JP2020112168A - Construction machine - Google Patents

Abstract

To provide a construction machine capable of improving workability (easiness in insertion, easiness in mounting/demounting) of a mounting/demounting work of a hub and a rotating shaft.SOLUTION: A female spline tooth 34 of a hub 32 has a female-side transmission tooth surface 34C positioned at one side in a circumferential direction, and a female-side non-transmission tooth surface 34D positioned at the other side in the circumferential direction. On the other hand, a male spline tooth 37 of a rotating shaft 35 has a male-side transmission tooth surface 37C positioned at one side in the circumferential direction, and a male-side non-transmission tooth surface 37D positioned at the other side in the circumferential direction. Here, the transmission tooth surfaces 34C, 37C extend in an axial direction (that is, extended in parallel with center axes O1-O1, O2-O2), and transmit torque on the basis of the contact of the transmission tooth surfaces 34C, 37C. On the other hand, the non-transmission tooth surfaces 34D, 37D are extended while tilted to the transmission tooth surfaces 34C, 37C.SELECTED DRAWING: Figure 11

Description

The present invention relates to a construction machine such as a hydraulic excavator including a spline connecting device that transmits a rotational force between a drive source and a hydraulic pump.

For example, a hydraulic excavator, which is a typical example of construction machinery, drives a boom, an arm, a traveling device, a turning device, and the like by a hydraulic actuator such as a hydraulic cylinder and a hydraulic motor. Therefore, the hydraulic excavator is equipped with a hydraulic pump for supplying high pressure oil to each hydraulic actuator. A rotary shaft (input shaft) of a hydraulic pump is connected to an output shaft of a prime mover (driving source) such as an engine or an electric motor (electric motor) via a hub, an elastic shaft joint made of a highly elastic body or the like. Since the elastic body shaft coupling transmits the rotating torque of the prime mover, for example, the elastic body shaft coupling constitutes a joint structure capable of rotating the output shaft and the rotating shaft in one direction. In this case, the hub of the elastic shaft joint and the rotary shaft of the hydraulic pump are connected by spline connection (spline fitting), and the rotational torque can be transmitted between them.

The engine, which is a prime mover, outputs a high torque, for example, while maintaining a rated output state during operation. For this reason, it is preferable that the spline joint between the hub and the rotary shaft be lubricated with oil lubrication (the lubricating oil is circulated through the spline joint) in order to suppress spline wear. However, since the hydraulic excavator is transported by a trailer on an ordinary road, the widthwise dimension of the vehicle body is limited, and under this limitation, there is a narrow space between the engine and the hydraulic pump arranged in the vehicle body. .. Therefore, it is difficult to adopt a large-sized oil lubrication type connection structure between the engine and the hydraulic pump.

Therefore, it is conceivable to adopt, for example, the configuration described in Patent Document 1 as a connecting structure used in a hydraulic excavator or the like. That is, the rotary shaft of the hydraulic pump and the hub on the engine side are spline-fitted in a dry manner with a clearance fit. Further, the hub is provided with a bottomed (non-penetrating) screw hole from the outer peripheral side toward the female spline portion. At the bottom of the screw hole, a pilot hole having a flat bottom surface is formed continuously from the bottom of the screw hole up to the vicinity of the female spline portion. Then, a clamping screw having a flat tip portion is tightened into the screw hole, so that the tip portion of the clamping screw is pressed against the bottom surface of the prepared hole. According to this configuration, the female spline portion of the hub is deformed by the clamping screw and the female spline portion is pressed against the male spline portion of the rotating shaft, whereby the female spline portion and the male spline portion can be fixed. ..

Here, the rotational torque from the engine is transmitted to the hub spline-coupled to the rotary shaft of the hydraulic pump via the engine-side block (insert) fixed to the flywheel of the engine and the high elastic body. Then, the rotational torque is transmitted from the hub to the rotary shaft via the spline coupling portion between the hub and the rotary shaft, thereby driving the hydraulic pump. Therefore, in the case of the configuration in which the female spline portion is deformed by using the clamping screw as described above, the load on the clamping screw portion becomes large, which affects the life.

On the other hand, the spline joint is covered with a bell flange of the hydraulic pump and a flywheel housing of the engine for protection from dust due to sand and sand generated by excavation work of the hydraulic shovel, for example, and these are fastened with bolts. ing. Therefore, it is difficult to replace the hub while the engine and the hydraulic pump are mounted on the hydraulic excavator, and it may take time and labor to replace the hub.

On the other hand, Patent Document 2 describes a configuration in which a spacer is provided between the hydraulic pump and the pump mounting cover in order to improve the workability of the replacement work. According to the configuration described in Patent Document 2, the hydraulic pump can be removed together with the spacer from the pump mounting cover, and the workability of mounting and removing the hydraulic pump with respect to the engine can be improved. Further, for example, since the hub and the high elastic body can be attached to and detached from the engine side block together with the hydraulic pump, the detachability of the hub and the high elastic body from the engine side block can be improved.

Japanese Utility Model Publication No. 60-34123 JP, 2013-174105, A

However, Patent Document 2 does not consider the detachability of the rotary shaft of the hydraulic pump and the hub. Specifically, the hydraulic pump is connected in the same straight line as the engine, and the engine and the hydraulic pump are arranged so as to extend in the left and right directions which are directions orthogonal to the traveling direction of the vehicle body. Therefore, the width dimension (length dimension) of the engine and the hydraulic pump as a whole when the hydraulic pump is connected to the engine must be within the width dimension of the vehicle body. Therefore, the connecting portion between the output shaft of the engine and the rotating shaft of the hydraulic pump must be arranged in a narrow space between the engine and the hydraulic pump, and it is difficult to secure the axial length of the spline portion. Therefore, the disassembly and assembly workability cannot be ensured satisfactorily.

On the other hand, in order to stably transmit the rotational torque over a long period in the spline portion having a short axial length, it is preferable to reduce the clearance (gap) between the spline tooth surfaces to reduce the backlash. However, if the backlash is reduced, it is necessary to perform highly accurate phase alignment and axial center alignment during hub mounting work. That is, a high technique for alignment and working time are required, and a great deal of labor and time are required for mounting the hub and the rotary shaft. Therefore, it is desired that the hub and the rotary shaft can be easily attached and detached and the maintainability can be improved.

That is, the construction machine such as a hydraulic excavator has a limited vehicle width so that it can be transported on a general road, and thus the layout of various devices mounted behind the upper swing body is limited. For this reason, the spline connection device, which is arranged behind the upper revolving superstructure and in the machine room on the front side of the counterweight, transmits power in a narrow space between the engine and the hydraulic pump directly driven by the engine. It is desired that such a spline connecting device can improve workability of disassembly and assembly in a narrow space in a machine room behind the upper swing body.

The present invention has been made in view of the above-described problems of the related art, and an object of the present invention is to provide a narrow space between a drive source and a hydraulic pump at a rear position of an upper swing body (a narrow space where layout is limited). It is an object of the present invention to provide a construction machine capable of improving workability (easiness of insertion, ease of removal) of attachment and detachment work of a hub and a rotating shaft of a spline connection device arranged in the.

