JP2008051213A - transmission - Google Patents

Abstract

A transmission having a forward / reverse switching mechanism that can be reduced in size and cost by improving the configuration and arrangement of the forward / reverse switching mechanism.
A driven shaft 26 is arranged in parallel or substantially parallel to a drive shaft 25, and the output torque of a power source 1 input to a transmission input shaft 11 is converted without reversing the rotation direction. A forward state that is transmitted to the transmission output shaft 39, a reverse state that reverses the rotation direction and is transmitted to the transmission output shaft 39, and a neutral state that does not transmit output torque to the transmission output shaft 39 are selectively set. In the transmission 10 including the forward / reverse switching mechanism 8, the forward / reverse switching mechanism 8 is disposed between the drive shaft 25 and the driven shaft 26, and the transmission input shaft 11 is connected to the output shaft 2 of the power source 1. It is provided as an axis on the same axis and different from the drive shaft 25.
[Selection] Figure 1

Description

  The present invention relates to a transmission provided with a forward / reverse switching mechanism for selectively setting a power transmission state from an input side to an output side.

  In general, there is a continuously variable transmission that can control a gear ratio steplessly (continuously) for the purpose of operating an engine under optimum conditions according to the running state of the vehicle. As such a continuously variable transmission, a belt type continuously variable transmission or a toroidal type continuously variable transmission is known. Among these, the belt-type continuously variable transmission has two rotating members arranged in parallel, and a primary pulley and a secondary pulley separately attached to each rotating member. Both the primary pulley and the secondary pulley are configured by combining a fixed sheave and a movable sheave, and a V-shaped groove is formed between the fixed sheave and the movable sheave.

  In addition, a belt is wound around the groove of the primary pulley and the groove of the secondary pulley, and a hydraulic chamber is provided separately for applying an axial pressing force to the belt support member of the primary pulley and the belt support member of the secondary pulley. ing. When the groove width of each pulley is adjusted by independently controlling the hydraulic pressure in each hydraulic chamber, the groove width of each pulley changes, so that the belt winding radius with respect to each pulley changes. That is, the rotation speed ratio between the primary shaft and the secondary shaft, that is, the gear ratio is controlled. Further, by controlling the belt winding radius, the belt tension changes, and the torque transmitted between the primary pulley and the secondary pulley is adjusted.

  Incidentally, in the belt type continuously variable transmission as described above, the forward / reverse switching mechanism is provided because the rotational direction of the engine is limited to one direction. That is, the rotational direction of the engine is selectively switched between the rotational direction in which the vehicle moves forward and the rotational direction in which the vehicle moves backward, and the power from the engine side, that is, the input side is transmitted to the drive wheel side, that is, the output side. A forward / reverse switching mechanism that is a power transmission device is provided. As an example of the forward / reverse switching mechanism, Patent Document 1 discloses an invention relating to a “forward / reverse switching device” used in an automobile transmission or the like.

  The forward / reverse switching mechanism described in Patent Document 1 includes a forward gear and a reverse gear that are rotatably arranged on a driven shaft of a continuously variable transmission for a vehicle, and a forward gear and a reverse gear. A hub disposed at an intermediate position, a forward / reverse switching sleeve that selectively connects one of the forward gear and the reverse gear with the hub, and a fork that axially shifts the sleeve to forward, neutral, and backward positions. The forward / reverse switching sleeve is shifted, and the forward gear or the reverse gear is set by engaging the sleeve with the gear spline of the forward gear or the reverse gear.

  In Patent Document 2, as a forward / reverse switching mechanism of a V-belt continuously variable transmission, a forward gear and a reverse gear are provided on a hollow shaft that is provided on the outer peripheral side of a driven shaft and is intermittently connected to the driven shaft by a starting clutch. A configuration is described in which a gear is rotatably supported, and either the forward gear or the reverse gear is connected to a hollow shaft by a forward / reverse switching dog clutch.

  In Patent Document 3, as a forward / reverse switching mechanism for a belt-type continuously variable transmission, a forward / reverse switching gear mechanism is arranged at a joint portion of a driven shaft, that is, a driving shaft of a driving pulley and a pulley shaft of a driving pulley. A structure is described in which a forward drive system is formed by the action of a synchronizer ring when the shift fork slides to the left, and a reverse drive system is formed by meshing the outer teeth of the sleeve with the reverse gear when the shift fork slides to the right. ing.

