JP2014009650A - Hydraulic motor with speed reducer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a motor with a speed reducer capable of improving coupling force between a fixed casing of a hydraulic motor and a speed reducer side carrier, and equipped with a coupling portion of a carrier which does not receive stress concentration.SOLUTION: On an inner peripheral surface 42 of a collar portion 41 of a second carrier 29, a plurality of carrier side grooves 43 is formed. On an outer peripheral surface 44 of a fixed casing 4, a plurality of fixed casing side grooves 45 opposite to the carrier side groove 43 is formed. A fixing pin 47 is inserted in a space portion 46 formed by the carrier side groove 43 and the fixed casing side grooves 45, thereby regulating circumferential displacement of the second carrier 29 to the fixed casing 4.

Description

  The present invention relates to a hydraulic motor with a speed reducer, and more particularly to a carrier connecting portion for connecting a speed reducer-side carrier to a fixed casing of the hydraulic motor.

  As a technique for connecting a reduction gear carrier (hereinafter also simply referred to as a carrier) to a fixed casing of a hydraulic motor, for example, there are those described in Patent Documents 1 and 2. The hydraulic motor with a reduction gear described in Patent Document 1 is formed with a plurality of bolt holes on the mating surfaces of the housing 12 (fixed casing) of the hydraulic motor 1 and the holder 23 (carrier) of the reduction gear 2, The holder 23 is connected (fastened) to the housing 12 by fastening the bolt 5 to the bolt hole from the reduction gear 2 side. As a result, the holder 23 is prevented from being displaced in the circumferential direction with respect to the housing 12 by the force received by the planetary gear 24 or the like.

  Moreover, the hydraulic motor with a reduction gear described in Patent Document 2 is configured so that the inner surface of the flange portion of the carrier 33 is engaged with a shaft spline 3D formed on the outer surface of the motor casing 3, whereby the carrier 33 is moved to the motor casing. 3 is connected.

JP-A-9-257107 Japanese Patent No. 4532250

  However, in the reduction gear with a motor described in Patent Document 1, since the housing 12 and the holder 23 are connected (fastened) at the mating surface between the housing 12 and the holder 23, the following problems may occur. is there.

  First, the area of the mating surface is determined by the size and shape of the housing 12 and the holder 23 and is limited. Therefore, a large number of connecting bolts 5 cannot be provided, and the connection between the housing 12 and the holder 23 ( The fastening force may be reduced. In particular, when forming bolt holes on the mating surfaces, it is necessary to form bolt holes sufficiently inside the outer periphery of the housing 12 and the holder 23 from the viewpoint of preventing strength reduction and chipping, and a sufficient number along the circumferential direction. The bolt 5 may not be provided.

  Further, the force applied to the bolt 5 increases as the distance from the center of the housing 12 or the holder 23 increases. Therefore, the bolts 5 cannot be fastened at positions close to the center, and as a result, there is a possibility that a sufficient number of bolts 5 cannot be disposed.

  On the other hand, in the reduction gear with a motor described in Patent Document 2, since the carrier 33 is connected to the motor casing 3 by the shaft spline 3D, the above problem does not occur. However, in the case of spline coupling, there is a possibility that stress concentrates on the root part of the spline and the root part breaks.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a carrier connecting portion that can improve the connecting force between the stationary casing of the hydraulic motor and the speed reducer side carrier and is not subjected to stress concentration. It is to provide a motor with a reduction gear.

  In order to solve the above-described problems, a hydraulic motor with a reduction gear according to the present invention includes a stationary casing in which a motor mechanism is disposed, a rotating casing that is rotatably supported by the stationary casing, and an interior of the rotating casing. And a speed reduction mechanism coupled to the output shaft of the motor mechanism. In addition, the speed reduction mechanism holds a sun gear coupled to the output shaft, an output gear that transmits the output of the motor mechanism transmitted from the sun gear to the rotating casing, and the output gear rotatably. Have a carrier. And a plurality of carrier side grooves are formed on the inner peripheral surface of the collar portion of the carrier, and a plurality of fixed casing side grooves facing the carrier side groove are formed on the outer peripheral surface of the fixed casing, By inserting a fixing pin into a space formed by the carrier side groove and the fixed casing side groove, the carrier is restricted from being displaced in the circumferential direction with respect to the fixed casing.

