JPH0339627Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] This invention relates to a power transmission device with improved lubricity.

[Prior Art] Generally, a so-called viscous coupling device used as a power transmission device has a plurality of resistance plates engaged with each of the case side and the shaft side within a viscous fluid such as silicone oil sealed in the case. When a plurality of resistance plates that rotate together with the case and shaft attempt to cause relative rotation, power is transmitted by the viscous resistance of viscous fluid (see, for example, Japanese Patent Laid-Open No. 58-50349).

[Problems that the invention is intended to solve] By the way, in conventional coupling devices, the resistance plate on the shaft side is directly engaged with the shaft, and this shaft passes through the boss portion of the coupling case to the outside of the case. The space between the shaft and the boss of the case is sealed with an O-ring or the like. Therefore, when relative rotation occurs between the case side and the shaft during overload, the boss part of the case and the shaft slide, but inside the case beyond the seal, silicone oil, etc., which does not have a lubricating function, is It is interposed between the boss and the shaft, and lubrication between the two cannot be expected. Furthermore, since the space between the boss and the shaft on the outside of the case outside the seal becomes a bag due to the presence of the seal, sufficient lubricating oil cannot be expected to enter and exit, and lubrication between the two cannot be expected to be very good. For this reason, when the above-mentioned relative rotation occurs, seizure is likely to occur between the boss portion of the case and the shaft, resulting in a problem that durability is impaired.

This invention was devised in view of the above problems, and its purpose is to provide a viscous coupling device that can improve lubricity and improve durability.

[Means for Solving the Problems] In order to achieve the above object, the present invention provides a case that is provided with a relatively rotatable hub at the axial center and defines a sealed chamber containing a viscous fluid; a group of resistance plates arranged alternately in the room, one of which engages the case and the other of which engages the hub in a rotational direction; In a power transmission device consisting of a rotating shaft inserted into a core and rotationally engaged with the hub, a lubricant provided at one end of the case and communicating with one fitting part of the rotating shaft. an oil introduction path, and a fitting portion on the other end of the case and on the other side of the rotation shaft in order to discharge the lubricating oil introduced from the lubricant introduction path through the space between the case and the rotation shaft; and a lubricating oil discharge passage provided to communicate with the
The discharge port of this lubricating oil discharge path is located radially outward from the inlet of the lubricating oil introducing path.

[Function] Since the lubricating oil outlet is located radially outward than the inlet, the lubricating oil is discharged from the inlet due to the difference in centrifugal force acting on the outlet and the inlet. This flow creates a cycle in which new lubricating oil is introduced from the inlet and the lubricating oil flowing toward the outlet is discharged from the outlet.

[Embodiment] An embodiment of this invention will be described below based on the accompanying drawings.

Fig. 1 is a cross-sectional view of a so-called viscous coupling device according to an embodiment of the power transmission device of this invention, and Fig. 2 is a cross-sectional view taken along the line A-A in Fig. 1. In the figure, 1 and 3 are respectively A case 5 is provided on the outer periphery of the rotating shafts 1 and 3, which are a pair of rotating shafts that are arranged facing each other on the same center line, so as to surround them. This case 5 is a cylindrical member 7
and end plate members 9 and 11 connected to both ends of the cylindrical member 7.

A pair of hub members 13 and 15 are spline-engaged with the outer peripheries of the ends of the rotating shafts 1 and 3 facing into the case 5, respectively. Closed working chambers S ₁ and S ₂ are formed, and these working chambers
A viscous fluid such as silicone oil is sealed inside S ₁ and S ₂ . In FIG. 1, reference numeral 19 indicates a stopper ring 2 for positioning the rotating shafts 1 and 3 in the axial direction.
1... is a sealing member.

In the working chambers S ₁ and S ₂ , the case 5
A plurality of resistance plates 23 are spline-engaged to the inner periphery of the hub members 13 and 1 at appropriate intervals in the axial direction.
A plurality of resistance plates 25, which are also spline-engaged at appropriate intervals, are alternately arranged on the outer periphery of the resistance plate 5 to form a resistance plate group.

By the way, the end plate member 1 on one end side of the case 5
1, a plurality (three in the illustrated example) of lubricating oil introduction passages 27 are bored at equal angular pitches and communicate with the outer periphery of the rotating shaft 3, which is the outer periphery of one side of the rotating shaft, as shown in FIG. The inlet 27 of each of these inlet passages 27
A guide vane 29 is formed near point a and is curved toward the front in the rotational direction. Furthermore, a plurality of lubricating oil discharge passages 31 in the rotational radial direction are bored in the end plate member 9 on the other end side of the case 5, which communicate with the outer circumferential portion of the rotating shaft 1, which is the outer circumferential portion on the other side of the rotating shaft. . As shown in the figure, the radial position r ₁ of the discharge port 31a of these discharge passages 31 with respect to the center of rotation is set to be larger than the radial position r ₂ of the inlet port 27a (r ₁ >r ₂ ).

