JP3756702B2 - Planetary roller type power transmission device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a planetary roller type power transmission device to which power is transmitted through revolving motion of a plurality of planetary rollers.
[0002]
[Prior art]
The planetary roller type power transmission device transmits the power of the input shaft by decelerating or increasing the speed of the input shaft to the output shaft in the same axial direction. For example, as a speed increasing unit for a machining center in the field of machine tools and industrial machinery. It is used.
FIG. 5 is a partially omitted front view showing a conventional planetary roller power transmission device, and FIG. 6 is a sectional view.
This planetary roller power transmission device includes a sun roller 200 connected to one rotating shaft, a plurality of planetary rollers 300 that revolve while rotating around the sun roller 200, and the planetary roller 300 between the sun roller 200. The main part is composed of a fixed ring 100 that is housed in a pressure contact state, and a carrier plate 400 that is connected to the other rotating shaft 800 and is connected to one end of a planetary shaft 131 that supports the planetary roller 300.
For example, when used as a speed increasing unit for a machining center, the fixing ring 100 is fixed to a housing (not shown), the input shaft 800 to the carrier plate 400, and the output shaft (not shown) to the sun roller 200, respectively. By connecting, the rotational motion of the input shaft 800 can be increased and power can be transmitted to the output shaft. That is, the rotational motion of the carrier plate 400 is transmitted as a revolving motion of each planetary roller 300 around the sun roller 200, and the planetary roller 300 rotates the sun roller 200 while rotating around the planetary shaft 131.
By the way, the power transmission mechanism between the rollers is a traction drive mechanism using the friction force of the oil film between the grease-lubricated fixing ring 100 and the planetary roller 300 and between the sun roller 200 and the planetary roller 300. Is used. Therefore, in order to supply this oil film, an oil retainer 500 having a pocket 151 for enclosing the planetary roller 300 is interposed in a space between the fixing ring 100 and the sun roller 200. In this oil retainer 500, a plurality of grooves 152 for holding grease are formed concentrically with the sun roller 200, and this grease is supplied to the raceway surface 133 of the planetary roller 300 to form an oil film.
[0003]
[Problems to be solved by the invention]
In order to maintain the above-described traction drive mechanism, it is necessary to reliably supply grease to the track surface 133 of each planetary roller 300. However, since the grease is held in the groove 152 formed in the oil retainer 500 in the conventional device, the oil retainer 500 is rotated while the oil retainer 500 rotates around the sun roller 200 together with the planetary roller 300. From the opening of the groove 152, the grease gradually leaks and depletes. For this reason, there is a problem that the raceway surface 133 of the planetary roller 300 is burned and the life is shortened.
In view of the above-described conventional problems, an object of the present invention is to provide a planetary roller power transmission device that prevents the grease from being depleted and has an improved service life.
[0004]
[Means for Solving the Problems]
In order to achieve the above object, a planetary roller power transmission device of the present invention includes a fixed ring, a sun roller that is inserted concentrically with the fixed ring, and a pressure contact state between the sun roller and the fixed ring. A plurality of planetary rollers arranged, a carrier plate connected to one end of a plurality of planetary shafts that pivotally support the planetary rollers, and a space between the fixing ring and the sun roller are rotatably housed, An oil retainer for supplying grease to the planetary roller, and the oil retainer communicates between the plurality of pockets for storing the plurality of planetary rollers and the respective pockets. A plurality of tunnel-shaped passages that are open only at both ends facing the surface, and in this tunnel-shaped passage, the grease to be supplied to the track surface of each planetary roller is held, and the oil retainer is two A plurality of oil retaining plates of the same shape are overlapped, and the tunnel-shaped passage is formed on one side of each oil retaining plate, and the openings of a plurality of grooves concentrically with the sun roller are opposed to each other. Each oil retaining plate is formed with a tunnel-shaped passage wall in a direction perpendicular to the axis of the planetary roller, and escapes toward both ends of the orbital surface of the planetary roller. The grease flow is restrained by the road wall and returns to the center of the track . According to the planetary roller type power transmission device having the above configuration, the grease can be held in a plurality of tunnel-shaped passages provided in the oil retainer, so that the grease moves along the tunnel-shaped passage and travels to other than the planetary roller raceway surface. Outflow is regulated. Further, the grease that escapes toward both ends of the planetary roller raceway surface is blocked by the road walls on both sides of the tunnel-like passage perpendicular to the axis of the planetary roller and returns to the center of the orbit. For this reason, it can suppress that grease leaks from the both ends of a planetary roller.