  According to the present invention, since the fixing pins are inserted into the outer peripheral surface of the fixed casing, a large number of fixing pins can be provided, and the coupling force between the fixed casing and the carrier can be improved. Further, since the fixed casing and the carrier are connected by the fixed pin, the force received by the connecting portion (fixed pin) can be dispersed as compared with the case where the fixed casing and the carrier are connected by spline coupling. From the above, it is possible to provide a motor with a reduction gear that can improve the coupling force and includes a carrier coupling portion that does not receive stress concentration.

It is sectional drawing which shows the hydraulic motor with a reduction gear which concerns on embodiment of this invention. It is II-II sectional drawing of the hydraulic motor with a reduction gear shown in FIG. It is an enlarged view of the A section shown in FIG. It is an enlarged view of the B section shown in FIG.

  Hereinafter, the form for implementing the hydraulic motor with a reduction gear of this invention is demonstrated, referring FIGS. 1-4.

(Hydraulic motor 1 with reduction gear)
As shown in FIG. 1, the hydraulic motor 1 with a speed reducer has a hydraulic motor 2 and a speed reducer 3. The hydraulic motor 1 with a reduction gear is used for a traveling device in a construction vehicle such as a hydraulic excavator, for example. In addition, it is not limited to the use for construction vehicles.

(Hydraulic motor 2)
The hydraulic motor 2 includes a fixed casing 4 and a motor mechanism 5 disposed inside the fixed casing 4.

(Fixed casing 4)
The fixed casing 4 has a bottomed cylindrical shape, and a hole 12 through which the output shaft 13 of the motor mechanism 5 is inserted is formed in the center portion of the bottom portion 11. The fixed casing 4 is connected to the rotating casing 6 in a state where the bottom 11 side is inserted into the rotating casing 6 described later.

  The motor mechanism 5 is a motor portion having the output shaft 13 described above, and is disposed inside the fixed casing 4. The output of the motor mechanism 5 is transmitted to the speed reducer 3 by the output shaft 13. As the motor mechanism 5, a known one can be used, and detailed description thereof is omitted in the present application (the configuration of the motor mechanism 5 is also omitted in FIG. 1).

(Reduction gear 3)
The speed reducer 3 includes a rotating casing 6 and a speed reducing mechanism 7 disposed inside the rotating casing 6.

(Rotating casing 6)
The rotary casing 6 has a hollow cylindrical shape, and the bottom 11 side of the fixed casing 4 is inserted from one opening side thereof. The other opening is closed by a lid 21. The rotary casing 6 is rotatably supported by the fixed casing 4 via casing bearings 22 a and 22 b disposed between the outer periphery of the fixed casing 4 and the inner periphery of the rotary casing 6.

(Deceleration mechanism 7)
The speed reduction mechanism 7 is disposed inside the rotary casing 6 and is connected to the output shaft 13 of the motor mechanism 5, and includes an input shaft 23, a first sun gear 24 (sun gear), a first planetary gear 25, a first gear. 1 carrier 26, second sun gear 27, second planetary gear 28 (output gear), second carrier 29 (carrier), and internal teeth 30. The speed reduction mechanism 7 transmits the output of the motor mechanism 5 while reducing the rotational speed, and finally drives the rotary casing 6 to rotate through a sprocket (not shown) attached to the flange portion 31. A non-driving part (not shown) is driven.

  The input shaft 23 is connected to the output shaft 13 of the motor mechanism 5 and rotates together with the output shaft 13. The first sun gear 24 (sun gear) is connected to the output shaft 13 of the motor mechanism 5 via the input shaft 23 and rotates together with the input shaft 23. More specifically, the first sun gear 24 is connected to the end on the opposite side of the output shaft 13 from both ends of the input shaft 23.

  Three first planetary gears 25 are provided around the first sun gear 24 (one of which is shown in the cross-sectional view of FIG. 1), and each meshes with the first sun gear 24. Yes. The three first planetary gears 25 are rotatably supported with respect to the first carrier 26. Thereby, each 1st planetary gear 25 revolves around the 1st sun gear 24, rotating. Further, the first planetary gear 25 is arranged so as to mesh with the internal teeth 30 provided on the inner periphery of the rotary casing 6. The number of first planetary gears 25 is not limited to three.

