JPH09144854A - Reduction gear - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the penetration of foreign matters, such as wear powder, mixed in lube oil into a bearing and secure smooth rotation of an output shaft for a long period. SOLUTION: A detent member 47 to prevent loosening of a nut member 33 to pre-load upper and lower bearings 16 and 17 comprises an engaging cover part 48 engaged with an output shaft 18 and the nut member 33, and a skirt part 49 integrally formed on the outer peripheral side of an engaging cover part 48, and the outer peripheral side of the upper bearing 16 is covered with the skirt part 49 throughout a whole periphery. This constitution prevents penetration of foreign matter G, such as wear powder, mixed in lubrication oil into the upper and lower bearings 16 and 17 and ensures smooth rotation of the output shaft 18 for a long period of time.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a speed reducer suitable for use in turning devices such as hydraulic excavators and hydraulic cranes.

[0002]

2. Description of the Related Art In general, turning devices such as hydraulic excavators and hydraulic cranes are equipped with a speed reducer for increasing the output of a motor as a rotation source.

Therefore, a case where the speed reducer according to the related art of this type is applied to the turning device of the hydraulic excavator shown in FIGS. 5 and 6 will be described as an example.

In the drawing, reference numeral 1 denotes a turning device disposed between a lower traveling structure of an excavator and an upper turning structure (both not shown). The turning device 1 is supplied with hydraulic oil from the outside. A hydraulic motor 2 as a rotation source for rotating the output shaft 2A by being discharged, and a reduction gear 4 for reducing the rotation of the output shaft 2A of the hydraulic motor 2 and transmitting the rotation to the turning wheel 3 are roughly constituted. I have.

Here, the revolving wheel 3 is disposed between the inner wheel 5 disposed on the lower traveling body side, the outer wheel 7 fixed to the revolving frame 6 of the upper revolving body, and between the outer wheel 7 and the inner wheel 5. A plurality of steel balls 8 (1) that smoothly rotate the outer ring 7 relative to the inner ring 5
(Only shown). The outer ring 7 rotates around the inner ring 5 via the steel balls 8, and the revolving frame 6 rotates together with the outer ring 7, whereby the upper revolving structure revolves with respect to the lower traveling structure. .

Reference numeral 9 denotes a housing which is an outer shell of the speed reducer 4 and which is vertically arranged on the revolving frame 6. The housing 9 has an upper housing 11 whose inner peripheral side is a speed reduction mechanism accommodating portion 10. The lower housing 13 is provided with a shaft support 12 on the inner peripheral side, and a mounting flange 2B of the hydraulic motor 2 is fixed to the upper end of the upper housing 11.

The upper housing 11 and the lower housing 13 are fixed to each other through a plurality of bolts 14, and the lower housing 13 is fixed to the revolving frame 6 through a plurality of bolts 15. Here, the upper housing 11
On the inner peripheral side of the small-diameter internal tooth 11A which constitutes a part of a planetary gear mechanism 23 described later, and a large-diameter internal tooth 11B which is located below the small-diameter internal tooth 11A and constitutes a part of the planetary gear mechanism 28. And are formed over the entire circumference.

Reference numeral 16 denotes an upper bearing attached to the center of the upper portion of the shaft supporting portion 12 provided in the lower housing 13, and 17 denotes a lower bearing attached to the lower portion of the shaft supporting portion 12, respectively. Tapered roller bearings are applied to the lower bearing 16 and the lower bearing 17.

Reference numeral 18 denotes a shaft support portion 12 of the lower housing 13.
Shows an output shaft that is rotatably supported via an upper bearing 16 and a lower bearing 17, and the outer periphery of the upper end side of the output shaft 18 has teeth that are spline-coupled with inner teeth 32A of a carrier 32 described later. A portion 18A is formed, and a screw portion 18B to which a nut member 33 described later is screwed is formed on the lower side of the tooth portion 18A.
Is screwed. Further, the lower end side of the output shaft 18 projects below the revolving frame 6 to form a pinion 19, and the pinion 19 meshes with internal teeth 5A formed on the inner ring 5 of the revolving wheel 3. As a result, the output shaft 18 becomes the pinion 19
At the same time, the inner frame 5 revolves around the inner teeth 5A while revolving, and the revolving force causes the revolving frame 6 to revolve through the housing 9.

