JP2014043924A - Hydraulic continuously variable transmission - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a hydraulic continuously variable transmission capable of suppressing occurrence of seizure, for example, between a plunger and a swash plate body slidably kept into contact with the plunger, due to poor lubrication.SOLUTION: In a hydraulic continuously variable transmission 10, a swash plate 50 for a hydraulic pump and a swash plate 70 for a hydraulic motor have a swash plate body 54 for the pump and a swash plate body 74 for the motor with which a plunger 40 for the hydraulic pump and a plunger 60 for the hydraulic motor are slidably kept into contact respectively. The swash plate body 54 for the pump and the swash plate body 74 for the motor have slide contact portions 54a and 74a, flanges 54b and 74b formed to extend from an outer peripheral side of the swash plate body 54 for the pump and the swash plate body 74 for the motor toward an axial center at an inner diameter side with respect to the slide contact portions 54a and 74a, and communication holes 54d and 74d for communicating between the slide contact portions 54a and 74a and oil collection spaces 54c and 74c formed at the inner diameter side with respect to the slide contact portions 54a and 74a adjacent to the flanges 54b and 74b.

Description

  The present invention relates to a hydraulic continuously variable transmission in which a cylinder block for a hydraulic pump and a cylinder block for a hydraulic motor are composed of a single cylinder block, and more particularly to a cylinder block having a characteristic cooling structure.

  Conventionally, a hydraulic continuously variable transmission (HST) disclosed in Patent Documents 1 to 3 below is known as a type of continuously variable transmission.

  The hydrostatic continuously variable transmission disclosed in Patent Documents 1 and 2 includes a variable displacement type hydraulic pump and a hydraulic motor, and a cylinder block shared between the hydraulic pump and the hydraulic motor is provided between the hydraulic pump and the hydraulic motor. It is installed. On one side in the axial direction of the cylinder block, as a hydraulic pump component, a hydraulic pump plunger fitted in the cylinder block so as to be slidable in a reciprocating manner, and a hydraulic pump swash plate slidably contacting the end of the hydraulic pump plunger And a hydraulic servo for changing the inclination amount of the swash plate for the hydraulic pump. Also, on the other axial direction of the cylinder block, as a hydraulic motor component, a hydraulic motor plunger fitted in the cylinder block so as to be slidable back and forth, and a fixed inclination angle slidably contacting the end of the hydraulic motor plunger Swash plate for hydraulic motors.

  The cylinder block rotates integrally with the input shaft, and a hydraulic pump plunger fitted in the cylinder block is reciprocated by a hydraulic pump swash plate or the like inclined with respect to the axial direction to generate hydraulic pressure. The generated hydraulic pressure causes the hydraulic motor plunger to reciprocate, whereby rotational power is transmitted to the hydraulic motor swash plate pressed by the hydraulic motor plunger.

  The hydraulic continuously variable transmission disclosed in Patent Document 3 has a configuration in which a hydraulic pump and a hydraulic motor are combined as in Patent Documents 1 and 2 above. In this hydraulic continuously variable transmission, the head of a cylinder formed in a dome shape is lubricated by using lubricating oil scattered by hydraulic pressure and centrifugal force from an input shaft. Further, the angular bearing and the radial bearing are lubricated by receiving the lubricating oil scattered by the centrifugal force or the like by the member on the outer peripheral side of the bearing.

JP 2008-185111 A JP 2010-264809 A JP 2004-301285 A

  However, the lubricating structure as described in Patent Document 3 described above can be configured by arranging a member slidably contacting the cylinder head on the inner peripheral side of a bearing such as an angular bearing or a radial bearing. Therefore, when the arrangement of the member that is in sliding contact with the head of the cylinder and the bearing is reversed, the lubricating structure as in Patent Document 3 cannot be adopted, and there is a concern that seizure due to poor lubrication may occur. .

  Accordingly, an object of the present invention is to provide a hydraulic continuously variable transmission that can suppress the occurrence of seizure between a plunger and a swash plate body with which the plunger slides due to poor lubrication.