JP-A-2005-240858 Japanese Patent Publication No. 6-74847 No. 6-39140

  The forward / reverse switching mechanism of the continuously variable transmission described in Patent Document 1 and Patent Document 2 described above includes a meshing engagement mechanism including a forward gear, a reverse gear, a hub, and a forward / reverse switching sleeve, and a continuously variable transmission. A starting clutch that transmits and cuts off the power transmission path between the driven shaft of the transmission and the output shaft connected to the wheels is disposed on the driven shaft of the continuously variable transmission, that is, the output side of the continuously variable transmission. . Therefore, each member constituting the forward / reverse switching mechanism is easily affected by the speed change by the continuously variable transmission, and the safety strength must be ensured in consideration of the influence.

  That is, when the gear ratio set by the continuously variable transmission is large, a large torque is transmitted to the driven shaft, so the forward / reverse switching mechanism arranged on the driven shaft side supports high torque. Need to design. On the other hand, when the speed ratio set by the continuously variable transmission is small, the driven shaft is driven at a high rotational speed, and therefore the forward / reverse switching mechanism arranged on the driven shaft side has a high rotational speed. It is necessary to design corresponding to.

  Therefore, when the forward / reverse switching mechanism is disposed on the driven shaft side of the continuously variable transmission, as in the forward / reverse switching mechanism described in Patent Document 1 and Patent Document 2, the forward / reverse switching mechanism is increased. The structure must be able to cope with torque and high rotation, and in order to ensure the strength of each member constituting the forward / reverse switching mechanism, the size or cost of each member must be increased. As a result, the physique or cost of the forward / reverse switching mechanism increases, which has been a factor that hinders downsizing of the forward / reverse switching mechanism and the transmission including the forward / reverse switching mechanism.

  Further, the forward / reverse switching mechanism described in Patent Document 3 is provided with a forward / reverse switching mechanism on the drive shaft side of the continuously variable transmission. Therefore, compared with the case where the forward / reverse switching mechanism is arranged on the driven shaft side of the continuously variable transmission, it is less susceptible to the shift by the continuously variable transmission, which is advantageous in terms of strength. However, the forward / reverse switching mechanism described in Patent Document 3 reverses torque for reverse rotation on the same axis as the drive shaft of the continuously variable transmission, that is, the output shaft from the engine. For example, a reverse gear, an idler gear, a counter gear, etc., for example, are required at least two reverse shafts for the reverse gear. Eventually, in this case as well, the physique or cost of the forward / reverse switching mechanism increased, and there was still room for improvement.

  The present invention has been made paying attention to the above technical problem, and by improving the configuration and arrangement of the forward / reverse switching mechanism for selectively setting the rotational state of the torque input from the power source to the transmission. An object of the present invention is to provide a transmission including a forward / reverse switching mechanism that can be reduced in size and cost.

  In order to achieve the above object, the invention of claim 1 is characterized in that the driven shaft is arranged in parallel or substantially parallel to the drive shaft and the output torque of the power source input to the transmission input shaft is A forward state in which the rotation direction is not reversed but transmitted to the transmission output shaft, a reverse state in which the rotation direction is reversed and transmitted to the transmission output shaft, and the output torque is not transmitted to the transmission output shaft In a transmission including a forward / reverse switching mechanism for selectively setting a neutral state, the forward / backward switching mechanism is disposed between the drive shaft and a driven shaft, and the transmission input shaft is connected to the power. It is characterized by being provided as an axis on the same axis as the output shaft of the source and as a different axis from the drive shaft.

  According to a second aspect of the invention, in the first aspect of the invention, the forward / reverse switching mechanism sets the forward state by transmitting the output torque to the drive shaft via a forward gear pair, It is characterized in that the reverse state is set by directly transmitting the output torque to the driven shaft via a reverse gear pair and a counter gear.

  According to a third aspect of the present invention, in the second aspect of the present invention, the forward gear pair is configured to amplify the output torque, decelerate and reverse its rotation, and transmit it to the drive shaft. It is what.

  According to a fourth aspect of the present invention, in the second or third aspect of the present invention, the power transmission path constituted by the reverse gear pair and the counter gear is disposed between the drive shaft and the driven shaft. It is characterized by.

  According to a fifth aspect of the present invention, in the invention according to any one of the second to fourth aspects, the forward / reverse switching mechanism selectively connects the transmission input shaft and the forward gear pair or the reverse gear pair. -It is characterized by comprising a meshing clutch that shuts off.

  According to a sixth aspect of the present invention, in the invention according to any one of the second to fifth aspects, the forward / reverse switching mechanism is configured such that the reverse gear pair is provided in a power transmission path between the transmission input shaft and the driven shaft. It has an intermediate shaft to which any of the gears is attached.

