WO2005078053A1

WO2005078053A1 - Grease composition for use in constant velocity joint for steering and constant velocity joint for steering

Info

Publication number: WO2005078053A1
Application number: PCT/JP2005/002304
Authority: WO
Inventors: Takashi Takizawa; Takashi Okaniwa; Kenta Yamazaki; Minoru Ishijima
Original assignee: Kyodo Yushi Co., Ltd.; Ntn Corporation
Priority date: 2004-02-16
Filing date: 2005-02-16
Publication date: 2005-08-25
Also published as: JP2005226038A

Abstract

A grease composition for use in a constant velocity joint for a steering which comprises (a) a base oil including a synthetic oil, (b) a thickener, (c) at least one molybdenum compound selected from the group consisting of a sulfurized molybdenum dialkyldithiocarbamate, a sulfurized molybdenum dialkyldithiophosphate, a sulfurized molybdenum diaryldithiocarbamate, a sulfurized molybdenum diaryldithiophosphate and molybdenum disulfide and (d) zinc dithiophosphate, and optionally (e) a fatty acid amide; and a constant velocity joint for a steering having the grease composition therein. The above grease composition reduces a rotary torque of a constant velocity joint for a steering in the start at a low temperature and also reduces the obstruction in bending, which results in the high rotating durability thereof.

Description

Specification

Grease composition for constant velocity joint for steering and constant velocity joint for steering

Technical field

The present invention relates to a grease composition for a constant velocity joint for steering (hereinafter also referred to as “CVJ”) and a constant velocity joint for steering enclosing the same.

Background art

[0002] Steering of an automobile is performed by transmitting rotational torque of a steering wheel to a steering gear and wheels via a steering joint. Since the steering joint is connected to the steering directly operated by the driver, it is particularly desirable that the operating torque be small and the low-temperature operation be excellent.

Conventionally, a universal joint, which is a cross joint, has been used as a steering joint. However, when the mounting angle is increased, constant speed is lost, and there is a problem that the mountability is restricted. To solve these problems, an attempt was made to apply a constant velocity joint used for a drive shaft to a steering joint. For example, a steering device described in Patent Document 1 can be cited.

[0003] Specifically, as shown in FIG. 1, for example, when the pressing portion 11 is provided on the inner member 6 and the receiving portion 15 is provided on the retainer 4, the elasticity of the pressing portion 11 and the receiving portion 15 is provided. The axial contact causes relative movement between the retainer 4 and the inner ring 2 due to the abutment. Due to this relative movement, the ball 3 is pushed in the direction in which the ball track is reduced via the retainer 4, so that the axial gap between the tracks is reduced, and the occurrence of rotational backlash is prevented. On the other hand, when the pressing portion 11 is provided on the retainer 4 and the receiving portion 15 is provided on the inner member 6, the ball 3 is similarly pushed in the direction in which the ball tracks are reduced, and as a result, the axial gap between the tracks is reduced. To prevent rotational backlash. The inner member 6 includes the inner ring 2 and the shaft 5.

As is evident from the above, it is necessary to apply a natural pressing force so that the ball is pushed into the reduction side of the ball track.コ As a means of generating sexual pressing force, A panel member such as a coil spring, a wave spring, a disc spring, or the like, or an elastic member having an elastic material force such as resin or rubber can be considered.

[0004] In general, in a fixed type constant velocity universal joint, a minute spherical gap is formed between the inner ring and the retainer and between the outer ring and the retainer for processing and functional reasons. If the axial gap formed by the spherical gap between the inner ring and the cage is smaller than the axial gap between the tracks, the inner ring and the cage abut before the axial gap between the tracks is completely filled. Therefore, there is a limit in further reducing the axial gap between tracks. Therefore, it is desirable that the axial clearance between the inner ring and the retainer is larger than the axial clearance between the tracks.

[0005] One of the pressing portion 11 and the receiving portion 15 provided on the retainer 4 (for example, the receiving portion 15 in FIG. 1) is desirably formed in a concave spherical shape having a larger diameter than the spherical outer surface 2b of the inner ring 2. . Accordingly, even when the operating angle is set, it is possible to prevent one of the holders 4 from contacting and interfering with the spherical outer surface 2b of the inner race 2, thereby enabling a smooth angular displacement.