  The first carrier 26 is a member that rotatably holds the first planetary gear 25 and is spline-coupled to the second sun gear 27. The second sun gear 27 is a cylindrical member in which the input shaft 23 is inserted. The second sun gear 27 meshes with the second planetary gear 28 in addition to the first carrier 26.

  The second planetary gear 28 (output gear) outputs the output of the motor mechanism 5 transmitted from the first sun gear 24 via the first planetary gear 25, the first carrier 26, and the second sun gear 27 to the internal teeth 30. It is a gearwheel which transmits to the rotation casing 6 via.

  Three second planetary gears 28 are provided around the second sun gear 27 (one of them is shown in the cross-sectional view of FIG. 1), and each meshes with the second sun gear 27. ing. The three second planetary gears 28 are rotatably supported with respect to the second carrier 29. Further, the second planetary gear 28 is arranged so as to mesh with the internal teeth 30. Note that the number of the second planetary gears 28 is not limited to three.

  The second carrier 29 (carrier) is a member that rotatably holds the second planetary gear 28. As will be described in detail later, the second carrier 29 is displaced in the fixed casing 4 of the hydraulic motor 2 and the second carrier 29 is displaced in the circumferential direction of the fixed casing 4 with respect to the fixed casing 4 (hereinafter simply referred to as the circumferential direction). It is connected so as not to. For this reason, the second carrier 29 does not rotate even when the second planetary gear 28 rotates.

  The operation of the speed reducer 3 configured as described above will be described. When the motor mechanism 5 disposed inside the fixed casing 4 rotates, the output is transmitted to the input shaft 23 connected to the output shaft 13. Then, the first sun gear 24 rotates with the rotation of the input shaft 23, and each first planetary gear 25 meshing with the first sun gear 24 meshes with the internal teeth 30, while the first sun gear 24 rotates. Revolving motion will be performed around. As the first planetary gear 25 revolves, the first carrier 26 rotates, and the second sun gear 27 splined with the first carrier 26 rotates. As the second sun gear 27 rotates, each second planetary gear 28 rotatably supported by the second carrier 29 rotates (spins), whereby the second planetary gear 28 and the internal teeth 30 are rotated. The rotary casing 6 is rotationally driven through the meshing.

(Connection between fixed casing 4 and second carrier 29)
Next, the connection between the fixed casing 4 and the second carrier 29 of the hydraulic motor 1 with a reduction gear will be described in detail with reference to FIGS.

  As shown in FIGS. 1 and 2, the fixed casing 4 and the second carrier 29 are formed in a plurality on the carrier side groove 43 formed on the inner peripheral surface 42 of the flange 41 and on the outer peripheral surface 44 of the fixed casing 4. The fixed casing 47 is connected by a fixed pin 47 inserted into a space 46 formed by the fixed casing side groove 45.

  In FIG. 2, only one of the plurality of carrier side grooves 43, the fixed casing side grooves 45, the space 46, and the fixed pins 47 is provided with a reference numeral in order to avoid complexity. Further, in order to easily understand the state of connection between the fixed casing 4 and the second carrier 29, one of the plurality of space portions 46 is illustrated with no fixed pin 47 inserted (actually). The fixing pin 47 is also inserted into the space 46).

  As shown in FIG. 1, the flange 41 is an annular flange extending from the outer peripheral portion of the second carrier 29 in the axial direction of the output shaft 13 (hereinafter also simply referred to as the axial direction) and toward the motor mechanism 5. . As shown in FIG. 2, the inner peripheral surface 42 of the flange portion 41 is in contact with the outer peripheral surface 44 of the fixed casing 4 (the contact portion 41 may simply be in close proximity without contacting).

  A plurality of carrier side grooves 43 are formed on the inner peripheral surface 42. The carrier side grooves 43 are formed at regular angular intervals at the same radial position with the output shaft 13 as the central axis (for example, a total of 15 are formed every 24 °). The carrier-side groove 43 has an arc shape (more specifically, a substantially semicircular shape) in a vertical cross-sectional view with respect to the axial direction (for example, a cross-sectional view shown in FIG. 2). It extends to. The carrier side groove 43 is processed by a machining center, for example.

