JP3683711B2 - Traction grease composition and traction drive device - Google Patents

Description

【００３４】
【発明の効果】
以上説明したように、本発明のトラクショングリース組成物は、パーフルオロアルキルポリエーテル系オイルを含む基油、及び、ポリテトラフルオロエチレン系樹脂を含む増稠剤を含有しているので、高温における耐久性に優れ、良好にトラクションドライブ装置を駆動させることができる。
【００３５】
また、本発明のトラクションドライブ装置は、上記トラクショングリース組成物を用いているので、上記の極めて広い温度領域で駆動させることができる。また、低騒音、低振動であるとともに、高精度で回転の制御が可能なトラクションドライブ装置となり、高温にさらされる自動車パワーステアリング、エンジンを過給するスーパーチャージャー、オルタネーターの補機の駆動用等のトラクションドライブ装置に用いることができる。
【図面の簡単な説明】
【図１】トラクションドライブ機構の１種である遊星ローラ型トラクションドライブ装置を模式的に示した断面図であり、（ｂ）は（ａ）におけるＡ−Ａ線断面図である。
【図２】本発明のトラクションドライブ装置が用いられた電動パワーステアリングシステムの概要を示したブロック図である。
【図３】トラクションドライブ装置における本発明のグリース組成物の伝達トルクとすべり率の関係を示すグラフである。
【図４】本発明のグリース組成物単体での蒸発量と時間の関係を示すグラフである。
【符号の説明】
１０ 遊星ローラ型トラクションドライブ装置
１１ 固定軸
１２ 低速軸
１２ａ ピン
１３ 太陽軸
１４ 遊星ローラ
２６ トラクションドライブ装置[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a traction grease composition for a traction drive device excellent in durability at high temperatures and a traction drive device using the same.
[0002]
[Prior art]
The principle of rotating the other roller with the traction force by the shear force of the oil film by forming an oil film of lubricating oil that increases in viscosity under high pressure between a pair of rollers to which a pressure contact force is applied and driving one roller. The applied traction drive mechanism is used in various devices such as a continuously variable transmission, and there are many types.
[0003]
FIG. 1 is a cross-sectional view schematically showing a planetary roller type traction drive device using this traction drive mechanism, and (b) is a cross-sectional view taken along line AA in (a).
[0004]
The planetary roller type traction drive device 10 includes a fixed shaft 11 constituting a housing, a sun shaft 13 positioned at the axis of the fixed shaft 11, and a plurality of members interposed between the fixed shaft 11 and the sun shaft 13. A planetary roller 14, a low-speed shaft 12 coaxial with the fixed shaft 11, and a pin 12a provided on the end surface of the low-speed shaft 12 and supporting the planetary roller 14 are supported. Lubricating grease is contained inside the device. Filled.
[0005]
And, for example, when the sun shaft 13 is connected to the power source, the rotation at the power source is decelerated to a lower speed, the torque is amplified and transmitted to the low speed shaft 12, while the low speed shaft 12 is connected to the power source, The rotation at the power source is increased at a higher speed and transmitted to the sun shaft 13.
[0006]
The planetary roller type traction drive device 10 having such a configuration is 1) low noise, low vibration and smooth rotation, 2) high speed rotation compared to gears, and 3) almost no backlash and high accuracy. 4) Because it has excellent features such as low cost and compactness due to its simple structure, it is used for machine tools and other transmissions, for driving power steering of automobiles, etc. .
[0007]
Conventionally, in this type of traction drive device, a lubricating grease based on synthetic naphthene such as 2,4-dicyclohexyl-2-methylpentane, dibenzyltoluene hydride, alkylbenzene, or the like has been used.
[0008]
Since this traction drive device is always subjected to a pressure contact force, the temperature is likely to rise. In particular, when used in the engine room of an automobile, the temperature is, for example, around 120 ° C. due to the influence of the engine temperature. There is also.
[0009]
However, the lubricating grease based on synthetic naphthene or the like has a large amount of evaporation of the base oil at a temperature of 100 ° C. or higher, and the maximum operating temperature limit is about 100 ° C. In an environment exceeding 100 ° C. There was a problem that the use of was difficult.
[0010]
[Problems to be solved by the invention]
In view of the above, the present invention provides a traction grease composition having excellent durability in a wide temperature range up to a high temperature such as around 120 ° C. and exhibiting high traction force, and a traction drive device using this traction grease composition. It is intended to provide.
[0011]
[Means for Solving the Problems]
The traction grease composition of the present invention is a traction grease composition used for a planetary roller type traction drive device containing a base oil and a thickener, and the base oil contains a perfluoroalkyl polyether oil. are those, the thickener is state, and are those containing polytetrafluoroethylene resin, the perfluoroalkyl polyether oils, those having a -CF _(CF 3) CF 2 _O- structure therein it is characterized in that.
[0012]
A traction drive device according to the present invention is characterized by using the traction grease composition.
The present invention is described in detail below.
[0013]
The traction grease composition of the present invention is a traction grease composition used for a planetary roller type traction drive device containing a base oil and a thickener. The planetary roller type traction drive device in which the traction grease composition is used usually has the configuration shown in FIG. 1, but its type is not particularly limited, and is of other types. Also good. The planetary roller type traction drive device will be described in detail later.
[0014]
The base oil is an oil constituting the main component of the traction grease composition, and includes perfluoroalkyl polyether (hereinafter referred to as “PFAE”) oil.
A PFAE oil is an alkyl compound represented by R—O—R ′ in which two hydrocarbon residues are bonded to an oxygen atom, and is an oily compound in which all terminal groups in the compound are replaced with fluorine. Say.
[0015]
The above PFAE oil has excellent properties such as low vapor pressure and heat resistance, and there are oils having various viscosities and molecular weights. However, in the present invention, the PFAE oil is used for a traction drive device. From such a viewpoint, the kinematic viscosity at 40 ° C. is preferably 50 to ²⁰⁰ mm ² / s.
[0016]
When the kinematic viscosity is less than 50 mm ² / s, the kinematic viscosity is too small. Therefore, even if a thickener is added, the power transmission capability, that is, the traction force is low, whereas when the kinematic viscosity exceeds 200 mm ² / s, Since the kinematic viscosity is too large, the planetary roller type traction drive device is difficult to rotate smoothly.
[0017]
The PFAE oil is not particularly limited. For example, C ₃ F ₇ O (CF ₂ CF ₂ CF ₂ O) _a C ₂ F ₅ , F (CF (CF ₃ ) CF ₂ O) _b C ₂ F ₅ , C ₃ F ₇ O (CF (CF ₃ ) CF ₂ O) _c C ₂ F ₅ , CF ₃ O (CF ₂ CF ₂ O) _d (CF ₂ O) _e CF ₃ , C ₃ F ₇ O (CF (CF _{3) CF 2 O) f (} CF 2 O) g CF 3 and the like. The molecular weight of these PFAE oils is preferably within the above kinematic viscosity range.