  The hydraulic continuously variable transmission according to the present invention provided to solve the above-described problem includes an input shaft that is provided with an oil passage through which pressure oil is supplied, and that receives the rotational power of the engine. A hydraulic continuously variable transmission that is connected to be capable of transmitting power, and an output shaft that is arranged along the input shaft and is connected to the output side of the hydraulic continuously variable transmission so as to be capable of transmitting power. The hydraulic continuously variable transmission section is arranged on a coaxial line that is integrally rotated with the input shaft on a coaxial line, and on one side in the axial direction of the cylinder block, there is an interval on the circumference around the coaxial line. A plurality of plungers for hydraulic pumps inserted so as to be reciprocally slidable, a swash plate for hydraulic pumps slidably contacting the tips of the plungers for the hydraulic pumps, and on the other axial direction of the cylinder block, Spacing on the circumference A hydraulic motor plunger inserted in a reciprocating manner; and a hydraulic motor swash plate with which a tip of the hydraulic motor plunger is slidably contacted, and the hydraulic pump swash plate and the hydraulic motor swash plate. One or both of the swash plates have a swash plate main body with which the plunger is slidably contacted, and the swash plate main body has a slidable contact portion with which the plunger slidably contacts, and an inner diameter side with respect to the slidable contact portion. A flange formed so as to extend from the outer peripheral side of the swash plate main body toward the axial center side, an oil collection space formed at a position adjacent to the flange on the inner diameter side with respect to the sliding contact portion, and the It has a communicating hole which makes a sliding contact part communicate.

  In such a configuration, oil supplied from the inner peripheral side to the swash plate main body can be received in the oil collection space formed at a position adjacent to the flange, and supplied to the sliding contact portion via the communication hole. . Thereby, between a plunger and a sliding contact part is fully lubricated, generation | occurrence | production of image sticking can be suppressed.

  In the hydraulic continuously variable transmission according to the present invention described above, one or both of the swash plate for the hydraulic pump and the swash plate for the hydraulic motor are supported by the swash plate body and the swash plate body as a bearing. It is preferable that the cradle is rotatably supported through the communication hole, and the communication hole communicates the oil collection space and the sliding contact portion.

  In the hydraulic continuously variable transmission according to the present invention, in addition to the function of forming an oil collection space for receiving the oil supplied from the inner peripheral side to the swash plate body, the flange is used as a bearing retainer. It also has the function. Therefore, according to the present invention, it is possible to suppress problems associated with the dropout of the bearing while suppressing seizure associated with poor supply of the lubricating oil.

  Further, the hydraulic continuously variable transmission of the present invention described above communicates with the oil passage of the input shaft at a position radially inward of the oil collection space, and can discharge oil toward the oil collection space. It is desirable that a simple oil discharge path is provided.

  In such a configuration, the oil supplied through the oil passage of the input shaft can be discharged toward the oil collection space. As a result, it is possible to reliably secure the supply route of the lubricating oil to the oil collection space, and the occurrence of seizure can be further reduced.

  According to the present invention, it is possible to provide a hydraulic continuously variable transmission that can suppress the occurrence of seizure between a plunger and a swash plate main body with which the plunger slides due to poor lubrication.

It is sectional drawing which shows the drive train of the vehicle carrying a hydraulic continuously variable transmission.

  Hereinafter, a hydraulic continuously variable transmission 10 according to an embodiment of the present invention will be described in detail with reference to the drawings. The hydraulic continuously variable transmission 10 shown in FIG. 1 is a so-called HMT or the like. The hydraulic continuously variable transmission 10 includes an input shaft 20, a cylinder block 30, a hydraulic pump plunger 40, a hydraulic pump swash plate 50, a hydraulic motor plunger 60, a hydraulic motor swash plate 70, and the like as main components. I have.

  The hydraulic continuously variable transmission 10 includes a hydraulic continuously variable transmission X that is configured by disposing a variable displacement hydraulic pump P and a hydraulic motor M with respect to the cylinder block 30. The hydraulic continuously variable transmission section X can supply hydraulic pressure generated in the hydraulic pump P to the hydraulic motor M by the input shaft 20 and the cylinder block 30 rotating together, and output rotational power to the output side. It is possible. Hereinafter, the configuration of each part of the hydraulic continuously variable transmission 10 configured around the hydraulic continuously variable transmission part X will be described in more detail.

