JP6687982B2 - Construction machinery - Google Patents

Description

The invention, for example, about the construction machinery such as a hydraulic excavator.

  In a construction machine such as a hydraulic excavator, for example, an output shaft of an engine (motor) and an input shaft of a hydraulic pump are connected via an elastic shaft joint. The input shaft of the hydraulic pump is rotationally driven by the rotational force from the engine via the hub of the elastic body shaft coupling. Here, the input shaft of the hydraulic pump is spline-coupled to the hub of the elastic shaft joint, and the hub and the input shaft form a spline coupling device. As a disclosure of such a spline coupling device, there is, for example, Patent Document 1.

  In Patent Document 1, a cylindrical hub provided with a female spline portion (inner spline portion) on the inner peripheral side, and a male spline portion (outer spline portion) spline-coupled with the female spline portion on the outer peripheral side are provided. A spline coupling device is described, which comprises a rotation axis.

  On the other hand, for example, Patent Document 2 discloses a spline coupling body used for a rotating shaft of a vehicle power transmission device.

  In Patent Document 2, an annular member (hub) having inner spline teeth on the inner circumference, outer spline teeth on the outer circumference, and tooth heights gradually increasing from the one shaft end side and linked to the outer spline teeth at the same pitch There is described a spline coupling body composed of a shaft member (input shaft) having guide teeth.

JP-A-2015-124816 Japanese Patent No. 5202041

  In the spline coupling device described in Patent Document 1, when the spline coupling is performed between the inner spline portion provided on the inner peripheral side of the hub and the outer spline portion provided on the outer peripheral side of the input shaft, shaft centering and phase alignment are performed. Labor is required.

  On the other hand, in the spline combination described in Patent Document 2, the gap between the guide tooth and the inner spline tooth is gradually narrowed in the process of inserting the annular member (hub), and the relative posture between the annular member and the shaft member is corrected. As a result, the phases in the circumferential direction are aligned, and the tilt is regulated so that the axes match. This makes it possible to easily perform axis alignment and phase alignment.

  However, in the spline combination described in Patent Document 2, the contact area between the guide tooth and the inner spline tooth is small, and the portion where the guide tooth and the inner spline tooth mesh with each other and the portion where the outer spline tooth and the inner spline tooth mesh with each other. Non-uniform tooth surface pressure occurs. Therefore, when applied to a spline coupling device for a hydraulic pump that transmits high torque, there is a risk of damage to the inner spline teeth or the outer spline teeth.

  On the other hand, it is considered that the axial length of the outer spline tooth is made larger than the axial length of the inner spline tooth, and the axial end portion of the outer spline tooth that does not mesh with the inner spline tooth is processed to form the guide tooth. However, in that case, there arises a problem that the input shaft becomes long.

  The present invention has been made in view of the above problems, and an object thereof is to prevent lengthening of an input shaft of a hydraulic pump and to easily perform phase alignment between the input shaft of the hydraulic pump and a hub. An object is to provide a spline coupling device for a hydraulic pump.