Reference numeral 20 denotes an annular large-diameter retainer fitted to the lower end side of the lower housing 13, and the large-diameter retainer 20 and the shaft bearing portion 12 of the lower housing 13 form a lower bearing 17.
Holding the outer ring. Reference numeral 21 is an annular small-diameter retainer inserted into the output shaft 18, and the small-diameter retainer 21 is located between the pinion 19 of the output shaft 18 and the lower bearing 17 and holds the inner ring of the lower bearing 17. ing.

Reference numeral 22 denotes a large diameter retainer 20 and a small diameter retainer 2.
1 shows an annular oil seal provided between the inner ring 5 and the inner teeth 5A of the inner ring 5 forming the slewing ring 3 and the pinion 19 of the output shaft 18, and It is intended to prevent the jetting and the intrusion into the housing 9 due to the pumping action by the meshing of the pinion 19 with the pinion 19.

Numeral 23 is located below the hydraulic motor 2 and is disposed inside the speed reduction mechanism housing portion 10 of the upper housing 11.
The planetary gear mechanism of the second stage is shown, and the planetary gear mechanism 23 meshes with the sun gear 24 spline-coupled to the output shaft 9A of the hydraulic motor 2 and the sun gear 24 and the small-diameter internal teeth 11A of the upper housing 11. , For example, three planetary gears 25 (only one is shown) that revolve around the sun gear 24 while rotating, and a plurality of pins 26 (only one is shown) that rotatably support each planetary gear 25. , And a carrier 27 that supports the planetary gears 25 via the pins 26.

Reference numeral 28 denotes a second-stage planetary gear mechanism which is located below the planetary gear mechanism 23 and is disposed in the reduction mechanism accommodating portion 10 of the upper housing 11, and the planetary gear mechanism 28 is provided.
Is a carrier 27 that constitutes the first stage planetary gear mechanism 23.
The sun gear 29 that is spline-coupled to the internal teeth 27A provided on the sun gear 29, and the sun gear 29 and the large-diameter internal teeth 11B of the upper housing 11 mesh with each other and revolve around the sun gear 29 while revolving around, for example, three Planetary gear 30 (only one shown)
And a plurality of pins 31 (only one is shown) that rotatably support each planetary gear 30, and a carrier 32 that supports each planetary gear 30 via each pin 31.

The inner teeth 32A of the carrier 32 are spline-coupled to the teeth 18A of the output shaft 18, and the planetary gears 3
The revolution of 0 is transmitted to the output shaft 18. As a result, the rotation of the output shaft 2A of the hydraulic motor 2 is reduced in two stages by the planetary gear mechanisms 23, 28, and the output shaft 1
Rotate 8 with great torque.

Reference numeral 33 denotes a nut member which is located on the outer peripheral side of the output shaft 18 and is arranged above the upper bearing 16, and the nut member 33 is screwed into the threaded portion 18B of the output shaft 18 to form the nut member 33. It moves in the axial direction of the output shaft 18. Then, the nut member 33 appropriately preloads the upper bearing 16 and the lower bearing 17 between the nut member 33 and the shaft support portion 12 of the lower housing 13 according to the tightening amount, and performs torque management. There is.

Reference numeral 34 denotes a rotation stopping plate 34 which is inserted into the output shaft 18 and is disposed above the nut member 33 as a loosening prevention member. The rotation stopping plate 34 is formed in a hollow disc shape as a whole. 6, as shown in FIG. 6, the protrusion 34A that engages with the key groove 18C provided in the output shaft 18, and the nut member 3
3 has a pin insertion hole 34B formed at a position corresponding to the pin hole 33A formed in No. 3. Then, the fixing pin 35 is press-fitted into the pin hole 33A of the nut member 33 through the pin insertion hole 34B, so that the nut member 33 is stopped from rotating with respect to the output shaft 18. As a result, the nut member 33 is prevented from being loosened and displaced in the axial direction, and the preload state of the nut member 33 on the upper bearing 16 and the lower bearing 17 is maintained.