[0018]
Among the PFAE oils described above, in particular, F (CF (CF ₃ ) CF ₂ O) _b C ₂ F ₅ , C ₃ F ₇ O having a —CF (CF ₃ ) CF ₂ O— structure inside. _{(CF (CF 3) CF 2} O) c C 2 F 5, C 3 F 7 O (CF (CF 3) CF 2 O) f (CF 2 O) g CF 3 and the like are preferable.
[0019]
The thickener is added to increase the kinematic viscosity of the traction grease composition and increase its traction force, and includes a polytetrafluoroethylene (hereinafter referred to as “PTFE”) resin.
The PTFE resin is a polymer of tetrafluoroethylene, and its molecular weight is preferably 10,000 to 100,000.
Further, the content of the PTFE resin in the traction grease composition is preferably such that the consistency of the traction grease composition is about 2 in the 265 to 295 (NLGI) grade when the consistency is 60 times.
NLGI is National Lubricating Grease Institute (American Grease Association).
[0020]
In the traction grease composition, an extreme pressure agent such as molybdenum disulfide and graphite; a rust preventive agent such as sodium sulfite; a derivative of PFAE, such as an acid group such as carboxylic acid and sulfonic acid, a phosphate ester, etc. An additive having an ester group or the like may be contained.
[0021]
The traction grease composition is composed mainly of PFAE oil and PTFE resin, which are perfluoro compounds, and its kinematic viscosity is adjusted by the addition of PTFE resin, so it was used in a traction drive device. In this case, it exhibits high traction, and exhibits excellent oxidative stability, thermal stability and nonflammability, and is extremely stable chemically and inert, and therefore exhibits excellent durability.
[0022]
Further, by using the traction grease composition, the traction drive device can be driven well in an extremely high temperature range, for example, around 120 ° C.
Therefore, it is possible to provide a traction drive device that can control rotation with high accuracy while having low noise and vibration.
[0023]
The traction drive device of the present invention using the traction grease composition is not particularly limited. For example, a traction drive device for driving a power steering for an automobile, a supercharger for supercharging an engine of an automobile, etc. Examples thereof include a traction drive device for driving, a traction drive device for driving auxiliary machines such as an air conditioner compressor and an alternator in an engine room of an automobile or the like.
[0024]
FIG. 2 is a block diagram showing an outline of an electric power steering system in which the traction drive device of the present invention is used.
This electric power steering system includes a torque sensor 21, a vehicle speed sensor 22, a control unit 23, a motor 24, a clutch 25, a traction drive device 26, and the like.
[0025]
In this electric power steering system, first, when the steering wheel 28 is operated, the torque sensor 21 senses the operation torque and transmits a torque signal to the control unit 23. The control unit 23 receives this torque signal and controls the current to the motor 24 in accordance with the vehicle speed signal transmitted from the vehicle speed sensor 22. The torque of the motor 24 driven by this control current is transmitted to the sun shaft of the traction drive device 26 through the clutch 25, and the torque is amplified by being sufficiently decelerated by the traction drive device 26, so that the low-speed shaft is driven. And transmitted to the pinion shaft 27. When the pinion shaft 27 is driven, the rack 29 moves and the direction of the tire is changed.
[0026]
The traction drive device 26 of the present invention used in the electric power steering system is configured in the same manner as the conventional device shown in FIG. 1 except that the traction grease composition is used. Yes.
[0027]
In a supercharger that supercharges an engine such as an automobile as described above, the rotation of the engine transmitted from the engine via a belt is accelerated at high speed by the traction drive device of the present invention and transmitted to the impeller, and compressed by the impeller. The high-pressure air thus supplied is supplied from the discharge port to the engine cylinder or the like. This supercharger is different from the electric power steering system in that the low speed shaft of the traction drive device is connected to the engine side in order to increase the rotation of the engine at high speed.
[0028]
Further, in an engine room of an automobile or the like, the traction drive device of the present invention is interposed between the engine and an auxiliary machine such as an air conditioner compressor or an alternator, and the rotation transmitted from the engine via a belt or the like. The speed is changed and transmitted to the auxiliary machine.
[0029]
In any of the above traction drive devices, the inside of the traction drive device is likely to have a high temperature and may exceed 120 ° C. In the present invention, the traction grease composition containing PFAE oil and PTFE resin is used. Since it is used, the traction drive device can be driven well in an extremely wide temperature range of −40 to 150 ° C. In addition, the traction drive device has low noise and low vibration and can control rotation with high accuracy.
[0030]
【Example】
EXAMPLES Hereinafter, the present invention will be described in detail with reference to examples, but the present invention is not limited only to these examples.
[0031]
As the traction grease composition for the planetary roller type traction drive device shown in FIG. 1, the following composition is used, the relationship between the slip ratio and the transmission torque (FIG. 3), and the evaporation amount by the grease composition alone. The performance was investigated from the relationship with the test time (FIG. 4).
[0032]
Table 1 shows examples and comparative examples. In the traction grease composition of Example 1, a PFAE oil having a F (CF (CF ₃ ) CF ₂ O) _b C ₂ F ₅ structure and a 40 ° C. kinematic viscosity of 60 mm ² / s is used as a base oil. As a thickener, PTFE was added, and the 60-th blending consistency was 280 (NLGI) grade 2 composition. The traction grease composition of Example 2 had F (CF (CF ₃ ) as the base oil. PFAE oil having a CF ₂ O) _b C ₂ F ₅ structure and a kinematic viscosity of 40 ° C. of 160 mm ² / s was used, and PTFE was added as a thickener. The composition of 2.
[0033]
[Table 1]

