be used.

[0002]

2. Description of the Related Art A driving force from an automobile engine is transmitted to a drive wheel axle through a drive shaft. The drive shaft is provided with constant velocity joints (joints) at both ends so that it can cope with variations in length and angle due to changes in the relative positions of the engine and the drive wheels. Conventional drive shafts generally use a solid or hollow steel shaft 1 as shown in FIG.

[0003]

A steel drive shaft 1 has a dynamic damper 2 at an intermediate portion when the drive shaft becomes a long axis.
Since measures against vibration such as mounting (FIG. 7B) are required, improvements are currently required in terms of weight, mounting space, cost, and the like.

Accordingly, the present invention has been proposed in order to meet the above-mentioned demands for improvement, and aims to reduce the weight by eliminating the dynamic damper parts, to save space around the drive shaft, to reduce the cost, and to reduce the cost. The purpose is to increase the rigidity of the drive shaft.

[0005]

According to the present invention, a fiber-reinforced resin layer 20 having a thickness of 0.01 mm or more and 10 mm or less is provided on the outer periphery of a solid metal shaft 10 as shown in FIG. It is solved by providing (claim 1).
By providing a fiber reinforced resin (hereinafter, referred to as FRP) layer 20 having high bending rigidity on the outer peripheral portion of the metal shaft 10, high rigidity is realized. Therefore, it is not necessary to provide the dynamic damper 2 (see FIG. 7B) at the intermediate portion, and a reduction in weight and space can be achieved. Here, a hollow metal shaft has features such as light weight and improved vibration and noise characteristics, but if it is considered that the diameter and cost will be larger than those of a solid metal shaft, Is more preferable.

[0006] The thickness of the FRP layer 20, that is, the thickness t is equal to 0.
It is preferably from 01 mm to 10 mm. FRP layer 20
When the thickness t is smaller than 0.01 mm, it is difficult to obtain a bending rigidity that satisfies the required natural frequency of bending even if an FRP layer having a large specific elastic modulus is added. F
When the thickness t of the RP layer 20 is larger than 10 mm, FRP
Although the addition of a layer can be expected to improve the bending rigidity, the amount of FRP to be used is relatively large, so that the production cost becomes large, and the outer diameter of the completed power transmission shaft becomes large, resulting in space-saving problems. Occurs.

The dimensions of the composite power transmission shaft composed of the metal shaft 10 and the FRP layer 20 are determined by the natural frequency of bending required for the power transmission shaft.
That is, if the required natural frequency of bending is to be satisfied only by the metal shaft 10, the diameter becomes large, and if the weight becomes heavy, for example, the outer diameter of the metal shaft 10 satisfies only the required static torsional strength. The FRP layer 20 having a large elastic modulus so as to satisfy the natural frequency of bending required for the outer peripheral portion of the metal shaft 1.
Is provided. Thereby, the outermost diameter can be reduced and the weight can be reduced.

The length PL of the metal shaft 10 is preferably not less than 50 mm and not more than 1,200 mm, more preferably, not more than 200 mm.
It is preferably at least 1,000 mm. When the length PL of the metal shaft 10 is shorter than 50 mm, the rigidity is already high with the metal shaft diameter satisfying the required static torsional strength, and it is not necessary to add the FRP layer 20. Conversely, if the length PL of the metal shaft 10 is longer than 1,200 mm, even if an FRP layer having a large elastic modulus is added, the thickness of the metal shaft 10 becomes large, and it is difficult to manufacture the metal shaft 10 at low cost. In addition,
Serrations (or splines) at both ends for joining with constant velocity joints or similar joint elements (not shown)
The parts are indicated by reference numerals 12 and 14.