Reference numeral 36 denotes an oil supply port provided on the mounting flange 2B of the hydraulic motor 2, and the lubricating oil supplied into the housing 9 through the oil supply pipe 37 attached to the oil supply port 36 is sealed by the oil seal 22. Are stored in the housing 9 and lubricate the planetary gear mechanisms 23, 28, the upper bearing 16, the lower bearing 17, and the like.

Reference numeral 38 denotes an oil drain port provided in the lower housing 13 located near the upper bearing 16, and the lubricating oil stored in the housing 9 is drained from the oil drain port 3 at the time of regular replacement.
The oil is discharged from the oil drain pipe 39 attached to the housing 8 to the outside of the housing 9.

In the hydraulic excavator having the speed reducer 4 constructed as above, when the upper revolving structure is revolved on the lower traveling structure, the output shaft 2A rotates when the hydraulic oil is supplied to or discharged from the hydraulic motor 2. Then, this rotation is decelerated in two stages by the planetary gear mechanisms 23 and 28 in the housing 9 of the reduction gear 4, and a high torque rotational force is transmitted to the output shaft 18.

The pinion 19 of the output shaft 18 meshes with the inner teeth 5A of the revolving wheel 3, the inner ring 5 of the revolving wheel 3 is attached to the lower traveling body, and the outer wheel 7 is attached to the revolving frame 6 of the upper revolving body. Since it is fixed, the pinion 19 revolves around the inner teeth 5A of the inner ring 5 while rotating about its own axis.
8 is transmitted to the revolving frame 6 through the housing 9 so that the upper revolving structure turns on the lower traveling structure.

In the speed reducer 4 according to the prior art described above, the planetary gear mechanisms 23, 28 and the like are always lubricated by the lubricating oil stored in the housing 9. The foreign matter G such as wear powder generated by the meshing of the gears forming the gear 28 settles in the lubricating oil and reaches the shaft support portion 12 of the lower housing 13, and is eventually attached to the shaft support portion 12. Upper bearing 1
6 enters between the inner ring and the outer ring, or passes through the upper bearing 16 and enters between the inner ring and the outer ring of the lower bearing 17. As a result, there is a problem in that the rolling elements of the upper bearing 16 and the lower bearing 17 are damaged by the foreign matter G and the smooth rotation of the output shaft 18 is hindered, so that stable operation of the swivel device 1 cannot be compensated for a long period of time. is there.

To solve such a problem, for example, the actual Kaihei 3-
In Japanese Patent No. 93854, a conical cage is provided between an upper bearing and a lower bearing that rotatably support an output shaft in a housing, and the lower bearing is covered by the cage, so that the lubricating oil There is described a planetary gear speed reducer capable of preventing foreign matter mixed in the lower bearing from entering the lower bearing.

Further, for example, in Japanese Utility Model Laid-Open No. 5-73367, a downward projection is provided on the lower surface side of a carrier that constitutes a planetary gear mechanism, and a concave cross-section is formed around the upper bearing in the housing to face the downward projection. The upward protrusion of
Lubricating oil flows into the upper bearing side through the labyrinth portion formed between the downward and upward protrusions, preventing foreign matter mixed in the lubricating oil from entering the upper bearing by the labyrinth portion. There is described a planetary gear speed reducer capable of preventing the occurrence of the above.

[0024]

However, in the planetary gear speed reducer disclosed in Japanese Utility Model Laid-Open No. 3-93854, the foreign matter mixed in the lubricating oil is prevented from entering the lower bearing. Since the cage is provided as a separate part, there is a problem that the number of parts and the number of assembling steps increase. Further, since the cage is configured to exclusively cover the lower bearing, there is a problem that foreign matter cannot be prevented from entering the upper bearing.

Further, in the planetary gear speed reducer disclosed in Japanese Utility Model Laid-Open No. 5-73367, the labyrinth portion is formed by the downward projection attached to the lower surface of the carrier and the upward projection attached to the housing. However, there is a problem that the weight of the carrier and the housing is increased. Particularly, when the weight of the carrier increases and the inertia increases, there is a problem that smooth start and stop of the planetary gear mechanism are hindered.

