JP2014206139A - Hydraulic motor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a hydraulic motor having a seal mechanism which eliminates the need of labor hours for removing a flange and enables a seal case to be easily removed.SOLUTION: A hydraulic motor includes: a motor housing (10); an output shaft (20); and a seal case (40) into which an oil seal fits. A seal case removing recessed part (a groove 40b) is formed at a part of an outer peripheral surface of the seal case (40) which is located near an axial outer side end part.

Description

  The present invention relates to a hydraulic motor, and more particularly to a sealing mechanism for a hydraulic motor.

Leakage of lubricating oil in the hydraulic motor may be directly connected to a situation where the entire hydraulic motor must be replaced. An oil seal is provided to prevent such leakage of softening dew.
The oil seal replacement operation is very important in order to maintain the performance of the oil seal and prevent leakage of the lubricating oil.

A conventional hydraulic motor 100J is shown in FIG.
When exchanging the seal S in the hydraulic motor 100J, the following procedures (1) to (3) are performed.
(1) Remove the bolt B in FIG.
(2) Remove the key K in FIG.
(3) The flange F in FIG. 6 is removed from the motor housing C by hitting it in the direction of the white arrow with a copper hammer, for example.
However, if the flange F is removed, there is a risk that parts (for example, the shaft seal M) may fall and be lost.
Further, the bearing BR may come off and the shaft ST may come off.
Further, when removing the bolt B, a hexagon wrench is required, but the hexagon wrench is often not prepared at the installation location of the hydraulic motor 100J.

In order to eliminate the drawbacks of the prior art shown in FIG. 6, there is a hydraulic motor 100K that forms a motor housing by integrating a flange and a housing (FIG. 7).
In the hydraulic motor 100K shown in FIG. 7, it is not necessary to remove the flange, and the seal can be replaced by removing the seal case 40 from the motor housing 10J.
In the hydraulic motor 100K shown in FIG. 7, the seal case 40 is attached to the motor housing 10J by a snap ring SR.
Here, in order to remove the seal case 40 from the motor housing 10J, the snap ring SR must be removed from the motor housing 10J.
However, the snap ring SR needs to be removed with a pliers (not shown). Then, in order to remove the snap ring SR from the motor housing 10J with a pliers (not shown), the pliers must be put into the motor housing 10J from a minute gap formed on the end surface (the upper end surface in FIG. 7) of the motor housing 10J. So it is very difficult.

Further, when the seal case 40 is removed from the motor housing 10J, if the seal case 40 is inclined with respect to the motor housing 10J, the end of the inclined seal case 40 abuts on the motor housing 10J (so-called “twist”). The seal case 40 cannot be removed.
Therefore, it is necessary to take out the seal case 40 without inclining with respect to the motor housing 10J. However, for that purpose, a special jig is required, and a considerable amount of labor is required.

  That is, in a hydraulic motor, there is a need for a sealing mechanism that does not require the effort to remove the flange and that allows the seal case to be easily removed, but such a sealing mechanism has not been proposed yet.

As another conventional technique, there has been proposed a hydraulic motor that prevents cavitation when rotating due to inertia and prevents hydraulic oil from leaking to the outside of the housing (see Patent Document 1).
However, the related art (Patent Document 1) is a technique related to the arrangement of the hydraulic oil passage and the check valve, and does not provide a seal mechanism that does not require the effort to remove the flange and that allows the seal case to be easily removed. .

Japanese Patent Laid-Open No. 10-30547

  The present invention has been proposed in view of the above-described problems of the prior art, and it is an object of the present invention to provide a hydraulic motor having a seal mechanism that does not require the effort of removing the flange and that allows the seal case to be easily removed.

The hydraulic motor of the present invention has a motor housing (10), an output shaft (20), and a seal case (40) fitted with an oil seal (OS). Further, a seal case removing recess (groove 40b) is formed in the vicinity of the outer end in the axial direction.
Here, the recess for removing the seal case (40b) may be a groove formed on the entire outer periphery of the seal case (40). Alternatively, it may be at least two indentations arranged at equal intervals in the circumferential direction.

In the present invention, the seal case (40) has a portion protruding outward in the radial direction (outer peripheral surface 40o of the seal case), and the axially outer side (end surface 40t of the seal case 40) of the protruding portion (40o). It is preferable that a wiring (8) for holding the seal case is disposed on the side), and a groove (15) for mounting the wiring (8) is formed in the motor housing (10).
In this case, it is preferable to form a portion (16) having a large radial dimension (at least one portion) in the annular gap (δ) on the end surface (14) of the motor housing (10).