In order to achieve the above-mentioned object, the present invention provides a lower traveling body provided with a traveling motor, an upper revolving body provided with a revolving motor, a boom, an arm, a bucket attached to the front side of the upper revolving body, A front device having a boom cylinder, an arm cylinder, and a bucket cylinder, a swing frame forming a support structure for the upper swing body, a cab provided on the left front side of the swing frame, and a rear end portion of the swing frame. A counterweight mounted on the swivel frame, an exterior cover that is disposed on the swivel frame and forms a machine chamber between the cab and the counterweight, and the traveling motor and the swivel motor housed in the machine chamber. A hydraulic pump for supplying pressure oil to the boom cylinder, the arm cylinder, and the bucket cylinder, and the machine chamber An elastic shaft joint that is housed in the engine and the machine chamber and that connects the output shaft of the engine and the input shaft of the hydraulic pump, and is housed in the machine chamber, and is attached to one end side of the engine. A cooling fan and a heat exchanger housed in the machine chamber and arranged to face the cooling fan. The outer peripheral portion of the input shaft includes a plurality of outer spline teeth extending in the axial direction. An outer spline portion is provided, and the elastic body shaft coupling includes a hub having an inner spline portion on the inner peripheral side, the inner spline portion spline-coupled to the outer spline portion being provided, and the input shaft is integrally formed at an end portion thereof. is, a construction machine provided with a first guide shaft portion having a smaller radius than the root radius of the outer spline portion, said input shaft, said first guide and the axial portion where the outer spline portion is provided E Bei the second guide shaft portion located between the shaft portion, the second guide shaft has on its outer periphery, has the outer spline portion of the same number of teeth and root radii, the outer comprising a plurality of guide teeth have a tip circle radius larger addendum circle radius than in and the inner spline section smaller than the addendum circle radius of the splines, the plurality of guide teeth, the tooth tip circle radius Since the inner spline teeth are housed within the first predetermined radial width, a circumferential gap is formed between the plurality of inner spline teeth and the inner spline portions .

  According to the present invention configured as described above, a radius that is integrally formed at the end of the input shaft, is provided with neither the outer spline teeth nor the guide teeth, and is smaller than the tip circle radius of the inner spline part. Since the first guide shaft portion having the above is provided, in the process of inserting the first guide shaft portion into the hub, the shaft center of the input shaft and the hub are allowed while allowing the phase shift between the outer spline portion and the inner spline portion. Since the misalignment with the shaft center can be kept within a predetermined range, the subsequent centering of the shaft becomes easy.

  Further, a guide having the same number of teeth and the same root radius as the outer spline portion on the outer peripheral side of the second guide shaft portion and having a circumferential gap with respect to the inner spline tooth when meshed with the inner spline tooth. Since the teeth are formed, a phase shift is allowed due to the circumferential gap in the process of inserting the second guide shaft portion into the hub, so that the shaft centering can be easily performed. Further, since the phase shift after the axial centering is completed is limited to such a degree that it can be accommodated in the circumferential gap, the subsequent phase alignment becomes easy.

  Further, since the second guide shaft portion projects from the end surface of the hub when the hub is attached to the input shaft, the guide tooth having a smaller tooth surface area than the outer spline tooth does not mesh with the inner spline tooth. As a result, it is possible to prevent uneven tooth surface pressure when the outer spline teeth and the inner spline teeth mesh with each other. Further, since the action and effect as the second guide shaft portion described above can be obtained without increasing the axial length of the guide tooth, the length of the input shaft can be increased by reducing the axial length of the second guide shaft portion. Can be prevented.

  According to the present invention, in the spline coupling device for a hydraulic pump, it is possible to prevent the input shaft of the hydraulic pump from being lengthened and to easily perform phase alignment between the input shaft of the hydraulic pump and the hub.

It is a side view of the hydraulic excavator to which the spline coupling device according to the first embodiment of the present invention is applied. It is the top view which looked at the hydraulic excavator from the state where the front device and the upper cover were removed. It is a figure which shows the connection structure of a hydraulic pump and an engine. It is the top view which looked at the elastic body shaft coupling from the hydraulic pump side. It is the top view which looked at the elastic body shaft coupling from the engine side. It is a top view which expands and shows the inner peripheral side shape of a hub. It is a side view which expands and shows the input shaft of a hydraulic pump. It is sectional drawing of the spline coupling device in the state just before inserting the 1st guide shaft part of an input shaft into a hub. It is sectional drawing of the spline coupling device in the state which a part of 1st guide shaft part of an input shaft was inserted in the hub. It is a partial cross section figure of the spline coupling device seen from the A direction of FIG. It is sectional drawing of the spline coupling device in the state which inserted a part of 2nd guide shaft part of an input shaft into a hub. FIG. 12 is a partial cross-sectional view of the spline coupling device as viewed from the direction B of FIG. 11. 3 is a sectional view of the spline coupling device in a state where a part of the outer spline portion of the input shaft is inserted in the hub. FIG. 14 is a partial cross-sectional view of the spline coupling device as seen from the direction C of FIG. 13. FIG. 13 is a partial cross-sectional view showing a spline coupling device according to a second embodiment of the present invention in a state similar to that of FIG. 12.

