Ball spline with lubricating oil flow passage

Abstract

To provide a ball spline with a lubricating oil flow passage.SOLUTION: A ball spline with a lubricating oil flow passage includes a spline shaft, a sleeve body, and two circulation members. The sleeve body is movably attached to cover the spline shaft, and forms a load passage for storing a plurality of balls between the spline shaft and itself. The sleeve body has an oil guidance passage in the inside thereof. The two circulation members are respectively arranged on the outer end surface of the sleeve body. The spline shaft passes through the two circulation members. Each of the two circulation members has an oil injection hole, an oil chamber, and an oil guidance portion. The oil chamber is connected with the oil injection hole, the load passage, and the oil guidance passage of the sleeve body. The oil guidance portion is arranged in the oil chamber so as to correspond with the oil injection hole, and protrudes toward the oil guidance passage. With the above-described structure features, only by injecting lubricating oil from the oil injection hole of one of the circulation members, the balls on both sides can be lubricated with the lubricating oil through the oil guidance portion and the oil guidance passage, and the lubrication effect can be improved.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a ball spline, particularly a ball spline with a lubricating oil flow path.

Background Art

[0002] The ball spline disclosed in Patent Document 1 has a sleeve and two side caps arranged at both ends of the sleeve. The sleeve has a metal cylindrical portion and two plastic cages. The metal cylindrical portion has two oil through-flow paths. The two plastic cages are relatively arranged within the metal cylindrical portion and each has an internal oil flow path at its outer edge portion. The internal oil flow path and the oil through-flow path are connected to each other to form an oil transmission flow path. Lubricating oil flows from the oil through-flow path into the internal oil flow path, and then flows along the internal oil flow path through an extension flow path to the direction-changing passage of the side cap, while lubricating the balls that have passed through.

[0003] In Patent Document 1, since the outer edge portion of the plastic cage is in close contact with the inner surface of the metal cylindrical portion, when the hydraulic pressure is too high, the outer edge portion of the plastic cage is pushed backward and deviates from the inner surface of the metal cylindrical portion, causing oil leakage.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] The main object of the present invention is to provide a ball spline with a lubricating oil flow path that achieves a lubricating effect on both sides and does not leak oil.

Means for Solving the Problems

[0006] To solve the above problems, the ball spline with a lubricating oil flow path includes a spline shaft, a sleeve body, two reflux members, and a plurality of balls. The spline shaft has a first rolling groove on its outer peripheral surface. The sleeve body is movably sleeved on the spline shaft and has a second rolling groove formed on its inner peripheral surface and a load path formed between the second rolling groove and the first rolling groove of the spline shaft. The sleeve body has a non-load path and an oil guiding path inside. Both ends of the non-load path and both ends of the oil guiding path penetrate two opposite outer end surfaces of the sleeve body. The two reflux members are respectively arranged on the outer end surfaces of the sleeve body. The spline shaft penetrates the two reflux members. The two reflux members respectively have a reflux groove, an oil injection hole, an oil chamber, and an oil guiding portion. One end of the reflux groove is connected to the load path, and the other end is connected to the non-load path to form a circulation path for rolling a plurality of balls. The oil chamber is connected to the oil injection hole, the load path, and the oil guiding path of the sleeve body. The oil guiding portion is arranged in the oil chamber corresponding to the oil injection hole and protrudes toward the oil guiding path, so that the lubricating oil flowing into the oil chamber from the oil injection hole can be sent into the oil guiding path.

[0007] Specifically, if lubricating oil is injected from the oil injection hole of one reflux member, the lubricating oil flows through the oil chamber into the load path to lubricate the balls on one side, and at the same time flows into the oil guiding path through the oil guiding portion, and then flows through the oil guiding path into the oil chamber of the other reflux member and into the other load path to lubricate the balls on the other side. In other words, since the ball spline with a lubricating oil flow path according to the present invention has the oil guiding path of the sleeve body and the oil guiding portions of the two reflux members, as long as lubricating oil is injected from one oil injection hole, the effect of lubricating the balls on both sides, that is, the bidirectional lubricating effect, can be exerted. In addition, since the oil guiding path is arranged inside the sleeve body, it can not only withstand a relatively large oil pressure, but also prevent oil leakage.

