JP5342248B2 - Traveling unit for construction machinery - Google Patents

Description

  The present invention relates to a traveling unit for construction machinery that outputs by reducing the rotation of a motor.

  In general, a crawler is often used as a traveling device for a construction machine such as a hydraulic excavator, and a traveling unit combining a hydraulic motor mechanism and a planetary speed reduction mechanism is used as a driving device for the crawler. Conventionally, as this traveling unit, there exists a thing as described in patent document 1, for example. A travel unit (reduction gear device) described in Patent Literature 1 is rotatably fitted to a main body case (2) that houses a hydraulic motor mechanism, and a main body case (2), and a transmission (1B) is provided. A rotating case (5) for housing is provided. Here, in this traveling unit (reduction gear device), the lid (28) is fitted inside the opening at the end of the rotating case (5), and the main body case (2) and the lid (28) are attached. It is fixed (see FIG. 1 of Patent Document 1).

  However, as described in Patent Document 1, the lid (28) is fitted inside the opening of the rotating case (5) to fix the main body case (2) and the lid (28). In the traveling unit, the lubricating oil in the rotating case (5) may leak from between the rotating case (5) and the lid (28). As the gear inside the speed reducer moves, the rotating case (5) is deformed to the outside, and this deformation creates a gap between the rotating case (5) and the lid (28), and the lubricating oil leaks. is there. As a countermeasure, a sealant is applied between the rotating case (5) and the lid (28). However, with this countermeasure, the processing and assembling properties are poor and the manufacturing cost is high.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a construction machine having a structure capable of preventing leakage of lubricating oil in the rotating case by suppressing deformation to the outside of the rotating case. It is to provide a traveling unit for use.

  In order to achieve the above object, the present invention includes a main body case fixed to a construction machine, a rotating case that is rotatably held with respect to the main body case and has inner teeth formed on an inner periphery thereof, and the rotating case. A speed reduction mechanism that is housed and meshes with the inner teeth, a lid member that covers the opening of the rotating case, a fixing means that fixes the lid member to the rotating case, and a lid member and the rotating case. And the lid member includes a bottom portion that covers the opening, and a cylindrical portion that extends from an end of the bottom portion in a case axial direction, and the cylindrical portion is provided on an outer peripheral surface of the rotating case end portion. A traveling unit for construction machines is provided in which the inner peripheral surface is fitted and the rotating case and the lid member are fixed.

  According to this configuration, even if the rotating case is deformed to the outside by fixing the rotating case and the lid member by fitting the inner peripheral surface of the cylindrical portion of the lid member to the outer peripheral surface of the rotating case end, Deformation is suppressed by the cylindrical portion of the lid member. Further, even if the rotating case is slightly deformed to the outside, a gap does not increase between the outer peripheral end of the rotating case and the cylindrical portion of the lid member, and the sealing performance can be maintained.

  Moreover, in this invention, it is preferable that the said seal | sticker is arrange | positioned between the outer peripheral surface of the said rotation case edge part, and the internal peripheral surface of the said cylinder part.

  According to this configuration, even when the rotating case is going to be deformed outward or when the rotating case is deformed outward, between the outer peripheral surface of the end of the rotating case and the inner peripheral surface of the cylindrical portion of the lid member. The seal continues to be pinched. Thereby, the leakage of the lubricating oil in the rotating case can be prevented more reliably.

  Furthermore, in the present invention, it is preferable that the seal is disposed in a groove formed on the inner peripheral surface of the cylindrical portion.

  According to this structure, the crushing cost of a seal becomes large and can improve sealing performance.

  Furthermore, in this invention, it is preferable that the level | step difference is formed in the outer peripheral surface of the said rotation case edge part.

  According to this configuration, it is possible to reduce the amount of the outer peripheral surface of the cylindrical portion of the lid member protruding outward from the outer peripheral surface of the rotating case, and as a result, the earth and sand that flows between these outer peripheral surfaces and the crawler of the construction machine , Can be prevented from accumulating during this time.

  Further, in the present invention, the fixing means is a bolt arranged from the outer periphery of the cylindrical portion toward the center of the case axis, and 2 to 10 bolts are equally arranged on the outer periphery of the cylindrical portion. Is preferred.

  According to this configuration, the main role of the bolt is to fix the lid member to the rotating case, that is, there is no need to particularly consider the tightening force by the bolt with respect to the sealing performance between the lid member and the rotating case. The number of bolts can be reduced.

  According to the present invention, by the lid member having the cylindrical portion extending in the case axial direction from the end of the bottom portion, particularly the inner periphery of the cylindrical portion of the lid member on the outer peripheral surface of the rotating case end portion. By fitting the surfaces and fixing the rotating case, deformation to the outside of the rotating case can be suppressed, and as a result, leakage of lubricating oil in the rotating case can be prevented.

It is a partially cutaway sectional view of a traveling unit for construction machines according to an embodiment of the present invention. It is the A section enlarged view of FIG.

  Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings. The construction machine travel unit (hereinafter referred to as “travel unit”) according to the present invention is used as a drive device for a crawler (travel device) of a construction machine such as a hydraulic excavator.