The present invention has been made in view of the above-mentioned problems of the prior art, and reliably prevents foreign matter such as abrasion powder from entering the bearing without increasing the number of parts or the weight. An object of the present invention is to provide a speed reducer capable of compensating smooth rotation of the output shaft for a long period of time.

[0027]

In order to solve the above-mentioned problems, the invention of claim 1 is such that the upper side is a speed reduction mechanism accommodating portion and the lower side is a shaft supporting portion, and the housing is arranged vertically, and A deceleration mechanism that is provided in the deceleration mechanism accommodating portion of the housing and that decelerates the rotation of the rotation source; an output shaft that is inserted through the shaft support portion of the housing and that outputs the rotation decelerated by the deceleration mechanism; A bearing that is provided in the shaft support portion and rotatably supports the output shaft;
The nut member is provided on the outer peripheral side of the output shaft and applies a preload to the bearing between the shaft supporting portion of the housing, and a locking member that prevents the nut member from loosening and axially displacing. It is applied to speed reducers.

The invention according to claim 1 is characterized in that the locking member is located on an upper side in the axial direction and is engaged with the output shaft and the nut member, and the inside of the housing. In order to prevent foreign matter mixed in the lubricating oil that lubricates the speed reduction mechanism from entering the bearing, it is integrally provided so as to hang downward from the engaging lid portion and cover the outer peripheral side of the bearing. It consists of a skirt part.

According to the above construction, by engaging the engagement lid portion of the loosening prevention member with the output shaft and the nut member, the nut member is prevented from rotating with respect to the output shaft, and the bearing is preloaded by the nut member. Hold the state. At this time, the skirt portion hanging from the engagement lid portion of the loosening prevention member covers the outer peripheral side of the bearing. Thus, even if foreign matter such as wear powder is mixed in the lubricating oil that lubricates the speed reduction mechanism in the housing, the foreign matter can be prevented from entering the bearing by the skirt portion of the locking member.

According to a second aspect of the present invention, an annular step portion is formed on the shaft supporting portion of the housing on the outer peripheral side of the bearing, and the annular step portion is formed between the tip of the locking member and the step portion. This is because the labyrinth part was constructed with.

According to the above construction, the lubricating oil in the housing flows into the bearing side through the labyrinth portion formed between the step portion formed in the shaft support portion and the tip of the skirt portion of the loosening prevention member, but The labyrinth portion prevents foreign matter such as abrasion powder mixed in the oil from entering the bearing side, and prevents the foreign matter from entering the bearing.

Further, according to a third aspect of the present invention, an annular groove inclined from the inner peripheral side toward the outer peripheral side is formed in the shaft supporting portion of the housing, and the outer peripheral side of the annular groove is formed inside the housing. It is configured to open an oil discharge port for discharging the lubricating oil to the outside.

According to the above construction, foreign matter such as abrasion powder mixed in the lubricating oil is deposited in the annular groove while settling in the housing due to its own weight. This not only prevents foreign matter from entering the bearing, but also drains the foreign matter from the housing together with the drained oil by draining the lubricating oil in the housing from the oil drain port that is opened on the outer peripheral side of the annular groove. You can

According to a fourth aspect of the present invention, the annular groove is formed so that the groove depth gradually increases in the radial direction.
The oil drain port is configured to open to the outer peripheral side of the annular groove at a position where the groove depth is almost maximum.

According to the above structure, foreign matter such as abrasion powder mixed in the lubricating oil is settled while swirling in the housing in accordance with the operation of the speed reducing mechanism, and is accumulated in a portion of the annular groove having a large groove depth. Since it accumulates in a concentrated manner, a large amount of foreign matter is discharged outside the housing along with the drained oil by draining the lubricating oil inside the housing from the drainage port that opens on the outer peripheral side of the annular groove at the position where the groove depth is almost maximum. can do.

[0036]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. In the embodiments, the same components as those of the conventional technique shown in FIGS. 5 and 6 described above are designated by the same reference numerals, and the description thereof will be omitted.

In the figure, reference numeral 41 denotes a speed reducer according to the present embodiment, and a housing 42 of the speed reducer 41 has an upper housing 11 whose inner peripheral side is a speed reducing mechanism accommodating portion 10 like the housing 9 according to the prior art. Although it is composed of a lower housing 43 described later, the lower housing 4
The configuration of the shaft support portion 44 provided on the inner peripheral side of 3 is different from that of the related art.