If the other of the pressing portion 11 and the receiving portion 15 provided on the inner member 6 (the pressing portion 11 in the above example) is formed in a convex spherical shape having a smaller diameter than the one, the pressing portion 11 and the receiving portion 15 are formed. The sliding can be performed smoothly, and the displacement of the operating angle can be easily performed.

From the above, the fixed type constant velocity universal joints of the above-mentioned type, which are either of the above-mentioned types, such as a tweeper type or an undercut-free type, do not cause a rotational backlash. It is also suitable for applications that dislike rotating backlash.

[0006] If the fixed type constant velocity universal joint is used for a steering device, there is no rotational backlash! Therefore, a good steering feeling can be obtained, and vibration during traveling can be reduced. I have. As a conventional constant velocity joint lubricant disclosed in such a patent document, there has been proposed a constant velocity joint dulce composition containing a mineral oil as a base oil and a molybdenum compound as an additive (for example, Patent Reference 2). In the case of constant velocity joints used in drive shafts, the rotation durability is sufficient, but because they are caught during bending or because a relatively large amount of grease is sealed for internal lubrication. When the joint angle is set, the internal grease becomes unbalanced. Since the grease solidified as it was, it became a resistance at low temperature startup, and there was a drawback that the rotating torque increased significantly.

[0007] Patent Document 1: JP 2003-130082

Patent Document 2: JP 2001-11481

Disclosure of the invention

Problems to be solved by the invention

[0008] Accordingly, an object of the present invention is to reduce the low-temperature starting rotational torque of a constant velocity joint for steering, and to reduce the hooking force at the time of bending and to achieve high rotational durability while achieving a constant velocity joint for steering. Is to provide a grease composition.

Another object of the present invention is to provide a constant velocity joint for steering in which the grease composition for constant velocity joint for steering is sealed.

Means for solving the problem

[0009] The present invention provides the following grease thread for a constant velocity joint for steering and a constant velocity joint for steering.

1. A grease yarn for a constant velocity joint for steering, comprising the following components (a) to (d):

(a) a base oil containing a synthetic oil,

(b) a thickening agent,

(c) Molybdenum sulfide dialkyldithiol molybdenum, molybdenum dialkyldithiophosphate, molybdenum diaryldithiol molybdenum rubinate, molybdenum dialkyldithiolate molybdenum diphosphate, and molybdenum disulfide diaryldithiophosphate At least one molybdenum compound selected, and

(d) Zinc dithiophosphate.

2. The grease composition for a constant velocity joint for steering according to the above item 1, further comprising component (e) a fatty acid amide.

3. The dusty composition for a constant velocity joint for steering according to 1 or 2 above, wherein the base oil contains mineral oil.

4. The Darris yarn composition for a constant velocity joint for steering according to any one of the above items 1 to 3, wherein the synthetic oil is a synthetic hydrocarbon oil. 5. The grease composition for a constant velocity joint for a steering according to any one of the above items 1 to 4, wherein the component (c) is a dialkyldithiosulfide molybdenum rubinate.

6. The darryse composition for a constant velocity joint for steering according to any one of the above items 15 to 15, wherein the component (b) is a urea thickening agent.

7. The grease composition for a constant velocity joint for steering according to any one of the above items 1 to 6, wherein the content of the component (c) is 0.1 to 10% by mass relative to the total mass of the grease composition.

8. Content force of component (d) The darrying composition for a constant velocity joint for steering according to any one of the above items 1 to 7, which is 0.1 to 10% by mass relative to the total mass of the grease composition.

9. The grease composition for a constant velocity joint for steering according to any one of the above 2-8, wherein the content of component (e) is 0.1 to 10% by mass relative to the total mass of the grease composition.

10. A constant velocity joint for steering, wherein the darryse composition according to 1 or 9 above is enclosed.

The invention's effect

[0010] The grease composition of the present invention can reduce the low-temperature start-up rotational torque of a constant velocity joint for steering, and at the same time, can reduce both the hooking force at the time of bending and high rotational durability.

BEST MODE FOR CARRYING OUT THE INVENTION

[0011] The base oil of component (a) used in the grease composition of the present invention contains a synthetic oil. Synthetic oils include ester-based synthetic oils such as diesters and polyol esters, synthetic hydrocarbon oils such as poly-α-olefin and polybutene, and ether-based synthetic oils such as alkyl diphenyl ether and polypropylene glycol. Various synthetic oils such as oil, silicone oil, and fluorinated oil can be used, but synthetic hydrocarbon oil is most preferable. The content of the synthetic oil in the base oil of the present invention is preferably 100 to 30% by mass, and more preferably 100 to 40% by mass. If it is less than 30% by mass, the low-temperature property tends to deteriorate.