  Hereinafter, a case where the spline coupling device for a hydraulic pump according to an embodiment of the present invention is applied to a connecting portion between an engine mounted on a hydraulic excavator and a hydraulic pump will be described as an example with reference to the drawings. In the drawings, the same members are designated by the same reference numerals, and the duplicated description will be appropriately omitted.

  A first embodiment of the present invention will be described with reference to FIGS.

  FIG. 1 is a side view of a hydraulic excavator to which the spline coupling device according to the present embodiment is applied.

  In FIG. 1, a hydraulic excavator 100 includes a self-propelled lower traveling body 101, an upper revolving body 103 rotatably mounted on the lower traveling body 101 via a revolving wheel 102, and a front side of the upper revolving body 103. The front device 104 is attached so as to be rotatable in the up-and-down direction and is used for excavating earth and sand.

  Here, the lower traveling body 101 is provided with a traveling motor (not shown), and the upper revolving body 103 is provided with a revolving motor (not shown). The lower traveling body 101 performs a traveling operation such as forward and backward movement by a traveling motor, and the upper revolving body 103 performs a revolving operation by a revolving motor.

  The front device 104 includes a boom 105, an arm 106, and a bucket 107, and a boom cylinder 108, an arm cylinder 109, and a bucket cylinder 110 are attached to the boom 105, the arm 106, and the bucket 107. These cylinders 108 to 110 are driven by pressure oil discharged from a hydraulic pump 2 described later, together with a traveling motor and a swing motor.

  The revolving frame 111 is a support frame that forms a support structure for the upper revolving structure 103, and is rotatably mounted on the lower traveling structure 101. A cab 112, a counterweight 113, an engine 1, a hydraulic pump 2, a heat exchanger 117, etc., which will be described later, are mounted on the revolving frame 111.

  The cab 112 is mounted on the front left side of the turning frame 111. Inside the cab 112, a driver's seat on which an operator sits, an operating lever for traveling, an operating lever for working, and the like are arranged.

  The counterweight 113 is attached to the rear end of the revolving frame 111. The counterweight 113 balances the weight with the front device 104, and is formed as a substantially arcuate heavy object.

On the rotating frame 111, outer cover 114 which covers the space between the key catcher Bed 112 and the counterweight 113 is disposed. The exterior cover 114, together with the counterweight 113, forms a machine chamber 115 in which onboard equipment such as the engine 1, the hydraulic pump 2, and a heat exchanger 117 described later is housed. The exterior cover 114 includes a top cover 114a that covers the top of the mounted device, a side cover 114b that covers the sides of the mounted device, and the like.

  FIG. 2 is a plan view of the hydraulic excavator 100 with the front device 104 and the top cover 115a removed, as seen from above.

  The engine 1 is located on the front side of the counterweight 113 and is provided on the rear end side of the revolving frame 111. The engine 1 is configured as, for example, a diesel engine, and is mounted on the upper-part turning body 103 in a horizontally installed state in which the output shaft 3 thereof extends in the left-right direction. A cooling fan 116 for supplying cooling air to a heat exchanger 117 described later is attached to one end side (right side in FIG. 2) of the output shaft 3 of the engine 1. A heat exchanger 117 is arranged on the left side (right side in FIG. 2) of the engine 1 so as to face the cooling fan 116. The heat exchanger 117 cools various kinds of fluid whose temperature has risen by cooling air. For example, return heat from hydraulic actuators (travel motor, swing motor, boom cylinder 108, arm cylinder 109, bucket cylinder 110, etc.) It is configured to include an oil cooler for cooling, a condenser for cooling a refrigerant supplied from an indoor unit (not shown) in the cab 112, and the like. The hydraulic pump 2 is attached to the other end side (left side in FIG. 2) of the output shaft 3 of the engine 1 via a power transmission device 118.