Reference numeral 43 denotes a lower housing which constitutes the housing 42 together with the upper housing 11. The lower housing 43 has its upper end side fixed to the upper housing 11 via a plurality of bolts 14, and its lower end side a plurality of bolts 1.
It is fixed on the revolving frame 6 via 5. A shaft support portion 44 is provided on the inner peripheral side of the lower housing 43 so as to project radially inward over the entire circumference thereof, and the upper bearing 16 is attached to the center of the upper portion of the shaft support portion 44. A lower bearing 17 is attached to the center of the lower part.

Reference numeral 45 denotes an annular groove which is located on the upper surface side of the shaft support portion 44 and is provided on the outer peripheral side of the upper bearing 16 so as to be recessed over the entire circumference thereof. As shown in FIG. Perimeter side 45
It has a cross-sectional shape that is inclined from A toward the outer peripheral side surface 45B, and is formed such that the height position of its bottom surface 45C is lower than the upper surface of the upper bearing 16.

Further, the annular groove 45 is formed such that the groove depth thereof gradually increases along the radial direction. For example, as shown in FIG. 2, the annular groove 45 is formed on one side in the radial direction (left side in the drawing). The groove depth t1 is minimized, and the groove depth t2 on the other side in the radial direction (the right side in the drawing) is maximized (t2> t1). Further, in the present embodiment, the oil discharge port 38 for discharging the lubricating oil in the housing 42 to the outside is located at the position where the groove depth of the annular groove 45 is substantially maximum, and the outer peripheral side surface 4 of the annular groove 45 is
It is configured to open to 5B.

Reference numeral 46 denotes an annular step portion formed on the shaft support portion 44 at the upper end portion of the inner peripheral side surface 45A of the annular groove 45, and the step portion 46 is attached to the shaft support portion 44 by the upper bearing 16. A labyrinth portion 50 is formed so as to surround the outer peripheral side of the skirt portion 49 and a tip end edge of a skirt portion 49 of a rotation stopping member 47 described later.

Reference numeral 47 is a rotation stopping member as a loosening prevention member according to the present embodiment, which is used in place of the rotation stopping plate 34 according to the prior art, and the rotation stopping member 47 as a whole is bent as shown in FIGS. A hollow disk-shaped engagement lid portion 48 having a bowl shape and a skirt portion 49 that extends downward from the outer peripheral side of the engagement lid portion 48 and hangs downward are integrally formed. Further, the engagement lid portion 48 is formed with a projection portion 48A that engages with the key groove 18C of the output shaft 18, and a pin insertion hole 48B into which the fixing pin 35 is inserted.

Then, the detent member 47 is provided on the engaging lid 4
The protrusion 48A of No. 8 is engaged with the key groove 18C of the output shaft 18, and the nut member 33 is inserted through the pin insertion hole 48B.
By pressing the fixing pin 35 into the pin hole 33A of
Nut member 3 in which the upper bearing 16 and the lower bearing 17 are preloaded
3, the nut member 33 is prevented from slackening and axially displacing.

At this time, the skirt portion 49 provided on the rotation stopping member 47 covers the upper bearing 16 over the entire circumference, and the tip edge of the skirt portion 49 has the shaft of the lower housing 43 as shown in FIG. A labyrinth portion 50 having a minute gap is formed between the step portion 46 formed on the support portion 44 and the step portion 46.

The speed reducer 41 according to this embodiment has the above-mentioned structure. When the hydraulic motor 2 is supplied with pressure oil from the outside, the output shaft 2A rotates, and this rotation causes the speed reducer 41 to rotate.
In the housing 42 of the planetary gear mechanism 23, 28, the speed is reduced in two stages, a high torque rotational force is transmitted to the output shaft 18, and the pinion 19 revolves while revolving via the internal teeth 5A of the inner ring 5. The upper revolving structure performs a revolving motion on the lower traveling structure.