The outer diameter D ₂ of the metal shaft 10 is preferably 1 mm or more and 40 mm or less. The outer diameter D ₂ of the metal shaft 10 is 1
If it is smaller than mm, the metal shaft 10 may be damaged during transportation or fitting of the FRP layer. Further, it is difficult to design the power transmission shaft to satisfy only the static torsional strength required. Outer diameter D of metal shaft 10
_{If 2} is larger than 40 mm, the drive shaft used for a passenger car is too heavy, and the purpose of weight reduction cannot be achieved.

The axial length FL of the FRP layer 20 is determined by the length PL of the metal shaft 10 and the axial length F of the FRP layer 20.
It is preferable to set the value of the ratio FL / PL of L to be 0.1 or more and 1.0 or less (claim 2). When the value of FL / PL is smaller than 0.1, even if the specific elastic modulus is large,
Even with the addition of the RP layer, it is difficult to achieve the required bending rigidity. Conversely, when the value of FL / PL is larger than 1.0, the FRP layer 20 is longer than the metal shaft 10. As a result, at least one end of the obtained composite shaft cannot be used for joining with a joint element such as a constant velocity joint, which is not preferable.

The fiber constituting the FRP layer 20 is desirably a material having a low density and a high elastic modulus in order to increase the bending resonance point of the power transmission shaft. As such a fiber,
PAN-based and pitch-based carbon fibers, silicon carbide fibers, alumina fibers, boron fibers, glass fibers, para-aramid (eg, Kevlar manufactured by DuPont) fibers, metals (steel,
Aluminum alloy, titanium alloy, copper, tungsten) fiber and the like.

Tension of reinforcing fiber used for FRP layer 20
The elastic modulus is 20,000kgf / mm ^Two(196 GPa)
More preferably, more preferably 25,000 kgf / m
m^Two(245 GPa) or more (claim 3). Fibrous
Tensile modulus of elasticity is 20,000kgf / mm^Two(196G
Less than Pa), how to configure the fiber orientation angle of FRP
Can not raise the resonance point of the bending of the shaft
No.

When PAN-based carbon fiber is used, its wire diameter is preferably 1 μm or more and 20 μm or less, and more preferably 5 μm or more and 8 μm or less. When the wire diameter of the PAN-based carbon fiber is less than 1 μm, the cost of the acrylic fiber as a raw material is high, and it is difficult to control when firing to process the carbon fiber, and the price of the fiber becomes high. A composite shaft cannot be established. If the wire diameter of the PAN-based carbon fiber is 20 μm or more, a fiber having a high elastic modulus cannot be produced.

When pitch-based carbon fibers are used, mesoface pitch-based carbon fibers which are long fibers and have a high modulus of elasticity are preferred.

In order to further reduce the cost, two or more different kinds of fibers may be used in combination. The use of a fiber having a large specific elastic modulus for the drive shaft is preferred because the effect of reducing the weight is great. In other words, PAN-based carbon fibers are favorable for specific strength, and mesoface pitch-based carbon fibers are favorable for specific elastic modulus. However, from the viewpoint of cost reduction, it is also possible to use these carbon fibers or a hybrid of these carbon fibers and glass fibers.

The thermosetting resin used as the matrix of the FRP layer 20 is not particularly limited. Generally, thermosetting epoxy resin, phenol resin, unsaturated polyester resin, vinyl ester resin, urethane resin,
Alkyd resin, xylene resin, melamine resin, furan resin, silicon resin, polyimide resin, etc. can be used, but epoxy resin is preferred from the viewpoint of strength. When an epoxy resin is used for the matrix, the heat resistance after epoxy curing is preferably 60 ° C. or higher at the glass transition point, and more preferably 80 ° C. or higher. When used as a drive shaft of an automobile, the ambient temperature is about 60 ° C., and if the heat resistance after epoxy curing is less than 60 ° C., serious problems such as breakage may occur, and the epoxy resin cannot be used as a matrix. It is also possible to use a modified epoxy resin in which rubber particles are interposed in an epoxy resin to form a sea-island structure to impart impact resistance, or a modified epoxy resin in which a main chain or a side chain is chemically modified. At this time, damping can be imparted to the obtained composite shaft structure. Further, an epoxy resin having conductivity by dispersing a filler such as conductive carbon black or a metal powder in the epoxy resin may be used.

