JPH04101054U - Planetary roller type power transmission device - Google Patents

Abstract

(57) [Summary] [Purpose] To prevent lubricant from running out due to centrifugal force during high-speed rotation. [Structure] A portion of the inner circumferential surface of the fixed ring 8 having a predetermined width L excluding both axially-directed portions is defined as a raceway surface 8a of a planetary roller 10. An oil reservoir circumferential groove 8b is formed on both sides of the fixed ring raceway surface 8a, and a lubricant oil film step portion 8c is formed on the outside of the oil reservoir circumferential groove 8b. This lubricant oil film step portion 8c has a narrowness that prevents the lubricant m in the oil reservoir circumferential groove 8b from flowing outward. Therefore, the lubricant m pushed to both sides of the fixed ring 8 by the planetary roller 10 is transferred to the oil sump circumferential groove 8.
Since the lubricant m in the oil reservoir circumferential groove 8b is prevented from flowing out by the lubricant oil film step portion 8c, there is no shortage of lubricant m on the fixed ring raceway surface 8a.

Description

[Detailed explanation of the idea]

0001

[Industrial application field]

This invention has multiple planetary rollers pressed between the outer circumferential surface of the sun shaft and the inner circumferential surface of the fixed ring. In this system, the planetary rollers are held rotatably by a carrier. Regarding star roller type power transmission device.

0002

[Conventional technology]

Fig. 4 is a sectional view showing a conventional planetary roller type power transmission device, and Fig. 5 is a side view thereof. Ru. In the figure, 2 is the first shaft body, 4 is the sun axis formed at the end of the first shaft body 2, and 6 is the housing. 8 is a fixed ring fitted into the housing 6, and 10 is fixed to the outer peripheral surface of the sun shaft 4. A plurality of planetary rollers 1 are interposed equidistantly in the circumferential direction in pressure contact with the inner circumferential surface of the fixed ring 8. 2 is a support shaft that rotatably supports the planetary roller 10, and 14 is a cap that holds the support shaft 12. The rear 16 is a second shaft body formed integrally with the carrier 14.

0003 Here, the first shaft body 2 is used as an input shaft, and the second shaft body 16 is used as an output shaft, and the machine is used as a reducer. Let us explain the case where it is enabled. As the first shaft body 2 rotates, the rotational force of the sun shaft 4 is applied to each planet. When the roller 10 is provided, the planetary roller sandwiched between the sun shaft 4 and the fixed ring 8 10 revolves along the inner circumferential surface of the fixed ring 8 while rotating around the support shaft 12 .

0004 As the spindle 12 rotates around the axis of the sun axis 4 due to this revolution, the carrier 1 4 and the second shaft 16 also rotate. The direction of revolution of the planetary roller 10 around the spindle 12 is the opposite direction to the rotation direction of the sun shaft 4, but the support shaft 12, carrier 14, and second shaft body 16 is in the same direction as the solar axis 4.

[0005] Note that the above relationship can be reversed by using the first shaft body 2 as the output shaft and the second shaft body 16 as the input shaft. Then it will function as a speed increaser.

[0006] By the way, the planetary roller type power transmission device transmits rotational force using frictional force. Since it is a traction drive, the planetary roller 10, the sun shaft 4 and the fixed wheel 8 must be pressed firmly enough. However, the frictional force is due to rotation. The planetary roller 10 is relative to both the sun axis 4 and the fixed ring 8. It is necessary to rotate while sliding on the target. Therefore, it is possible to prevent burn-in and ensure smooth running. In order to perform rotation, a lubricant m (grease) is applied to the surface of the planetary roller 10 and the sun shaft 4. and the inner circumferential surface of the fixed ring 8.

[0007]

[Problem that the idea aims to solve]

By the way, most of the lubricant m that scatters due to the centrifugal force that accompanies rotation is inside the fixed ring 8. Adheres to the surrounding surface. The planetary roller 10 rolling on the inner peripheral surface of the fixed ring 8 is shown in FIG. In this way, the lubricant m is pushed and gathered toward the front side of the planetary roller 10 in the direction of movement. A collection of the press A part of the lubricant m moistens the surface of the planetary roller 10 and the inner peripheral surface of the fixed ring 8. , a portion is pushed aside on both sides of the planetary roller 10 to the rear side, as shown in FIG.

[0008] Also, the amount of lubricant m sealed inside the planetary roller type power transmission device is limited. Therefore, after a certain rotation time, the inside of the fixed ring 8 will be damaged due to the centrifugal force of rotation. The amount of lubricant m that is pushed aside is greater than the amount of lubricant that adheres to the peripheral surface, and the result is As a result, the amount of lubricant m remaining on the rolling surface becomes insufficient. This kind of oil depletion condition When this happens, the contact surfaces between the planetary roller 10, the sun shaft 4, and the fixed ring 8 increase in temperature, and There is a risk of burn-in.