At this time, the planetary gear mechanisms 23 and 28, which operate to reduce the rotation of the output shaft 2A of the hydraulic motor 2, are constantly lubricated by the lubricating oil stored in the housing 42, and the planetary gear mechanisms 23 and 28 are constantly lubricated. Foreign matter G such as abrasion powder generated by the meshing of the gears that make up the
3 is settled in the lubricating oil toward the shaft support portion 44. However, the upper bearing 16 attached to the shaft support portion 44 has the skirt portion 4 of the rotation stopping member 47 that rotates together with the output shaft 18.
Since it is always covered with 9, foreign matter G settling in the lubricating oil can be prevented from entering the upper bearing 16, and foreign matter to the lower bearing 17 disposed below the upper bearing 16 can be prevented. It is possible to prevent G from entering.

The lubricating oil in the housing 42 is agitated by the operation of the planetary gear mechanisms 23, 28, and passes through the labyrinth portion 50 as shown by arrow F in FIG.
Although the foreign matter G flowing into the 6 side is agitated together with the lubricating oil, the labyrinth portion 50 prevents the foreign matter G from flowing into the upper bearing 16 side.
Further, it is possible to reliably prevent the intrusion into the lower bearing 17.

The foreign matter G, which is prevented from entering the upper bearing 16, sinks in the housing 42 due to its own weight and is located in the annular groove 4 at a position lower than the upper surface of the upper bearing 16.
The foreign matter G can be prevented from entering the upper bearing 16 and the lower bearing 17 because the foreign matter G is deposited in the lower bearing 17.

Moreover, since the annular groove 45 is formed so that its groove depth gradually increases in the radial direction, the foreign matter G agitated with the lubricating oil by the operation of the planetary gear mechanisms 23, 28. As shown in FIG. 2, eventually, the gas will be concentratedly deposited at a position where the groove depth of the annular groove 45 becomes substantially maximum, that is, in the vicinity of the opening position of the oil drain port 38. In this state, by discharging the lubricating oil in the housing 42 from the oil drain port 38 to the outside, most of the accumulated foreign matter G can be discharged to the outside of the housing 42 together with the drain oil.

As described above, according to this embodiment, the detent member 47 for pre-loading the upper bearing 16 and the lower bearing 17 to prevent the nut member 33 from loosening is engaged with the output shaft 18 and the nut member 33. The engaging lid portion 48 and the skirt portion 49 integrally provided on the outer peripheral side of the engaging lid portion 48,
Since the upper bearing 16 is covered with the skirt portion 49 over the entire circumference thereof, foreign matter G such as abrasion powder mixed in the lubricating oil for lubricating the planetary gear mechanisms 23, 28 and the like in the housing 42 is It is possible to prevent the intrusion into the upper bearing 16 and the lower bearing 17 arranged below the upper bearing 16. As a result, it is possible to prevent damage to the upper bearing 16 and the lower bearing 17 due to the intrusion of the foreign matter G, and it is possible to compensate for smooth rotation of the output shaft 18 and stable operation of the reduction gear 41 for a long period of time. .

Moreover, by providing the skirt portion 49 having the above-described excellent effect and effect integrally with the engaging lid portion 48 of the rotation stopping member 47, the foreign matter mixed in the lubricating oil as in the prior art described above. It is possible to prevent an increase in the number of parts and the number of assembling steps as compared with the case where a separate part is provided to prevent the intrusion into the bearing.

Further, an annular step portion 46 is formed on the shaft support portion 44 provided in the lower housing 43 on the outer peripheral side of the upper bearing 16, and the step portion 46 and the skirt portion of the rotation stopping member 47 are formed. 49. By forming the labyrinth portion 50 with the leading edge, only the lubricating oil out of the lubricating oil and the foreign matter G agitated by the operation of the planetary gear mechanisms 23, 28 passes through the labyrinth portion 50 to the upper bearing 16 side. The foreign matter G mixed in the lubricating oil can flow into the upper bearing 16
It is possible to reliably prevent the intrusion into the lower bearing 17.

Moreover, the skirt portion 49 of the anti-rotation member 47
Since the labyrinth portion 50 is formed between the tip edge and the step portion 46 provided on the shaft support portion 44, the downward projection and the housing provided on the lower surface side of the carrier that constitutes the planetary gear mechanism as in the above-described conventional art. It is possible to prevent the weight of the carrier and the housing from increasing as compared with the case where the labyrinth portion is formed by the upward protrusion provided on the.