(Configuration of traveling unit)
FIG. 1 is a partially cutaway sectional view of a traveling unit 1 according to an embodiment of the present invention. FIG. 2 is an enlarged view of part A in FIG.

  As shown in FIG. 1, a traveling unit 1 according to this embodiment includes a main body case 2 fixed to a vehicle body (not shown) of a construction machine, a rotating case 3 that is rotatably held with respect to the main body case 2, A lid member 6 that covers the opening at the end of the rotating case 3. A bearing such as a ball bearing is fitted between the outer peripheral surface of the main body case 2 and the inner peripheral surface of the rotating case 3, and the rotating case 3 is rotatably held with respect to the main body case 2 via this bearing. (Not shown).

(Body case)
The main body case 2 is made of metal, and a motor mechanism 4 (not shown) is accommodated therein. The main body case 2 has a flange portion 2a formed on the outer periphery thereof. The traveling unit 1 is fixed to the vehicle body of the construction machine at the flange portion 2a. The main body case 2 is formed in a cylindrical shape as a whole.

  Here, the motor mechanism 4 is a hydraulic motor mechanism that operates by hydraulic pressure. An output shaft 11 (not shown) is disposed at the rotation center of the motor mechanism 4. The output shaft 11 is rotated by the operation of the motor mechanism 4.

(Rotating case)
The rotating case 3 is made of metal, and the speed reduction mechanism 5 is accommodated therein. A flange portion 3 c is formed on the outer periphery of one end portion of the rotating case 3. A sprocket for driving a construction machine (not shown) is attached to the flange portion 3c. The crawler (not shown) is driven when the rotating case 3 to which the driving sprocket is attached is rotated by the motor mechanism 4 via the speed reduction mechanism 5. Further, as shown in FIG. 2 with reference numerals, a step is formed on the outer peripheral surface 3 b of the other end of the rotating case 3. This step is a step that falls toward the center of the case axis. In addition, a bottomed hole 3d into which the tip of the bolt 7 is inserted is formed in the step portion. In addition, this hole 3d is good also as a screw hole by which the screw | thread was cut by the inner periphery. The rotating case 3 is formed in a cylindrical shape as a whole, and lubricating oil for the speed reduction mechanism 5 is sealed inside.

  The speed reduction mechanism 5 is composed of a planetary gear mechanism, and an output shaft 11 of the motor mechanism 4 is attached to the center thereof. An inner tooth 3 a that meshes with a gear (planetary gear) of the speed reduction mechanism 5 is formed on the inner periphery of the rotating case 3. The speed reduction mechanism 5 reduces the rotational speed of the output shaft 11 and transmits the output from the motor mechanism 4 to the rotary case 3 via the internal teeth 3a.

(Cover member)
The opening at the other end of the rotating case 3 is closed by a lid member 6. The lid member 6 is made of metal and has a bottom portion 9 on a disc that covers the opening of the rotating case 3 and a cylindrical portion 10 that extends from the end of the bottom portion 9 in the case axial direction.

  The bottom portion 9 is sequentially distinguished from the center in the radial direction into a first thick portion 9a, a thin portion 9b, and a second thick portion 9c. Moreover, the center part of the outer side of the bottom part 9 becomes the recessed part 9d.

  As shown in FIG. 2 which is an enlarged view of the portion A in FIG. 1, the tube portion 10 includes a screw hole 10 c into which the bolt 7 is screwed at the tip portion. Further, a groove portion 10b having a U-shaped cross section is formed on the inner peripheral surface 10a of the cylindrical portion 10 over the entire circumference. The groove 10b is provided closer to the bottom 9 than the screw hole 10c. An O-ring 8 (seal) is placed in the groove 10b. A groove portion may be formed on the outer peripheral surface 3b of the end portion of the rotating case 3 instead of the inner peripheral surface 10a of the cylindrical portion 10, and the O-ring 8 may be disposed in this groove portion. Moreover, the seal | sticker arrange | positioned in the groove part 10b is not restricted to the O-ring 8, The seal of various ring forms can be used.

  The lid member 6 is fixed to the rotating case 3 as follows. First, the inner peripheral surface 10a of the cylindrical portion 10 is fitted to the outer peripheral surface 3b at the end of the rotating case 3. And the bolt 7 is screwed in from the outer periphery of the cylinder part 10 toward the hole 3d formed in the outer peripheral surface 3b of the rotation case 3 edge part. In this way, the rotating case 3 and the lid member 6 are fixed. At this time, the O-ring 8 is crushed and sandwiched between the outer peripheral surface 3 b at the end of the rotating case 3 and the inner peripheral surface 10 a (groove portion 10 b) of the cylindrical portion 10.

  Here, the inner diameter of the cylindrical portion 10 is made slightly smaller than the outer diameter of the outer peripheral surface 3b at the end of the rotating case 3. Thereby, the fitting force of the cylinder part 10 of the cover member 6 and the rotation case 3 is ensured.