In order to solve the above-mentioned problems, a construction machine according to the present invention is a self-propelled lower traveling structure, an upper revolving structure rotatably mounted on the lower traveling structure, and a work device provided on the upper revolving structure. The upper revolving structure comprises a revolving frame having a support structure and having the working device mounted on the front side thereof, and a counterweight mounted at the rear end of the revolving frame for balancing the weight of the working device. A drive source located on the front side of the counterweight and provided on the rear end side of the revolving frame; a hydraulic pump driven by the drive source to discharge pressure oil; and a drive source and the hydraulic pump. A spline connection device for transmitting a rotational force between the spline connection device, the spline connection device having a female spline portion on the inner peripheral side and rotating in one direction by the drive source, and the outer peripheral side on the cylindrical hub. In a construction machine having a female spline portion and a male spline portion that is spline-coupled, and a rotary shaft of the hydraulic pump that rotates based on rotation of the hub, a female spline tooth that constitutes the female spline portion of the hub. Is larger in tooth thickness at the back side end portion than at the inlet side end portion on the hydraulic pump side, and the male spline tooth forming the male spline portion of the rotary shaft is the drive source. The tooth thickness of the proximal end portion on the proximal side is larger than the tooth thickness of the distal end portion on the side, and the female spline teeth extend in parallel to the central axis of the hub and the rotational force of the hub. To the rotary shaft, and the inlet side over the range in which the female spline teeth and the male spline teeth abut between the inlet side end and the back side end. A male non-transmission tooth surface that extends obliquely with respect to the female transmission tooth surface so that the tooth thickness increases from the end portion toward the rear end portion, The female spline extends between the male side transmission tooth surface that extends parallel to the central axis of the shaft and abuts on the female side transmission tooth surface of the female spline tooth, and the distal end side end portion and the proximal end side end portion. Over the range in which the tooth and the male spline tooth come into contact with each other, the tooth extends toward the male side transmission tooth surface so that the tooth thickness increases from the tip end side end toward the base end side end. It has a male non-transmission tooth surface.

ADVANTAGE OF THE INVENTION According to this invention, the hub of a spline connection device and the rotation shaft which are arrange|positioned at the narrow position (the narrow space where layout is limited) between a drive source and a hydraulic pump in the rear position of an upper revolving structure are attached and removed. The workability outside can be improved.

That is, the female spline teeth have a small tooth thickness at the end on the hydraulic pump side, that is, the inlet side end that is the inlet side when the rotary shaft is inserted into the hub, and the male spline teeth have the drive source side end. That is, the tooth thickness at the tip end portion on the insertion tip side when inserting the rotary shaft into the hub is small. Therefore, when inserting the male spline portion into the female spline portion, a gap (clearance) between the tooth surfaces facing each other in the circumferential direction is generated between the tip end side end portion of the male spline tooth and the inlet side end portion of the female spline tooth. growing. As a result, when the hub and the rotary shaft are mounted (splined), it is possible to reduce the time and effort of phase matching of the spline teeth, and improve the workability of mounting.

Further, the female spline tooth has a female non-transmission tooth surface that extends so as to increase the tooth thickness from the inlet end toward the inner end, and the male spline tooth has a distal end. The male non-transmission tooth surface extends so as to increase in tooth thickness from the portion toward the proximal end. Therefore, when the male spline part is pulled out from the female spline part, if the hub and the rotating shaft start to move relative to each other in the axial direction (if the hub starts to move with respect to the rotating shaft), the space between the tooth surfaces facing each other in the circumferential direction The clearance (clearance) spreads over the entire axial direction. Accordingly, when the hub and the rotary shaft are detached, the resistance due to the drag (rubbing) between the tooth surfaces can be reduced, and the workability of removal can be improved.

Further, the female spline tooth has a female-side transmission tooth surface extending parallel to the central axis of the hub, and the male spline tooth has a male-side transmission tooth surface extending parallel to the central axis of the rotating shaft. Have That is, the female-side transmission tooth surface and the male-side transmission tooth surface that are in contact with each other and transmit the rotational force extend parallel to the central axis. Therefore, for example, compared with a configuration in which the female transmission male surface and the male transmission tooth surface are inclined with respect to the central axis, the contact surface (contact surface) between the female transmission male surface and the male transmission tooth surface is compared. ), an axial load (axial load) can be suppressed from being generated. As a result, it is possible to suppress an axial load from being applied to the rotary shaft, and it is possible to suppress a reduction in the life of the rolling bearing (bearing) that rotatably supports the rotary shaft.

It is a front view showing a hydraulic excavator according to an embodiment. It is the expanded sectional view which looked at the upper revolving superstructure of a hydraulic excavator from the arrow II-II direction in FIG. FIG. 3 is an enlarged view of a partial cross section of an engine, an elastic body shaft coupling, a hydraulic pump, etc. as viewed from the same direction as FIG. 2. It is an exploded perspective view showing a flywheel, an elastic body shaft coupling, a hydraulic pump, and the like. FIG. 3 is a front view of a hub, a pump side block, a rotary shaft, etc. as viewed from the engine side. FIG. 6 is a cross-sectional view of the hub, the rotating shaft, and the like in FIG. 5 together with the flywheel, as viewed in the direction of arrows VI-VI. It is an exploded sectional view showing a flywheel, a nut for retaining, a hub, and a rotating shaft. It is explanatory drawing (schematic) which shows the state before attaching a hub to a rotating shaft. It is explanatory drawing (schematic) which shows the state which started attaching the hub to the rotating shaft. It is explanatory drawing (schematic) which shows the state which attached the hub to the rotating shaft. FIG. 11 is an explanatory view (schematic diagram) showing a state in which a retaining nut is screwed onto the rotary shaft in FIG. 10.

Hereinafter, a construction machine according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings, taking a case where the construction machine is applied to a hydraulic excavator as an example.

In FIG. 1, a hydraulic excavator 1 as a typical example of a construction machine includes a self-propelled crawler-type lower traveling body 2 and an upper revolving body mounted on the lower traveling body 2 via a revolving wheel 3 so as to be rotatable. 4 and a front device 5 provided on the upper revolving structure 4 so as to be able to move up and down. In this case, the lower traveling structure 2 and the upper revolving structure 4 constitute the vehicle body of the hydraulic excavator 1.

The front device 5, which is also called a work device, is a multi-joint structure work machine for excavating earth and sand, and the like, and is attached to the front side of the upper revolving structure 4 so as to be able to move up and down. The front device 5 includes a boom 5A rotatably attached to the revolving frame 6 of the upper revolving structure 4, an arm 5B rotatably attached to the tip of the boom 5A, and a pivot to the tip of the arm 5B. It is constituted by a bucket 5C that is movably attached, a boom cylinder 5D that drives the boom 5A, an arm cylinder 5E that drives the arm 5B, and a bucket cylinder 5F that drives the bucket 5C. These cylinders 5D, 5E, 5F form a hydraulic actuator (not shown) driven by the pressure oil discharged from the hydraulic pump 16.

The revolving frame 6 is a support frame forming a support structure for the upper revolving structure 4, and is mounted on the lower traveling structure 2 so as to be revolvable. A cab 7, a counterweight 8, various devices such as an engine 10, a hydraulic pump 16, a heat exchanger 18, and a control valve (not shown) are mounted on the revolving frame 6. These various devices are covered with an exterior cover 9 that forms the outer shell of the upper swing body 4.