Further, an annular groove 45 whose groove depth gradually increases along the radial direction is provided on the upper surface of the shaft support portion 44, and the groove depth of the annular groove 45 is substantially maximum. By opening the oil drain port 38 at the position, the housing 42
The foreign matter G mixed in the lubricating oil inside can be concentratedly deposited at a position where the groove depth of the annular groove 45 is substantially maximum, that is, in the vicinity of the opening position of the oil discharge port 38. As a result, most of the foreign matter G mixed in the lubricating oil can be removed every time the lubricating oil is regularly replaced, so that the life of the upper bearing 16 and the lower bearing 17 can be extended, and the smooth rotation and deceleration of the output shaft 18 can be achieved. The stable operation of the device 41 can be compensated for a longer period of time.

In the above embodiment, the rotation stopping member 47 is used.
The labyrinth portion 50 is formed between the tip edge of the skirt portion 49 provided in the lower housing 43 and the step portion 46 formed in the shaft support portion 44 of the lower housing 43, and foreign matter mixed in the lubricating oil is transferred to the upper bearing 16 side. Although the labyrinth portion 50 is used to prevent the inflow, the present invention is not limited to this. For example, a sliding plate made of a flexible material such as rubber is fixed to the tip edge of the skirt portion 49, This sliding plate is used as the shaft support portion 44.
It is also possible to prevent the foreign matter in the lubricating oil from flowing into the upper bearing 16 side by constantly sliding it on.

Further, in the above-mentioned embodiment, the detent member 47 is provided.
Although the case where the engaging lid portion 48 and the skirt portion 49 that constitute the above is integrally formed is described as an example, the present invention is not limited to this, and for example, the engaging lid portion 48 and the skirt portion 49 are separately formed. After that, they may be integrated by welding or the like.

Further, in the above-mentioned embodiment, the speed reducer provided with the two-stage planetary gear mechanism has been described as an example, but the present invention is not limited to this, and the one-stage planetary gear mechanism or three or more stages. The invention may be applied to a speed reducer equipped with a planetary gear mechanism, and may also be applied to a speed reducer equipped with a type of speed reducer mechanism that does not use a planetary gear.

Further, in the above-described embodiment, the case where the upper bearing 16 and the lower bearing 17 are used as the bearings for supporting the output shaft 18 is taken as an example, but one bearing or three or more bearings is used. The output shaft may be supported by.

[0059]

As described in detail above, according to the invention of claim 1, a locking member for locking the nut member is provided with an engagement lid portion for engaging the output shaft and the nut member, and the engagement member. A skirt portion that hangs from the lid and covers the outer peripheral side of the bearing, and prevents the foreign matter mixed in the lubricating oil that lubricates the reduction mechanism in the housing from entering the bearing. By doing so, it is possible to prevent the bearing from being damaged by the entry of foreign matter mixed in the lubricating oil,
The smooth rotation of the output shaft can be compensated for over a long period of time. In addition, by providing the skirt portion integrally with the engagement lid portion of the anti-loosening member, compared to the case where a separate component is provided to prevent foreign matter mixed in the lubricating oil from entering the bearing. It is possible to prevent an increase in the number of parts and the number of assembly steps.

According to the second aspect of the invention, an annular step portion is formed on the shaft support portion of the housing on the outer peripheral side of the bearing, and the skirt portion tip of the loosening prevention member and the step portion are formed. By forming the labyrinth part between them, only the lubricating oil, out of the lubricating oil and foreign matter agitated by the operation of the speed reduction mechanism, can flow into the bearing side through the labyrinth part. It is possible to reliably prevent foreign matter from entering the bearing. Further, since the labyrinth portion is formed between the tip of the skirt portion of the loosening prevention member and the stepped portion formed on the shaft support portion of the housing, it is compared to the case where a special structure for forming the labyrinth portion is attached. Then, it is possible to avoid the problem that the weight of the entire apparatus increases.