The base oil of the present invention may be composed only of a synthetic oil, or may contain a mineral oil. In the base oil of the present invention, the content of the mineral oil is preferably 70% by mass or less, more preferably 60% by mass or less. If it exceeds 70% by mass, the low-temperature property tends to be poor.

[0012] The agent for increasing the component (b) used in the grease composition of the present invention is not particularly limited. For example, preferable examples include soap-based thickeners such as Li soap and complex Li soap, urea-based thickeners such as diurea, and inorganic thickeners such as organic clay and silica. And an organic thickening agent represented by PTFE. Particularly preferred are urea thickeners. Urea-based thickeners are relatively inexpensive with few disadvantages compared to other thickeners, and are highly practical.

[0013] Examples of the urea thickening agent used in the present invention include a diurea compound and a polyurea compound.

The diurea compound is obtained, for example, by reacting a diisocyanate with a monoamine. Examples of diisocyanates include phenylene diisocyanate, diphenyl diisocyanate, phenyl diisocyanate, diphenyl methane diisocyanate, otaca decane diisocyanate, decane diisocyanate, and hexane. Sandiisocyanate and the like, and monoamines include octylamine, dodecylamine, hexadecylamine, octadecylamine, oleylamine, a-line, p-toluidine, cyclohexylamine and the like.

The polyurea compound is obtained, for example, by reacting diisocyanate with diamine. Examples of the diisocyanate include the same ones as used for the production of the diurea compound. Examples of the diamine include ethylenediamine, propanediamine, butanediamine, hexanediamine, octanediamine, phenylenediamine, tolylenediamine, xylenediamine and the like.

[0014] Particularly preferred! / The urea thickening agent is an aliphatic amine such as octylamine, dodecylamine, hexadecylamine, octadecylamine, or oleylamine, cyclohexylamine, or a mixture thereof, A diurea compound obtained by a reaction with an isocyanate compound, particularly an aromatic diisocyanate compound, having an aryl group in the diurea compound or having seven carbon atoms and having an aryl group in the diurea compound. A cyclohexyl group having a ratio of 100 to 0% is preferable.

The content of the thickener in the grease composition of the present invention varies depending on the type of the thickener. The consistency of the grease composition of the present invention is preferably 200 to 400 force S, and the content of the thickening agent is an amount necessary for obtaining this consistency. In the grease composition of the present invention, the content of the thickening agent is usually 2 to 30% by mass, preferably 3 to 20% by mass. [0015] The molybdenum conjugate of the component (c) used in the grease composition of the present invention includes a molybdenum sulphide dialkyldithio-potassium molybdenum, a molybdenum dialkyldithiophosphate, and a diaryldithiocarno sulfide. Molybdenum silicate, molybdenum disulfide dimolybdate, and molybdenum disulfide molybdenum power are at least one selected from the group consisting of molybdenum phosphate and molybdenum disulfide.

Preferable examples of the sulfidani dialkyldithiophosphate and the molybdenum diaryldithiophosphate include those represented by the following formulas.

[0016] [Formula 1]

[0017] (where,

R ³ and R ⁴ each independently represent an alkyl group having 1 to 24 carbon atoms, preferably 3 to 20 carbon atoms, or an aryl group having 6 to 30 carbon atoms, preferably 8 to 18 carbon atoms. Preferred examples of the dialkyldithiol molybdenum rubinate are those represented by the following formula.

[0018] [Formula 2]

(Wherein, R ⁵ and R ⁶ each independently represent an alkyl group having 1 to 24 carbon atoms, preferably 3 to 18 carbon atoms, m is 0 to 3, n is 4 to 1, m + n = 4.)

A preferred molybdenum compound as the component (c) of the grease composition of the present invention is dialkyldithio sulfide molybdenum rubinate, and particularly preferred are those represented by the above formula. Dialkyldithiol molybdenum rubinate.

The amounts of the components of the grease composition (c) of the present invention is preferably 0.5 1 10 mass ^_0/0, more preferably 0.5 1 5 wt%. If the amount is less than 0.1% by mass, the effect is insufficient, and if it exceeds 10% by mass, no further improvement in the effect is observed.