[0009] The present invention was devised in view of these circumstances, and is especially suitable for high-speed rotation. The objective is to prevent lubricant from running out due to centrifugal force.

0010

[Means to solve the problem]

In order to achieve these challenges, the present invention has developed a system that Planetary roller type power transmission in which multiple planetary rollers are interposed in pressure contact with the surface. The device has the following configuration.

[0011] The planetary roller type power transmission device of the present invention is characterized in that both axial directions of the inner circumferential surface of the fixed ring are provided. A portion of a predetermined width excluding the side portions is formed on the raceway surface on which the planetary roller rolls, and , an oil sump circumference of a predetermined depth that is continuous over the entire circumference on each side of this raceway surface. A groove is formed, and a planetary rotor is formed on the axially outer side of each oil sump circumferential groove. Resistance to outward flow of lubricant between the rolling trajectory surface of the outer diameter of the ring and the inner circumferential surface of the fixed ring. It is characterized in that a lubricant oil film step portion is formed with a narrowness of .

0012

[Effect]

Pushed forward in the direction of travel by planetary rollers rolling on the fixed ring raceway surface When the lubricant is pushed away from the concentrated area to both sides of the rear side, flows into. The outside of this oil sump circumferential groove is a stepped part for the lubricant oil film. Since it acts as a resistance to the outward flow of lubricant, the moisture accumulated in the oil sump circumferential groove is It functions to retain lubricant in the oil sump circumferential groove. Some lubricants may cause the oil sump groove to Even if it crosses over and reaches the step for the lubricant oil film, it will return axially inward on the rear side of the planetary roller. and flows into the oil sump circumferential groove.

[0013] The lubricant accumulated in the circumferential groove for the oil sump is caused by the planetary rollers as they rotate. The fluid flows along the circumferential direction within the oil sump groove due to the pushing action of In this case, the oil will be distributed almost evenly throughout. In addition, as the rotation speed increases, Due to the increase in centrifugal force and the presence of a lubricant film on the step for lubricant film. This prevents the lubricant from scattering outward and creates moisture between the planetary roller and fixed ring raceway. This will provide a good supply of lubricant.

[0014]

【Example】

First Embodiment FIG. 1 is a sectional view showing a planetary roller type power transmission device according to a first embodiment of the present invention, and FIG. 2 is a partially cutaway perspective view of the main parts thereof.

[0015] In the figure, 2 is the first shaft, 4 is the sun axis, 6 is the housing, 8 is the fixed ring, and 10 is the planet. roller, 12 is a support shaft, 14 is a carrier, 16 is a second shaft body, and these basic The configuration is the same as that described in the conventional example.

[0016] Hereinafter, the configuration of this embodiment that is different from the conventional example will be explained. That is, fixed wheel 8 On the inner circumferential surface of the planetary roller 10, a portion having a predetermined width L excluding both side portions in the axial direction is is an effective raceway surface 8a on which the wheels substantially roll. on both sides of fixed ring raceway surface 8a Each has an oil sump circumference of a predetermined depth continuous over the entire circumference on the inner peripheral surface of the fixed ring 8. A groove 8b is formed. This oil sump circumferential groove 8b is filled with a lubricant m for preventing seizure. (grease) is stored there. The axis of each oil sump circumferential groove 8b On the outside in the direction, the rolling trajectory surface of the outer diameter portion of the planetary roller 10 and the inner peripheral surface of the fixed ring 8 A narrow gap (several 100 μm) is created between the two to provide resistance to the outward flow of the lubricant m. A stepped portion 8c for a lubricant oil film is formed.

[0017] Note that the axial width of the fixed ring 8 is larger than the axial width of the planetary roller 10. ing. The width L of the fixed ring raceway surface 8a is naturally smaller than the width of the planetary roller 10. However, this width L is such that the contact surface pressure of the planetary roller 10 with respect to the fixed ring 8 exceeds a certain value. It is set to an appropriate value to make it higher.

[0018] Next, the operation will be explained.

[0019] The planetary roller 10 rotates automatically around the support shaft 12 as the first shaft body 2 and the sun shaft 4 rotate. When the planetary roller 10 revolves along the fixed ring raceway surface 8a while rotating, the planetary roller 10 absorbs oil on both sides. The lubricant m is applied to the outer circumferential surface from the circumferential groove 8b for the reservoir, and the lubricant m is applied as it rolls. It is supplied to the fixed ring raceway surface 8a and the outer peripheral surface of the sun shaft 4.