[0008] In a relatively preferable case, each oil guiding portion has a first end and a second end. The first end is connected to the wall surface of the oil chamber. The second end is arranged to be adjacent to the oil guiding path. Each oil guiding portion further has an inclined surface facing the oil injection hole. Since the inclined surface inclines downward from the first end to the second end and its position is higher than the bottom surface of the oil guiding path, the oil guiding portion can efficiently feed lubricating oil into the oil guiding path by means of the inclined surface.

[0009] In a relatively preferable case, since the width of each oil guiding portion gradually decreases from the first end to the second end, lubricating oil can flow efficiently to the lower load path.

[0010] In a relatively preferable case, since the width of the second end of each oil guiding portion is smaller than or equal to the width of the oil guiding path, lubricating oil can flow efficiently into the oil guiding path.

[0011] In a relatively preferable case, each oil guiding portion separately has recessed portions on two opposite side surfaces. The recessed portions reduce the backflow phenomenon of the lubricating oil flowing from the oil guiding path into the oil guiding portion, and can efficiently make the lubricating oil flow to the lower load path.

[0012] In a relatively preferable case, the sleeve body has lubricating passages on each outer end surface. Since the lubricating passages are connected to the second rolling groove and the oil chamber, the lubricating oil flows from each oil guiding portion to the lower lubricating passages, then shunts along the lubricating passages and separately flows into the two load paths.

[0013] In a relatively preferable case, the lubricating passages are closer to the spline shaft than the oil guiding path.

[0014] In a relatively preferable case, the oil guiding path extends along the axial direction of the spline shaft.

[0015] The detailed structure, features, assembly, or usage method of the ball spline with a lubricating oil flow path according to the present invention will be clarified through the following detailed description of the embodiments. Also, the following detailed description and the embodiments presented by the present invention are merely examples for explaining the present invention, and it should be understandable to those with common sense in the field related to the present invention that the claims of the present invention cannot be limited thereby.

Brief Description of the Drawings

[0016]

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Mode for Carrying Out the Invention

[0017] Hereinafter, a ball spline with a lubricating oil flow path according to the present invention will be described with reference to the drawings. In the specification and drawings, directional terms are expressed based on the directions in the drawings. The same reference numerals indicate the structural features of the same or similar components.

[0018] (One Embodiment) As shown in FIGS. 1 and 2, a ball spline 10 with a lubricating oil flow path according to an embodiment of the present invention includes a spline shaft 20, a sleeve body 30, two reflux members 40, two dust-proof members 50, and a plurality of balls 60.

[0019] The spline shaft 20 has two pairs of first rolling grooves 22 on its outer peripheral surface. Each of the first rolling grooves 22 extends along the axial direction of the spline shaft 20.

[0020] The sleeve body 30 has two opposing outer end faces 31 and a shaft hole 32 passing through the two outer end faces 31. The sleeve body 30 can move along the axial direction of the spline shaft 20 after covering the spline shaft 20 through the shaft hole 32. The shaft hole 32 has two pairs of second rolling grooves 33 on its wall surface. As shown in FIG. 3, the two pairs of second rolling grooves 33 of the sleeve body 30 and the two pairs of first rolling grooves 22 of the spline shaft 20 correspond to each other one by one to form a load path 62. The sleeve body 30 further has two pairs of non-load paths 34 and two oil guiding paths 35. Each of the non-load paths 34 and each of the oil guiding paths 35 penetrate the two outer end faces 31 of the sleeve body 30 along the axial direction of the spline shaft 20. As shown in FIGS. 4 and 5, the sleeve body 30 separately has two opposing lubricating passages 36 on each of the outer end faces 31. The lubricating passage 36 is closer to the spline shaft 20 than the oil guiding path 35. Both ends of the lubricating passage 36 are connected to a pair of second rolling grooves 33.