[0020] Component (d) of the grease composition of the present invention is zinc dithiophosphate such as zinc diaryldithiophosphate, zinc dialkyldithiophosphate.

The amounts of the components of the grease composition (d) of the present invention is preferably 0.5 1 10 mass ^_0/0, more preferably 0.5 1 5 wt%. If the amount is less than 0.1% by mass, the effect is insufficient, and if it exceeds 10% by mass, no further improvement in the effect is observed.

[0021] The grease composition of the present invention preferably further contains a fatty acid amide as the component (e). Fatty acid amide is adsorbed on the metal surface to prevent contact between metals and reduce friction.

Examples of fatty acid amides are monoamides represented by R ⁷ — CONH, R ⁸ CONH— R ⁹ — NH

2

CO—R ^1Q is a bisamide. Where

R ⁸ and R ^1Q represent an alkyl group having 1 to ²⁴ carbon atoms, preferably 8 to 18 carbon atoms, and R ⁹ represents an alkylene group having 1 to 18 carbon atoms. Monoamides are more preferred.

The amounts of the components of the grease composition (e) of the present invention is preferably 0.5 1 10 mass ^_0/0, more preferably 0.5 1 5 wt%. If the amount is less than 0.1% by mass, the effect is insufficient, and if it exceeds 10% by mass, no further improvement in the effect is observed.

[0022] The grease composition for a constant velocity joint of the present invention is preferably the base oil of the component (a): 50 to 97.8% by mass, and the component (b) increased with respect to the total mass of the grease composition. Deodorant: 2-30% by mass, molybdenum compound of component (c): 0.1-10% by mass, and zinc dithiophosphate of component (d): 0.1-110% by mass.

The grease composition for a constant velocity joint of the present invention is more preferably 40 to 97.7% by mass of the base oil of the component (a), and the component (b) increases, based on the total mass of the grease composition. agent: 2-30 weight ^_0/0, (c) component of the molybdenum compound: 0. 1-10 wt%, (d) component of Jichiorin zinc: 0.1 one 10 wt%, and component (e) Fatty acid amide: contains 0.1-10% by mass.

[0023] The grease composition for a constant velocity joint of the present invention is more preferably a base oil of component (a): 70 to 96.8% by mass, and a component (b) based on the total mass of the grease composition. Urea thickener: 3 20 wt%, (c) component of molybdenum Chio carbamate: 0. 1 5% by weight, and component (d) Jichiorin zinc: contains 0.1 one 5 mass ^_0/0, Ru.

The grease composition for a constant velocity joint of the present invention is more preferably 65 to 96.7% by mass of the base oil of the component (a) and the urea-based component of the component (b), based on the total mass of the grease composition. Detergent: 3-20% by mass, molybdenum dithiocarbamate of component (c): 0.1-5% by mass, zinc dithiophosphate of component (d): 0.1-5% by mass, and component (e) Fatty acid amide: contains 0.1-5% by mass.

[0024] Various additives can be added to the grease composition of the present invention as needed.

Examples of such additives include an antioxidant, a deterrent, a metal corrosion inhibitor, an oil agent, an antiwear agent, an extreme pressure agent, and a solid lubricant.

The grease composition of the present invention can be easily produced by mixing the above components and other additives at a desired mixing ratio.

[0025] The grease composition of the present invention is sealed in various constant velocity joints for steering to reduce the low-temperature starting rotational torque of the constant velocity joint for steering, to reduce the hooking force at the time of bending, and to increase the rotation. Durability can be compatible.

Example

[Examples 1-4, Comparative Examples 1-1 5]

460 g of base oil and 38.7 g of diphenylmethane 4,4'-diisocyanate were placed in a container, and the mixture was heated to 70 to 80 ° C. In a separate container, 460 g of base oil, 24.6 g of cyclohexylamine and 16.7 g of stearylamine were heated to 70-80 ° C, added to the previous container, and allowed to react for 30 minutes while stirring well. . Thereafter, while stirring, the temperature was raised to 160 ° C., and after standing to cool, a base-less grease was obtained. Additives were added to this base grease according to the formulation shown in Table 1, and an appropriate base oil was added. The resulting mixture was adjusted to a consistency No. 1 grade using a three-stage roll mill.

With these greases, using the apparatus shown in FIG. 4, physical properties were evaluated by the following test methods.