  Therefore, according to the first aspect of the present invention, the forward / reverse switching mechanism that selectively sets the rotation direction of the output torque of the power source and the transmission state to the transmission output shaft has the drive shaft and the driven shaft in parallel or substantially. It is arranged in a space between the drive shaft and the driven shaft of the transmission arranged in parallel, and in the power transmission path between the drive shaft of the transmission and the power source, that is, on the drive shaft side of the transmission In addition, the transmission input shaft to which the output torque of the power source is input and the output shaft of the power source are on the same axis line, and the transmission input shaft and the drive shaft of the transmission are different axes. It is provided to become. Therefore, it is not necessary to design the forward / reverse switching mechanism to cope with the high torque and high rotation operation state in consideration of the effect of the shift by the transmission, so that the power transmission device can be reduced in size and cost. Thus, an increase in the size of the transmission or an increase in cost can be avoided or suppressed.

  According to the second aspect of the invention, the forward state is set by transmitting the output torque of the power source to the drive shaft of the transmission via the forward gear pair of the forward / reverse switching mechanism. Directly transmitted to the driven shaft of the transmission via the reverse gear pair of the mechanism and the counter gear, that is, directly transmitted to the driven shaft of the transmission without passing through the transmission mechanism between the drive shaft and the driven shaft. Therefore, the reverse state is set. Therefore, when the transmission is operated in the reverse drive state, the power transmission efficiency can be improved by the amount that the transmitted torque does not pass through the transmission mechanism between the drive shaft and the driven shaft. In addition, since only one reverse-dedicated shaft is required to configure the power transmission path for setting the reverse state, the forward / reverse switching is performed as compared with the case where two or more reverse-dedicated shafts are conventionally required. The mechanism can be reduced in size and cost.

  According to the invention of claim 3, when the output torque of the power source is transmitted to the drive shaft of the transmission via the forward gear pair, the gear ratio of the forward gear pair is set large. Thus, the output torque is input to the transmission after its rotation is decelerated and reversed. Therefore, for example, when the present invention is applied to a belt-type continuously variable transmission in which power transmission efficiency during operation in a high-speed region is lower than that in operation in a low-speed region, the belt-type continuously variable transmission Amplifying the torque input to the motor and decelerating the rotation thereof, the belt type continuously variable transmission can be operated in a lower rotation region. As a result, the power transmission efficiency of the belt type continuously variable transmission can be improved.

  According to the fourth aspect of the present invention, the power transmission path, which is constituted by the reverse gear pair and the counter gear and directly transmits the output torque of the power source to the driven shaft of the transmission, includes the drive shaft and the driven shaft of the transmission. To shorten the power transmission path, that is, to reduce the outer diameter of the reverse gear pair and the counter gear, and to reduce the shaft diameter of the shaft on which the reverse gear is mounted. Is possible.

  According to the invention of claim 5, the forward / reverse switching mechanism provided in the transmission is constituted by a meshing clutch. Therefore, by operating the engagement / disengagement state of the meshing clutch, the connection / disconnection state between the transmission input shaft and the forward gear pair or the reverse gear pair can be easily set.

  According to the sixth aspect of the present invention, the intermediate shaft to which one of the gears of the reverse gear pair is attached is provided in the power transmission path for directly transmitting the output torque of the power source to the driven shaft of the transmission. Therefore, the outer diameters of the reverse gear pair and the counter gear, etc., constituting the power transmission path can be further reduced.

  Next, the present invention will be specifically described with reference to the drawings. FIG. 1 is a skeleton diagram of a vehicle in which the present invention is applied to a belt type continuously variable transmission having a forward / reverse switching mechanism. In FIG. 1, reference numeral 1 denotes a power source of a vehicle. Examples of the power source 1 include engines (internal combustion engines) such as gasoline engines, diesel engines, and LPG engines, electric motors (motors), and engine and power running / regenerative control. For example, a hybrid system combined with an electric motor (motor / generator) capable of performing the above is used. Here, for convenience, an example using the engine 1 in which the crankshaft 2, that is, the output shaft 2 of the power source 1, is arranged in the vehicle width direction will be described as the power source 1.

  A transaxle 3 is provided on the output side of the engine 1. The transaxle 3 includes a transaxle housing 4 attached to the rear end side of the engine 1, a transaxle case 5 attached to an open end of the transaxle housing 4 opposite to the engine 1, and a transaxle case 5. The transaxle housing 4 has a transaxle rear cover 6 attached to an opening end opposite to the transaxle housing 4.

