JPH0522927U - Lubrication structure of reduction gear - Google Patents

Abstract

(57) [Summary] [Object] The present invention is to provide a lubricating structure for a speed reducer in which the lubricating effect in the bearing portion of a fine planetary gear is enhanced by the outflow and renewal of impurities that accumulate due to the flow action. .. [Structure] A vertical hole penetrating through a shaft pin that rotatably supports a planetary gear via a bearing and a horizontal hole that intersects with this vertical hole and communicates with the inner peripheral surface of the bearing are formed. Semi-circular protrusions are formed at the upper and lower ends to allow lubricating oil to flow through the vertical holes when the planetary gear revolves around the sun gear and revolves in the direction of the cut surface of the lower protrusion formed on the shaft pin. At the same time, the lubricating oil of the bearing is made to flow by utilizing the pressure difference from the lateral hole.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a lubrication structure of a reduction gear suitable for an upper turning vehicle such as a hydraulic excavator and a hydraulic crane.

[0002]

[Prior Art]

 For example, a hydraulic excavator for excavating and loading earth and sand is installed between a lower traveling body, an upper revolving structure provided on the lower traveling structure, and the lower traveling structure and the upper revolving structure. The turning device includes a turning wheel on the side of the lower traveling body, a turning motor on the side of the upper turning body, a one-stage or multi-step speed reducing device that reduces the rotation of the turning motor, and the turning wheel. And a pinion that meshes with and rotates the upper revolving structure by decelerated rotation from the speed reducer.

FIG. 4 is a cross-sectional view of a single-step planetary gear speed reducer used in a conventional swivel device. In the figure, reference numeral 1 is an upper swing body frame, and 2 is a casing fixed to the frame 1 by bolts 3. Reference numeral 4 denotes a ring gear attached to the casing 2, and an internal gear 5 is formed on the inner peripheral surface of the ring gear 4. Reference numeral 6 denotes a cover attached to the upper side of the ring gear 4, and the cover 6 and the ring gear 4 are integrally attached to the casing 2 with bolts 7. Reference numeral 8 denotes a turning hydraulic motor which is attached to the cover 6 with bolts 9. A sun gear 11 is connected to the motor shaft 10 projecting into the cover 6 by a spline 12 so that the hydraulic motor 8 can be rotationally driven. Has become. Reference numeral 13 is a carrier, and the lower portion of the carrier 13 is connected to the output shaft 14 by a spline 15, and a plurality of planetary gears 16 are rotatably supported by shaft pins 17, respectively. Engages with the internal gear 5 of the ring gear 4 and the sun gear 11. Therefore, when the sun gear 11 is rotationally driven by the hydraulic motor 8, the planetary gear 16 revolves around the sun gear 11 while rotating on its own axis, so that the carrier 13 to which the planetary gear 16 is mounted becomes a planetary gear. Decelerates at the same speed as the revolution speed of 16. Here, the planetary gear 16 forms a one-step reduction gear mechanism by decelerating by a tooth number ratio with the sun gear 11 and revolving.

The output shaft 14 coupled to the carrier 13 and the spline 15 is rotatably supported by upper and lower bearings 18 a and 18 b, and the pinion gear 19 integrally formed on the lower portion is a slewing wheel 21 provided on the lower traveling body frame 20. Meshes with. By the way, although oil bath lubrication is generally used as a lubricating means in the speed reducer configured as described above, a planetary gear rotatably supported on the shaft pin 17 through a bearing 22 such as a needle bearing on the carrier 13 is used. No. 16 is near the liquid level 23, there is a problem that the oil bath lubrication of the bearing 22 is not performed. Of course, in order to deal with this problem, the shaft pin 17 is provided with a lubrication passage hole composed of an axial vertical hole 17a and a radial horizontal hole 17b which intersects with the vertical hole 24a and communicates with the inner peripheral surface portion of the bearing 22. The lubricating oil is provided so that the lubricating oil flows into the bearing 22.

[0005]

[Problems to be solved by the device]

 However, even if the shaft pin 17 is simply provided with the lubrication-conducting hole consisting of the vertical hole 17a and the horizontal hole 17b as described above, the lubricating oil does not circulate and only stays in the vertical hole 17a and the horizontal hole 17b. As a result, there is a drawback that impurities such as abrasion powder and deteriorated oil in the bearing 22 cannot be removed, and a lubricating effect cannot be obtained. Of course, there is also a method of raising the liquid level 23 of the filled lubricating oil upward, but on the other hand, there is a problem that the stirring resistance is increased and the oil temperature rises, and at the same time, even if oil bath lubrication is performed, such a needle bearing In such bearings, the lubricating oil simply stays and does not solve the above problems.

The present invention has been made for the purpose of improving the above-mentioned conventional problems, and it is a fine bearing, particularly a needle bearing, which is in an upper position while maintaining a low liquid level required for lubrication. A lubrication structure of a reduction gear having an improved lubrication effect on a bearing of a planetary gear that uses

[0007]

[Means for Solving the Problems]

 In order to achieve the above object, the present invention provides a planetary gear type speed reducer comprising a planetary gear that is rotated and revolved by a sun gear supported by a carrier, and an output shaft that is rotated by the revolution of the planetary gear. Approximately semicircular protrusions are formed at opposite positions on the upper and lower ends of a shaft pin that rotatably supports a planetary gear via bearings, and a vertical hole that penetrates the shaft pin in the axial direction and the vertical hole. The object was achieved by using a lubrication structure in which lateral holes that intersect each other and communicate with the bearing surface are provided.

[0008]

[Action]

 Therefore, according to the rotation of the carrier, the lower lubricating oil is scooped up by the lower protrusion of the shaft pin of the planetary gear and circulated from the vertical hole to the bearing through the horizontal hole. Lubricating oil in the bearing is made to flow and then flows upward from the upper opening of the vertical hole to constantly circulate lubricate the bearing.