[0034]
【The invention's effect】
As described above, the traction grease composition of the present invention contains a base oil containing a perfluoroalkyl polyether-based oil and a thickener containing a polytetrafluoroethylene-based resin. The traction drive device can be driven well with excellent performance.
[0035]
Further, since the traction drive device of the present invention uses the traction grease composition, it can be driven in the extremely wide temperature range. In addition, it is a low-noise, low-vibration traction drive device that can control rotation with high precision, such as automotive power steering exposed to high temperatures, superchargers that supercharge engines, and alternator auxiliary drives It can be used for a traction drive device.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view schematically showing a planetary roller type traction drive device which is a kind of traction drive mechanism, and FIG. 1 (b) is a cross-sectional view taken along line AA in FIG.
FIG. 2 is a block diagram showing an outline of an electric power steering system in which the traction drive device of the present invention is used.
FIG. 3 is a graph showing the relationship between the transmission torque and the slip ratio of the grease composition of the present invention in a traction drive device.
FIG. 4 is a graph showing the relationship between the amount of evaporation and time for a single grease composition of the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 Planetary roller type traction drive device 11 Fixed shaft 12 Low speed shaft 12a Pin 13 Sun shaft 14 Planetary roller 26 Traction drive device

Claims (3)

A trunkion grease composition for use in a planetary roller type trunkion drive device comprising a base oil and a thickener,
The base oil contains perfluoroalkyl polyether oil,
The thickener is state, and are those containing polytetrafluoroethylene resin,
The perfluoroalkyl polyether-based oil has a —CF (CF ₃ ) CF ₂ O— structure inside . The traction grease composition according to claim 1, wherein the perfluoroalkyl polyether oil has a kinematic viscosity at 40 ° C. of 50 to ²⁰⁰ mm ² / s.   A traction drive device using the traction grease composition according to claim 1 or 2.

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