The revolving frame 6 is provided with a bottom plate 6A made of a thick steel plate extending in the front and rear directions, and a left vertical plate 6B extending in the front and rear directions at a predetermined interval in the left and right directions. Right vertical plate 6C, left side frames 6D and right side frames 6E, which are arranged on the left and right outer sides of the respective vertical plates 6B and 6C with a space and extend in the front and rear directions, a bottom plate 6A, and respective vertical plates 6B and 6C From the left to the right, and a plurality of overhanging beams 6F that support the left and right side frames 6D and 6E are included at the tips thereof. A boom 5A of the front device 5 is attached to the front side of each of the vertical plates 6B and 6C so that the boom 5A can be lifted and lowered.

As shown in FIG. 2, on the rear side of the revolving frame 6, a mounting pedestal 6G that is located between the left vertical plate 6B and the right vertical plate 6C and extends upward is provided with a space in the front and rear directions. .. The engine 10 is mounted on each mounting base 6G in a vibration-damped state.

The cab 7 is mounted on the front left side of the turning frame 6. Inside the cab 7, a driver's seat on which an operator is seated, a traveling operation lever, a work operation lever, and the like are arranged. The operator can perform traveling of the hydraulic excavator 1, revolving of the upper revolving structure 4, excavation work by the front device 5, and the like by getting on the cab 7 and operating the operation lever, operation pedal, and the like.

The counterweight 8 is attached to the rear ends of the left and right vertical plates 6B and 6C that form the turning frame 6. The counterweight 8 is a heavy object that balances the weight with the front device 5, and has a rear end surface formed in an arc shape. The counterweight 8 rises upward from the rear end of the revolving frame 6 and covers various devices such as the engine 10, the hydraulic pump 16, the heat exchanger 18, and the control valve from the rear side.

The exterior cover 9 is located between the cab 7 and the counterweight 8 and disposed on the revolving frame 6. The exterior cover 9 is configured to include an upper surface cover 9A, an engine cover 9B, a left side surface cover 9C, and a right side surface cover 9D. The exterior cover 9 accommodates on-board devices such as the engine 10, the hydraulic pump 16, the heat exchanger 18, the exhaust gas treatment device 19, and the control valve.

In this case, as shown in FIG. 2, in the exterior cover 9, the engine 10, the hydraulic pump 16, and the heat exchanger 18 are arranged in a straight line in the width direction (left and right directions) of the upper swing body 4. ing. The heat exchanger 18 faces the cooling fan 12 of the engine 10 and cools engine cooling water and the like. The exhaust gas processing device 19 is located between the engine 10 and the hydraulic pump 16 and above them, and includes an exhaust muffler, a catalyst, a filter (all not shown) connected to an exhaust manifold of the engine 10. It is configured to include.

The engine 10 as a drive source (power source, drive mechanism) is located on the front side of the counterweight 8 and provided on the rear end side of the revolving frame 6. The engine 10 is a prime mover of the hydraulic excavator 1, and for example, a diesel engine is used. The engine 10 is mounted on the upper-part turning body 4 in a horizontally placed state in which a crankshaft 13 serving as an output shaft extends in the left and right directions of the vehicle body. The engine 10 includes an engine body 11, a plurality (eg, 6) cylinders (not shown) provided in the engine body 11, and a plurality of (eg, 6) pistons (not shown) that reciprocate in each cylinder. ) And a crankshaft 13 (hereinafter, referred to as an output shaft 13) that is connected to each piston via a connecting rod (not shown) and outputs the reciprocating motion of each piston as a rotational force.

As shown in FIG. 2, the engine body 11 includes a crankcase 11A formed as a hollow container for housing the output shaft 13, an oil pan 11B provided under the crankcase 11A for housing engine oil, and a crankcase. It is configured to include a cylinder block 11C mounted on 11A and forming a cylinder, and a cylinder head 11D mounted on the cylinder block 11C.

A cooling fan 12 for supplying cooling air to the heat exchanger 18 is provided on one end side (left side in FIG. 2) of the engine body 11. A water jacket (not shown) in which engine cooling water circulates is formed in the cylinder block 11C and the cylinder head 11D of the engine body 11. The water jacket is connected to the heat exchanger 18 that releases the heat of the cooling water.

As shown in FIG. 3, a disc-shaped flywheel 14 that rotates in one direction together with the output shaft 13 is provided on the other end side (the right end side in FIG. 3) of the output shaft 13 of the engine 10. The flywheel 14 is provided with a plurality of (for example, four) female screw holes 14A and a recess 14B. The female screw holes 14A are formed at four positions on an arc centered around the rotation center of the flywheel 14 at equal intervals in the circumferential direction. A first bolt 22 for attaching the engine side block 21 of the elastic body shaft coupling 20 to the flywheel 14 is screwed into each of the female screw holes 14A.

The recess 14B is provided on one side surface of the flywheel 14, that is, the side surface opposite to the engine 10 (the hydraulic pump 16 side). The recess 14</b>B is formed on one side surface of the flywheel 14 at a position axially opposed to the rotary shaft 35 of the hydraulic pump 16 and recessed from the one side surface toward the engine 10. As will be described later, the recess 14B forms a housing chamber in which the projecting end portion 38 of the rotary shaft 35 and the nut 39 screwed into the projecting end portion 38 are housed (see FIG. 6).

As shown in FIGS. 2 and 3, a short cylindrical flywheel housing 15 is provided on the other end side (right side in FIG. 2) of the engine body 11. The flywheel housing 15 accommodates the flywheel 14 and the elastic body shaft coupling 20. The open end of the flywheel housing 15 serves as a flange attachment portion 15A to which the flange portion 16A1 of the hydraulic pump 16 is attached. The flywheel 14 and the elastic shaft coupling 20 are covered with the flywheel housing 15 and the flange portion 16A1 of the hydraulic pump 16.

The hydraulic pump 16 as a driven device (powered device, driven mechanism) is rotationally driven by the engine 10. The hydraulic pump 16 is attached to the engine 10 via the flywheel housing 15. The hydraulic pump 16 is driven by the engine 10 to discharge pressure oil for operation toward various hydraulic actuators mounted on the hydraulic excavator 1. Here, the hydraulic pump 16 includes, for example, a pump mechanism (not shown) configured by an oblique shaft hydraulic pump and a swash plate hydraulic pump, a pump casing 16A that houses the pump mechanism, and a protrusion from the center of the pump casing 16A. The rotary shaft 35 is provided and is connected to the pump mechanism, which will be described later.

The pump casing 16A houses the pump mechanism. The base end side (left side in FIGS. 2 to 3) of the pump casing 16A is a flange portion 16A1 which is an annular flange portion whose diameter is expanded over the entire circumference as compared with other portions. The flange portion 16A1 is also called a bell flange and is formed as a mounting plate for mounting the hydraulic pump 16 on the engine 10. The flange portion 16A1 is attached to the flange attachment portion 15A of the flywheel housing 15 using a fixing bolt 17.

Next, the elastic shaft coupling 20 that connects the output shaft 13 of the engine 10 and the rotating shaft 35 of the hydraulic pump 16 will be described.

The elastic shaft joint 20 is provided between the output shaft 13 of the engine 10 (more specifically, the flywheel 14 provided on the output shaft 13) and the rotary shaft 35 of the hydraulic pump 16. Due to the elastic deformation of the elastic body 23, the elastic body shaft coupling 20 causes torque fluctuations between the output shaft 13 (flywheel 14) of the engine 10 and the rotary shaft 35 of the hydraulic pump 16, and central axis lines O1-O1 and O2-O2. Absorb the deviation. As a result, torque can be stably transmitted from the engine 10 to the hydraulic pump 16.

