Ball spline with lubricating oil 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, and more particularly to a ball spline with a lubricating oil passage. [Background technology]

[0002] The ball spline disclosed in Patent Document 1 has a sleeve and two side caps disposed on 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 passages. The two plastic cages are disposed relative to each other within the metal cylindrical portion, and each has an internal oil passage on its outer periphery. The internal oil passages and the oil through-flow passage are interconnected to form an oil transmission passage. Lubricating oil flows from the oil through-flow passage into the internal oil passage, then flows along the internal oil passage through an extension passage to the direction-changing passage in the side cap, while simultaneously lubricating the balls passing through.

[0003] In Patent Document 1, the outer edge of the plastic retainer is in close contact with the inner surface of the metal cylindrical portion, so if the oil pressure is too high, the outer edge of the plastic retainer is pushed back and deviates from the inner surface of the metal cylindrical portion, causing oil to leak. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Taiwan Publication M615588 Summary of the Invention [Problem to be solved by the invention]

[0005] The main object of the present invention is to provide a ball spline with lubricating oil passages that provides lubrication on both sides and prevents oil leakage. [Means for solving the problem]

[0006] To solve the above-mentioned problems, the ball spline with lubricating oil passage comprises a spline shaft, a sleeve body, two return members, and a plurality of balls. The spline shaft has a first rolling groove on its outer circumferential surface. The sleeve body movably fits over the spline shaft and has a second rolling groove formed on its inner circumferential 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 guide path inside. Both ends of the non-load path and both ends of the oil guide path penetrate two opposing outer end faces of the sleeve body. Two return members are respectively disposed on the outer end face of the sleeve body. The spline shaft penetrates the two return members. Each of the two return members has a return groove, an oil injection hole, an oil chamber, and an oil guide portion. One end of the return groove is connected to the load path and the other end is connected to the non-load path, forming a circulation path for rolling the plurality of balls. The oil chamber is connected to the oil injection hole, the load path, and the oil guide path of the sleeve body. The oil guide portion is disposed in the oil chamber so as to correspond to the oil filling hole and protrudes toward the oil guide path, so that the lubricating oil that flows into the oil chamber from the oil filling hole can be sent to the oil guide path.

[0007]

[0003] Specifically, when lubricating oil is injected through the oil inlet of one return member, the lubricating oil passes through the oil chamber into the load path, moistening the balls on one side, and then flows into the oil guide path via the oil guide portion. Then, along the oil guide path, it passes through the oil chamber of another return member and flows into another load path, moistening the balls on the other side. In other words, because the ball spline with lubricating oil channels according to the present invention has an oil guide path in the sleeve body and oil guide portions in two return members, it can moisten the balls on both sides simply by injecting lubricating oil through one oil inlet, i.e., achieves bidirectional lubrication. Furthermore, because the oil guide path is located inside the sleeve body, it can withstand relatively high hydraulic pressure and does not leak oil.

[0008] In a more preferred embodiment, each oil guide portion has a first end and a second end. The first end is connected to a wall surface of the oil chamber. The second end is disposed adjacent to the oil guide path. Each oil guide portion further has a slope facing the oil injection hole. The slope slopes downward from the first end to the second end and is located higher than the bottom surface of the oil guide path, so that the slope of the oil guide portion can efficiently deliver lubricating oil to the oil guide path.

[0009] In a relatively preferred case, the width of each oil guide portion gradually decreases from the first end toward the second end, thereby allowing the lubricating oil to flow efficiently to the load path below.

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

[0011] In a relatively preferable case, each oil guide portion has separate recesses on two opposing sides, which reduce the backflow of lubricating oil that has flowed from the oil guide path into the oil guide portion, allowing the lubricating oil to flow efficiently to the load path below.

[0012] In a more preferable case, the sleeve body has a lubrication passage on each outer end surface, and the lubrication passage is connected to the second rolling groove and the oil chamber, so that the lubricating oil flows from each oil guide portion to the lower lubrication passage, and then branches along the lubrication passage to flow separately into the two load paths.

[0013] In a relatively preferred case, the lubrication passage is closer to the spline shaft than the oil guide path.