The surface of the reinforcing fiber to be used is surface-activated by ozone oxidation treatment or irradiation with ultraviolet rays, or wet-treated with a silane coupling agent or a titanium coupling agent to improve the affinity or to increase the reactivity. By forming a functional group site on the fiber surface and imparting a strong bond having a chemical bond after curing with the thermosetting matrix resin, the interface strength between the matrix and the fiber can be improved.

As a means for forming the FRP layer 20, as shown in FIG. 2, a sheet trap forming method using the metal shaft 10 as a mandrel (claim 7), a filament winding method, or a drawing method in advance is used. Connect the FRP pipe 22 (FIG. 3) to the metal shaft 1
A method of press-fitting into the outer periphery of the 0 (claim 8) or a method of fitting can be adopted, and both can be implemented at low cost. Although the FRP pipe can be formed in advance by a sheet wrap method, the use of pultrusion may be more advantageous in terms of cost because material loss during manufacturing can be greatly reduced. In addition, a prepreg sheet winding step, a shrink tape and a shrink tape winding step, and a prepreg curing step (heat treatment) can be omitted as compared with the sheet wrap method.

An FRP layer 20 is formed on the outer periphery of the metal shaft 10.
Is advantageous in that bending rigidity and torsional rigidity can be controlled by laminating and combining layers in which the fiber orientation angle is 0 ° and ± 45 ° with respect to the axial direction of the shaft. It is. The bending and torsional rigidity of the shaft may be controlled by the length and thickness of the FRP layer 20 fitted on the metal shaft 10 and the elastic modulus of the reinforcing fiber used. At this time, as shown in FIG. 2, a semi-cured sheet-like prepreg 22 in which a reinforcing fiber is impregnated with a thermosetting resin is used using a metal shaft 10 as a mandrel, and the arrangement of the yarns is fixed in one direction. The sheet wrap method in which the fiber is wound at an arbitrary fiber orientation angle while maintaining the above-mentioned value can be adopted.

The prepreg 2 is attached to the outer periphery of the metal shaft 10.
2 is wound and laminated, and then the bending and torsional rigidity of the shaft is controlled by the thickness and width of the FRP layer 20 obtained by heating and curing, and the elastic modulus (fiber type and fiber content, prepreg thickness) of the prepreg to be used. You may. The thickness of the prepreg 22 to be wound is preferably 5 μm or more and 300 μm or less. If the thickness of the prepreg 22 is less than 5 μm, wrinkles are likely to occur during the winding process, and when a torque is applied to the composite shaft after curing, the wrinkles may be a starting point of cracks. The thickness of the prepreg 22 is 30
When it is thicker than 0 μm, it is difficult to wind due to its thickness, and even if it is wound, a step is generated in appearance after curing.

Further, the reinforcing fibers are impregnated into the uncured matrix resin, and the plurality of tows are continuously cured while overwinding, whereby a molded article having a uniform cross section such as a pipe can be efficiently produced. Pultrusion molding may be employed. In this case, as shown in FIG. 3, it is possible to press-fit the metal shaft 10 into the molded FRP pipe 24 to form a composite shaft. The cross-sectional shape of the FRP pipe 24 may be a drawn material having a slit (a gap, a tear, etc.) in a part thereof, or a deformed cross-section having a shallow groove forming an adhesive pool. When an FRP pipe having a laminated structure is to be obtained by pultrusion molding, it can be formed by overwinding, but the number of layers is preferably within 20 layers (claim 6). 20 layers
If it is attempted to obtain a molded body exceeding the above, the setup work becomes very complicated and mass productivity is impaired.