The elastic body shaft coupling 20 is arranged (accommodated) inside the flywheel housing 15 (elastic body shaft coupling chamber) so as to be adjacent to the flywheel 14 in the axial direction. The elastic body shaft coupling 20 includes a plurality (for example, four) engine side blocks 21 (driving source side blocks), an elastic body 23, and a plurality (for example, four) pump side blocks 24 (driven devices). The side block) and the hub 32.

The four engine-side blocks 21 are attached to the flywheel 14 provided on the output shaft 13 side of the engine 10 at intervals in the circumferential direction (rotational direction). Each engine-side block 21 is also called an insert, is made of a fan-shaped block body, and has a first bolt insertion hole 21A extending in the axial direction. Each engine-side block 21 is integrally attached to the side surface of the flywheel 14 by screwing the first bolt 22 inserted into the first bolt insertion hole 21A into the female screw hole 14A of the flywheel 14.

The engine side block 21 is provided with first flange portions 21B located on the outer diameter side and projecting to both sides in the circumferential direction. As will be described later, the first collar portion 21B, together with the second collar portion 24B of the pump side block 24, regulates the radial displacement of the elastic body 23. That is, the first collar portion 21B of the engine side block 21 and the second collar portion 24B of the pump side block 24 contact the outer peripheral surface of the elastic body 23, so that the elastic body 23 is displaced radially outward. Stop.

The elastic body 23 is formed in a thick cylindrical shape using, for example, an elastic resin material and rubber material, and is arranged so as to surround the hub 32. The elastic body 23 is formed with engine-side block engagement groove portions 23B and pump-side block engagement groove portions 23C, which are recessed radially inward from the outer peripheral surface 23A, alternately in the circumferential direction. The engine side block 21 is fitted in the engine side block engagement groove portion 23B, and the pump side block 24 is fitted in the pump side block engagement groove portion 23C.

That is, the elastic body 23 has a hub accommodating portion 23D that accommodates the hub 32 near the center, and four engine side block engaging groove portions 23B and four pump side blocks are provided around the hub accommodating portion 23D. The engagement groove portions 23C are alternately arranged at intervals in the circumferential direction. In this case, between the engine side block engaging groove portions 23B and the pump side block engaging groove portions 23C, there is a compression portion 23E that is circumferentially compressed (sandwiched) by the engine side block 21 and the pump side block 24, respectively. Has become.

The four pump-side blocks 24 are mounted at intervals in the circumferential direction of the hub 32 while projecting radially outward from the hub 32. Each pump-side block 24 is composed of a fan-shaped block body, and has a second bolt insertion hole 24A extending in the radial direction. Each pump-side block 24 is integrally attached to the outer peripheral side 32A of the hub 32 by screwing the second bolt 25 inserted into the second bolt insertion hole 24A into the screw hole 32B of the hub 32. The pump side block 24 is provided with second flange portions 24B located on the outer diameter side and projecting to both sides in the circumferential direction. Each of the second flange portions 24B, like the first flange portion 21B of the engine side block 21, regulates the radial displacement of the elastic body 23.

Next, the spline connection device 31 including the rotary shaft 35 of the hydraulic pump 16 and the hub 32 of the elastic body shaft coupling 20 will be described.

The spline connection device 31 is a power transmission device (coupling device) that transmits a rotational force between the engine 10 and the hydraulic pump 16. The spline connection device 31 includes a hub 32 of the elastic shaft joint 20 and a rotary shaft 35 of the hydraulic pump 16.

The hub 32 of the elastic body shaft coupling 20 is housed in the hub housing portion 23D of the elastic body 23. The hub 32 rotates in one direction by the engine 10 as a drive source. That is, the hub 32 rotates with the output shaft 13 (flywheel 14) of the engine 10 based on the rotation of the output shaft 13 (flywheel 14) of the engine 10. The hub 32 is formed in a thick cylindrical shape. The hub 32 serves as a driving member (driving body) that rotationally drives the rotating shaft 35 of the hydraulic pump 16 by the rotational force from the engine 10, and is provided on the engine 10 side. As shown in FIG. 5, on the outer peripheral side 32A of the hub 32, screw holes 32B into which the second bolts 25 for mounting the pump side block 24 are screwed are provided at four positions spaced apart in the circumferential direction. ..

The hub 32 has a female spline portion 33 on the inner peripheral side 32C. That is, on the inner peripheral side 32C of the hub 32, a plurality of female spline teeth 34 that are spaced apart in the circumferential direction and extend in the axial direction are formed. The female spline portion 33 (female spline tooth 34) is spline-connected with the male spline portion 36 (male spline tooth 37) of the rotary shaft 35. As shown in FIGS. 6 and 7, the female spline portion 33 (female spline tooth 34) is provided between the side surfaces 32D and 32E of the hub 32, that is, the inlet side surface 32D which is the side surface on the hydraulic pump 16 side and the engine 10 side. It is formed so as to extend in the axial direction between the inner side surface 32E which is the side surface of the. The inner diameter B of the female spline portion 33, more specifically, the small diameter B (FIG. 6) is larger than the outer diameter A (FIG. 6) of the protruding end portion 38 of the rotating shaft 35.

The female spline teeth 34 forming the female spline portion 33 of the hub 32 have an inlet side end portion 34A and a rear side end portion 34B. The inlet-side end portion 34A corresponds to the end portion of the female spline teeth 34 on the hydraulic pump 16 side, that is, the end portion located on the inlet side of the female spline portion 33 when the rotary shaft 35 is inserted into the hub 32. .. The back side end 34B corresponds to the end of the female spline tooth 34 on the engine 10 side, that is, the end located on the back side of the inlet side end 34A when the rotating shaft 35 is inserted into the hub 32. To do. The female spline tooth 34 has a tooth thickness T2 (FIG. 8) at the back end 34B that is larger than a tooth thickness T1 (FIG. 8) at the inlet end 34A.

Here, the female spline teeth 34 include a female-side transmission tooth surface 34C located on one side (or the other side) in the circumferential direction of the hub 32 (female spline portion 33) and a circumferential direction of the hub 32 (female spline portion 33). With respect to the other side (or one side), the female non-transmission tooth surface 34D. The female-side transmission tooth surface 34C and the female-side non-transmission tooth surface 34D are connected by the tooth crests of the female spline teeth 34 on the radially inner side of the hub 32.

The female side transmission tooth surface 34C, which is a parallel surface, extends parallel to the central axis O1-O1 (axial direction) of the hub 32 (extends in the axial direction). The female-side transmission tooth surface 34C is in contact with the male-side transmission tooth surface 37C of the male spline tooth 37 of the rotary shaft 35 over its entirety, and transmits the rotational force of the hub 32 to the rotary shaft 35. That is, when the rotation of the output shaft 13 of the engine 10 is transmitted to the hub 32 via the flywheel 14, the engine side block 21, the elastic body 23, and the pump side block 24, the rotation of the hub 32 is transmitted to the female side transmission teeth. It is transmitted to the rotary shaft 35 based on the contact between the surface 34C and the male side transmission tooth surface 37C.