  A torque converter 7 is provided inside the transaxle housing 4, and a belt type continuously variable transmission 10 provided with a forward / reverse switching mechanism 8 and a differential 9 inside the transaxle case 5 and the transaxle rear cover 6. Is provided.

  The torque converter 7 is provided with an input shaft 11 that can rotate around the same axis as the crankshaft 2, that is, a transmission input shaft 11 according to the present invention to which the output torque of the engine 1 is input from the crankshaft 2. A turbine runner 12 is attached to an end of the input shaft 11 on the engine 1 side. On the other hand, a front cover 14 is connected to the rear end of the crankshaft 2 via a drive plate 13, and a pump impeller 15 is connected to the front cover 14. The turbine runner 12 and the pump impeller 15 are disposed to face each other, and a stator 16 is provided inside the turbine runner 12 and the pump impeller 15. A hollow shaft 18 is connected to the stator 16 via a one-way clutch 17. The hollow shaft 18 is fixed to the transaxle case 5 in a non-rotatable manner, and the input shaft 11 is disposed inside the hollow shaft 18. A lockup clutch 20 is provided at the end of the input shaft 11 on the side of the front cover 14 via a damper mechanism 19. Oil as a working fluid is supplied into a casing (not shown) formed by the front cover 14 and the pump impeller 15 configured as described above.

  With the above configuration, power (torque) of the engine 1 is transmitted from the crankshaft 2 to the front cover 14. At this time, when the lockup clutch 20 is released, the torque of the pump impeller 15 is transmitted to the turbine runner 12 by the fluid and then to the input shaft 11. Note that the torque transmitted from the pump impeller 15 to the turbine runner 12 can be amplified by the stator 16. On the other hand, when the lockup clutch 20 is engaged, the torque of the front cover 14 is mechanically transmitted to the input shaft 11.

  An oil pump 21 is provided between the torque converter 7 and the forward / reverse switching mechanism 8. The rotor 22 of the oil pump 21 and the pump impeller 15 are connected by a cylindrical hub 23. The body 24 of the oil pump 21 is fixed to the transaxle case 5 side. With this configuration, the power of the engine 1 is transmitted to the rotor 22 via the pump impeller 15 and the oil pump 21 can be driven.

  The forward / reverse switching mechanism 8 is provided in a power transmission path between the input shaft 11 and the speed change mechanism 10 a of the belt type continuously variable transmission 10. The forward / reverse switching mechanism 8 is a mechanism that is employed when the rotational direction of the engine 1 is limited to one direction, and outputs the input torque as it is or reversely outputs it. It is configured. In the present invention, the configuration of the forward / reverse switching mechanism 8 or the arrangement thereof is improved so that the size of the belt type continuously variable transmission 10 can be reduced or the cost can be reduced. A detailed description thereof will be described later.

  The transmission mechanism 10a of the belt-type continuously variable transmission 10 is arranged so as to be separate from the input shaft 11, in other words, the primary shaft 25 arranged so as not to be concentric with the input shaft 11, that is, in the present invention. It has a drive shaft 25 and a secondary shaft 26 arranged parallel to the primary shaft 25, that is, the driven shaft 26 in the present invention. A primary pulley 27 is provided on the primary shaft 25 side, and a secondary pulley 28 is provided on the secondary shaft 26 side. The primary pulley 27 has a fixed sheave 29 integrally formed on the outer periphery of the primary shaft 25 and a movable sheave 30 configured to be movable in the axial direction of the primary shaft 25. A V-shaped groove, that is, a belt winding groove 31 is formed between the opposed surfaces of the fixed sheave 29 and the movable sheave 30.

  In addition, a hydraulic actuator 32 is provided that moves the movable sheave 30 in the axial direction of the primary shaft 25 to move the movable sheave 30 and the fixed sheave 29 closer to or away from each other. On the other hand, the secondary pulley 28 has a fixed sheave 33 integrally formed on the outer periphery of the secondary shaft 26 and a movable sheave 34 configured to be movable in the axial direction of the secondary shaft 26. A V-shaped groove (belt winding groove) 35 is formed between the opposed surfaces of the fixed sheave 33 and the movable sheave 34. In addition, a hydraulic actuator 36 is provided that moves the movable sheave 34 in the axial direction of the secondary shaft 26 to move the movable sheave 34 and the fixed sheave 33 closer to or away from each other. Further, a transmission belt 37 is wound around the belt winding groove 31 of the primary pulley 27 and the belt winding groove 35 of the secondary pulley 28 configured as described above.