As shown in FIG. 4, when an FRP pipe 26 having a slit 25 extending through the FRP pipe from one end to the other end and extending in the axial direction is attached to the outer peripheral portion of the metal shaft 10, the slit 25 4D, the FRP pipe 26 can be elastically deformed (expanded) in the circumferential direction as shown by an arrow in FIG. 4D, and the metal shaft 10 is pressed into a simple FRP pipe without a slit. In comparison, the assembling process becomes overwhelmingly easy. That is, the FRP pipe inner diameter D1 and the metal shaft outer diameter D2
Since there is a dimensional tolerance in each case, it is necessary to match the dimensions of a simple cylindrical pipe in order to control the press-fitting in the process. On the other hand, when an FRP pipe having a slit is incorporated, such a matching step becomes unnecessary, and the press-fitting can be small. Regarding the width W of the slit 25 (FIG. 4C), F
It is preferable to set it to 40% or less of the outer circumference of the RP pipe 26 (claim 10). If the slit width W is larger than 40% of the outer circumference of the FRP pipe 26, even if the FRP pipe 26 is fitted, the desired high rigidity may not be achieved.

The cross-sectional shape of the slit 25 is not limited, but it goes without saying that it is more convenient if it can be formed continuously during pultruding. Of course, the FRP cylindrical pipe may be formed in advance, and the slit may be formed by shaving in a post-process. In particular, when the slits are formed continuously during the pultrusion molding, a slit 25 'having a bias angle θ with respect to the axial direction can be inserted into the FRP pipe 26 as shown in FIG. In this case, the bias angle θ is preferably within ± 30 °.
1). When the bias angle of the slit 25 ′ exceeds 30 °, the tow orientation follows the direction, so that the contribution to the improvement of the bending rigidity of the composite shaft after the FRP pipe is incorporated is impaired even if a reinforcing fiber having a large elastic modulus is used. Will be.

Inner diameter D1 of FRP pipe 26 with slit
May be formed to be equal to or slightly smaller than the outer diameter D2 of the metal pipe 10 so as to be elastically deformed (expanded) in the circumferential direction during assembly. In this case, the FRP pipe inner diameter D1
Of the ratio D1 / D2 between the diameter of the metal shaft and the outer diameter D2 of the metal shaft is 0.7.
It is desirable that the value be not less than 1.1 and not more than 1.1 (claim 12).
If the value of D1 / D2 is smaller than 0.7, the FRP pipe 2
6 does not follow the outer peripheral surface of the metal shaft 10 and causes a problem. Conversely, if the value of D1 / D2 is greater than 1.1, F
There is a case where a clearance is generated between the RP pipe 26 and the metal shaft 10 so that the metal shaft 10 cannot be fixed properly. After assembling, the FRP pipe 26 is stretched on the metal shaft 10 to return to the inner diameter at the time of molding.
Pressing force at P interface, FR on metal shaft 10
An attempt is made to fix the P pipe 26. This fixing force is more convenient when the FRP pipe is axially fixed on the metal shaft 10 using a snap ring or an adhesive.

As a method of fixing the FRP pipes 24 and 26 on the metal shaft 10, as shown in FIG.
An annular retaining ring groove 16 may be formed on the outer peripheral surface of the metal shaft 10 in advance, and both ends thereof may be fixed by retaining rings 30 after the FRP pipe is assembled.
3). As the retaining ring 30, for example, a spring washer can be used.