  The input shaft 20 is rotatably supported in the transmission case 16 via ball bearings 22 and 24. Specifically, the transmission case 16 has a wall surface 16a on the distal end side (downstream side of power transmission) of the input shaft 20. An input shaft boss portion 16b is provided at a position corresponding to the input shaft 20 on the wall surface 16a. The tip of the input shaft 20 is rotatably supported by a ball bearing 22 provided in the input shaft boss 16b. The base end side (upstream side of power transmission) of the input shaft 20 is rotatably supported by a ball bearing 24. Rotational power of an engine (not shown) is transmitted to the input shaft 20 via a damper (not shown), an oil pump 14 and the like.

  An oil passage 21 is formed in the input shaft 20 and pressure oil is supplied from the oil pump 14. The oil passage 21 has a main oil passage 21a formed so as to extend in the axial direction at a substantially axial position of the input shaft 20, and a sub oil passage 21b so as to branch in the radial direction in the middle of the main oil passage 21a. . The pressure oil supplied to the oil passage 21 is used not only for lubrication of each part and for replenishment of operating oil for the hydraulic continuously variable transmission 10 but also for cooling the cylinder block 30.

  In the input shaft 20, a sleeve 26 is mounted at a position adjacent to one side (engine side) in the axial direction with respect to the cylinder block 30. The sleeve 26 is formed with an oil discharge passage 26 a communicating with the oil passage 21 of the input shaft 20. The oil discharge path 26 a is a hole formed so as to extend in the direction intersecting the oil path 21 extending in the axial direction of the input shaft 20, that is, in the radial direction. The oil discharge path 26a can discharge part of the pressure oil flowing in the oil path 21 from the input shaft 20 side toward the radially outer side.

  The cylinder block 30 has a substantially columnar shape and is integrally provided at a midway position of the input shaft 20. The input shaft 20 is provided so as to pass through a substantially axial center position of the cylinder block 30. A hydraulic pump P is configured on one side (engine side) of the cylinder block 30 in the axial direction, and a hydraulic motor M is configured on the other side.

  Specifically, the main part of the hydraulic pump P is constituted by a hydraulic pump plunger 40 and a hydraulic pump swash plate 50 provided on one side of the cylinder block 30. The hydraulic pump plunger 40 can be slidably reciprocated on each of a plurality of pump plunger bores 42 provided on the one side (engine side) of the cylinder block 30 at equal intervals on the circumference around the axis. Has been inserted. The hydraulic pump plunger 40 is biased toward the hydraulic pump swash plate 50 by a spring. In the present embodiment, the hydraulic pump plunger 40 is an odd number of three or more.

  The main part of the hydraulic pump swash plate 50 is constituted by a pump cradle 52 (first cradle), a pump swash plate main body 54, and bearings 56 and 58. The hydraulic pump swash plate 50 is configured such that a pump swash plate main body 54 is attached to a pump cradle 52.

  The pump cradle 52 is supported so as not to rotate about the axis of the input shaft 20. The pump cradle 52 is disposed on the outer peripheral side of the sleeve 26 attached to the input shaft 20 at a position adjacent to one side (engine side) in the axial direction with respect to the cylinder block 30. The pump cradle 52 is connected to a swash plate inclination adjusting mechanism (not shown), and the pump scradle 52 is swung by operating the swash plate inclination adjusting mechanism to swing the pump cradle 52. The amount of inclination of the main body 54 with respect to the axis of the input shaft 20 can be arbitrarily adjusted.

  The pump swash plate body 54 is attached to the pump cradle 52 via bearings 56 and 58. Thus, the pump swash plate main body 54 is rotatably supported with respect to the pump cradle 52. Further, the distal end portion of the hydraulic pump plunger 40 is in sliding contact with the pump swash plate body 54.

  The pump swash plate body 54 includes a sliding contact portion 54a, a flange 54b, an oil collection space 54c, and a communication hole 54d. The slidable contact portion 54 a is a portion where the hydraulic pump plunger 40 is slidably contacted, and is a concave portion curved in a hemispherical shape in accordance with the tip shape of the hydraulic motor plunger 60. The flange 54b is located on the inner diameter side (axial center side) of the pump swash plate main body 54 with respect to the sliding contact portion 54a, in the direction from the outer peripheral side of the pump swash plate main body 54 to the axial center side, that is, 54 is formed so as to extend from the radially outer side toward the inner side. That is, the flange 54b is formed to extend radially inward in the opening portion of the pump swash plate main body 54 on the side (sliding contact portion 54a side) where the hydraulic pump plunger 40 is slidably contacted. As a result, an oil collection space 54c is formed between the bearings 56 and 58 and the flange 54b.