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

[0015] The detailed structure, features, assembly and use of the ball spline with lubricating oil passage according to the present invention will be made clear through the following detailed description of the embodiments. It should be understood by those skilled in the art that the following detailed description and the embodiments presented by the present invention are merely examples for explaining the present invention and cannot limit the scope of the claims of the present invention. [Brief explanation of the drawings]

[0016] [Figure 1] FIG. 1 is a perspective view showing a ball spline with a lubricating oil passage according to an embodiment of the present invention. [Figure 2] FIG. 1 is an exploded perspective view showing a ball spline with a lubricating oil passage according to an embodiment of the present invention. [Figure 3] 1 is a cross-sectional view showing a ball spline with a lubricating oil passage according to an embodiment of the present invention. FIG. [Figure 4] 1 is an exploded perspective view showing a sleeve body and a return member of a ball spline with a lubricating oil passage according to an embodiment of the present invention. FIG. [Figure 5] FIG. 10 is an exploded perspective view of the sleeve body and the return member of the ball spline with lubricating oil passages according to an embodiment of the present invention, as viewed from a different angle. [Figure 6] 4 is an enlarged view showing a portion of a return member of the ball spline with a lubricating oil passage according to an embodiment of the present invention. FIG. [Figure 7] 1 is a cross-sectional view showing a portion of a ball spline with a lubricating oil passage according to an embodiment of the present invention. [Figure 8] FIG. 8 is a cross-sectional view taken along line 8-8 in FIG. 7. [Figure 9a] FIG. 10 is an enlarged view showing a portion of another type of return member of the ball spline with a lubricating oil passage according to an embodiment of the present invention. [Figure 9b] FIG. 10 is a plan view showing a portion of another type of return member of the ball spline with a lubricating oil passage according to an embodiment of the present invention. [Figure 10a]1 is an enlarged view showing a portion of a different type of return member of a ball spline with a lubricating oil passage according to an embodiment of the present invention. FIG. [Figure 10b] 1 is a plan view showing a portion of a different type of return member of a ball spline with a lubricating oil passage according to an embodiment of the present invention; FIG. [Figure 11a] 1 is an enlarged view showing a portion of a different type of return member of a ball spline with a lubricating oil passage according to an embodiment of the present invention. FIG. [Figure 11b] 1 is a plan view showing a portion of a different type of return member of a ball spline with a lubricating oil passage according to an embodiment of the present invention; FIG. [Figure 12a] 1 is an enlarged view showing a portion of a different type of return member of a ball spline with a lubricating oil passage according to an embodiment of the present invention. FIG. [Figure 12b] 1 is a plan view showing a portion of a different type of return member of a ball spline with a lubricating oil passage according to an embodiment of the present invention; FIG. [Figure 13a] 1 is an enlarged view showing a portion of a different type of return member of a ball spline with a lubricating oil passage according to an embodiment of the present invention. FIG. [Figure 13b] 1 is a plan view showing a portion of a different type of return member of a ball spline with a lubricating oil passage according to an embodiment of the present invention; FIG. DETAILED DESCRIPTION OF THE INVENTION

[0017] The ball spline with lubricating oil passages according to the present invention will now 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 structural features of the same or similar parts.

[0018] (One embodiment) As shown in FIGS. 1 and 2, a ball spline 10 with a lubricating oil passage according to one embodiment of the present invention includes a spline shaft 20, a sleeve body 30, two return members 40, two dustproof members 50, and a plurality of balls 60.

[0019] The spline shaft 20 has two pairs of first rolling grooves 22 on its outer circumferential 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 surfaces 31 and a shaft hole 32 penetrating the two outer end surfaces 31. The sleeve body 30 fits over the spline shaft 20 via the shaft hole 32 and can move along the axial direction of the spline shaft 20. The shaft hole 32 has two pairs of second rolling grooves 33 on its wall. As shown in FIG. 3, the two pairs of second rolling grooves 33 on the sleeve body 30 correspond to the two pairs of first rolling grooves 22 on the spline shaft 20, forming a load path 62. The sleeve body 30 also has two pairs of non-load paths 34 and two oil guide paths 35. Each non-load path 34 and each oil guide path 35 penetrates the two outer end surfaces 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 has two opposing lubrication passages 36 on each outer end surface 31. The lubrication passages 36 are closer to the spline shaft 20 than the oil guide paths 35. The lubrication passage 36 is connected at both ends to a pair of second rolling grooves 33 .