When assembling the FRP pipe to the outer peripheral portion of the metal shaft 10, it may be fixed together with an adhesive.
In particular, when press-fitting the FRP pipe 24 having a simple cylindrical pipe shape, the adhesive may be scraped off and an adhesive layer may not be formed at the interface between the metal and the FRP. In order to improve this problem, as shown in FIG. 5, an annular groove 18 that forms a pool of adhesive between the metal shaft 10 and the FRP pipe 24 after being assembled may be provided on the outer peripheral portion of the metal shaft 10 (see FIG. 5). Claim 14). Alternatively, as shown in FIG.
For example, an annular groove 28 may be machined in advance on the inner peripheral surface of the P pipe 24 as a portion where an adhesive pool is formed after being assembled (claim 15). The adhesive used is not particularly limited as long as it can bond metal and FRP. For example, Metal-F described in “Science and Practice of Adhesion” published by Kobunshi Publishing Co., Ltd.
Although any adhesive for RP can be used, a preferable adhesive has a viscosity of 2,000 cps (mPa · s) or more and 350,
000 cps (mPa · s) or less, more preferably 20,000 cps (mPa · s) or more and 40,000
cps (mPa · s) or less is preferable. 2,000 cps
When the viscosity is smaller than (mPa · s), the viscosity may be too low to hold the adhesive well even if a groove for storing the adhesive is provided, and the intended adhesive effect may not be exhibited. On the other hand, if it is larger than 350,000 cps (mPa · s), the groove may be too viscous to be filled well.

Further, while covering with a film-like or tubular heat-shrinkable tape, the FRP
The pipes 24 and 26 may be fixed. Although various methods for fixing the FRP pipes 24 and 26 on the metal shaft 10 have been described, it is needless to say that a fixing method combining these methods can be adopted as a more reliable fixing method.

[0028]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention applied to a drive shaft of an automobile will be described as typical examples of a power transmission shaft, but the present invention is not limited to these embodiments. Here, the hammering method was used as a method for evaluating bending stiffness, and if the measured value of the natural frequency of the primary bending at both ends supported was 170 Hz or more, it was determined that the bending stiffness level was sufficient even without using a dynamic damper.

Embodiment 1 As shown in FIG. 5A, an annular groove 1 serving as an adhesive reservoir is provided.
8 provided with an iron solid shaft 10 (S40C-HM
Material, outer diameter 22 mm, length 600 mm, both ends supported, bending primary natural frequency 150 Hz), elastic modulus 30 × 1,000
0 kgf / mm ² (294 GPa) PAN-based carbon fiber Pyrofil CF Tow (registered trademark of Mitsubishi Rayon Co., Ltd.) as a reinforcing fiber and epoxy-based cured resin (Epicoat 10)
01 (registered trademark of Yuka Shell Epoxy Co., Ltd.): 40
Part, Epicoat 828 (registered trademark of Yuka Shell Epoxy Co., Ltd.): 32 parts, Sumi-Epoxy ELM120 (registered trademark of Sumitomo Chemical Co., Ltd.): 14 parts, 4.4 'diaminodiphenyl sulfone: 14 parts Then, a cylindrical FRP pipe 24 (inner diameter 22 mm, wall thickness 2.0 mm, length 400 mm) manufactured by drawing was pressed into the center of a solid iron shaft (FIG. 5B). After that, the FRP pipe 2 is
4 was fixed using a retaining ring 30 and a two-part epoxy adhesive (E set M, a registered trademark of Konishi Co., Ltd.) (FIG. 5 (C)). For the obtained composite FRP shaft, the both ends were supported, and the bending primary natural frequency was measured using the hammering method. As a result, at 200 Hz, sufficient bending rigidity was obtained without using a dynamic damper as a drive shaft of an automobile. Level.

In Examples 2 to 5 and Comparative Examples 1 and 2 shown below, the steel type, reinforcing fiber,
The impregnating resin (matrix resin) and the adhesive were used in Example 1.
The same material was used.

Embodiment 2 As shown in FIG. 5A, an annular groove 1 serving as an adhesive reservoir is provided.
As shown in FIG. 4 (A), a cylindrical FRP pipe 26 with a slit 25 (inner diameter 22 mm, wall thickness 2.0 mm,
(Length 400 mm) was fitted to the center of the shaft 10 (FIG. 5B). After that, the FR on the shaft
The P pipe was fixed using the retaining ring 30 and a two-part epoxy adhesive in combination (FIG. 5C). About the obtained composite FRP shaft, as a result of measuring the natural frequency of the bending primary using the hammering method while supporting both ends, at 200 Hz,
The bending stiffness level was sufficient even without using a dynamic damper as the drive shaft of an automobile.