  As described above, according to the traveling unit 1 of the present embodiment, the rotary case 3 and the lid member 6 are formed by fitting the inner peripheral surface 10a of the cylindrical portion 10 of the lid member 6 to the outer peripheral surface 3b of the end of the rotary case 3. , Even if the rotating case 3 tries to deform outward in the radial direction, the deformation is suppressed by the cylindrical portion 10 of the lid member 6. Further, even if the rotating case 3 is slightly deformed outward, the cylindrical portion 10 is also deformed accordingly, and a gap is generated between the outer peripheral surface 3b of the end of the rotating case 3 and the cylindrical portion 10 of the lid member 6. And the sealing performance can be maintained. As a result, leakage of lubricating oil in the rotating case 3 can be prevented.

  Further, as described above, the bottom portion 9 is formed so as to have the first thick portion 9a, the thin portion 9b, and the second thick portion 9c. Thereby, the bottom part 9 is easy to elastically deform in the thin part 9b. Therefore, when the rotating case 3 tries to deform outward in the radial direction, the load acting on the cylindrical portion 10 can be received even by elastic deformation of the bottom portion 9. That is, when the rotating case 3 tries to be deformed outward in the radial direction, the cylindrical portion 10 can follow the deformation without difficulty, and the lid member 6 can be prevented from being damaged. In addition, the concave portion 9d formed in the outer central portion of the bottom portion 9 also contributes to the ease of elastic deformation of the bottom portion 9.

  Further, by arranging the O-ring 8 between the outer peripheral surface 3b at the end of the rotating case 3 and the inner peripheral surface 10a of the cylindrical portion 10, even when the rotating case 3 is going to deform outward in the radial direction, or Even when the rotating case 3 is deformed radially outward, the O-ring 8 continues to be sandwiched between the outer peripheral surface 3b at the end of the rotating case 3 and the inner peripheral surface 10a of the cylindrical portion 10 of the lid member 6. Thereby, the leakage of the lubricating oil in the rotating case 3 can be further prevented.

  FIG. 2 shows an end surface 3e of the rotating case 3 in the case axial direction. An O-ring 8 may be disposed between the end surface 3 e and the inner surface of the bottom portion 9.

  Further, by disposing the O-ring 8 in the groove portion 10b formed on the inner peripheral surface 10a of the cylindrical portion 10, the crushing allowance of the O-ring 8 is increased, and the sealing performance can be further improved.

  Further, by providing a step on the outer peripheral surface 3 b at the end of the rotating case 3, the amount of the outer peripheral surface of the cylindrical portion 10 of the lid member 6 projecting outward from the outer peripheral surface of the rotating case 3 can be reduced. As a result, it is possible to prevent the earth and sand flowing between these outer peripheral surfaces and the crawler of the construction machine from accumulating during this time.

  In addition, although it is preferable to arrange about six bolts 7 on the outer periphery of the cylindrical portion 10 of the lid member 6, 2 to 10 bolts 7 may be arranged. The bolts 7 are preferably arranged evenly, but may be arranged symmetrically about the axis. The role of the bolt 7 is to fix the lid member 6 to the rotating case 3 without shifting in the case axial direction. That is, regarding the sealing performance between the lid member 6 and the rotary case 3, it is not necessary to consider the tightening force by the bolts 7, and thus the number of the bolts 7 can be reduced in this way. As a result, the processing and assembling properties of the lid member 6 and the rotating case 3 are improved, and the manufacturing cost of the traveling unit 1 can be suppressed as compared with the conventional case.

  Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and various modifications can be made as long as they are described in the claims. .

1: Traveling unit 2: Body case 3: Rotating case 3a: Inner teeth 4: Motor mechanism 5: Deceleration mechanism 6: Lid member 7: Bolt (fixing means)
8: O-ring (seal)
9: Bottom 10: Tube

JP 2000-65164 A

Claims (3)

A main body case fixed to the construction machine;
A rotating case that is rotatably held with respect to the main body case and has inner teeth formed on the inner periphery;
A speed reduction mechanism housed in the rotating case and meshing with the inner teeth;
A lid member covering the opening of the rotating case;
Fixing means for fixing the lid member to the rotating case;
A seal disposed between the lid member and the rotating case,
The lid member is
A bottom covering the opening;
A cylindrical portion extending in the case axial direction from the end of the bottom,
Said the outer peripheral surface of the rotary case end is fitted to the inner peripheral surface of the cylindrical portion, Ri Na to fix the said lid member with the rotatable case,
The seal is disposed between the outer peripheral surface of the end of the rotating case and the inner peripheral surface of the cylindrical portion, and is disposed in a groove formed in the inner peripheral surface of the cylindrical portion;
It said fixing means, Ru bolt der disposed towards the casing axis center from the outer periphery of the tubular portion, construction equipment traveling unit. In the traveling unit for construction machines according to claim 1,
A step is formed on the outer peripheral surface of the end portion of the rotating case toward the center of the case axis , and the inner peripheral surface of the cylindrical portion of the lid member is fitted to the step portion. A traveling unit for construction machinery. In the traveling unit for construction machines according to claim 1 or 2,
The traveling unit for construction machines, wherein the groove is provided closer to the bottom of the lid member than the bolt.

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