  FIG. 3 is a diagram showing the structure of the power transmission device 118.

  In FIG. 3, the power transmission device 118 is configured to include the flywheel 4, the elastic body shaft coupling 5, and the flywheel housing 6.

  A disc-shaped flywheel 4 is provided at the other end of the output shaft 3 of the engine 1 (not shown) protruding into a flywheel housing 6 described later. An engine-side block 9 (shown in FIG. 4) of an elastic shaft joint 5 described later is attached to the flywheel 4.

  A short cylindrical flywheel housing 6 is provided on the other end side (right side in FIG. 2) of the output shaft 3 of the engine 1. The flywheel 4 and the elastic body shaft joint 5 are arranged in the flywheel housing 6. A flange portion 7a of a pump casing 7, which will be described later, is attached to the open end of the flywheel housing 6.

  The hydraulic pump 2 includes, for example, a pump mechanism (not shown) including an oblique shaft hydraulic pump and a swash plate hydraulic pump, a pump casing 7 that houses the pump mechanism, and a pump mechanism that is connected to the pump mechanism and projects from the pump casing 7. It is configured to include an input shaft 8 which will be described later. A flange portion 7a is provided on the side of the pump casing 7 on which the input shaft 8 projects (on the right side in FIG. 3). The flange portion 7a serves as a mounting plate for mounting the hydraulic pump 2 on the engine 1, and is mounted on the flywheel housing 6 using bolts or the like. The hydraulic pump 2 is driven by the engine 1 to discharge pressure oil for operation toward various hydraulic actuators mounted on the hydraulic excavator 100.

  The elastic body shaft coupling 5 connects the output shaft 3 of the engine 1 (more specifically, the flywheel 4 provided on the output shaft 3) and the input shaft 8 of the hydraulic pump 2, and a high elastic body 10 described later. This elastic deformation absorbs torque fluctuations between the output shaft 3 (flywheel 4) of the engine 1 and the input shaft 8 of the hydraulic pump 2, deviation of the rotation center axis line, and the like. The elastic body shaft coupling 5 is arranged (accommodated) inside the flywheel housing 6 (elastic body shaft coupling chamber) so as to be adjacent to the flywheel 4 in the axial direction.

  FIG. 4 is a plan view of the elastic body shaft coupling 5 viewed from the hydraulic pump 2 side, and FIG. 5 is a plan view of the elastic body shaft coupling 5 viewed from the engine 1 side.

  4 or 5, the elastic body shaft coupling 5 includes a plurality (4) of engine-side blocks 9, a high-elastic body 10, a plurality (4) of pump-side blocks 11, and a hub 12. There is.

  The engine side block 9 is formed as a substantially fan-shaped block body, and is attached to the flywheel 4 on the output shaft 3 side of the engine 1 at intervals in the circumferential direction (rotational direction). The engine side block 9 is provided with a flange portion 9a located on the outer diameter side and extending on both sides in the circumferential direction. These flange portions 9a together with the flange portion 11a of the pump side block 11 described later regulate the radial displacement of the high elastic body 10. That is, the collar portion 9a of the engine-side block 9 and the collar portion 11a of the pump-side block 11 contact the outer peripheral surface of the high-elasticity body 10 to prevent the high-elasticity body 10 from being further displaced radially outward. To do.

  The high elastic body 10 is formed in a thick cylindrical shape using, for example, an elastic resin material or rubber material, and is arranged so as to surround a hub 12 described later. A hub accommodating portion 10c for accommodating the hub 12 is formed at the center of the high elastic body 10, and an engine side block engaging groove portion 10a for accommodating the engine side block 9 and an after-mentioned outer peripheral side of the high elastic body 10 are provided. The pump-side block engaging groove portions 10b for accommodating the pump-side blocks 11 are alternately formed in the circumferential direction. Between each engine side block engagement groove portion 10a and each pump side block engagement groove portion 10b is a compression portion 10d which is circumferentially compressed (sandwiched) by the engine side block 9 and the pump side block 11, respectively. .