[0021] The two reflux members 40 are respectively arranged on the outer end surface 31 of the sleeve body 30. The spline shaft 20 penetrates through the two reflux members 40. The two reflux members 40 respectively have an inner end surface 41 facing the sleeve body 30 and an outer end surface 42 facing away from the sleeve body 30. As shown in FIGS. 2, 4 and 5, each inner end surface 41 has four reflux grooves 43 and two opposite oil chambers 44. As shown in FIG. 3, one end of each reflux groove 43 is connected to the load path 62, and the other end is connected to the non-load path 34 to form a circulation path 64 for rolling a plurality of balls 60. As shown in FIGS. 4, 5 and 7, the oil chamber 44 is connected to the oil guiding path 35 of the axial sleeve body 30 and at the same time is connected to the lubrication passage 36 of the radial sleeve body 30. As shown in FIGS. 4 and 5, each reflux member 40 has two opposite oil injection holes 45 on the outer peripheral surface. The two oil injection holes 45 are respectively connected to the oil chamber 44 along the radial direction. As shown in FIGS. 6 and 7, each reflux member 40 further has two oil guiding portions 46. The two oil guiding portions 46 are respectively arranged in the oil chamber 44 so as to protrude toward the oil guiding path 35. Each oil guiding path 35 corresponds to one oil injection hole 45, the oil chamber 44 and the oil guiding portion 46. Specifically, the oil guiding portion 46 has a first end 461, a second end 462 and an inclined surface 463. The first end 461 is connected to the wall surface of the oil chamber 44. As shown in FIG. 8, the second end 462 is arranged adjacent to the oil guiding path 35, and the width W2 is smaller than or equal to the width W1 of the oil guiding path 35 (that is, W2≦W1). As shown in FIG. 7, the inclined surface 463 is inclined downward from the first end 461 to the second end 462 relative to the oil injection hole 45, and the position is higher than the bottom surface 352 of the oil guiding path 35. As shown in FIG. 6, each oil guiding portion 46 has a width that gradually decreases from the first end 461 to the second end 462, and respectively has arc-shaped recesses 47 on two opposite side surfaces. As shown in FIG. 2, each reflux member 40 respectively has positioning holes 48 on two opposite side surfaces of the oil chamber 44. The positioning holes 48 penetrate through the inner end surface 41 and the outer end surface 42 of the reflux member 40.

[0022] The two dust-proof members 50 have two pairs of columnar positioning portions 52 on their inner end faces. If each columnar positioning portion 52 of the dust-proof member 50 is inserted into the positioning hole 48 of the reflux member 40, the reflux member 40 and the sleeve body 30 can be fixedly assembled together with a screw (not shown in the figure).

[0023] Summarizing the above, as shown in FIG. 7, if lubricating oil is injected from the oil injection hole 45 of the reflux member 40 on one side, the lubricating oil passes through the oil chamber 44 on the same side and flows into the lower lubricating passage 36, and then diverges and flows into the load path 62 to lubricate the balls 60 on the same side inside. At the same time, a part of the lubricating oil flows into the oil guiding path 35 through the oil guiding portion 46, and then continues to flow into the lower lubricating passage 36 through the oil chamber 44 of the reflux member 40 on the other side along the oil guiding path 35, and then diverges and flows into the load path 62 on the other side to lubricate the balls 60 on the other side inside. When the lubricating oil flows, since the relationship between the width W2 of the inclined surface 463 of the oil guiding portion 46 and the width W1 of the oil guiding path 35 is W2≦W1, the lubricating oil can efficiently flow from the oil chamber 44 into the oil guiding path 35. In addition, since the oil guiding portion 46 has recessed portions 47 on both sides, the lubricating oil not only reduces the reverse flow at the inclined surface 463 of the oil guiding portion 46 when flowing from the oil guiding path 35 to the oil guiding portion 46, but also can efficiently flow into the oil chamber 44 on the other side. That is, by designing to gradually reduce the width of the oil guiding portion 46 and arranging the recessed portions 47 on both sides of the oil guiding portion 46, the lubricating oil can be efficiently flowed from the oil chamber 44 to the lower lubricating passage 36.