[0021] Two return flow members 40 are respectively disposed on the outer end surface 31 of the sleeve body 30. The spline shaft 20 passes through the two return flow members 40. Each of the two return flow members 40 has an inner end surface 41 facing toward 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 return flow grooves 43 and two opposing oil chambers 44. As shown in FIG. 3, each return flow groove 43 has one end connected to the load path 62 and the other end connected to the non-load path 34, thereby forming a circulation path 64 for rolling multiple balls 60. As shown in FIGS. 4, 5, and 7, the oil chambers 44 are connected to the oil guide path 35 of the sleeve body 30 in the axial direction and to the lubrication passage 36 of the sleeve body 30 in the radial direction. As shown in FIGS. 4 and 5, each return flow member 40 has two opposing oil injection holes 45 on its outer surface. Each of the two oil injection holes 45 is connected to an oil chamber 44 along the radial direction. As shown in FIGS. 6 and 7, each reflux member 40 further includes two oil guide portions 46. The two oil guide portions 46 are disposed in the oil chamber 44 so as to protrude toward the oil guide path 35. Each oil guide path 35 corresponds to one oil injection hole 45, oil chamber 44, and oil guide portion 46. Specifically, the oil guide portion 46 has a first end 461, a second end 462, and a slope 463. The first end 461 is connected to the wall of the oil chamber 44. As shown in FIG. 8, the second end 462 is disposed adjacent to the oil guide path 35, and its width W2 is less than or equal to the width W1 of the oil guide path 35 (i.e., W2≦W1). As shown in FIG. 7, the slope 463 slopes downward from the first end 461 to the second end 462 facing the oil injection hole 45, and is located higher than the bottom surface 352 of the oil guide path 35. As shown in Fig. 6, each oil guide portion 46 has a width that gradually decreases from a first end 461 to a second end 462, and has arc-shaped recesses 47 on two opposing side surfaces. As shown in Fig. 2, each return flow member 40 has positioning holes 48 on two opposing side surfaces of the oil chamber 44. The positioning holes 48 penetrate the inner end surface 41 and the outer end surface 42 of the return flow member 40.

[0022] The two dustproof members 50 have two pairs of columnar positioning portions 52 on their inner end surfaces. By inserting each columnar positioning portion 52 of the dustproof member 50 into the positioning hole 48 of the return flow member 40, the return flow member 40 and the sleeve body 30 can be fixed together with screws (not shown in the figure).

[0023] To summarize the above, as shown in Figure 7, when lubricating oil is injected through the oil injection hole 45 of one return member 40, the lubricating oil passes through the oil chamber 44 on that side and flows into the lower lubrication passage 36, then branches off and flows into the load path 62 to lubricate the balls 60 on the same side. At the same time, a portion of the lubricating oil flows through the oil guide portion 46 and into the oil guide path 35, then flows along the oil guide path 35 through the oil chamber 44 of the return member 40 on the other side and flows into the lower lubrication passage 36, then branches off and flows into the load path 62 on the other side to lubricate the balls 60 on the other side. As the lubricating oil flows, the relationship between the width W2 of the slope 463 of the oil guide portion 46 and the width W1 of the oil guide path 35 is W2 ≤ W1, so the lubricating oil can efficiently flow from the oil chamber 44 to the oil guide path 35. In addition, the oil guide portion 46 has recesses 47 on both sides, which allows the lubricating oil to flow from the oil guide path 35 to the oil guide portion 46, reducing backflow at the slope 463 of the oil guide portion 46 and allowing the lubricating oil to flow efficiently to the oil chamber 44 on the other side. In other words, by gradually reducing the width of the oil guide portion 46 and arranging the recesses 47 on both sides of the oil guide portion 46, the lubricating oil can efficiently flow from the oil chamber 44 to the lubrication passage 36 below.