  The pump-side block 11 is formed as a substantially fan-shaped block body, and is attached to the outer peripheral side of a hub 12, which will be described later, at intervals in the circumferential direction. The pump-side block 11 is provided with flange portions 11a located on the outer diameter side and extending on both sides in the circumferential direction. Each of these collar portions 11a regulates the displacement of the high elastic body 10 in the radial direction, like the collar portion 9a of the engine side block 9.

  Next, a spline coupling device 200 including the input shaft 8 of the hydraulic pump 2 and the hub 12 of the elastic body shaft coupling 5 will be described.

  The spline coupling device 200 transmits a rotational force between the engine 1 and the hydraulic pump 2, and includes a hub 12 of the elastic body shaft coupling 5 and an input shaft 8 of the hydraulic pump 2. .

  The hub 12 is formed as a thick cylindrical body, and is housed in the hub housing portion 10 c of the high elastic body 10. The hub 12 constitutes the spline coupling device 200 together with the input shaft 8, and rotationally drives the input shaft 8 by the rotational force from the engine 1.

  FIG. 6 is an enlarged view showing the inner peripheral side shape of the hub 12 shown in FIGS. 4 and 5.

  In FIG. 6, an inner spline portion 16 including a plurality of inner spline teeth 15 extending in the axial direction is provided on the inner peripheral side of the hub 12. The inner spline portion 16 is spline-coupled to an outer spline portion 18 of the input shaft 8 described later.

  FIG. 7 is a side view showing the input shaft 8 of the hydraulic pump 2 in an enlarged manner.

  In FIG. 7, an outer spline portion 18 including a plurality of outer spline teeth 17 extending in the axial direction is provided on the outer peripheral side of the input shaft 8. The outer spline portion 18 is spline-coupled to the inner spline portion 16 of the hub 12.

  The end portion of the input shaft 8 has neither the outer spline teeth 17 nor the guide teeth 21 described later, and is formed to have a smaller diameter than the outer spline teeth 17 or other shaft portions having the guide teeth 21 described later. And constitutes the first guide shaft portion 19.

  A second guide shaft portion 20 is provided between the first guide shaft portion 19 and a shaft portion of the input shaft 8 where the outer spline portion 18 is provided. On the outer peripheral side of the second guide shaft portion 20, a plurality of guide teeth 21 having a shape obtained by cutting the tips of the plurality of outer spline teeth 17 are provided.

  The procedure for attaching the hub 12 to the input shaft 8 in the spline coupling device configured as described above will be described with reference to FIGS. 8 to 13.

  FIG. 8 is a partial cross-sectional view of the spline coupling device 200 in a state immediately before the first guide shaft portion 19 of the input shaft 8 is inserted into the hub 12 as seen from the circumferential direction.

  First, the shaft center of the input shaft 8 and the shaft center of the hub 12 are arranged so as to substantially coincide with each other, and the first guide shaft portion 19 of the input shaft 8 is inserted into the hub 12.

  FIG. 9 is a partial cross-sectional view of the spline coupling device 200 in a state in which a part of the first guide shaft portion 19 of the input shaft 8 is inserted into the hub 12, as seen from the circumferential direction, and FIG. It is a fragmentary sectional view of the spline coupling device 200 seen from the direction.

  9 or 10, the first guide shaft portion 19 does not have the outer spline teeth 17 or the guide teeth 21, and the radius R5 of the first guide shaft portion 19 is smaller than the root radius R2 of the outer spline portion 18. Is also small (that is, smaller than the tip radius R0 of the inner spline portion 16), even if the inner spline portion 16 is out of phase with respect to the outer spline portion 18, and also with respect to the axis of the input shaft 8. The first guide shaft portion 19 can be inserted into the hub 12 even if the axis of the hub 12 is slightly displaced.