  As described above, the transmission mechanism 10a of the belt-type continuously variable transmission 10 includes a primary pulley 27 as an input member and a secondary pulley 28 as an output member, which are arranged in parallel to each other, and fixed sheaves 29 and 33, respectively. The movable sheaves 30 and 34 are moved back and forth in the axial direction by hydraulic actuators 32 and 36. Therefore, the groove widths of the pulleys 27 and 28 are changed by moving the movable sheaves 30 and 34 in the axial direction, and accordingly the winding radius of the transmission belt 37 wound around the pulleys 27 and 28 (each pulley 27 , 28) is continuously changed, and the gear ratio is changed steplessly.

  The hydraulic actuator 36 in the secondary pulley 28 is supplied with a hydraulic pressure (line pressure or its correction pressure) corresponding to the torque input to the belt type continuously variable transmission 10. Therefore, when the sheaves 33 and 34 in the secondary pulley 28 sandwich the transmission belt 37, tension is applied to the transmission belt 37, and the clamping pressure (contact pressure) between the pulleys 27 and 28 and the transmission belt 37 is secured. It has become so. In other words, the torque capacity corresponding to the clamping pressure is set. On the other hand, the hydraulic actuator 32 in the primary pulley 27 is supplied with pressure oil corresponding to the gear ratio to be set, and is set to a groove width (effective diameter) corresponding to the target gear ratio. .

  A primary shaft 25 that is a drive shaft of the belt type continuously variable transmission 10 is connected to a forward gear pair 106 that is an output member of the forward / reverse switching mechanism 8 described later, and the driven type of the belt type continuously variable transmission 10 is driven. A secondary shaft 26 that is a shaft is connected to a gear pair 38 and a differential 9, and the differential 9 is connected to a drive wheel 40 via a drive shaft 39, that is, a transmission output shaft 39 in the present invention.

  As described above, the transmission provided with the forward / reverse switching mechanism according to the present invention improves the configuration or arrangement of the forward / reverse switching mechanism 8 provided in the belt-type continuously variable transmission 10 described above. The forward / reverse switching mechanism 8 can be downsized or reduced in cost, and the size of the entire transmission or the increase in cost can be avoided or suppressed. Examples of a transmission provided with such a forward / reverse switching mechanism 8 will be sequentially described below.

  In FIG. 1, a forward / reverse switching mechanism 8 of a belt type continuously variable transmission 10 to which the present invention is applied includes a hub 101 that rotates integrally with an input shaft (transmission input shaft) 11 fixedly or integrally with the input shaft 11. Is formed. Further, on both sides of the hub 101 (on the left and right sides in FIG. 1), the forward hollow shaft 102 into which the input shaft 11 is inserted and the reverse hollow shaft 103 are respectively inserted into the outer periphery of the input shaft 11. 11 is supported so as to be relatively rotatable.

  A forward hub 104 that rotates integrally with the forward hollow shaft 102 is fixed or integrally formed at one end (the right end in FIG. 1) of the forward hollow shaft 102 on the hub 101 side. . A reverse hub 105 that rotates integrally with the reverse hollow shaft 103 is fixed or integrally formed at one end (the left end in FIG. 1) of the reverse hollow shaft 103 on the hub 101 side. ing.

  One forward gear 106a of the forward gear pair 106 is fixed or integrally formed at the other end (the left end in FIG. 1) of the forward hollow shaft 102. The other forward gear 106b of the forward gear pair 106 meshed with the forward gear 106a is fixed to the end of the primary shaft 25 on the forward / reverse switching mechanism 8 side (the right end in FIG. 1) or It is integrally formed.

  On the other hand, one reverse gear 107a of the reverse gear pair 107 is fixed or integrally formed at the other end (the right end in FIG. 1) of the reverse hollow shaft 103. At one end of the reverse intermediate shaft 108 on the engine 1 side (right side in FIG. 1), the other reverse gear 107b of the reverse gear pair 107 meshed with the reverse gear 107a is fixed or integrated. Is formed.

  A reverse gear 107c is fixed or integrally formed at the other end of the reverse intermediate shaft 108 on the side of the speed change mechanism 10a (left side in FIG. 1) of the belt type continuously variable transmission 10. Further, a counter gear 109 meshed with the reverse gear 107c is fixed or integrally formed at the end of the secondary shaft 26 on the forward / reverse switching mechanism 8 side (the right end in FIG. 1).