[0024] The oil guide portion 46 is not limited to the above-described configuration and may have a different structure depending on actual needs. For example, as shown in FIGS. 9a and 9b, the oil guide portion 46 may be a pyramidal shape having a slope 463 and a depression 47. As shown in FIGS. 10a and 10b, the oil guide portion 46 may be a rectangular pyramidal shape having a slope 463 but no depression 47. As shown in FIGS. 11a and 11b, the oil guide portion 46 may be a circular arc shape having a slope 463 but no depression 47. As shown in FIGS. 12a and 12b, the oil guide portion 46 may be a rectangular pyramidal shape without the slope 463 and depression 47. As shown in FIGS. 13a and 13b, the oil guide portion 46 may be a circular arc shape without the slope 463 and depression 47. In other words, the oil guide portion 46 of any of the above-mentioned structures can redirect the lubricating oil and cause a portion of the lubricating oil to flow into the oil guide path 35, thereby providing a lubricating effect to the ball 60 on the other side inside.

[0025] To summarize the above, the ball spline 10 with lubricating oil passages according to the present invention has the oil guide path 35 in the sleeve body 30 and the oil guide portions 46 in the two return members 49, so that simply injecting lubricating oil through one oil injection hole 45 will have the effect of moistening the balls 60 on both sides, i.e., a bidirectional lubrication effect, thereby improving lubrication efficiency. Furthermore, the oil guide path 35 is disposed inside the sleeve body 30 and penetrates the sleeve body 30 along the axial direction of the spline shaft 20, so that it can withstand relatively high oil pressure and will not leak oil. [Explanation of symbols]

[0026] 10: Ball spline with lubricating oil passage 20: Spline shaft 22: First rolling groove 30: Sleeve body 31:Outer end surface 32: Shaft hole 33:Second rolling groove 34: Non-load path 35: Oil induction path 352: Bottom 36: Lubrication passage 40: Circulation member 41: Inner end surface 42:Outer end surface 43: Reflux groove 44: Oil chamber 45: Oil filling hole 46: Oil guide section 461: First end 462:Second end 463: Slope 47: Depression 48: Positioning hole 50: Dustproof material 52: Pillar positioning part 60: Ball 62: Load path 64: Circulation route W1: Width of oil guide path W2: Width of the 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 circumferential surface, the sleeve body is movably fitted over the spline shaft and has a second rolling groove formed on an inner circumferential surface thereof, and a load path formed between the second rolling groove and the first rolling groove of the spline shaft, the sleeve body has an internal non-load path and an oil guide path, both ends of the non-load path and both ends of the oil guide path penetrate two opposing outer end surfaces of the sleeve body; The two reflux members are respectively disposed on the outer end surfaces of the sleeve body, The spline shaft passes through the two reflux members, The two return members each have a return groove, an oil injection hole, an oil chamber, and an oil guide portion, one end of the return groove is connected to the loaded path and the other end is connected to the non-loaded path to form a circulation path, the oil chamber is connected to the oil injection hole, the loaded path, and the oil guide path of the sleeve body, the oil guide portion is disposed in the oil chamber to correspond to the oil injection hole, and protrudes toward the oil guide path, a plurality of the balls disposed in the circulation path;

2. 2. The ball spline with lubricating oil passage according to claim 1, wherein the return member has an oil chamber on its inner end surface facing the sleeve body, the outer peripheral surface of the return member has the oil filling hole connected to the oil chamber along the radial direction, each of the oil guide portions has a first end, a second end and a slope, the first end is connected to a wall surface of the oil chamber and the second end is disposed adjacent to the oil guide passage, the slope is inclined from the first end toward the second end while facing the oil filling hole and is located higher than a bottom surface of the oil guide passage.

3. 3. The ball spline with lubricating oil passage according to claim 2, wherein the width of each of the oil guide portions gradually decreases from the first end toward the second end.

4. 4. The ball spline with lubricating oil passage according to claim 3, wherein the width of the second end of each of the oil guide portions is smaller than or equal to the width of the oil guide path.

5. 5. The ball spline with lubricating oil passage according to claim 1, wherein each of the oil guide portions has recesses on the left and right side surfaces thereof, respectively.

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