Set the constant velocity joint containing the test sample (grease sample) in the low temperature bath (-40 ° C) After leaving it at the set temperature (140 ° C) for 5 hours or more, it is driven to rotate by a motor, the drive torque is detected by a torque meter, and this value is used as the low-temperature operating torque. Table 1 shows the relative values when the low-temperature operating torque value of Comparative Example 1 is set to 100.

[0028] <Bending torque>

Set the constant velocity joint containing the test sample (grease sample) at room temperature, detect the torque when the shaft is bent in the direction of the operating angle in a non-rotating state, and use this value as the bending torque. Table 1 shows relative values when the bending torque value of Comparative Example 1 is set to 100.

[0029] [Table 1]

[0030] MoDTC: trade name Molyvan A, manufactured by R.T.Vanderbilt

MoS: trade name Molysulfide, manufactured by Climax Molybdenum, average particle size 0.45 μm

2

ZnDTP: brand name Lubrizol 1360, manufactured by Lubrizol Japan

Fatty acid amide: trade name Aramide HT powder, manufactured by Lion Axo

[0031] The composition containing the components (a)-(d) and the composition further containing the component (e) are different from the grease composition for a constant velocity joint for steering, in which both the low-temperature operating torque and the bending torque are low. I'm good! /

On the other hand, in Comparative Example 1 containing no synthetic oil, the low-temperature operating torque and the bending torque were high, and Comparative Examples 2 and 5 containing no component (d), zinc dithiophosphate, and Comparative Example 1 containing no component (c) were used. In Examples 3 and 4, it can be seen that the grease composition for a constant velocity joint for steering, which has a high bending torque, has sufficient characteristics.

Brief Description of Drawings

[FIG. 1] Implementation of a fixed type constant velocity universal joint in which a pressing portion is provided on an inner member and a receiving portion is provided on a retainer. It is sectional drawing which shows a form.

FIG. 2 is an enlarged cross-sectional view near a shaft end in the embodiment of FIG. 1.

FIG. 3 is an enlarged sectional view of a main part in the embodiment of FIG. 1.

FIG. 4 is a drawing schematically showing an apparatus for measuring low-temperature operating torque. Explanation of symbols

1 Outer member (outer ring)

la track groove

lal straight 咅

lb spherical inner surface

2 Inner ring

2a track groove

2a 1 straight 咅

2b spherical outer surface

3 ball

4 cage

4a ket

4b outer peripheral surface

4c inner circumference

5 shaft

6 Inner member

10Pressing member

11Pressing part

12 elastic members

14 receiving member

15 receiving part

O fitting center

Ol outer wheel truck center

02Inner track center

Claims

The scope of the claims

[1] A grease yarn for a constant velocity joint for steering, comprising the following components (a) to (d):

(a) a base oil containing a synthetic oil,

(b) a thickening agent,

(c) Molybdenum sulfide dialkyldithiol molybdenum sulfide, molybdenum dialkyldithiophosphate, molybdenum diaryldithiol molybdenum rubinate, molybdenum dialkyldithiol molybdenum diphosphate, and molybdenum diyldithiolate molybdenum diphosphate At least one molybdenum compound selected, and

(d) Zinc dithiophosphate.

[2] The grease composition for a constant velocity joint for steering according to claim 1, further comprising component (e) a fatty acid amide.

3. The grease composition for a constant velocity joint for steering according to claim 1, wherein the base oil contains mineral oil.

[4] The Darris yarn composition for a constant velocity joint for steering according to any one of claims 13 to 13, wherein the synthetic oil is a synthetic hydrocarbon oil.

[5] The grease composition for a constant velocity joint for steering according to [14], wherein the component (c) is a dialkyldithiol molybdenum rubamate.

[6] The dullice composition for a constant velocity joint for steering according to any one of [15] to [15], wherein the component (b) is an urea thickening agent.

[7] The constant velocity joint for steering according to any one of [16] to [16], wherein the content of the component (c) is 0.1 to 10% by mass based on the total mass of the grease thread and the product. Grease composition.

[8] The constant velocity joint for steering according to any one of [1] to [7], wherein the content of the component (d) is 0.1 to 10% by mass relative to the total mass of the grease composition. Darryce composition.

[9] The grease composition for a constant velocity joint for steering according to any one of claims 2 to 8, wherein the content force of the component (e) is 0.1 to 10% by mass based on the total mass of the grease composition. .

[10] A constant velocity joint for steering, wherein the grease composition according to any one of claims 11 to 9 is enclosed.