In the practice of the present invention, the axial position of the seal case removing groove (40b) is preferably outside the wiring (8).
The depth of the groove (40b) is such that the flathead screwdriver is sufficiently caught and the periphery of the groove (40b) is not damaged when the seal case (40) is removed from the motor housing (10). Is preferred. For example, about 1 mm to 3 mm is preferable.
Further, the axial position of the wiring (8) is a position where the motor housing (10) is not damaged even when the internal pressure of the hydraulic motor (100) is applied, and is inside the outer end face (14) of the motor housing (10). It is preferable that it is located in.

According to the present invention having the above-described configuration, the motor housing (10) has a structure in which the housing (C) and the flange (F) in the hydraulic motor (100J) of FIG. There is no need.
Therefore, according to the present invention, the flange does not come off during the replacement of the seal, and there is no fear that the components inside the hydraulic motor will fall and be damaged or lost.
Further, there is no possibility that the output shaft (20) is detached when the bearing is detached when the flange is detached.
Further, since the flange fixing bolt is unnecessary, it is not necessary to equip the hexagon wrench to remove the flange fixing bolt.

Further, according to the present invention, the tips of the two minus drivers (Td) are inserted into the motor housing (10) from the annular gap (δ: see FIG. 3) in the housing end surface (14) to remove the seal case. The seal case (40) can be easily removed from the motor housing (10) by hooking it in the groove (40b) and rotating or turning the two flat-blade screwdrivers (Td) (so-called “pivoting” operation). I can do it.
According to the present invention, the seal case (40) is not inclined with respect to the motor housing (10) (the so-called “twisted” state) by rotating or rotating the two minus drivers (Td) simultaneously. Therefore, it is not necessary to use a special jig when removing the seal case (40).

In the present invention, a portion protruding outward in the radial direction (the outer peripheral surface 40o of the seal case) is formed on the seal case (40), and straddles the radially outer side and the radially inner side of the protruding portion (40o). If the wiring (8) is arranged, the wiring case (5) prevents the seal case (40) from moving outward in the axial direction with respect to the motor housing (10). Therefore, the seal case (40) does not move outward in the axial direction due to the internal pressure of the hydraulic motor (100).
If a portion having a large radial dimension (spot portion 16) is formed in the annular gap (δ) on the end surface (14) of the motor housing, the minus driver (Td) of the minus driver (Td) is formed from the portion (spot portion 16). The tip can be inserted into the hydraulic motor and easily removed from the groove (14) in which the wiring (8) is fitted. As a result, there is no need to use a pliers.

And according to this invention, since it is not necessary to provide an extra part and installation for oil seal replacement | exchange, the cost for oil seal replacement | exchange can be reduced.
At the same time, it is possible to reduce the number of parts and reduce the weight of the hydraulic motor.

It is sectional drawing of embodiment of this invention. It is a Y arrow line view of FIG. It is X1-X1 arrow sectional drawing of FIG. 2, Comprising: It is a principal part expanded sectional view of FIG. It is X1-X1 arrow sectional drawing of FIG. 2, Comprising: It is explanatory drawing which shows the state which removes a wiring. It is X1-X1 arrow sectional drawing of FIG. 2, Comprising: It is explanatory drawing which shows the state which removes a seal case. It is sectional drawing of the conventional hydraulic motor. FIG. 7 is a cross-sectional view of a conventional hydraulic motor of a type different from that of FIG. 6.

Embodiments of the present invention will be described below with reference to the accompanying drawings.
First, the sealing mechanism of the hydraulic motor according to the illustrated embodiment will be described with reference to FIGS.

In FIG. 1, a hydraulic motor 100 to which an embodiment of the present invention is applied includes a motor housing 10, an output shaft 20, a spacer plate 50, a gyro roller assembly 60, and an end cover 70.
The motor housing 10 includes an output shaft insertion portion 11, a thrust bearing mounting portion 12 that houses the thrust bearing 5, and a seal case mounting portion 13. The inner diameters of these portions increase in the order of the output shaft insertion portion 11, the thrust bearing mounting portion 12, and the seal case mounting portion 13. The output shaft insertion portion 11, the thrust bearing mounting portion 12, and the seal case mounting portion 13 are formed continuously.
The seal case mounting portion 13 is open on the end surface 14 of the housing (the side from which the output shaft 20 protrudes: the upper side in FIG. 1).