  The forward / reverse switching mechanism 8 can selectively transmit the torque between the input shaft 11 and the forward gear pair 106 or the input shaft 11 and the reverse gear pair 107. An engagement mechanism is provided in which the input shaft 11 is not connected to either the forward gear pair 106 or the reverse gear pair 107 and is in a neutral state where torque cannot be transmitted between them. It has been.

  That is, the forward / reverse switching mechanism 8 is provided on the outer periphery of the hub 101, the forward hub 104, the reverse hub 105, and the hubs 101, 104, 105, and the hub 101, 104, 105 The outer peripheral part is comprised by the engagement mechanism which consists of the switching sleeve 110 which can slide to an axial direction (left-right direction in FIG. 1). The engagement mechanism by the hubs 101, 104, 105 and the switching sleeve 110 is constituted by, for example, a meshing clutch mechanism that selectively connects and disconnects the hubs 101, 104, 105 and the switching sleeve 110. Yes.

  Specifically, spline external teeth are formed on the outer peripheral portions of the hubs 101, 104, and 105, and the inner periphery of the switching sleeve 110 is formed on the inner periphery of the spline that fits the external teeth of the hubs 101, 104, and 105 The teeth are formed, and the switching sleeve 110 is configured by a spline mechanism that can be selectively fitted to and released from the switching sleeve 110 by moving the switching sleeve 110 in the axial direction of each hub 101, 104, 105. ing.

  Therefore, by moving the switching sleeve 110 to the forward hub 104 side (left side in FIG. 1) and fitting the switching sleeve 110, the forward hub 104 and the hub 101 simultaneously, the input shaft 11 and the forward hollow shaft are fitted. 102 and the input shaft 11 and the forward gear 106a can be integrally rotated.

  On the other hand, the switching sleeve 110 is moved to the reverse hub 105 side (the right side in FIG. 1), and the switching sleeve 110 and the reverse hub 105 and the hub 101 are fitted simultaneously, so that the input shaft 11 and the reverse shaft are reversely moved. The hollow shaft 103 can be connected, and the input shaft 11 and the reverse gear 107a can be integrally rotated.

  Further, by holding the switching sleeve 110 on the outer periphery of the hub 101, that is, by not fitting the switching sleeve 110 to either the forward hub 104 or the reverse hub 105, the input shaft 11 can be A neutral state that is not connected to any of the reverse hollow shafts 103 can also be set.

  FIG. 2 shows the arrangement of the shafts 11, 25, 26, 39, 108 and the gear pairs or gears 106, 107, 109, or the pulleys 27, 28. It is the schematic diagram represented on the plane of the direction perpendicular | vertical to the axial direction of 108. FIG. In FIG. 2, the input shaft 11 is disposed in a space between the primary shaft 25 and the secondary shaft 26, and the input shaft 11 and the primary shaft 25 are separate axes. Specifically, the distance L2 between the input shaft 11 and the secondary shaft 26 is shorter than the distance L1 between the primary shaft 25 and the secondary shaft 26, so that the input shaft 11 and the primary shaft 25 are The input shaft 11 is arranged so as to have different axes.

  Further, when the hub 101 and the forward movement hub 104 are integrally fitted by the switching sleeve 110, the forward movement gear 106a that is connected to the input shaft 11 and rotates integrally with the primary pulley 27 and the primary shaft 25 rotates integrally. It arrange | positions so that it may mesh with the forward gear 106b which does.

  On the other hand, when the hub 101 and the reverse hub 105 are integrally fitted by the switching sleeve 110, the reverse gear 107a that is connected to the input shaft 11 and rotates integrally is reversely rotated with the reverse intermediate shaft 108. It arrange | positions so that it may mesh with the use gear 107b. Further, a reverse gear 107 c that rotates integrally with the reverse intermediate shaft 108 and the reverse gear 107 b is arranged so as to mesh with the counter gear 109 that rotates integrally with the secondary pulley 28 and the secondary shaft 26.

  A counter gear 109 that rotates integrally with the secondary pulley 28 and the secondary shaft 26 is disposed so as to mesh with the ring gear 9 a of the differential 9 connected to the drive shaft 39.

  In this way, the input shaft 11 and the primary shaft 25 are arranged so as to be different from each other, and when the hub 101 and the forward movement hub 104 are integrally fitted by the switching sleeve 110, Power transmission from the input shaft 11 to the belt-type continuously variable transmission 10 is performed via the forward gear pair 106 by the forward gear 106a and the forward gear 106b, that is, the forward state is set. ing. Therefore, by appropriately setting the gear ratio of the forward gear pair 106, the torque input to the input shaft 11 is transmitted to the primary shaft 25 in a state where the rotation is appropriately decelerated or increased, or in a directly connected state. can do.