  The oil collection space 54c is a space that can receive the lubricating oil scattered from the input shaft 20 side. The oil collection space 54c exists at a position radially outside the oil discharge path 26a provided in the sleeve 26 described above. Therefore, the pressure oil discharged from the oil discharge path 26a can be received in the oil collection space 54c.

  The communication hole 54d is a communication hole formed so that the oil collection space 54c and the sliding contact portion 54a communicate with each other. Therefore, the lubricating oil collected in the oil collection space 54c can be supplied to the sliding contact portion 74a side through the communication hole 74d and used for lubrication at the contact portion between the hydraulic motor plunger 60 and the sliding contact portion 74a. . Further, a part of the lubricating oil collected in the oil collecting space 74c is also supplied to the bearings 76 and 78 and used for lubricating them.

  The hydraulic pump P activates the pump action when the cylinder block 30 and the hydraulic pump plunger 40 attached to the cylinder block 30 rotate about the axis along with the rotation of the input shaft 20. Specifically, the hydraulic pump plungers 40 are stroked between the cylinder block 30 and the pump swash plate body 54 while the cylinder block 30 makes a round around the axis of the input shaft 20 in conjunction with the input shaft 20. The possible length increases or decreases. Therefore, when the input shaft 20 rotates, the cylinder block 30 and the hydraulic pump plunger 40 attached to the cylinder block 30 rotate about the axis of the input shaft 20, and the hydraulic pump for sliding contact with the pump swash plate main body 54. The plunger 40 reciprocates, and the pump action is activated. The hydraulic pressure generated in the hydraulic pump P can be adjusted according to the amount of inclination of the hydraulic pump swash plate 50. The hydraulic pressure generated in the hydraulic pump P is supplied to the hydraulic motor M side (the hydraulic chamber in the cylinder block 30 that presses the base of the hydraulic motor plunger 60).

  The main part of the hydraulic motor M is constituted by a hydraulic motor plunger 60 and a hydraulic motor swash plate 70 provided on the other side in the axial direction of the cylinder block 30 (opposite the engine and the hydraulic pump P). The hydraulic motor plunger 60 is inserted into each of a plurality of motor plunger bores 62 provided at equal intervals on a circumference around the axis of the input shaft 20 so as to be reciprocally slidable. The hydraulic motor plunger 60 is biased toward the hydraulic motor swash plate 70 by a spring. The hydraulic pump plunger 40 and the hydraulic motor plunger 60 have different circumferential positions in the cylinder block 30. In the present embodiment, the hydraulic motor plunger 60 is an odd number of three or more.

  The main part of the swash plate for hydraulic motor 70 includes a motor cradle 72 (second cradle), a motor swash plate main body 74, and bearings 76 and 78. The hydraulic motor swash plate 70 is configured such that a motor swash plate main body 74 is attached to a motor cradle 72. Bearings 76 and 78 are interposed between the motor cradle 72 and the motor swash plate main body 74. Thus, the motor swash plate body 74 is supported so as to be rotatable with respect to the motor cradle 72.

  Unlike the above-described pump cradle 52, the motor cradle 72 cannot be adjusted in angle. Specifically, the motor cradle 72 is supported via a ball bearing 80 so as to be rotatable relative to the input shaft 20. The hydraulic motor swash plate 70 is rotatably supported in the transmission case 16 by an angular ball bearing 88 mounted on the outer peripheral side at the end of the motor cradle 72.

  The motor cradle 72 is formed with an oil discharge path 72 a communicating with the oil path 21 of the input shaft 20. The oil discharge path 72a is a hole formed so as to extend in the direction intersecting the oil path 21 extending in the axial direction of the input shaft 20, that is, in the radial direction. The oil discharge path 72a can discharge part of the pressure oil flowing through the oil path 21 from the input shaft 20 side toward the radially outer side.

  The motor swash plate body 74 is attached to the motor cradle 72 described above. Therefore, unlike the swash plate main body 54 of the hydraulic pump swash plate 50 described above, the hydraulic motor swash plate 70 cannot change the amount of inclination of the motor swash plate main body 74. Further, the front end portion of the hydraulic motor plunger 60 is in sliding contact with the motor swash plate body 74.