The output shaft 20 includes a drive housing portion 21, a seal case engaging portion 22, and an output shaft portion 23.
At the center of the drive accommodating portion 21 in the output shaft 20, a drive accommodating chamber 21c that accommodates the drive 7 that generates rotational force is formed.
The seal case engaging portion 22 in the output shaft 20 is formed to be rotatably engaged with an inner peripheral surface 40i of a seal case 40 described later.
A key groove 23k that engages with the key 3 is formed in the output shaft portion 23 of the output shaft 20.

In FIG. 3, a dust seal mounting portion 41 is formed at the upper end portion (the end portion on the side from which the output shaft 20 protrudes) of the seal case 40 on the inner peripheral surface 40 i side, and on the inner peripheral surface 40 i side of the seal case 40. An oil seal mounting groove 42 is formed at the lower end (side away from the dust seal mounting portion 41).
On the outer peripheral side of the seal case 40, the flange portion 40a, the seal case take-out groove 40b, the first taper portion 40c, the wiring contact surface 40d, and the outer peripheral surface 40o are sequentially arranged downward from the upper end surface 40t in FIG. A second taper portion 40e is formed.
The outer diameter of the outer peripheral surface 40 o is the maximum diameter in the seal case 40.

The first taper portion 40c is formed as a taper surface whose diameter increases (expands) from the side portion below the seal case take-out groove 40b in FIG. 3 toward the wiring contact surface 40d.
The wiring contact surface 40d is in contact with the later-described wire ring 8 to prevent the seal case 40 from being detached from the seal case mounting portion 13 (of the motor housing 10) due to the internal pressure of the motor housing 10, for example.
The second taper portion 40e is provided so as to be easily inserted when the seal case 40 is mounted (fitted) to the seal case mounting portion 13 of the motor housing 10.

In the illustrated embodiment, a wire ring (stop ring) 8 is employed instead of the snap ring in the prior art. If it is the wiring 8, it can be easily fitted in the motor housing 10 manually.
A wiring mounting groove 15 having a semicircular cross-sectional shape is formed in the seal case mounting portion (cylindrical inner peripheral surface) 13 of the motor housing 10 over the entire circumference in the circumferential direction. The wiring 8 is fitted in the wiring mounting groove 15. In other words, the wire ring 8 is disposed on the outer side in the axial direction of the outer peripheral surface 40o (upper side in FIG. 3), which is a portion protruding radially outward of the seal case 40.
In FIG. 3, the distance (height direction dimension in FIG. 3) Hw from the boundary between the thrust bearing mounting part 12 and the seal case mounting part 13 to the center point of the wiring mounting groove 15 is the dimension indicated by the symbol Hs. It is preferably equal to the value of the radius dimension plus tolerance. Here, the dimension indicated by the symbol Hs is a numerical value obtained by adding the height direction dimension of the outer peripheral surface 40o of the seal case 40 and the height direction dimension of the second tapered portion 40e.

2 and 3, an annular gap δ is formed between the seal case mounting portion (cylindrical inner peripheral surface) 13 of the motor housing 10 and the outer periphery of the flange portion 40 a of the seal case 40.
A counterbore 16 is formed in at least one place (two places in the illustrated embodiment) of the seal case mounting portion (cylindrical inner peripheral surface) 13, and an annular gap δ is formed in the counterbore 16. It has been expanded.
The depth of the spot facing portion 16 from the housing end surface 14 is set so that the bottom face of the spot facing portion 16 is flush with the lower end of the wiring mounting groove 15 in FIG. 3.

In order to remove the seal case 40 from the motor housing 10 in the illustrated embodiment, the wire ring 8 must be removed from the wire groove 15. Here, the wire ring 8 is a member provided to prevent the seal case 40 from falling off the motor housing 10.
In order to remove the wire ring 8 from the wiring groove 15, first, as shown in FIG. 4, the tip of the minus driver Td is inserted into the motor housing 10 from the counterbore 16, and the tip of the minus driver Td is placed outside the wire ring 8. Apply.
In this state, if the portion separated from the tip of the minus driver Td is brought into contact with the upper edge 16t of the counterbore 16 and the minus driver Td is tilted in the direction of the arrow R, the minus driver Td acts as a “lever” and the wiring 8 Can be easily removed from the groove 15.
Therefore, in the illustrated embodiment, it is not necessary to use a plier when removing the seal case 40 from the motor housing 10.