  The belt-type continuously variable transmission 10 generally tends to have lower power transmission efficiency when operated in a high rotation range than when operated in a low rotation range. Therefore, as described above, the input shaft 11 and the primary shaft 25 are arranged on separate axes, and the forward gear pair 106 is provided between them, and the input shaft 11 is input via the forward gear pair 106. By decelerating the rotation of the torque that is transmitted to the primary shaft 25, the belt-type continuously variable transmission 10 can be operated in the rotation region on the lower rotation speed side, and the power transmission efficiency is reduced. It can be avoided or suppressed.

  Further, when the hub 101 and the reverse hub 105 are integrally fitted by the switching sleeve 110, the power transmission from the input shaft 11 to the belt type continuously variable transmission 10 is transmitted to the reverse gear 107a and the reverse gear 107b. The reverse gear pair 107, the reverse intermediate shaft 108, and the counter gear 109 are used. In other words, the torque of the input shaft 11 is applied to the reverse gear pair 107, the reverse intermediate shaft 108, and the counter gear. 109 is configured to be input directly to the secondary shaft 26 via 109, that is, the reverse state is set. Therefore, when the reverse drive state is set, the torque input to the input shaft 11 is directly transmitted to the secondary shaft 26 without passing through the belt transmission portion inside the transmission mechanism 10a of the belt type continuously variable transmission 10. Power transmission efficiency can be improved.

  The operation of the forward / reverse switching mechanism 8 configured as described above and the forward / backward switching function will be described. First, when the forward position is selected, that is, when the forward state is set, the switching sleeve 110 is moved to the forward hub 104 side, and the spline of the switching sleeve 110 is moved between the spline of the hub 101 and the forward hub 104. It is simultaneously fitted to the spline. As a result, the input shaft 11 and the forward advance hollow shaft 102 are connected.

  In this state, when the torque (in other words, power) of the engine 1 is transmitted to the input shaft 11 via the torque converter 7, the input shaft 11, the forward advance hollow shaft 102, and the forward advance gear 106a are integrated. Rotate. The torque transmitted to the forward hollow shaft 102 and the forward gear 106a is transmitted to the primary shaft 25 via the forward gear 106b. At this time, the torque of the input shaft 11 is transmitted to the primary shaft 25 after its rotation is decelerated or increased according to the gear ratio of the forward gear pair 106 by the forward gear 106a and the forward gear 106b.

  The torque of the primary shaft 25 is transmitted to the secondary shaft 26 via the primary pulley 27, the transmission belt 37, and the secondary pulley 28 as shown in FIG. The torque transmitted to the secondary shaft 26 is transmitted to the drive shaft 39 and the drive wheels 40 via the gear pair 38 of the counter gear 109 and the ring gear 9a and the differential 9, and the vehicle advances.

  On the other hand, when the reverse position is selected, that is, when the reverse state is set, the switching sleeve 110 is moved to the reverse hub 105 side, and the spline of the switching sleeve 110 and the spline of the hub 101 are reversely moved. It is simultaneously fitted to the spline of the hub 105. As a result, the input shaft 11 and the reverse hollow shaft 103 are connected.

  In this state, when the torque of the engine 1 is transmitted to the input shaft 11, the input shaft 11, the reverse hollow shaft 103, and the reverse gear 107a rotate integrally. The torque transmitted to the reverse hollow shaft 103 and the reverse gear 107a is transmitted to the counter gear 109, that is, the secondary gear 107b via the reverse gear 107b, the reverse hollow shaft 108 and the reverse gear 107c that rotate together with the reverse gear 107b. It is transmitted to the shaft 26.

  Therefore, the torque of the input shaft 11 is transmitted to the secondary shaft 26 via the reverse hollow shaft 103, the reverse gear pair 107, and the counter gear 109 as described above. At this time, the rotational direction of the torque of the input shaft 11 is reversed at two locations between the reverse gear 107a and the reverse gear 107b and between the reverse gear 107c and the counter gear 109. That is, the torque of the input shaft 11 is transmitted to the secondary shaft 26 with the rotation direction reversed twice. Therefore, the rotation direction of the secondary shaft 26 at the reverse position is opposite to the rotation direction of the secondary shaft 26 at the forward position where the torque of the input shaft 11 is reversed once and transmitted to the secondary shaft 26. As a result, the rotating members such as the secondary shaft 26 and the differential 9 rotate in the opposite direction to the forward position, and the vehicle moves backward.