On the other hand, the female non-transmission tooth surface 34D, which is an inclined surface, extends obliquely with respect to the female transmission tooth surface 34C. In this case, the range in which the female spline teeth 34 and the male spline teeth 37 contact between the inlet side end 34A and the back side end 34B is the spline contact range. The female non-transmission tooth surface 34D has a tooth thickness larger than that of the female transmission tooth surface 34C so that the tooth thickness increases from the inlet end 34A toward the rear end 34B over the entire spline contact range. It is inclined. The female non-transmission tooth surface 34D covers the entire spline contact range with the male non-transmission tooth surface 37D of the male spline tooth 37 in a state in which the female spline portion 33 and the male spline portion 36 are spline-coupled to each other. Abut.

The rotary shaft 35 of the hydraulic pump 16 constitutes the spline connection device 31 together with the hub 32. The rotary shaft 35 has a male spline portion 36 on the outer peripheral side. That is, on the outer peripheral side of the rotary shaft 35, a plurality of male spline teeth 37 that are spaced apart in the circumferential direction and extend in the axial direction are formed. In this case, the rotating shaft 35 has a large diameter portion 35A having a large outer diameter dimension and a diameter dimension smaller than that of the large diameter portion 35A from the base end side which is the hydraulic pump 16 side to the tip end side which is the engine 10 side. It has a reduced small diameter portion 35B, a male spline portion 36, and a protruding end portion 38.

The male spline portion 36 (male spline tooth 37) is spline-coupled with the female spline portion 33 (female spline tooth 34) of the hub 32. As a result, the rotary shaft 35 of the hydraulic pump 16 rotates based on the rotation of the hub 32 when the power is transmitted from the engine 10. The rotary shaft 35 is connected to the pump mechanism of the hydraulic pump 16 and projects from the center of the pump casing 16A. That is, the rotary shaft 35 is a driven member (driven shaft, driven body) that is rotationally driven by the rotational force from the engine 10 via the hub 32 of the elastic body shaft coupling 20.

The male spline tooth 37 that constitutes the male spline portion 36 of the rotary shaft 35 has a tip end portion 37A and a base end portion 37B. The front end portion 37A corresponds to the end portion of the male spline teeth 37 on the engine 10 side, that is, the end portion of the male spline portion 36 located on the insertion front end side when the rotary shaft 35 is inserted. .. The proximal end portion 37B is an end portion of the male spline teeth 37 that is located on the hydraulic pump 16 side end portion, that is, an end portion located closer to the proximal end side than the distal end portion 37A when the rotary shaft 35 is inserted into the hub 32. Corresponds to the department. In the male spline tooth 37, the tooth thickness T4 (FIG. 8) of the proximal end portion 37B is larger than the tooth thickness T3 (FIG. 8) of the distal end portion 37A.

Here, the male spline teeth 37 include a male-side transmission tooth surface 37C located on one side (or the other side) in the circumferential direction of the rotary shaft 35 (male spline portion 36) and the rotary shaft 35 (male spline portion 36). It has a male non-transmission tooth surface 37D located on the other side (or one side) in the circumferential direction. The male-side transmission tooth surface 37C and the male-side non-transmission tooth surface 37D are connected by the tooth crests of the male spline teeth 37 on the outer side in the radial direction of the rotary shaft 35.

The male-side transmission tooth surface 37C, which is a parallel surface, extends parallel to the central axis O2-O2 (axial direction) of the rotary shaft 35 (extends in the axial direction). The male side transmission tooth surface 37C is in contact with the female side transmission tooth surface 34C of the female spline tooth 34 of the hub 32 over the entire surface, and the female side transmission tooth surface 34C and the male side transmission tooth surface 37C are in contact with each other. Rotational force is transmitted based on the contact.

On the other hand, the male non-transmission tooth surface 37D, which is an inclined surface, extends obliquely with respect to the male transmission tooth surface 37C. In this case, the range in which the male spline teeth 37 and the female spline teeth 34 contact between the tip end 37A and the base end 37B is referred to as the spline contact range. The male-side non-transmission tooth surface 37D has a thickness larger than that of the male-side transmission tooth surface 37C so that the tooth thickness increases from the distal end portion 37A toward the proximal end portion 37B over the entire spline contact range. Is inclined. The male non-transmission tooth surface 37D covers the entire spline contact range with the female non-transmission tooth surface 34D of the female spline tooth 34 in a state where the female spline portion 33 and the male spline portion 36 are spline-coupled. Abut.

Next, the inclination angles α and β (FIG. 7) of the female non-transmission tooth surface 34D and the male non-transmission tooth surface 37D will be described. In the embodiment, as shown in FIG. 7, the inclination angle α of the female non-transmission tooth surface 34D with respect to the female transmission tooth surface 34C is 0.3° or more and 5° or less, more preferably 0.3° or more 2 ° Set below. The inclination angle β of the male non-transmission tooth surface 37D with respect to the male transmission tooth surface 37C is also set to 0.3° or more and 5° or less, more preferably 0.3° or more and 2° or less. That is, the values of the inclination angles α and β are set within the ranges shown in the following formulas 1 and 2. 6 to 11, the inclination angles α and β are exaggerated for easy understanding of the inclination.

By regulating the inclination angles α and β in this way, as shown in FIGS. 8 and 9, when the rotary shaft 35 is inserted into the hub 32 (when the insertion is started), the female splines adjacent to each other in the circumferential direction are provided. The circumferential clearance (gap) between the tooth 34 and the male spline tooth 37 can be increased. In addition, also when removing, it is possible to easily separate the tooth surfaces based on the inclination. Therefore, the workability of attaching the hub 32 and the rotary shaft 35 (ease of insertion) and the workability of removal (ease of removal) can be improved.

If the inclination angles α and β are smaller than 0.3°, it becomes difficult to secure the clearance, and there is a possibility that the mounting workability and the removal workability are deteriorated. On the other hand, when the inclination angles α and β are larger than 2° (or 5°), the male non-transmission tooth surface 37D interferes with (overlaps, contacts) the male transmission tooth surface 37C of the adjacent male spline tooth 37. )there is a possibility. Further, the female non-transmission tooth surface 34D may interfere with the female transmission tooth surface 34C of the adjacent female spline tooth 34. Further, if the interference is avoided, the strength of the minimum tooth thickness portion of each spline tooth 34, 37 (the inlet side end portion 34A of the female spline portion 33 and the tip side end portion 37A of the male spline portion 36) cannot be secured. there is a possibility. Therefore, in the embodiment, the values of the inclination angles α and β are set within the ranges shown in Formula 1 and Formula 2.

Further, in the embodiment, as shown in FIG. 8 to FIG. 11, the inclination angle α of the female non-transmission tooth surface 34D with respect to the female transmission tooth surface 34C is equal to the male non-transmission tooth surface with respect to the male transmission tooth surface 37C. It is set to be the same as the inclination angle β of 37D (α=β). Further, the minimum tooth thickness Ta of the female spline teeth 34 is set to be the same as the minimum tooth thickness Tb of the male spline teeth 37 (Ta=Tb). Then, when the rotary shaft 35 is inserted into the hub 32 and the end surface 36A on the tip side of the male spline portion 36 and the back side surface 32E on the back side of the hub 32 are arranged on the same plane, the female spline teeth 34 and The clearance with the male spline teeth 37 is set to 0. As a result, the "male side transmission tooth surface 37C and the female side transmission tooth surface 34C" and the "male side non-transmission tooth surface" are formed over the entire axial direction of each spline portion 33, 36 (without leaving any tooth surface). 37D and the female non-transmission tooth surface 34D" can be brought into contact (contact), and the surface pressure of the spline portions 33 and 36 can be reduced.