Example 3 As shown in FIG. 4 (B), a cylindrical FRP pipe 26 with a slit 25 'formed by drawing at a bias angle of 10 ° (inner diameter 22 mm, wall thickness 2.0 mm, length 400 mm, slit width 1 mm) ) Was fitted to the center of a solid iron shaft 10 provided with an annular groove 18 serving as an adhesive pool (FIG. 5B). Thereafter, the FRP pipe 26 was fixed on the shaft 10 by using both the retaining ring 30 mounted on the retaining ring groove 16 of the shaft 10 and the two-component epoxy adhesive (FIG. 5).
(C)). For the obtained composite FRP shaft, the both ends were supported, and the bending primary natural frequency was measured using the hammering method. As a result, at 200 Hz, sufficient bending rigidity was obtained without using a dynamic damper as a drive shaft of an automobile. Level.

Example 4 As shown in FIG. 6 (B), a cylindrical F was previously drawn by a drawing method.
RP pipe (inner diameter 22mm, wall thickness 2.0mm, length 40
0 mm), and an FRP pipe 24 in which an annular groove 28 serving as an adhesive pool is provided on the inner peripheral surface by turning. The two-part epoxy adhesive was applied to the inner peripheral surface of the FRP pipe 24, fitted to the center of the solid iron shaft 10 (FIG. 6 (A)), and bonded and fixed. Composite F obtained
As for the RP shaft, the both ends were supported, and the bending primary natural frequency was measured using the hammering method.
At Hz, sufficient bending stiffness levels were achieved without using a dynamic damper as the drive shaft of the vehicle.

Example 5 As shown in FIG. 2 (A), using a solid iron shaft 10 as a mandrel, a prepreg 22 and an elastic modulus of 24 × 1,0 were used.
00 kgf / mm ² (235 GPa) PAN-based carbon fiber Pyrofil C prepreg TR350G200S, wound with a registered trademark of Mitsubishi Rayon Co., Ltd.
(Thickness: 2.0 mm, width: 400 mm) (FIG. 2)
(B)). With respect to the obtained composite FRP shaft, the both ends were supported and the natural frequency of the primary bending was measured by using the hammering method. As a result, the natural frequency was 200 Hz, which was sufficient bending without using a dynamic damper as a drive shaft of an automobile. Rigidity level.

COMPARATIVE EXAMPLE 1 Using a solid iron shaft 10 as a mandrel, a prepreg 22 ｛elastic modulus 24 × 1,000 kgf / mm ² (2
35GPa) PAN-based carbon fiber Pyrofil C prepreg TR350G8S, a registered trademark 三菱 of Mitsubishi Rayon Co., Ltd. wound and sheet-wrap molded to form a solid iron shaft 1
FRP layer 20 (wall thickness 8 μm, width 400 m)
m) was formed. With respect to the obtained composite FRP shaft, both ends were supported, and the natural frequency of the primary bending was measured by the hammering method. As a result, the frequency was 152 Hz, and the bending rigidity level was insufficient for a drive shaft of an automobile. It is considered that the cause is the insufficient thickness of the FRP layer 20.

[0036]

As is apparent from the above description, the power transmission shaft of the present invention has sufficient bending rigidity despite its light and compact structure, and has high reliability in terms of torsional strength and joint strength. Therefore, it can be suitably used as a power transmission shaft not only for automobile use but also for marine use, industrial machine use, aircraft use, etc., but especially when applied to a drive shaft of an automobile, a dynamic damper can be omitted. Therefore, a low-cost and low-cost drive shaft can be configured.

It is needless to say that a similar technique for increasing the rigidity of a shaft can be employed not only for a solid shaft but also for a hollow shaft. This method can also be applied to increasing the rigidity of an automotive propeller shaft (propulsion shaft).