Here, the counterbore part 16 should just be formed in at least one place in order to remove the wire ring 8. As shown in FIG. 2, only one spot 16 is formed in the illustrated embodiment.
Although not shown, it is also possible to form the counterbore 16 in a plurality (for example, two places).
The counterbore 16 is basically formed for removing the wire ring 8 and is not formed for removing the seal case 40 described later in FIG. Removal of the seal case 40 is performed by allowing the tips of the two minus drivers Td to enter from the annular gap δ. However, it is also possible to use the counterbore 16 for removing the seal case 40.

The inventor determines whether or not the sealing case 40 can withstand the pressure inside the motor housing 10 (for example, an internal pressure of about 1.8 t in terms of pressing force) and maintain the state shown in FIG. investigated.
As a result, it was confirmed that there was no problem in strength even when the wire ring 8 was adopted. In the inventor's experiment, even when an internal pressure of about 4 t is applied in terms of the pressing force, the wire ring 8 is not broken and the seal case 40 is not detached from the motor housing 10.

Here, the pressure (internal pressure) inside the motor housing 10 acts on the end face side (upper end face side in FIG. 3) of the motor housing 10 (cast product) via the wire ring 8.
If the location where the wire ring 8 is mounted is too close to the housing upper end surface 14, the internal pressure in the motor housing 10 acts on the region near the housing upper end surface 14 via the wire ring 8, and the end surface of the motor housing 10 (see FIG. In FIG. 3, the portion 14B (see FIG. 3) on the upper end surface may be damaged.

  In the illustrated embodiment, the axial position of the wire ring 8 is such that the motor housing 10 is not damaged even when internal pressure (acting on the motor housing 10 via the wire ring 8) is applied. In other words, the axial position of the wire ring 8 is such that the inner side of the motor housing 10 (see FIG. 3) is closer to the end surface 14 (upper end surface of FIG. 3) than the end surface 14 of the motor housing 10 to the extent that the motor housing 10 is not damaged even when internal pressure is applied. It is located on the lower side.

After the wire ring 8 is removed, the seal case 40 is removed from the motor housing 10 using two flat-blade screwdrivers Td as shown in FIG.
Specifically, the tips of the two minus drivers Td are inserted from the annular gap δ (see FIG. 2), hooked into the wiring groove 40b, and twisted in the direction of arrow R, whereby the seal case 40 is removed from the motor housing 10. It can be easily removed.
In the inventor's experiment, it has been confirmed that the seal case 40 is pulled out from the motor housing 10 with a force of about 1 to 3 kgf.

As shown in the left region of FIG. 5, the tips of the two minus drivers Td enter through the annular gap δ (see FIG. 2) in the housing end surface 14 and enter the groove 40 b formed in the seal case 40. Engage.
Here, if only the single minus driver Td is engaged with the groove 40b and the single minus driver Td is squeezed in the direction of the arrow R, the seal case 40 is inclined with respect to the motor housing 10. (A so-called “twisted” state) may not be removed from the motor housing 10.
Therefore, it is necessary to pry at the same time using at least two minus drivers Td.

The tip of the minus driver Td is allowed to enter through an annular gap δ in the motor housing end face 14, but the tip of one minus driver Td passes through the counterbore 16 as shown in the region on the right side of FIG. 10 can be invaded.
In this case, the minus driver Td on the side passing through the counterbore part 16 (right side in FIG. 5) has a small inclination angle with respect to the motor housing end surface 14, which is convenient for using the minus driver Td as a “lever”. is there.
Although not illustrated, when two countersunk screwdrivers 16 are formed at two positions symmetrical with respect to the center point of the output shaft 20 and the seal case 40 is removed from the motor housing 10, two minus drivers are used. It is also possible to configure so that the tip of Td engages with the groove 40b via two counterbore portions 16 respectively.

Here, if the groove 40b is too shallow, the minus driver Td is not caught.
On the other hand, if the groove 40b is too deep, the area around the groove 40b in the seal case 40 may be damaged when the seal case 40 is removed from the motor housing 10.
That is, it is preferable that the depth of the groove 40 b is such a depth that the minus driver Td is sufficiently caught and the peripheral portion of the groove 40 b is not damaged when the seal case 40 is removed from the motor housing 10.
According to the inventor's experiment, for example, about 1 mm to 3 mm, the minus driver Td is sufficiently caught, the operation of removing the seal case 40 by the minus driver Td is performed well, and the groove 40b of the motor housing 10 is formed. It has been confirmed that the strength to the extent that the peripheral portion does not break can be obtained.