[0005]
The oil retainer is configured by overlapping two oil retaining plates, and the tunnel-shaped passage is formed by facing openings of a plurality of grooves formed on one surface of each oil retaining plate. (Claim 2).
In this case, the tunnel-shaped passage can be easily formed by overlapping the grooves facing each other.
[0006]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. FIG. 1 is a partially omitted front view showing one embodiment of a planetary roller type power transmission device of the present invention, and FIG. 2 is a sectional view taken along line II-II in FIG.
1 and 2, this planetary roller power transmission device is concentric with the fixing ring 1 connected to the housing of the main unit (not shown), the carrier plate 4 connected to the input shaft 8, and the fixing ring 1. Are arranged in a shape and are respectively supported by a sun roller 2 to which an output shaft (not shown) is connected, and four planetary shafts 31 connected to end portions of the carrier plate 4, and the fixing ring 1 and the sun roller The main part is composed of four planetary rollers 3 that roll (rotate and revolve) and transmit power in a state sandwiched between two and an oil retainer 5 that supplies grease to the raceway surface 33 of the planetary roller 3. Has been.
[0007]
The fixed ring 1 holds the sun roller 2 in which a plurality of planetary rollers 3 are arranged on the inner peripheral portion of the ring and one end is inserted in the center portion in a pressure contact state via each track surface 33 of the planetary roller 3. Yes. The sun roller 2 is a long roller having a circular cross section, and an output shaft is coupled to the right side of FIG.
[0008]
The planetary roller 3 is a cylinder having the same length as the fixed ring 1, and the planetary shaft 31 is set in the hollow portion of the planetary roller 3 so as to be about twice as long as the planetary roller 3. However, it is rotatably fitted via a plurality of needle rollers 32 with the end portion protruding.
[0009]
The end of each planetary shaft 31 is connected to the carrier plate 4. The carrier plate 4 includes a connecting portion 41 having a cylindrical structure for inserting and connecting the input shaft 8, and is arranged coaxially with the sun roller 2 and in a non-contact state with the sun roller 2. The planetary shaft 31 is inserted into four connection holes 42 provided at every 90 ° phase on a concentric circle with respect to the sun roller 2 on the right end surface of the carrier plate 4 in FIG.
[0010]
A pair of collar rings 7 are superimposed on both cylindrical end faces of the fixing ring 1 so as to sandwich the fixing ring 1. The collar ring 7 is an annular body, has an outer diameter that is the same as that of the fixed ring 1, and an inner diameter that is set to a dimension that does not hinder the revolving motion of the planetary shaft 31. The collar ring 7 sandwiches the fixing ring 1 and a part of the outer peripheral side of the planetary roller 3 from both sides, thereby restricting the planetary roller 3 from sliding in the axial direction. .
[0011]
In a space between the fixing ring 1, the sun roller 2, and each planetary roller 3, for example, an oil retainer 5 made of nylon 66 is accommodated. The oil retainer 5 is obtained by stacking two oil retaining plates 51 shown in FIG. 3 facing each other as shown in FIG. A plurality of grooves 52 are formed on the overlapping surface 51 a side of the oil retaining plate 51. A stepped portion 53 corresponding to the thickness of the collar ring 7 is formed on the surface 51b side.
The outer diameter on the overlapping surface 51 a side of the oil retaining plate 51 is set to a size that is accommodated close to the inner peripheral portion of the fixing ring 1, and the outer diameter on the surface 51 b side is the inner diameter of the collar ring 7. The size is set to be stored close to the circumference. Further, a circular hole 54 having a diameter for inserting the sun roller 2 is provided at the center (see FIG. 4). The oil retaining plate 51 is provided with a circular pocket 55 for accommodating each planetary roller 3 with a space that allows rotation of each planetary roller 3 on the overlapping surface 51a side, and the planetary shaft 31 is accommodated on the surface 51b side. A pocket 56 is provided.