For example, the rotational input from the case 5 is transmitted to both the rotating shafts 1 and 3 via the resistance plate 23, the shear resistance of the viscous fluid, and the resistance plate 25.

When the case 5 is rotated in the above manner, the end plate members 9 and 11 of the case 5 are connected to the inlet passage 27 and the discharge passage 3.
The lubricating oil that has entered 1 tends to flow outward in the radial direction due to centrifugal action.

By the way, since the radial position r ₁ of the discharge port 31a is made larger than the radial position r ₂ of the inlet 27a as described above, the outflow force of the lubricating oil flowing in the radial direction inside the discharge port 31a is greater, and as a result, , the lubricating oil around the coupling device causes the guide vanes 29
The oil is introduced into the end plate member 11 from the inlet 27a, and the oil is guided by the rotating shaft 3 and the end plate member 11.
The lubricating oil is discharged through the spline engagement portion between the rotation shaft 3 and the hub member 15, the spline engagement portion between the rotation shaft 1 and the hub member 13, and between the rotation shaft 1 and the end plate member 9. It is discharged from the passage 31 through the same discharge port 31a, forming a lubricating oil cycle. Therefore, even when an overload acts on the rotating shafts 1 and 3 and relative rotation occurs between the case 5 and the rotating shafts 1 and 3, or between both the rotating shafts 1 and 3, the rotating shaft 1 , 3 and the end plate members 9 and 11, the relative rotation parts between the hub members 13 and 15 and the case 5, and the relative rotation parts between the hub members 13 and 15, etc., are lubricated by the action of the above-mentioned lubrication cycle. Seizure can be prevented by supplying oil and obtaining sufficient lubrication. As described above, since the viscous coupling device is provided with a means for actively promoting lubrication, the lubricity of the viscous coupling device is increased and its durability is improved.

Furthermore, this invention is not limited to the above embodiment. For example, the lubricating oil introduction path 27 is
It is sufficient that a is located radially inward than the discharge port 31a, and there is no need to provide a special provision, and the lubricating oil can also be introduced from the gap between the end plate member 11 and the rotating shaft 3. . Lubricating oil discharge path 3
1 is in the rotational radial direction, but it does not necessarily have to extend linearly; it is sufficient that the discharge port 31a is located in the rotational radial direction, and the shape of the discharge passage 31 in the middle thereof does not matter. Further, in this embodiment, two rotary shafts that can rotate relative to the case of the coupling device are provided concentrically, but the case is fixed to one of the rotary shafts, and only the other rotary shaft is connected to the case of the coupling device. It can also be applied to a type of power transmission from one rotating shaft to another by supporting it so that it can rotate relative to the rotating shaft. In this case, both the discharge passage and the introduction passage communicate with the outer periphery of one of the rotating shafts that rotates relative to the case.

[Effect of the invention] As is clear from the above explanation, according to this invention,
The difference in the radial positions of the outlet and inlet creates a cycle in which lubricating oil is forced to flow between the rotating shaft and the case, increasing the lubricity between the two and It is possible to prevent seizure when the and rotating shaft rotate relative to each other, and improve durability.

[Brief explanation of the drawing]

Fig. 1 is a longitudinal sectional view of a viscous coupling device according to an embodiment of the power transmission device of this invention;
The figure is a sectional view taken along the line A--A in FIG. 1. 1, 3... Rotating shaft, 5... Case, 23, 25
...Resistance plate (resistance plate group), 27...Lubricating oil introduction path,
27a...Inlet, 31...Lubricating oil discharge path, 31
a...Exhaust port.

Claims (1)

[Scope of utility model registration request] A case is provided with a relatively rotatable hub at the shaft center and defines a sealed chamber in which a viscous fluid is sealed; A power transmission device comprising a group of engaging resistance plates, and a rotating shaft that is fitted at both ends so as to be rotatable relative to the case, and that is inserted into the axial center of the hub and engaged with the hub in the rotational direction. A lubricating oil introduction passage provided at one end of the case and communicating with one fitting portion of the rotating shaft, and a lubricating oil introduced from the lubricating oil introduction passage between the case and the rotating shaft. a lubricating oil discharge path provided on the other end side of the case and communicating with the other fitting portion of the rotating shaft, in order to discharge the lubricating oil through the space between the lubricating oil discharge path and the rotating shaft; A power transmission device characterized in that a discharge port is located radially outside an inlet of a lubricating oil inlet.