  FIG. 11 is a partial cross-sectional view of the spline coupling device 200 in a state in which a part of the second guide shaft portion 20 of the input shaft 8 is inserted into the hub 12, as seen from the circumferential direction, and FIG. It is a fragmentary sectional view of the spline coupling device 200 seen from the direction.

  In FIG. 12, the tip circle radius R3 of the second guide shaft portion 20 is set so as to be within the radial width W0 of the chamfered portion 22 formed at the corner of the inner spline tooth 15. Therefore, a circumferential gap 23 is formed between the guide teeth 21 and the inner spline teeth 15, and a play is generated in the circumferential direction between the inner spline portion 16 and the second guide shaft portion 20 of the input shaft 8. As a result, in the state shown in FIG. 9 or 10, if the axis of the input shaft 8 and the axis of the hub 12 coincide with each other, even if the phase shifts within the play range defined by the gap 23. The second guide shaft portion 20 can be inserted into the hub 12. Further, since the root radius R4 of the second guide shaft portion 20 matches the root radius R2 of the outer spline portion 18, which will be described later, by inserting the second guide shaft portion 20, the shaft centering is performed. Is completed.

  13 is a partial sectional view of the spline coupling device 200 in which a part of the outer spline portion 18 of the input shaft 8 is inserted into the hub 12, and FIG. 14 is a spline coupling device viewed from the C direction in FIG. FIG. 20 is a partial cross-sectional view of 200.

  When the input shaft 8 is further inserted into the hub 12 from the state shown in FIG. 11, when the phase of the inner spline portion 16 matches the phase of the outer spline portion 18, as shown in FIGS. 13 and 14. The outer spline teeth 17 mesh with the inner spline teeth 15, and the input shaft 8 can be inserted thereafter. On the other hand, when the phase of the inner spline part 16 and the phase of the outer spline part 18 do not match, the shaft end surface of the outer spline tooth 17 and the shaft end surface of the inner spline tooth 15 abut, and the subsequent input shaft 8 Insertion is blocked. At this time, the shaft centering has already been completed, and the phase shift of the hub 12 with respect to the input shaft 8 is within the range of the circumferential gap 23 (shown in FIG. 12). Therefore, only by adjusting the phase of the inner spline portion 16 within the range of the circumferential gap 23, the outer spline teeth 17 and the inner spline teeth 15 mesh with each other as shown in FIGS. The shaft 8 can be inserted.

  After the outer spline teeth 17 and the inner spline teeth 15 mesh with each other, the input shaft 8 is inserted into the hub 12 until the first guide shaft portion 19 and the second guide shaft portion 20 protrude from the hub 12. By the above procedure, the attachment of the hub 12 to the input shaft 8 is completed.

  According to the present embodiment configured as described above, neither the outer spline tooth 17 nor the guide tooth 21 is provided at the end portion of the input shaft 8 and the radius of the tip circle R1 of the inner spline portion 16 is larger than the radius R1. By providing the first guide shaft portion 19 having the small radius R5, a phase shift between the outer spline portion 18 and the inner spline portion 16 is allowed in the process of inserting the first guide shaft portion 19 into the hub 12. Since the deviation between the axis of the input shaft 8 and the axis of the hub 12 can be kept within a predetermined range as it is, the subsequent centering of the shaft becomes easy.

  Further, the outer peripheral side of the second guide shaft portion 20 has the same number of teeth and the root radius R4 of the outer spline portion 18, and when meshed with the inner spline tooth 15, the inner spline tooth 15 is circumferentially arranged with respect to the inner spline tooth 15. By forming the guide teeth 21 having the gap 23, the phase gap is allowed by the gap 23 in the circumferential direction in the process of inserting the second guide shaft portion 20 into the hub 12, so that the centering of the shaft is easy. Can be done. Further, since the phase shift after the axial centering is completed is limited to the extent that it is accommodated in the circumferential gap 23, the subsequent phase alignment becomes easy.