  The motor swash plate body 74 has a sliding contact portion 74a, a flange 74b, an oil collection space 74c, and a communication hole 74d. The sliding contact portion 74 a is a portion with which the hydraulic motor plunger 60 is slidably contacted, and is a concave portion curved in a hemispherical shape in accordance with the tip shape of the hydraulic motor plunger 60.

  The flange 74b is on the inner diameter side (axial center side) of the motor swash plate main body 74 with respect to the sliding contact portion 74a, in the direction from the outer peripheral side of the motor swash plate main body 74 to the axial center side, that is, the motor swash plate main body. 74 is formed to extend in the radial direction. That is, the flange 74b is formed in the motor swash plate main body 74 so as to extend radially inward at an opening portion on the side (sliding contact portion 74a side) on which the hydraulic motor plunger 60 is slidably contacted. As a result, an oil collection space 74c is formed between the bearings 76 and 78 and the flange 74b. The oil collection space 74c can receive the lubricating oil scattered from the input shaft 20 side. The oil collection space 74c is present at a radially outer position with respect to the oil discharge path 72a provided in the motor cradle 72 described above. Therefore, the pressure oil discharged from the oil discharge path 72a can be received in the oil collection space 74c.

  The communication hole 74d is a communication hole formed so that the oil collection space 74c and the sliding contact portion 74a communicate with each other. Therefore, the lubricating oil collected in the oil collection space 74c is supplied to the sliding contact portion 74a side through the communication hole 74d, and is used for lubrication in a contact portion between the hydraulic motor plunger 60 and the sliding contact portion 74a. Further, a part of the lubricating oil collected in the oil collecting space 74c is also supplied to the bearings 76 and 78 and used for lubricating them.

  The hydraulic motor M exhibits its function as a motor when the cylinder block 30 and the hydraulic motor plunger 60 attached thereto rotate around the axis of the input shaft 20 as the input shaft 20 rotates. Specifically, the hydraulic motor plunger 60 reciprocates and slides with the pressure oil supplied from the hydraulic pump side, and while applying a thrust load to the hydraulic motor swash plate 70, the axis of the input shaft 20 together with the cylinder block 30. Rotate around. Thereby, the hydraulic motor M exhibits the function as a motor, and can output rotational power toward the output side. The rotational speed (reduction ratio) output from the hydraulic motor M changes according to the hydraulic pressure supplied from the hydraulic pump P described above. Therefore, the rotational speed (reduction ratio) output to the output side can be adjusted by operating a swash plate inclination adjusting mechanism (not shown) to change the inclination of the hydraulic pump swash plate 50.

  The above-described hydraulic oil inflow / outflow paths in the hydraulic pump P and the hydraulic motor M are switched by a pump spool valve 90 and a motor spool valve 92 provided in the cylinder block 30. The pump spool valve 90 and the motor spool valve 92 perform valve operations for opening and closing the hydraulic oil flow path formed in the cylinder block 30 according to the rotational positions of the corresponding plungers 40 and 60, respectively. , 60 to switch the flow of the hydraulic oil that is sucked or discharged.

  The output of the hydraulic motor M described above is transmitted through a first parallel shaft gear 94 provided integrally on the outer periphery of the motor cradle 72 and a second parallel shaft gear 96 provided on one end side of the output shaft 100. It is transmitted to the output shaft 100. The power transmitted to the output shaft 100 is output toward a differential gear (not shown) and a drive shaft connected thereto.

  As described above, in the hydraulic continuously variable transmission 10, the pump swash plate main body 54 and the motor swash plate main body 74 forming the hydraulic pump swash plate 50 and the hydraulic motor swash plate 70 are adjacent to the flanges 54b and 74b. In the oil collection spaces 54c and 74c formed at the positions where the oil is supplied, the oil supplied from the inner peripheral side to the pump swash plate main body 54 and the motor swash plate main body 74 is received and slidably contacted through the communication holes 54d and 74d The parts 54a and 74a can be supplied. Therefore, the sliding contact portions 54a and 74a can be sufficiently lubricated to suppress the occurrence of seizure.