  The radius of the arc of the carrier side groove 43 is substantially the same as the radius of the fixing pin 47. As a result, the carrier side groove 43 has an inner peripheral surface thereof as shown in FIG. Reference).

  Further, the axial length of the carrier-side groove 43 is, for example, substantially the same as the axial length L of the fixing pin 47 (see FIG. 3). Further, the carrier-side groove 43 is opened in the axial direction at one end surface 49 (see FIG. 3) of the flange portion 41 so that the fixing pin 47 can be easily inserted (not necessarily opened).

  On the other hand, a plurality of fixed casing side grooves 45 facing the carrier side grooves 43 are formed on the outer peripheral surface 44 of the fixed casing 4. Similar to the carrier side groove 43, the fixed casing side groove 45 is formed at constant angular intervals at the same radial position with the output shaft 13 as the central axis (for example, a total of 15 pieces are formed every 24 °). The fixed casing side groove 45 has an arc shape (more specifically, a substantially semicircular shape) in a vertical sectional view with respect to the axial direction of the output shaft 13 (for example, a cross-sectional view shown in FIG. 2). It extends in the axial direction while keeping it. The fixed casing side groove 45 is processed by, for example, a machining center. Further, in the present embodiment, the number of carrier side grooves 43 and the number of fixed casing side grooves 45 are the same number, but it is not necessarily the same number.

  The radius of the arc of the fixed casing side groove 45 is substantially the same as the radius of the fixed pin 47, and the fixed casing side groove 45 has its inner peripheral surface in contact with the outer peripheral surface 48 of the fixed pin 47 as shown in FIG. It has become.

  Further, the axial length of the fixed casing side groove 45 is, for example, substantially the same as the axial length L of the fixed pin 47. The fixed casing side groove 45 is opened in the axial direction on the one end face 50 (see FIG. 3) of the fixed casing 4 so that the fixed pin 47 can be easily inserted (not necessarily open). Further, the fixed casing side groove 45 extends to the vicinity of the concave portion 33 into which the lock washer mechanism 32 is inserted.

  The space portion 46 is a space portion formed by the carrier side groove 43 and the fixed casing side groove 45 described above, and the outer periphery of the space portion 46 (i.e., in the cross-sectional view shown in FIG. 2, for example, in the axial direction). The portion defined by the carrier side groove 43 and the fixed casing side groove 45 is substantially circular.

  A fixing pin 47 is inserted into the space 46. The fixing pin 47 has a cylindrical shape and restricts the second carrier 29 from being displaced in the circumferential direction with respect to the fixed casing 4. As shown in FIG. 1, the fixing pin 47 is inserted into the space 46 so that the axial direction thereof coincides with the axial direction of the output shaft 13. As shown in FIG. 3, the axial length L of the fixing pin 47 is larger than the diameter R of the fixing pin 47.

  The fixing pin 47 applies a force that the second carrier 29 tends to displace in the circumferential direction by the second planetary gear 28 or the like to a horizontal section S1 with respect to the axial direction of the fixing pin 47 (hatched portion of the fixing pin 47 in FIG. 3). Can be received at. In this embodiment, since the axial length L of the fixing pin 47 is larger than the diameter R, the horizontal cross section S1 is a vertical cross section S2 with respect to the axial direction of the fixing pin 47 (the hatched portion of the fixing pin 47 in FIG. 2). Bigger than. As a result, the fixing carrier is inserted into the mating surface of the fixing casing and the carrier as in the prior art, and the second carrier 29 tends to be displaced in the circumferential direction as compared with a case where a force is received in the vertical cross section of the fixing pin. The force can be received efficiently (with less stress concentration).