  Further, since the guide teeth 21 have a shape obtained by cutting the tips of the outer spline teeth 17, only the tip of the shaft end side portion of the outer spline teeth 17 is scraped off after the normal spline processing for forming the outer spline portion 18. Thus, the second guide shaft portion 20 can be molded. As a result, it is possible to keep the cost for processing the second guide shaft portion 20 low.

  Further, since the second guide shaft portion 20 projects from the end surface of the hub 12 when the hub 12 is attached to the input shaft 8, the guide tooth 21 having a tooth surface area smaller than that of the outer spline tooth 17 has the inner spline tooth 15 Will never engage. As a result, it is possible to prevent uneven tooth surface pressure when the outer spline teeth 17 and the inner spline teeth 15 mesh with each other. Furthermore, since the above-described function and effect of the second guide shaft portion 20 can be obtained without increasing the axial length of the guide teeth 21, the input shaft 8 is reduced by reducing the axial length of the second guide shaft portion 20. Can be prevented from lengthening.

  A second embodiment of the present invention will be described with reference to FIG. FIG. 15 is a partial cross-sectional view showing the spline coupling device 200 according to this embodiment in a state similar to that of FIG. Hereinafter, differences from the first embodiment will be mainly described.

  In FIG. 15, a chamfered portion 24 is formed at a corner of each guide tooth 21 of the second guide shaft portion 20 according to the present embodiment so as to face the chamfered portion 22 of the inner spline tooth 15. Specifically, the chamfered portion 24 is formed so that the radius R0 of the addendum circle of the inner spline portion 16 falls within the radial width W1 thereof. As a result, the circumferential gap 23 between the inner spline tooth 15 and the guide tooth 21 is enlarged.

  Also in the present embodiment configured as described above, the same effect as in the first embodiment can be obtained.

  Further, by providing the chamfered portion 22 at the corner portion of the guide tooth 21, the circumferential gap 23 generated between the inner spline tooth 15 of the hub 12 and the guide tooth 21 is enlarged, so that the inner spline of the hub 12 is expanded. Since the circumferential play of the second guide shaft portion 20 with respect to the portion 16 becomes large, it becomes easier to insert the second guide shaft portion 20 into the hub 12.

  In addition, in this embodiment, the chamfered portion 22 of the inner spline tooth 15 and the chamfered portion 24 are provided on the guide tooth 21 of the second guide shaft portion 20, but the present invention is not limited to this, and the guide tooth 21 is not limited to this. It is also possible to provide the chamfered portion 24 only on the inner side and omit the chamfered portion 22 of the inner spline tooth 15. Even in that case, since the circumferential gap 23 can be secured between the inner spline tooth 15 and the guide tooth 21, the same effect as that of the first embodiment can be obtained.

  Although the embodiments of the present invention have been described in detail above, the present invention is not limited to the above-described embodiments and includes various modifications. For example, the above-described embodiment is one in which the present invention is applied to the shaft coupling that connects the hydraulic pump 2 to the engine 1, but the present invention is not limited to this, and is applied to the shaft coupling that connects two hydraulic pumps in tandem. Can also be applied. Further, the above-described embodiments have been described in detail in order to explain the present invention in an easy-to-understand manner, and are not necessarily limited to those having all the configurations described. Further, it is possible to add a part of the configuration of another embodiment to the configuration of a certain embodiment, delete a part of the configuration of a certain embodiment, or replace it with a part of another embodiment. It is possible.