The protruding end portion 38 is located on the tip end side (the leftmost end side in FIG. 6) of the rotating shaft 35 and is arranged on the engine 10 side (flywheel 14 side) with respect to the male spline portion 36. That is, a protruding end portion 38 that protrudes toward the engine 10 side (flywheel 14 side) from the inner side surface 32E on the inner side of the hub 32 is provided on the tip side of the rotating shaft 35. On the outer peripheral side of the protruding end portion 38, a male screw portion 38A with which a nut 39 for preventing the hub 32 from coming off is screwed is provided. The outer diameter A of the protruding end portion 38 is smaller than the inner diameter B of the female spline portion 33 (see FIG. 6). The nut 39 is screwed to the male screw portion 38A of the protruding end portion 38.

The nut 39 prevents the hub 32 from rattling (withdrawing) in the axial direction with respect to the rotating shaft 35. In the embodiment, the male-side transmission tooth surface 37C and the female-side transmission tooth surface 34C are in contact with each other while the nut 39 is tightened (the nut 39 is in contact with the rear side surface 32E of the hub 32), and The side non-transmission tooth surface 37D and the female non-transmission tooth surface 34D contact each other. In this case, a preload may be applied to the contact surface.

Next, attachment and detachment work of the hub 32 and the rotary shaft 35 will be described with reference to FIGS. 8 to 11.

Regarding the attachment work, first, as shown in FIG. 8, the hub 32 is made to face the rotating shaft 35 having the male screw portion 38A provided on the protruding end portion 38 on the insertion tip side. At this time, in the hub 32, the side where the tooth thickness of the female spline teeth 34 of the hub 32 is small (the inlet side end 34A side) is arranged on the rotating shaft 35 side.

When the hub 32 is brought closer to the rotary shaft 35 from this state, as shown in FIG. 9, the female spline teeth 34 and the male spline teeth 37 come into contact with each other and start to mesh with each other. FIG. 9 shows a state in which the female spline portion 33 (female spline tooth 34) of the hub 32 and the male spline portion 36 (male spline tooth 37) of the rotary shaft 35 start to be meshed (spline coupled). In this case, the tooth thickness T1 of the inlet side end 34A of the female spline tooth 34 and the tooth thickness T3 of the tip side end 37A of the male spline tooth 37 are small. Therefore, it is possible to easily perform the work of starting the insertion (engagement) of the rotary shaft 35 and the hub 32, that is, the work of starting the insertion while aligning the female spline teeth 34 between the male spline teeth 37. it can.

When the rotation shaft 35 and the hub 32 are further inserted from the state shown in FIG. 9, the non-transmission tooth surfaces 34D and 37D of the spline portions 33 and 36 are inclined, so that the female spline teeth 34 and the male spline teeth are formed. The clearance between the teeth 37 gradually decreases. Then, when it is inserted up to the axial position corresponding to the inclination, as shown in FIG. 10, the transmission tooth surfaces 34C, 37C (non-transmission tooth surfaces 34D, 37D) contact (contact) with each other and are inserted. Ends. In this case, as described above, the female spline tooth 34 and the male spline tooth 37 have the same inclination angle α and the same inclination angle β, and the same minimum tooth thickness Ta and minimum tooth thickness Tb. Further, the female spline teeth 34 and the male spline teeth 37 have a clearance of 0 when the end surface 36A on the tip side of the male spline portion 36 is flush with the back side surface 32E on the back side of the hub 32. , The tooth thickness is set. Therefore, in this state, that is, in the state shown in FIG. 10, the female-side transmission tooth surface 34C and the male-side transmission tooth surface 37C abut over the entire surface, and the female-side non-transmission tooth surface 34D and the male-side non-transmission tooth surface 34C. The transmission tooth surface 37D abuts over the entire surface.

Next, as shown in FIG. 11, the nut 39 is screwed into the protruding end portion 38 of the rotating shaft 35 protruding from the inner side surface 32E of the hub 32. In this case, the nut 39 has a flat surface that comes into contact with the back side surface 32E of the hub 32. Therefore, by tightening the nut 39, the hub 32 can be restrained in the axial direction. Thereby, the hub 32 can be prevented from coming off and the backlash can be reduced.

On the other hand, regarding the removing work, first, the nut 39 is loosened, and the nut 39 is removed from the rotating shaft 35 (the protruding end portion 38). Next, a puller as a drawing device is attached to the rotary shaft 35 and the hub 32. When the force (withdrawal force) applied between the hub 32 and the rotary shaft 35 by the puller exceeds the frictional force between the spline fitting surfaces (each transmission tooth surface 34C, 37C and each non-transmission tooth surface 34D, 37D), The hub 32 begins to move with respect to the rotating shaft 35. In this case, when the tooth surface is not fixed (adhered) due to the frictional force, the clearance between the male spline tooth 37 and the female spline tooth 34 gradually increases in the pulling direction. Therefore, when the movement starts, the hub 32 can be easily removed thereafter without using a puller.

The hydraulic excavator 1 according to the embodiment has the above-described configuration, and its operation will be described below.

The operator who operates the hydraulic excavator 1 gets on the cab 7 of the upper swing body 4, starts the engine 10, and drives the hydraulic pump 16. As a result, pressure oil is discharged from the hydraulic pump 16, and this pressure oil is supplied to the hydraulic actuators such as the boom cylinder 5D, the arm cylinder 5E, and the bucket cylinder 5F via the control valve.

When the operator who rides on the cab 7 operates the operating lever for traveling, the vehicle can be moved forward or backward by the lower traveling body 2. On the other hand, when the operator operates the operation lever for work, the front device 5 can be moved up and down to perform excavation work of earth and sand. The torque output from the output shaft 13 of the engine 10 during operation of the hydraulic excavator 1 is transmitted to the rotary shaft 35 of the hydraulic pump 16 via the elastic body shaft coupling 20. At this time, the rotation of the engine 10 is transmitted to the hydraulic pump 16 via the spline coupling portion between the hub 32 of the elastic body shaft coupling 20 and the rotary shaft 35 of the hydraulic pump 16.

Here, when the hydraulic excavator 1 is manufactured, the work of attaching the hub 32 and the rotating shaft 35 is performed. During maintenance of the hydraulic excavator 1, the hub 32 and the rotary shaft 35 are attached and detached as necessary. On the other hand, in the hydraulic excavator 1, it is difficult to secure the axial length of the spline coupling portion between the hub 32 and the rotary shaft 35 because the margin space between the engine 10 and the hydraulic pump 16 is small. For this reason, adhesion tends to be induced at the spline joint portion, and a large force may be required to detach the rotating shaft 35 and the hub 32. Further, in order to perform stable torque transmission, it is preferable to reduce the clearance (gap) between the tooth surfaces in the splined state in order to reduce backlash. However, simply reducing the clearance requires highly accurate phase alignment and axial center alignment at the time of spline coupling, which may require a lot of labor and time.