About the axial direction position of the groove | channel 40b, the position of the outer side (upward in FIG. 1, FIG. 3-5) from the wire ring 8 is appropriate.
If the axial position of the groove 40b is on the inner side (lower side in FIG. 1) than the wire ring 8, the outer peripheral surface 40o of the seal case 40 becomes a shape that is embedded on the inner side (lower side in FIG. 1) of the hydraulic motor. May be insufficient.

The groove 40b for removing the seal case extends in the circumferential direction of the outer peripheral surface in the radial direction of the seal case 40, but instead of the groove 40b, at least two places arranged at equal intervals in the circumferential direction. A depression (not shown) may be formed.
The seal case 40 can also be removed from the motor housing 10 by hooking the tips of the two minus drivers Td in two recesses not shown.

According to the illustrated embodiment, the motor housing 10 of the hydraulic motor 100 has a configuration in which the casing C and the flange F in FIG. 6 are integrated, so there is no need to provide a separate flange.
Therefore, when replacing the seal, there is no possibility that the flange will come off and the parts inside the hydraulic motor will fall and be lost.
Further, there is no possibility that the bearing is detached when the flange is detached and the output shaft 20 is detached.
Furthermore, since the flange fixing bolt is not required, the hexagon wrench used for the flange fixing bolt is not required.

In the illustrated embodiment, a portion (outer peripheral surface of the seal case) 40o protruding outward in the radial direction is formed on the seal case 40, and on the outer side in the axial direction (on the end surface 40t side of the seal case 40) of the outer peripheral surface 40o of the seal case. Since the wire ring 8 is disposed, the wire case 8 prevents the seal case 40 from moving outward in the axial direction with respect to the motor housing 10. Therefore, the seal case 40 does not move outward in the axial direction due to the internal pressure of the hydraulic motor 100.
Since a portion (spot portion) 16 having a large radial dimension is formed in the annular gap δ on the end surface 14 of the motor housing, the tip of the minus driver Td is inserted into the hydraulic motor from the portion (spot portion) 16. It can be easily removed from the groove 15 into which the wire ring 8 is fitted. As a result, there is no need to use a pliers.

According to the illustrated embodiment, after the wire ring 8 is removed from the groove 15, the tips of the two minus drivers Td are inserted into the motor housing 10 through the annular gap δ on the housing end surface 14 to remove the seal case. The seal case 40 can be easily detached from the motor housing 10 by being hooked on the groove 40b and rotating or rotating the two minus drivers Td (so-called “pivoting” operation).
Then, by simultaneously rotating or rotating the two minus drivers Td, the seal case 40 is removed from the motor housing 10 without being inclined with respect to the motor housing 10 (without being in a so-called “twisted” state). Therefore, no special tool is required when removing the seal case 40.

According to the illustrated embodiment, it is not necessary to provide an extra part or facility for oil seal replacement, so the cost for oil seal replacement can be reduced.
At the same time, it is possible to reduce the number of parts and reduce the weight of the hydraulic motor.

  It should be noted that the illustrated embodiment is merely an example, and is not a description to limit the technical scope of the present invention.

DESCRIPTION OF SYMBOLS 8 ... Wiring 10 ... Motor housing 12 ... Thrust bearing mounting part 13 ... Seal case mounting part 14 ... Housing end surface 15 ... Wiring groove 16 ... Counterbore part 20 ... Output Shaft 40 ... seal case 40a ... collar 40b ... seal case take-out groove 40o ... outer peripheral surface 41 ... dust seal attachment part 42 ... oil seal attachment part

Claims (3)

  It has a motor housing, an output shaft, and a seal case fitted with an oil seal, and a seal case removal recess is formed on the outer side in the radial direction of the seal case and in the vicinity of the outer end in the axial direction. Features a hydraulic motor.   The seal case has a portion protruding outward in the radial direction. A wire for holding the seal case is disposed on the outer side in the axial direction of the protruded portion, and a groove for mounting the wire ring on the motor housing. The hydraulic motor according to claim 1, wherein:   The hydraulic motor according to claim 2, wherein a portion having a large radial dimension is formed in a cylindrical gap on an end surface of the motor housing.

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