[0020] The lubricant m on the fixed ring raceway surface 8a is applied to the planetary roller as the planetary roller 10 rotates. 10 are pushed forward in the direction of travel. The lubricant m is on the rear side from the concentrated point. When the oil is pushed aside, it flows into the oil reservoir circumferential grooves 8b on both sides. some lubrication The lubricant m passes through the oil reservoir circumferential groove 8b and reaches the lubricant oil film step 8c. It is prevented from flowing outside the portion 8c.

[0021] In the portion of the oil sump circumferential groove 8b after the planetary roller 10 has passed, lubricant is m has accumulated sufficiently, and the axially outer side of the lubricant oil film step 8c Because of this, even if large centrifugal force is applied due to high-speed rotation, the oil sump circumference remains The lubricant m in the groove 8b is prevented from flowing outward. In other words, the lubricant oil film step 8 This is because the oil film at c acts as a resistance to outflow.

[0022] As described above, a sufficient amount of lubricant m is always stored in the oil sump circumferential groove 8b, From there, lubricant m is supplied to the sun shaft 4 and fixed wheel 8 via the planetary roller 10. This prevents seizure between the planetary roller 10, the sun shaft 4, and the fixed ring 8, and makes it smooth. It is possible to exhibit a high-speed power transmission function for a long period of time.

Second Embodiment FIG. 3 is a sectional view showing a planetary roller type power transmission device according to a second embodiment of the present invention. In FIG. 3, the same reference numerals as those shown in FIG. 1 according to the first embodiment refer to the same parts, portions, etc. indicated by the reference numerals in this embodiment as well, so the explanation thereof will be omitted.

[0024] In the first embodiment, the inner end of the oil reservoir circumferential groove 8b in the axial direction also has a cross-sectional shape. Whereas the outer end was also formed at a right angle, in the second embodiment the outer end was formed at a right angle but the inner end was formed at a right angle. The edges are formed into obtuse slopes. Therefore, the lubricant m in the oil sump circumferential groove 8b The lubricant m is drawn between the planetary roller 10 and the fixed ring raceway surface. The effect of infiltration between 8a and 8a is superior to that of the first embodiment.

[0025]

[Effect of the idea]

As described above, according to the present invention, the oil sump circumferential grooves on both sides of the fixed ring raceway are used to push the oil outward. Receives the lubricant being applied and lubricates the peripheral groove for the oil sump by the step part for the lubricant oil film. This prevents the lubricant from scattering to the outside, so there is no shortage of lubricant in the planetary roller orbit. This not only prevents oil from occurring, but also ensures that oil is constantly removed from the oil sump circumferential groove regardless of high speed rotation. A predetermined amount of lubricant can be supplied to the raceway surface. Therefore, in the long term There is no seizure between the planetary roller and the sun shaft and fixed ring, making it smooth. It becomes possible to provide a planetary roller type power transmission device that can transmit power.

[Brief explanation of drawings]

FIG. 1 is a sectional view showing a planetary roller type power transmission device according to a first embodiment of the present invention.

FIG. 2 is a partially cutaway perspective view showing essential parts of the planetary roller type power transmission device of FIG. 1;

FIG. 3 is a sectional view showing a planetary roller type power transmission device according to a second embodiment of the present invention.

FIG. 4 is a sectional view showing a conventional planetary roller type power transmission device.

FIG. 5 is a side view of a conventional planetary roller type power transmission device.

FIG. 6 is an explanatory diagram showing how lubricant flows to both sides.

[Explanation of symbols]

4 Sun shaft 8 Fixed ring 8a Fixed ring raceway surface 8b Circumferential groove for oil reservoir 8c Step portion for lubricant oil film 10 Planetary roller m Lubricant

Claims (1)

[Scope of utility model registration request] 1. A planetary roller type power transmission device in which a plurality of planetary rollers are interposed in pressure contact between the outer circumferential surface of a sun shaft and the inner circumferential surface of a fixed ring, wherein the inner circumferential surface of the fixed ring A portion of a predetermined width excluding both sides in the axial direction is formed on the raceway surface on which the planetary roller rolls, and an oil sump with a predetermined depth continuous over the entire circumference on each of both sides of the raceway surface. A circumferential groove is formed, and a resistance against outward flow of lubricant is formed between the rolling trajectory surface of the outer diameter portion of the planetary roller and the inner circumferential surface of the fixed ring on the axially outer side of each circumferential groove for oil sump. A planetary roller type power transmission device characterized in that a stepped portion for a lubricant oil film is formed with a narrowness of .