On the other hand, in the embodiment, the female spline tooth 34 has a small tooth thickness T1 at the inlet end 34A, and the male spline tooth 37 has a small tooth thickness T3 at the tip end 37A. Therefore, as shown in FIGS. 8 and 9, when inserting the male spline portion 36 into the female spline portion 33, the distal end portion 37A of the male spline tooth 37 and the inlet end portion 34A of the female spline tooth 34 are , The clearances between the transmission tooth surfaces 34C, 37C (non-transmission tooth surfaces 34D, 37D) facing each other in the circumferential direction become large. As a result, when the hub 32 and the rotary shaft 35 are mounted (spline-coupled), the time and effort of phase matching of the spline teeth 34 and 37 can be reduced, and the workability of mounting can be improved. In other words, the tooth thickness T1 of the inlet-side end portion 34A of the female spline tooth 34 is smaller than that between the male spline teeth 37 (tooth-tooth gap) to which the female spline tooth 34 is fitted, so that a general spline (parallel It can be fitted more easily than a spline). At this time, as shown in FIG. 9, when the female transmission tooth surface 34C of the female spline tooth 34 and the male transmission tooth surface 37C of the male spline tooth 37 are brought into contact with each other, the transmission tooth surfaces 34C and 37C are inserted. Can be used as a guide surface.

Further, the female spline tooth 34 has a female non-transmission tooth surface 34D inclined with respect to the axial direction, and the male spline tooth 37 also has a male non-transmission tooth surface 37D inclined with respect to the axial direction. There is. Therefore, when the male spline portion 36 is pulled out from the female spline portion 33, if the hub 32 and the rotary shaft 35 start to move relative to each other in the axial direction (if the hub 32 starts to move with respect to the rotary shaft 35 ), the circumferential direction is reduced. The clearance (clearance) between the non-transmission tooth surfaces 34D and 37D (the transmission tooth surfaces 34C and 37C) facing each other extends over the entire axial direction. Thereby, when the hub 32 and the rotary shaft 35 are removed, the resistance due to the dragging (rubbing) of the non-transmission tooth surfaces 34D, 37D (the transmission tooth surfaces 34C, 37C) can be reduced, and the removal Workability can be improved.

Further, the female spline tooth 34 has a female side transmission tooth surface 34C extending in the axial direction of the hub 32, and the male spline tooth 37 also has a male side transmission tooth surface 37C extending in the axial direction of the rotating shaft 35. ing. That is, the female-side transmission tooth surface 34C and the male-side transmission tooth surface 37C that are in contact with each other and transmit the rotational force extend in the axial direction (parallel to the central axis lines O1-O1, O2-O2). Therefore, for example, as compared with the configuration in which the female side transmission tooth surface and the male side transmission tooth surface are inclined with respect to the axial direction (center axis), the female side transmission tooth surface 34C and the male side transmission tooth surface 37C are It is possible to suppress an axial load (axial load) from being generated on the contact surface (contact surface). As a result, it is possible to suppress an axial load from being applied to the rotary shaft 35, and it is possible to suppress, for example, a reduction in the life of a rolling bearing (not shown) that rotatably supports the rotary shaft 35.

As a result, the hub 32 and the rotary shaft 35 of the spline connection device 31 arranged in a narrow space (a narrow space where the layout is limited) between the engine 10 and the hydraulic pump 16 at the rear position of the upper swing body 4 are attached. The workability of removal can be improved.

According to the embodiment, the inclination angle α of the female non-transmission tooth surface 34D is 0.3° or more and 2° or less, and the inclination angle β of the male non-transmission tooth surface 37D is 0.3° or more and 2° or less. There is. Therefore, in particular, in the hydraulic excavator 1 in which the axial dimensions of the spline portions 33 and 36 are limited (the margin space between the engine 10 and the hydraulic pump 16 is limited), attachment of the hub 32 and the rotating shaft 35, It is possible to improve the removal workability and secure the strength of the tip side of each spline tooth 34, 37. That is, since the inclination angles α and β are set to 0.3° or more, the clearance can be secured. As a result, the workability of attaching the hub 32 and the rotary shaft 35 (ease of insertion) and the workability of removal (ease of removal) can be improved. Further, since the values of the inclination angles α and β are set to 2° or less, it is possible to prevent the male non-transmission tooth surface 37D from interfering (overlapping) with the male transmission tooth surface 37C of the adjacent male spline tooth 37. it can. Further, the strength of the minimum tooth thickness portion of each spline tooth 34, 37 (the inlet side end portion 34A of the female spline portion 33 and the tip side end portion 37A of the male spline portion 36) can be secured.

According to the embodiment, the inclination angle α is the same as the inclination angle β, and the minimum tooth thickness Ta of the female spline teeth 34 is the same as the minimum tooth thickness Tb of the male spline teeth 37. Further, when the rotary shaft 35 is inserted into the hub 32 and the end surface 36A on the tip side of the male spline portion 36 and the back side surface 32E on the back side of the hub 32 are arranged on the same plane, the female spline teeth 34 and The clearance with the male spline teeth 37 becomes zero. That is, when the end surface 36A on the distal end side of the male spline portion 36 and the back side surface 32E on the back side of the hub 32 are arranged on the same plane, the female non-transmission tooth surface 34D and the male non-transmission tooth surface 37D are The entire surface abuts, and the female side transmission tooth surface 34C and the male side transmission tooth surface 37C abut on the entire surface. As a result, the axial displacement of the spline portions 33 and 36 can be suppressed. In addition, “male side transmission tooth surface 37C and female side transmission tooth surface 34C” and “male side non-transmission tooth surface 37D and female side non-transmission tooth surface 34D” over the entire axial direction of each spline portion 33, 36. Can be brought into contact (contact), and the surface pressure of the spline portions 33 and 36 can be reduced.

According to the embodiment, the projecting end portion 38 of the rotary shaft 35 is provided with the male screw portion 38A, and the nut 39 is screwed into the male screw portion 38A. Therefore, by tightening the nut 39, the hub 32 can be suppressed in the axial direction, the hub 32 can be prevented from coming off, and backlash can be reduced.

In addition, in the embodiment, the case where the number of the engine-side blocks 21 and the number of the pump-side blocks 24 of the elastic body shaft coupling 20 are each set to four has been described as an example. However, without being limited to this, for example, the number of engine-side blocks and the number of pump-side blocks may be three, respectively, such as five, or a plurality other than four, and the number of engine-side blocks and pump-side blocks may be increased. You may change the number with.

In the embodiment, the case where the hydraulic pump 16 is configured by one pump mechanism (not shown) has been described as an example. However, not limited to this, for example, the hydraulic pump may be configured by a plurality of pump mechanisms. In this case, the plurality of pump mechanisms may be arranged in series in the axial direction or in parallel.

In the embodiment, the case where the recess 14B is provided on the side surface of the flywheel 14 and the tip side (protruding end 38) of the rotary shaft 35 is inserted into the recess 14B has been described as an example. However, the present invention is not limited to this, and for example, the concave portion may be omitted, and the tip end side (protruding end portion) of the rotary shaft may be brought into contact with the side surface of the flywheel or may be closely opposed (opposed with a gap).

In the embodiment, the case where the nut 39 for preventing the hub 32 from coming off is screwed onto the protruding end portion 38 of the rotary shaft 35 has been described as an example. However, the present invention is not limited to this, and for example, the protruding end portion and the nut may be omitted, and the hub may be positioned by abutting the side surface of the flywheel and the back side surface of the hub.