  Here, the central angle α of the arc of the fixed casing side groove 45 is larger than 180 ° as shown in FIG. Therefore, in the state where the fixing pin 47 is inserted in the fixed casing side groove 45, it can be prevented that the fixing pin 47 falls outside the fixed casing 4 (in the arrow direction in FIG. 4). As a result, at the time of assembling, the fixing pin 47 is first dropped by inserting the fixing pin 47 into the fixing casing side groove 45 from the one end face 50 (see FIG. 3) side of the fixing casing 4 and attaching the second carrier 29 thereafter. The fixed casing 4 and the second carrier 29 can be assembled without doing so. Although the upper limit of the central angle α is not particularly limited, it is set to, for example, 300 ° or less in consideration of the prevention of the fixing pin 47 from falling off and the coupling force between the fixing casing 4 and the second carrier 29, A direction close to 180 ° is preferable.

(Modification)
In the present embodiment, the axial direction of the fixing pin 47 is set to the output shaft so that the second carrier 29 can efficiently receive a force to be displaced in the circumferential direction and the second carrier 29 and the like can be miniaturized. Although it is made to coincide with the 13 axial directions, it is not always necessary to coincide. For example, the fixing pin 47 may be inserted into the space 46 so that the axial direction of the fixing pin 47 is orthogonal to the axial direction of the output shaft 13 by changing the shapes of the carrier side groove 43 and the fixed casing side groove 45.

  In this embodiment, the axial length L of the fixing pin 47 is larger than the diameter R, but it is not always necessary to make it larger than the diameter R. Further, the fixing pin 47 does not necessarily have a cylindrical shape. Similarly, the carrier side groove 43 and the fixed casing side groove 45 are not limited to the arc shape, and can be various shapes as long as the second carrier 29 can be restricted from being displaced in the circumferential direction by the fixing pin 47.

  In the present embodiment, the central angle α of the arc of the fixed casing side groove 45 is larger than 180 °, but the central angle β of the arc of the carrier side groove 43 (see FIG. 4) may be larger than 180 °. Good. In this case, in a state where the fixing pin 47 is inserted into the carrier-side groove 43, it is possible to prevent the fixing pin 47 from falling off inside the second carrier 29 (in the direction opposite to the arrow direction in FIG. 4). As a result, at the time of assembling, if the fixing pin 47 is first inserted into the carrier-side groove 43 from, for example, the one end face 49 side of the flange 41, and then the second carrier 29 is attached to the fixing casing 4, the fixing pin 47 falls off. As a result, the fixed casing 4 and the second carrier 29 can be assembled together. Although the upper limit of the central angle β is not particularly limited, it is set to, for example, 300 ° or less in consideration of the prevention of the fixing pin 47 from falling off and the coupling force between the fixing casing 4 and the second carrier 29, A direction close to 180 ° is preferable.

(effect)
(Effect 1)
Next, the effect of the present invention will be described. The hydraulic motor with a reduction gear according to the present invention has a plurality of carrier side grooves on the inner peripheral surface of the flange portion of the second carrier, and has a plurality of fixed casing side grooves facing the carrier side grooves on the outer peripheral surface of the fixed casing. The fixing pin is inserted into the space formed by the side groove and the fixed casing side groove, whereby the second carrier is restricted from being displaced in the circumferential direction with respect to the fixed casing.

  Therefore, since the fixing pin is inserted in the outer peripheral surface of the fixed casing, more fixing pins can be provided compared to the case where the fixing pin is provided on the mating surface of the fixed casing and the second carrier. As a result, the coupling force between the fixed casing and the second carrier can be improved. Moreover, since the fixed casing and the second carrier are connected by the fixed pin, the stress received can be dispersed compared to the case where the fixed casing and the second carrier are connected by spline coupling. From the above, it is possible to provide a motor with a reduction gear provided with a carrier connecting portion which can improve the connecting force and does not receive stress concentration.

  Furthermore, as a result of the above, since the design allowable stress of the carrier connecting portion can be improved, the carrier connecting portion can be reduced in size, and the outer diameter on the bottom side of the fixed casing can be reduced. Therefore, the inner / outer diameter difference between the outer diameter of the fixed casing and the inner diameter of the rotating casing can be increased, and the size of the rigid ball of the main bearing can be increased. As a result, the bearing capacity increases, leading to a longer life of the hydraulic motor with a reduction gear.