Further, according to the invention of claim 3, an annular groove inclined from the inner peripheral side toward the outer peripheral side is formed in the shaft supporting portion of the housing, and the outer peripheral side of the annular groove is formed inside the housing. Since it is configured to open the drainage port for discharging the lubricating oil to the outside, by removing the lubricating oil in the housing from the drainage port in the state that foreign substances mixed in the lubricating oil are accumulated in the annular groove, Foreign substances can be discharged to the outside of the housing together with oil drainage.

Further, according to the invention of claim 4, the annular groove is formed such that the groove depth gradually increases along the radial direction, and the oil drain port is annular at a position where the groove depth is substantially maximum. Since it is configured to open to the outer peripheral side of the groove, foreign matter mixed in the lubricating oil can be concentratedly accumulated at the position of the annular groove where the oil drain port is opened, and the lubrication inside the housing from the oil drain port is possible. By draining the oil, many foreign substances can be discharged to the outside of the housing together with the oil drain. As a result, most of the foreign substances mixed in during lubrication can be removed every time the lubricating oil is regularly replaced, so that the life of the bearing can be extended and smooth rotation of the output shaft can be compensated for a longer period of time.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view showing a speed reducer according to an embodiment of the present invention.

FIG. 2 is an enlarged cross-sectional view showing a main part of the reduction gear transmission shown in FIG.

FIG. 3 is an enlarged perspective view showing a rotation stop plate shown in FIG. 1.

FIG. 4 is an enlarged cross-sectional view showing a skirt portion and the like of the rotation stopping plate shown in FIG.

FIG. 5 is a vertical sectional view showing a speed reducer according to a conventional technique.

FIG. 6 is an enlarged cross-sectional view showing a rotation stop plate and the like of the speed reducer shown in FIG. 5 at the same position as in FIG.

[Explanation of symbols]

 2 Hydraulic Motor (Rotation Source) 10 Reduction Mechanism Housing 16 Upper Bearing 17 Lower Bearing 18 Output Shaft 23, 28 Planetary Gear Mechanism (Reduction Mechanism) 33 Nut Member 38 Oil Drain 42 Housing 44 Shaft Support 45 Annular Groove 46 Step Part 47 Anti-rotation member (slack prevention member) 48 Engaging lid part 49 Skirt part 50 Labyrinth part

 ──────────────────────────────────────────────────続 き Continuing from the front page (72) Inventor Yuji Igawa 650 Kandamachi, Tsuchiura-shi, Ibaraki Prefecture Within Hitachi Construction Machinery Engineering Co., Ltd.

Claims (4)

[Claims] 1. A housing which is disposed in an up-down direction with an upper portion serving as a speed reduction mechanism housing portion and a lower portion serving as a shaft support portion,
A deceleration mechanism provided in the deceleration mechanism accommodating portion of the housing for decelerating the rotation of the rotation source; an output shaft provided through the shaft support portion of the housing for outputting the rotation decelerated by the deceleration mechanism; And a nut member for rotatably supporting the output shaft, the nut member being provided on the outer peripheral side of the output shaft and applying a preload to the bearing between the shaft support part of the housing, and the nut. In a speed reducer including a loosening prevention member that prevents the member from slackening and axially displacing, the loosening prevention member is located on an upper side in the axial direction and engages with the output shaft and the nut member. In order to prevent foreign matter mixed in the lubricating oil for lubricating the speed reduction mechanism in the housing from entering the inside of the bearing, the engaging lid portion hangs downward from the engaging lid portion and integrally formed. Provided said shaft A speed reducer comprising a skirt portion covering an outer peripheral side of the bridge. 2. A shaft support portion of the housing is formed with an annular step portion located on the outer peripheral side of the bearing, and a labyrinth portion is formed between the tip of the skirt portion of the locking member and the step portion. The speed reducer according to claim 1. 3. A shaft supporting portion of the housing is formed with an annular groove inclined from the inner peripheral side toward the outer peripheral side, and the lubricating oil in the housing is discharged to the outside on the outer peripheral side of the annular groove. 2. A structure for opening an oil drain port for
Alternatively, the speed reducer described in 2. 4. The annular groove is formed so that the groove depth gradually increases along the radial direction, and the oil drain port is opened to the outer peripheral side of the annular groove at a position where the groove depth is substantially maximum. The speed reducer according to claim 3, wherein the speed reducer is configured to allow the speed reducer.