[0009]

【Example】

 An embodiment of the present invention will be described in detail below with reference to FIGS. The same components as those of the conventional technique are designated by the same reference numerals and the description thereof will be omitted.

FIG. 1 is a speed reducer suitable for a turning device of a hydraulic excavator similar to the above-described conventional speed reducer, and shows a lubrication structure for a bearing of a planetary gear according to the present invention. There is. In the figure, 11 is a sun gear coupled to a hydraulic motor shaft 10 by a spline 12, 13 is a carrier, and a plurality of planetary gears 16 supported at both ends by the carrier 13 are meshed between the sun gear 11 and the ring gear 4. In addition, the rotation of the sun gear 11 is decelerated, and the deceleration is transmitted to the output shaft 14.

The speed reducer is composed of oil bath lubrication, and the liquid level 23 of the lubricating oil is lowered to reduce the stirring resistance and improve the heat balance, and is approximately at an intermediate position of the planetary gear 16. Is done.

Therefore, in order to lubricate the bearing 22 composed of the needle bearing of the planetary gear 16 at the liquid level 23, the upper and lower end portions of the shaft pin 25 fixedly held by the upper and lower support pieces 13a and 13b of the carrier 13 The protrusions 26a, 26b having a substantially semicircular cross section are provided at the vertically opposite positions while protruding from the upper and lower support pieces 13a, 13b of the carrier 13. The cut surfaces 27a and 27b of the upper and lower protrusions 26a and 26b are attached so as to face the revolution start of the planetary gear 16, and the cut surfaces 27a of the lower protrusion 26a face the revolution direction shown by the arrow in FIG. Therefore, the cut surface 27b of the upper protrusion 26b is oriented in the direction opposite to the revolving direction. Of course, these cut surfaces 27a, 27b may be oriented in the direction of revolution opposite to the arrow. Further, the shaft pin 25 is formed with a vertical hole 24a penetrating along the axis and a radial horizontal hole 24b intersecting with the vertical hole 24a and communicating with the inner peripheral surface portion of the bearing 22. ..

Next, to describe the lubrication action of the lubrication structure configured as described above, when the planetary gear 16 revolves around the sun gear 11 via the sun gear 11 that rotates left and right in accordance with the turning direction, this revolution direction changes. When facing the cut surface 27a of the lower projection 26a formed on the shaft pin 25, the lubricating oil is introduced along with the revolution through the lower opening 28a scooped by the cut surface 27a into the vertical hole 24a, and at the upper projection 26b. At the same time as flowing out from the upper opening 28b surrounded by the rear, a pressure difference with the horizontal hole 24b is generated by the flow in the vertical hole 24a, and the lubricating oil in the horizontal hole 24b is sucked toward the vertical hole 24a. Due to this pressure difference phenomenon, the lubricating oil in the bearing 22 flows out to the vertical hole 24a through the lateral hole 24b, and then new lubricating oil flows into the bearing 22 and the lubricating oil in the bearing 22 circulates. This circulation is stopped when the planetary gear 16 revolves in the opposite direction, but the revolution direction is always changed, and therefore, circulation lubrication during one revolution is set in advance.

In the present embodiment, the one-stage planetary speed reducer has been described, but it is of course also applied as bearing lubrication for planetary gears in a two-stage or three-stage multi-stage planetary speed reducer.

[0015]

[Effect of the device]

 Since the present invention is configured as described above, the bearing lubrication of the speed reducer particularly in the upper position where the oil bath is difficult is improved, and moreover, the orbital motion of the planetary gears is used to circulate and lubricate the bearing. Since the lubricating oil is renewed, impurities such as metal powder are removed, which greatly improves the reliability and life of the bearing.

Moreover, in the above-mentioned circulation lubrication, if the revolution speed becomes faster, the circulation speed becomes proportionally faster and the lubrication effect is further improved. In addition, the liquid level is also low, so the stirring resistance can be reduced to suppress the oil temperature rise and prevent oil deterioration. Furthermore, since the lubrication structure has an extremely simple structure in which the oil hole and the protrusion are formed in the shaft pin, it is inexpensive and has a large practical effect.

[Brief description of drawings]

FIG. 1 is a sectional view of a speed reducer according to the present invention.

FIG. 2 is a sectional view of FIG. 1A-A.

FIG. 3 is a perspective view of a shaft pin of a planetary gear according to the present invention.

FIG. 4 is a sectional view of a conventional speed reducer.

[Explanation of symbols]

 2 Casing 4 Ring gear 5 Internal gear 8 Rotation hydraulic motor 11 Sun gear 13 Carrier 14 Output shaft 16 Planetary gear 17 Shaft pin 19 Pinion gear 21 Swivel wheel 22 Bearing 23 Liquid level 24a Vertical hole 24b Horizontal hole 25 Shaft pin 26a Lower protrusion 26b Upper protrusion 27a, b Cut face 28a, b Opening

Claims (1)

[Scope of utility model registration request] 1. A planetary gear type speed reducer comprising a planetary gear supported on a carrier and rotated and revolved by a sun gear, and an output shaft rotated by the revolution of the planetary gear, wherein the planetary gear is interposed by a bearing. Shaft pins rotatably and rotatably supported on the upper and lower ends of the shaft pin at substantially opposite positions, and a vertical hole penetrating the shaft pin in the axial direction and the vertical hole intersecting with the vertical hole. In addition to forming horizontal holes that communicate with the bearing surface, as the carrier rotates, the lower lubricating oil is picked up by the lower protrusions of the shaft pins to conduct to the vertical holes, and the pressure difference from the horizontal holes is used. To lubricate the bearing and allow the bearing to flow out through the upper opening.