  The hydraulic continuously variable transmission 10 communicates with the oil passage 21 of the input shaft 20 at a position radially inward of the oil collection spaces 54c and 74c, and discharges oil toward the oil collection spaces 54c and 74c. Possible oil discharge paths 26a, 72a. As a result, the oil supplied through the oil passage 21 of the input shaft 20 can be discharged toward the oil collection spaces 54c and 74c, and the supply path of the lubricating oil to the oil collection spaces 54c and 74c can be reliably ensured. Thus, the occurrence of image sticking can be further reduced.

  In the present embodiment, both the hydraulic pump swash plate 50 and the hydraulic motor swash plate 70 are provided with flanges 54b and 74b and communication holes 54d and 74d, and the lubricant collected in the oil collection spaces 54c and 74c is slidably contacted. Although the example which employ | adopted the lubrication structure which can be utilized for lubrication of the part 54a, 74a etc. was shown, this invention is not limited to this, Any of the swash plate 50 for hydraulic pumps and the swash plate 70 for hydraulic motors Such a lubrication structure may be formed only on one side.

  In addition, the configuration in which the oil discharge paths 26a, 72a are provided in the sleeve 26 and the motor cradle 72 in order to ensure the supply path of the lubricating oil to the oil collection spaces 54c, 74c has been exemplified, but the present invention is limited to this. However, the configuration may be such that either one or both of the oil discharge paths 26a and 72a are not provided.

  INDUSTRIAL APPLICABILITY The present invention can be used as, for example, a hydraulic continuously variable transmission mounted on a vehicle such as an automobile, a motorcycle, a working vehicle such as a tractor, and particularly in a compact vehicle such as a light vehicle. It can be suitably used.

DESCRIPTION OF SYMBOLS 10 Hydraulic continuously variable transmission 20 Input shaft 21 Oil path 26a Oil discharge path 30 Cylinder block 40 Hydraulic pump plunger 50 Hydraulic pump swash plate 54 Pump swash plate main body 54a Sliding contact portion 54b Flange 54c Oil collecting space 54d Communication hole 60 Plunger for hydraulic motor 70 Swash plate for hydraulic motor 74 Motor swash plate main body 74a Sliding contact portion 74b Flange 74c Oil collection space 74d Communication hole 100 Output shaft X Hydraulic stepless transmission portion X
M Hydraulic motor P Hydraulic pump

Claims (3)

An input shaft that is provided with an oil passage through which pressure oil is supplied and that receives engine rotational power;
A hydraulic continuously variable transmission portion connected to the input shaft so as to be capable of transmitting power;
An output shaft that is arranged along the input shaft and is connected to the output side of the hydraulic continuously variable transmission portion so that power can be transmitted;
The hydraulic continuously variable transmission is
A cylinder block provided on a coaxial line so as to rotate integrally with the input shaft;
Plural plungers for hydraulic pumps inserted in a reciprocating manner at intervals on a circumference around the coaxial line on one axial direction of the cylinder block;
A swash plate for a hydraulic pump that is in sliding contact with the tip of the plunger for the hydraulic pump;
On the other side in the axial direction of the cylinder block, a plunger for a hydraulic motor inserted so as to be reciprocally slidable on the circumference around the coaxial line; and
A swash plate for a hydraulic motor with which a tip of the plunger for the hydraulic motor is in sliding contact,
One or both of the swash plate for the hydraulic pump and the swash plate for the hydraulic motor have a swash plate body with which the plunger is in sliding contact,
The swash plate body is
A sliding contact portion with which the plunger slides,
A flange formed so as to extend from the outer peripheral side of the swash plate main body toward the axial center side on the inner diameter side with respect to the sliding contact portion;
A hydraulic continuously variable transmission having an oil collection space formed at a position adjacent to the flange on the inner diameter side with respect to the sliding contact portion and a communication hole for communicating the sliding contact portion. . Either one or both of the swash plate for the hydraulic pump and the swash plate for the hydraulic motor includes the swash plate body and a cradle that rotatably supports the swash plate body via a bearing. Is,
The hydraulic continuously variable transmission according to claim 1, wherein the communication hole communicates the oil collection space with the sliding contact portion.   An oil discharge path that communicates with an oil path of the input shaft and is capable of discharging oil toward the oil collection space is provided at a position radially inward of the oil collection space. Item 3. The hydraulic continuously variable transmission according to Item 1 or 2.

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