[0012]
The plurality of grooves 52 are concentric with respect to the sun roller 2, and each of the plurality of grooves 52 is divided into four in the circumferential direction by the presence of the pocket 55 (see FIG. 3). The tunnel-shaped passage 6 is formed by overlapping the two oil retaining plates 51 with the openings 52a of the grooves 52 facing each other. The pockets 55 communicate with each other through this tunnel-shaped passage 6. The tunnel passage 6 is filled with grease.
In addition, since the opening of the tunnel-shaped channel | path 6 is only the both ends which face the planetary roller 3, grease does not leak from parts other than the said both ends.
[0013]
With the above configuration, when the carrier plate 4 connected to the input shaft 8 rotates, the planetary roller 3 supported on the planetary shaft 31 rotates and revolves around the sun roller 2, and the sun roller is caused by frictional force. Rotate 2 The grease filled in the tunnel-like passage 6 of the oil retainer 5 is supplied to the pocket 55 along the passage 6 so that a lubricating oil film can be formed on the raceway surface 33 of the planetary roller 3.
Since the grease can flow out only in the direction along the tunnel-shaped passage 6, the grease does not leak out except for the pocket 55.
Further, the grease escaping toward both ends of the raceway surface 33 of the planetary roller 3 is prevented from flowing by the road walls on both sides of the tunnel-like passage 6 in the direction orthogonal to the axis of the planetary roller 3 and returns to the center of the orbit. . Therefore, leakage of grease from both end portions of the planetary roller 3 can be suppressed.
[0014]
Further, since the oil retainer 5 is formed by superposing a pair of grooved oil retaining plates 51, it is easy to form a tunnel by overlapping the openings 52a of the grooves 52 formed in the oil retaining plate 51 so as to face each other. A passage 6 can be formed.
In this embodiment, the oil retainer 5 is formed by overlapping two grooved oil retaining plates 51 having the same shape, but the shape of the oil retaining plate 51 is fitted to the retainer 5. Various shapes that can be formed are also possible. The number of planetary rollers 3 can be other than four.
[0015]
【The invention's effect】
As described above, according to the planetary roller type power transmission device of the first aspect, since the grease is held and supplied by the plurality of tunnel-shaped passages, the grease does not flow out to other than the raceway surface of the planetary roller. Further, the grease that escapes to both ends of the planetary roller can be retained in the tunnel-shaped passage. For this reason, depletion of the lubricant can be suppressed and the life can be improved.
[0016]
In addition , since the grooves are opposed to each other, the groove shape can be freely designed, and a tunnel-shaped passage can be easily formed. For this reason, the production cost can be reduced.
[Brief description of the drawings]
FIG. 1 is a partially omitted front view showing an embodiment of a planetary roller power transmission device of the present invention.
2 is a cross-sectional view taken along the line II-II in FIG.
FIG. 3 is a front view of an oil retaining plate.
4 is a cross-sectional view taken along the line IV-IV in FIG. 3;
FIG. 5 is a partially omitted front view of a conventional example.
6 is a VI-VI sectional view in FIG.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Fixing ring 2 Sun roller 3 Planetary roller 31 Planetary shaft 33 Raceway surface 4 Carrier plate 5 Oil retaining device 51 Oil retaining plate 52 Groove 52a Opening 55 Pocket 6 Tunnel-shaped passage

Claims (1)

A fixing ring, a sun roller that is inserted concentrically with the fixing ring, a plurality of planetary rollers that are arranged in pressure contact between the sun roller and the fixing ring, and a plurality of planetary rollers that pivotally support the planetary roller A carrier plate to which one end of a planetary shaft is connected; and an oil retainer that is rotatably accommodated in a space between the fixing ring and the sun roller and supplies grease to the planetary roller. Forming a plurality of pockets for accommodating the plurality of planetary rollers, and a plurality of tunnel-shaped passages communicating with the pockets and having openings at both ends facing the planetary rollers. In this tunnel-shaped passage, the grease to be supplied to the track surface of each planetary roller is held,
The oil retainer is configured by overlapping two oil retaining plates having the same shape, and the tunnel-shaped passage is formed on one surface of each oil retaining plate, and a plurality of grooves concentrically with the sun roller. And each oil retaining plate is formed with a tunnel-shaped passage wall in a direction perpendicular to the axis of the planetary roller, and the orbital surface of the planetary roller. A planetary roller power transmission device, wherein the flow of grease escaping toward both ends of the shaft is restrained by the road wall and returns to the center of the track .

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