  DESCRIPTION OF SYMBOLS 1 ... Engine, 2 ... Hydraulic pump, 3 ... Output shaft, 4 ... Flywheel, 5 ... Elastic body shaft coupling, 6 ... Flywheel housing, 7 ... Pump casing, 7a ... Flange part, 8 ... Input shaft, 9 ... Engine Side block, 9a ... Collar portion, 10 ... High elastic body, 10a ... Engine side block engaging groove portion, 10b ... Pump side block engaging groove portion, 10c ... Hub accommodating portion, 10d ... Compressing portion, 11 ... Pump side block, 11a ... Collar portion, 12 ... Hub, 15 ... Inner spline tooth, 16 ... Inner spline portion, 17 ... Outer spline tooth, 18 ... Outer spline portion, 19 ... First guide shaft portion, 20 ... Second guide shaft portion, 21 ... Guide tooth, 22 ... chamfered portion of inner spline tooth, 23 ... circumferential gap, 24 ... chamfered portion of guide tooth, 100 ... hydraulic excavator, 101 ... lower traveling body, 102 ... slewing wheel, 103 ... upper portion Revolving structure, 104 ... Front device, 105 ... Boom, 106 ... Arm, 107 ... Bucket, 108 ... Boom cylinder, 109 ... Arm cylinder, 110 ... Bucket cylinder, 111 ... Revolving frame, 112 ... Cab, 113 ... Counterweight, 114 ... Exterior cover, 114a ... Top cover, 114b ... Side cover, 115 ... Machine room, 116 ... Cooling fan, 117 ... Heat exchanger, 118 ... Power transmission device, 200 ... Spline coupling device, R0 ... Tip of inner spline part Radius of circle, R1 ... Radius of tip circle of outer spline part, R2 ... Radius of root circle of outer spline part, R3 ... Radius of tip circle of second guide shaft part, R4 ... Radius of root circle of second guide shaft part , R5 ... Radius of first guide shaft portion, W0 ... Radial width of chamfered portion of inner spline tooth (first predetermined radial width), W1 ... Take part of the radial width (second predetermined radial width).

Claims (2)

A lower traveling body provided with a traveling motor,
An upper swing body provided with a swing motor,
A front device attached to the front side of the upper swing body and having a boom, an arm, a bucket, a boom cylinder, an arm cylinder, and a bucket cylinder;
A swivel frame forming a support structure for the upper swivel body,
A cab provided on the left front side of the swing frame,
A counterweight attached to the rear end of the revolving frame,
An exterior cover which is disposed on the revolving frame and forms a machine room between the cab and the counterweight,
A hydraulic pump that is housed in the machine chamber and supplies pressure oil to the traveling motor, the swing motor, the boom cylinder, the arm cylinder, and the bucket cylinder;
An engine housed in the machine room,
An elastic shaft coupling that is housed in the machine room and connects the output shaft of the engine and the input shaft of the hydraulic pump,
A cooling fan housed in the machine room and attached to one end side of the engine,
A heat exchanger housed in the machine room and arranged to face the cooling fan;
An outer spline portion formed of a plurality of outer spline teeth extending in the axial direction is provided on the outer peripheral portion of the input shaft,
The elastic body shaft coupling includes a hub in which an inner spline portion that is spline-coupled with the outer spline portion is provided on an inner peripheral side,
In the construction machine, the input shaft is integrally formed at an end thereof, and includes a first guide shaft portion having a radius smaller than a root circle radius of the outer spline portion,
The input shaft is Bei give a second guide shaft which is located between the outer spline portion shaft portion provided with the first guide shaft,
The second guide shaft portion has the same number of teeth and the same root radius as the outer spline portion on the outer peripheral side, and is smaller than the tip circle radius of the outer spline portion and the teeth of the inner spline portion. comprising a plurality of guide teeth have a larger addendum circle radius than Sakien radius,
The plurality of inner spline teeth include a chamfered portion having a first predetermined radial width at a corner thereof,
Since the radius of the tip circle of each of the plurality of guide teeth is set within the first predetermined radial width, when the plurality of guide teeth mesh with the plurality of inner spline teeth, a circumferential direction is formed between the plurality of guide teeth and the inner spline portion. A construction machine characterized by having a gap . The construction machine according to claim 1,
Each of the plurality of guide teeth has a chamfered portion having a second predetermined radial width at its corner,
The construction machine characterized in that the radius of the addendum circle of the inner spline portion is within the second predetermined radial width .

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