In the embodiment, the case where the female spline portion 33 (female spline tooth 34) and the male spline portion 36 (male spline tooth 37) have the same axial length has been described as an example. However, not limited to this, for example, the female spline portion (female spline tooth) and the male spline portion (male spline tooth) may have different axial lengths.

In the embodiment, the case where the minimum tooth thickness Ta of the female spline tooth 34 and the minimum tooth thickness Tb of the male spline tooth 37 are the same has been described as an example. However, the present invention is not limited to this. For example, the female spline portion and the male spline portion may have different minimum tooth thicknesses. The same applies to the maximum tooth thickness of female spline teeth and the maximum tooth thickness of male spline teeth.

In the embodiment, when the rotary shaft 35 is inserted into the hub 32 and the end surface 36A on the tip side of the male spline portion 36 and the back side surface 32E on the back side of the hub 32 are arranged on the same plane, the female spline is formed. The case where the clearance between the tooth 34 and the male spline tooth 37 is zero has been described as an example. However, not limited to this, for example, when the rotary shaft is inserted into the hub, the clearance between the tooth flanks becomes 0 before the end surface on the distal end side of the male spline portion reaches the back side surface on the back side of the hub. May be

In the embodiment, the female non-transmission tooth surface 34D is an inclined surface extending at the same inclination angle over the entire axial direction, and the male non-transmission tooth surface 37D is at the same inclination angle over the entire axial direction. The description has been given by taking the case of the extending inclined surface as an example. However, the present invention is not limited to this, and the angle may be changed in the middle of the inclined surface. Further, the non-transmission tooth surface may be configured to have a parallel surface extending parallel to the axial direction of the rotating shaft and an inclined surface inclined with respect to the parallel surface. In the case of these configurations, the non-transmission tooth surface may be inclined with respect to the transmission tooth surface so that the tooth thickness increases from the inlet end portion to the rear end portion of the female spline portion.

In the embodiment, the case where the inclination angles α and β of the non-transmission tooth surfaces 34D and 37D with respect to the transmission tooth surfaces 34C and 37C are set to 0.3° or more and 2° or less, respectively, has been described as an example. However, the inclination angles α and β are not limited to this, and may be, for example, 0.3° or more and 5° or less, 0.5° or more and 7° or less, depending on the axial dimension of the spline portion, the tooth thickness, and the like. The setting range can be changed. In this case, the inclination angles α and β are necessary from the viewpoints of, for example, ease of mounting, ease of removal, avoidance of interference (overlap) between adjacent spline teeth, and securing of the strength of the minimum tooth thickness portion of the spline teeth. It can be set for performance.

In the embodiment, the case where the engine 10 is used as the prime mover (driving source, power source) of the hydraulic excavator 1 has been described as an example. However, the present invention is not limited to this, and an electric motor such as an electric motor or a generator motor (assist generator motor) may be used as the prime mover. Alternatively, a hybrid type prime mover in which an engine and an electric motor are combined may be used.

In the embodiment, the case where the spline connection device 31 is applied to the crawler type hydraulic excavator 1 has been described as an example. However, the present invention is not limited to this, and may be applied to various construction machines such as wheel-type hydraulic excavators and hydraulic cranes.

1 Hydraulic excavator (construction machinery)
2 Lower traveling structure 4 Upper revolving structure 5 Front device (working device)
6 Revolving frame 8 Counterweight 10 Engine (drive source)
16 Hydraulic Pump 31 Spline Connection Device 32 Hub 32C Inner Circumferential Side 32E Inner Surface (Side)
33 Female spline part 34 Female spline tooth 34A Inlet side end part 34B Back end part 34C Female side transmission tooth surface 34D Female non-transmission tooth surface 35 Rotating shaft 36 Male spline part 36A End surface 37 Male spline tooth 37A Tip side end part 37B Proximal end portion 37C Male-side transmission tooth surface 37D Male-side non-transmission tooth surface 38 Protruding end portion 38A Male screw portion 39 Nut O1-O1 Center axis O2-O2 Center axis α Inclination angle β Inclination angle T1 Tooth thickness T2 Tooth thickness T3 Tooth thickness T4 Tooth thickness Ta Minimum tooth thickness Tb Minimum tooth thickness

Claims (4)

A self-propelled lower traveling body, an upper revolving body rotatably mounted on the lower traveling body, and a work device provided on the upper revolving body,
The upper revolving structure includes a revolving frame on which a working structure is mounted on the front side without a support structure, a counterweight mounted on a rear end of the revolving frame to balance the weight of the working device, and a counterweight of the counterweight. A drive source located on the front side and provided on the rear end side of the revolving frame, a hydraulic pump driven by the drive source to discharge pressure oil, and a rotational force transmitted between the drive source and the hydraulic pump. And a spline connection device for
The spline connection device has a cylindrical hub that has a female spline portion on the inner peripheral side and rotates in one direction by the drive source, and a male spline portion that is spline-coupled to the female spline portion on the outer peripheral side. In a construction machine including a rotating shaft of the hydraulic pump that rotates based on rotation of a hub,
The female spline teeth forming the female spline portion of the hub have a tooth thickness at the back end that is farther back than a tooth thickness at the inlet end that is the hydraulic pump side,
The male spline teeth forming the male spline portion of the rotary shaft have a tooth thickness at the base end side end portion that is closer to the base end side than a tooth thickness at the tip end side end portion that is the drive source side,
The female spline tooth extends between the central axis of the hub and extends between the female side transmission tooth surface for transmitting the rotational force of the hub to the rotation shaft, and the inlet side end portion and the back side end portion. Is inclined with respect to the female-side transmission tooth surface so that the tooth thickness increases from the inlet-side end toward the rear-side end over the range where the female spline tooth and the male spline tooth contact each other. And a female-side non-transmission tooth surface that extends
The male spline tooth extends parallel to the central axis of the rotating shaft, and is in contact with the female side transmission tooth surface of the female spline tooth. The male side transmission tooth surface, the tip end portion, and the base end side end. The male-side transmission teeth so that the tooth thickness increases from the tip-side end toward the base-side end over the range where the female spline tooth and the male spline tooth contact each other. A construction machine having a male non-transmission tooth surface extending obliquely with respect to a surface. The construction machine according to claim 1,
The inclination angle of the female non-transmission tooth surface with respect to the female transmission tooth surface is 0.3° or more and 2° or less,
The construction machine, wherein an inclination angle of the male non-transmission tooth surface with respect to the male transmission tooth surface is 0.3° or more and 2° or less. The construction machine according to claim 1,
The inclination angle of the female non-transmission tooth surface with respect to the female transmission tooth surface is the same as the inclination angle of the male non-transmission tooth surface with respect to the male transmission tooth surface,
The minimum tooth thickness of the female spline teeth is the same as the minimum tooth thickness of the male spline teeth,
When the rotary shaft is inserted into the hub, and the end surface on the tip side of the male spline portion and the side surface on the back side of the hub are arranged on the same plane, the female spline teeth and the male spline teeth are Construction machine characterized by zero clearance. The construction machine according to claim 1,
On the tip end side of the rotating shaft, a protruding end portion that is protruded from the inner side surface of the hub is provided,
A construction machine, characterized in that a male screw portion with which a nut for retaining the hub is screwed is provided on the outer peripheral side of the projecting end portion.

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