[Brief description of the drawings]

FIG. It is a partially broken side view of a power transmission shaft.

FIG. 2A is a perspective view showing a prepreg sheet winding process. (B) is a partially broken side view of the power transmission shaft provided with the FRP layer by sheet wrap molding.

FIG. 3A is a partially cutaway side view of a power transmission shaft.
(B) is a perspective view of an FRP pipe, (C) is a perspective view of a retaining ring.

4A is a perspective view of an FRP pipe with an axial slit, and FIG. 4B is a perspective view of an FRP pipe with a slit with a bias angle. (C) is a side view of the FRP pipe with a slit, (D) is a cross-sectional view showing an assembled state,

FIG. 5 (A) is a partially broken side view of a metal shaft,
(B) is a partially broken side view which shows the state which fitted the FRP pipe. (C) is a partially broken side view in the state where the retaining ring was further attached.

FIG. 6A is a partially cutaway side view of a power transmission shaft,
(B) is a longitudinal sectional view of the FRP pipe.

FIG. 7A is a side view of a conventional steel power transmission shaft. (B) is a side view of the power transmission shaft with a dynamic damper.

[Explanation of symbols]

 10 Metal shaft 12 Joint joint  14 Joint joint 16 Annular groove 20 FRP layer 22 FRP prepreg sheet 24, 26 FRP pipe 25 Slit 28 Annular groove 30 Retaining ring D₁FRP pipe inner diameter (with slit) D_TwoMetal shaft outer diameter t FRP layer thickness W Slit width FL FRP layer length PL Metal shaft length

Claims (15)

[Claims] 1. An outer peripheral portion of a solid metal shaft has a thickness of 0.
A power transmission shaft provided with a fiber reinforced resin layer of not less than 01 mm and not more than 10 mm. 2. The value of FL / PL is 0.1 or more and 1.0 or less, where PL is the length of the metal shaft and FL is the length of the fiber reinforced resin layer in the axial direction. Item 1
A power transmission shaft according to item 1. 3. The power transmission shaft according to claim 1, wherein the tensile elastic modulus of the reinforcing fibers used in the fiber-reinforced resin layer is 20,000 kgf / mm ² or more. 4. The power transmission shaft according to claim 1, wherein the reinforcing fibers used for the fiber-reinforced resin layer are PAN-based carbon fibers having a wire diameter of 1 μm or more and 20 μm or less. 5. The drive shaft according to claim 1, wherein the reinforcing fibers used in the fiber-reinforced resin layer are mesoface pitch-based carbon fibers. 6. The power transmission shaft according to claim 1, wherein the fiber reinforced resin layer has a laminated structure of 20 layers or less. 7. The power transmission shaft according to claim 1, wherein the fiber reinforced resin layer is formed by a sheet wrap method. 8. The power transmission shaft according to claim 1, wherein a fiber-reinforced resin pipe formed thin by a drawing method is press-fitted into an outer peripheral portion of the metal shaft. 9. The power transmission shaft according to claim 8, wherein a slit cut from one end to the other end is provided in a peripheral wall of the pipe. 10. The width of the slit is 40% of the outer circumference of the pipe.
The drive shaft according to claim 9, wherein: 11. The power transmission shaft according to claim 9, wherein a bias angle of the slit with respect to the axial direction is within ± 30 °. 12. The value of D1 / D2 is 0.7 or more and 1.1 or less, where D1 is the inner diameter of the pipe and D2 is the outer diameter of the metal shaft.
A power transmission shaft according to any one of the above. 13. The power transmission shaft according to claim 8, wherein the pipe is fixed in an axial direction by a retaining ring mounted on a metal shaft. 14. A metal shaft is provided with a groove for forming a pool of adhesive on an outer peripheral surface thereof.
4. The power transmission shaft according to any one of 3. 15. The pipe according to claim 8, wherein a groove for forming an adhesive pool is provided on an inner peripheral surface of the pipe.
A power transmission shaft according to any one of the above.