  In spline processing, a dedicated processing machine such as a gear shaver or hobbing machine is required, and the processing time becomes long, so the product unit price increases. However, in the hydraulic motor with a reduction gear of the present invention, the fixed pin Can be machined at the machining center, so there is no need for a separate machine tool such as a gear shaver and the cost can be reduced by reducing the machining process. Become.

(Effect 2)
The fixed pin is inserted into the space so that the axial direction of the fixed pin and the axial direction of the output shaft coincide with each other, and the axial length of the fixed pin is longer than the diameter of the fixed pin. Therefore, the horizontal cross section S1 is larger than the vertical cross section S2. Accordingly, the force that the second carrier tends to displace in the circumferential direction can be received in the horizontal section S1 that is larger than the vertical section S2, and the second carrier is compared to the case where the force is received in the vertical section as in the prior art. It is possible to efficiently receive a force that tends to be displaced in the circumferential direction. As a result, the stress concentration on the fixing pin can be more dispersed.

(Effect 3)
In addition, the fixed casing side groove has an arc shape that comes into contact with the outer peripheral surface of the fixed pin in a vertical sectional view with respect to the axial direction of the output shaft, and the central angle of the arc is larger than 180 °. Therefore, it is possible to prevent the fixed pin from dropping out of the fixed casing in a state where the fixed pin is inserted into the fixed casing side groove. As a result, the fixing casing and the second carrier can be assembled without the fixing pin falling off.

(Effect 4)
Further, the carrier side groove may have an arc shape in contact with the outer peripheral surface of the fixing pin in a vertical sectional view with respect to the axial direction of the output shaft, and the size of the center angle of the arc may be larger than 180 °. As a result, it is possible to assemble the fixed casing and the second carrier without dropping the fixing pin as described above.

  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.

  Moreover, although this embodiment demonstrated the hydraulic motor with a reduction gear, this hydraulic motor with a reduction gear can be used also as a hydraulic pump with a reduction gear.

DESCRIPTION OF SYMBOLS 1 Hydraulic motor with reduction gear 2 Hydraulic motor 3 Reduction gear 4 Fixed casing 5 Motor mechanism 6 Rotary casing 7 Reduction mechanism 13 Output shaft 24 1st sun gear (sun gear)
28 Second planetary gear (output gear)
29 Second career (carrier)
41 flange 42 inner peripheral surface 43 carrier side groove 44 outer peripheral surface 45 fixed casing side groove 46 space 47 fixed pin 48 outer peripheral surface (outer peripheral surface of fixed pin)

Claims (4)

A fixed casing having a motor mechanism disposed therein;
A rotating casing rotatably supported by the fixed casing;
A speed reduction mechanism disposed inside the rotating casing and coupled to the output shaft of the motor mechanism;
With
The deceleration mechanism is
A sun gear coupled to the output shaft;
An output gear for transmitting the output of the motor mechanism transmitted from the sun gear to the rotating casing;
A carrier for rotatably holding the output gear;
Have
A plurality of carrier side grooves are formed on the inner peripheral surface of the collar portion of the carrier,
A plurality of fixed casing side grooves facing the carrier side groove are formed on the outer peripheral surface of the fixed casing,
The carrier is restricted from being displaced in the circumferential direction with respect to the fixed casing by inserting a fixing pin into a space formed by the carrier side groove and the fixed casing side groove. Hydraulic motor with reduction gear. In the hydraulic motor with a reduction gear according to claim 1,
The fixed pin is inserted into the space portion so that the axial direction of the fixed pin and the axial direction of the output shaft coincide with each other.
A hydraulic motor with a reduction gear, wherein an axial length of the fixed pin is longer than a diameter of the fixed pin. In the hydraulic motor with a reduction gear according to claim 1 or 2,
The fixed casing side groove has an arc shape that comes into contact with the outer peripheral surface of the fixed pin in a vertical sectional view with respect to the axial direction of the output shaft,
A hydraulic motor with a reduction gear, wherein a central angle of the arc is larger than 180 °. In the hydraulic motor with a reduction gear according to claim 1 or 2,
The carrier side groove has an arc shape that comes into contact with the outer peripheral surface of the fixing pin in a vertical sectional view with respect to the axial direction of the output shaft,
A hydraulic motor with a reduction gear, wherein a central angle of the arc is larger than 180 °.

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