[0024] The oil guiding part 46 is not limited to the above-described form, and its structure may change according to actual needs. For example, as shown in FIGS. 9a and 9b, the oil guiding part 46 may be a pyramid having an inclined surface 463 and a recessed part 47. As shown in FIGS. 10a and 10b, the oil guiding part 46 may be a rectangular pyramid having an inclined surface 463 without the recessed part 47 being arranged. As shown in FIGS. 11a and 11b, the oil guiding part 46 may be an arc body having an inclined surface 463 without the recessed part 47 being arranged. As shown in FIGS. 12a and 12b, the oil guiding part 46 may be a rectangular pyramid with the inclined surface 463 and the recessed part 47 omitted. As shown in FIGS. 13a and 13b, the oil guiding part 46 may be an arc body with the inclined surface 463 and the recessed part 47 omitted. That is, the oil guiding part 46 with any of the above-described structures can redirect the lubricating oil and allow a part of the lubricating oil to flow into the oil guiding path 35 to provide a lubricating effect to the balls 60 on the other side inside.

[0025] To summarize the above, the ball spline 10 with a lubricating oil flow path according to the present invention has the oil guiding path 35 of the sleeve body 30 and the oil guiding parts 46 of the two reflux members 49. Therefore, as long as lubricating oil is injected from one oil injection hole 45, it can exert the effect of lubricating the balls 60 on both sides, that is, a two-way lubricating effect, and improve the lubrication efficiency. In addition, the oil guiding path 35 is arranged inside the sleeve body 30 and penetrates the sleeve body 30 along the axial direction of the spline shaft 20. Therefore, it can not only withstand a relatively large oil pressure but also prevent oil leakage.

Explanation of Reference Numerals

[0026] 10: Ball spline with lubricating oil flow path 20: Spline shaft 22: First rolling groove 30: Sleeve body 31: Outer end face 32: Axial hole 33: Second rolling groove 34: Non-load path 35: Oil guiding path 352: Bottom face 36: Lubrication passage 40: Return member 41: Inner end face 42: Outer end face 43: Return groove 44: Oil chamber 45: Oil injection hole 46: Oil guiding part 461: First end 462: Second end 463: Inclined surface 47: Depressed part 48: Positioning hole 50: Dust-proof member 52: Columnar positioning part 60: Ball 62: Load path 64: Circulation path W1: Width of oil guiding path W2: Width of second end

Claims

1. A spline shaft, a sleeve body, two reflux members, and a plurality of balls, The spline shaft has a first rolling groove on its outer peripheral surface, The sleeve body is movably sleeved on the spline shaft and has a second rolling groove formed on its inner peripheral surface and a load path formed between the second rolling groove and the first rolling groove of the spline shaft, The sleeve body has a non-load path and an oil guiding path inside, and both ends of the non-load path and both ends of the oil guiding path penetrate two opposite outer end surfaces of the sleeve body, The two reflux members are respectively arranged on the outer end surfaces of the sleeve body, The spline shaft penetrates through the two reflux members, The two reflux members respectively have a reflux groove, an oil injection hole, an oil chamber, and an oil guiding portion. One end of the reflux groove is connected to the load path, and the other end is connected to the non-load path to form a circulation path. The oil chamber is connected to the oil injection hole, the load path, and the oil guiding path of the sleeve body. The oil guiding portion is arranged in the oil chamber corresponding to the oil injection hole and protrudes toward the oil guiding path, A ball spline with a lubricating oil flow path, characterized in that a plurality of the balls are arranged in the circulation path.

2. Each of the oil guiding portions has a first end, a second end, and an inclined surface. The first end is connected to the wall surface of the oil chamber, the second end is arranged adjacent to the oil guiding path, and the inclined surface is inclined downward from the first end to the second end relative to the oil injection hole and is higher than the bottom surface of the oil guiding path. The ball spline with a lubricating oil flow path according to Claim 1 is characterized in that the position is higher than the bottom surface of the oil guiding path.

3. The ball spline with a lubricating oil flow path according to Claim 2 is characterized in that the width of each of the oil guiding portions gradually decreases from the first end to the second end.

4. The ball spline with a lubricating oil flow path according to Claim 3 is characterized in that the width of the second end of each of the oil guiding portions is smaller than or equal to the width of the oil guiding path.

5. The ball spline with a lubricating oil flow path according to any one of Claims 1 to 4 is characterized in that each of the oil guiding portions separately has a recess on two opposite side surfaces.

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