  According to the transmission according to the present invention configured as described above (that is, the belt-type continuously variable transmission 10 in the above embodiment), the forward / reverse switching mechanism that selectively sets the rotational state of the output torque of the engine 1. 8 is arranged in a space between a primary shaft 25 that is a drive shaft of the belt-type continuously variable transmission 10 and a secondary shaft 26 that is a driven shaft, and a transmission input to which the output torque of the engine 1 is input The input shaft 11 that is the shaft and the output shaft of the engine 1, that is, the crankshaft 2 are provided on the same axis, and the input shaft 11 and the primary shaft 25 are provided on different axes.

  Therefore, the forward / reverse switching mechanism 8 is arranged on the drive shaft side, that is, the input side of the belt-type continuously variable transmission 10 that does not need to consider the influence of the speed change by the belt-type continuously variable transmission 10. Compared with the case where 8 is arranged on the driven shaft side of the belt-type continuously variable transmission 10, that is, the output side, the strength of the shaft, gear, supporting bearing, etc. constituting each part of the forward / reverse switching mechanism 8 is set low. Therefore, it is possible to reduce the size or cost of each part. As a result, it is possible to avoid or suppress an increase in size or cost of the main body of the belt type continuously variable transmission 10.

  Further, the output torque of the engine 1 is transmitted to the primary shaft 25 via the forward gear pair 106 of the forward / reverse switching mechanism 8 to set a forward state, and the reverse gear pair 107 and the forward / backward switching mechanism 8 The reverse transmission state is caused by being directly transmitted to the secondary shaft 26 via the counter gear 109, that is, directly transmitted to the secondary shaft 26 without passing through the belt transmission portion inside the transmission mechanism 10a of the belt type continuously variable transmission 10. Is set. Therefore, when the reverse state is set, the power transmission efficiency can be improved by the amount that the output torque of the engine 1 does not pass through the belt transmission unit. Further, since only one of the reverse intermediate shafts 108 is required as a dedicated shaft for configuring the power transmission path for setting the reverse drive state, two or more reverse dedicated shafts have conventionally been required. In comparison, the forward / reverse switching mechanism 8 can be reduced in size and cost.

  Further, when the output torque of the engine 1 is transmitted to the primary shaft 25 via the forward gear pair 106, the output torque can be rotated by setting the gear ratio of the forward gear pair 106 large. It is decelerated and reversed and transmitted to the primary shaft 25. Therefore, the rotation of the torque input to the belt-type continuously variable transmission 10 can be decelerated, and the belt-type continuously variable transmission 10 can be operated in a lower rotation region. Efficiency can be improved.

  A power transmission path that is configured by the reverse gear pair 107, the reverse intermediate shaft 108, and the counter gear 109 and that directly transmits the output torque of the engine 1 to the secondary shaft 26 is provided between the primary shaft 25 and the secondary shaft 26. By disposing, the power transmission path can be shortened, that is, the outer diameter of the reverse gear pair 107 or the counter gear 109 can be reduced, or the shaft diameter of the shaft to which these gears are attached can be reduced. In this respect, the forward / reverse switching mechanism 8 can be reduced in size and cost.

  The present invention is not limited to the above specific example, and the above specific example shows an example in which the present invention is applied to a belt type continuously variable transmission for a vehicle having a forward / reverse switching mechanism. However, the present invention is not limited to the forward / reverse switching mechanism, and may be provided with a power transmission device that can selectively set and output the rotational state of torque input from a power source. The transmission is not limited to a continuously variable transmission, and may be another type of transmission in which an output shaft is arranged in parallel or substantially parallel to an input shaft. Moreover, it is also possible to apply to the transmission provided with the power transmission device in other industrial machines and devices other than the vehicle.

  Further, in the above specific example, the forward / reverse switching mechanism is shown as an engagement clutch using a spline mechanism, but the forward / reverse switching mechanism is operated by an engagement clutch using a mechanism other than the spline mechanism. It may be configured. Further, the forward / reverse switching mechanism is not limited to the meshing clutch, and may be constituted by, for example, a friction clutch or an electromagnetic clutch.

1 is a schematic diagram (skeleton diagram) showing a schematic configuration of a transmission according to the present invention. FIG. 2 is a schematic diagram for explaining the arrangement of each part of the transmission shown in FIG. 1 on a plane perpendicular to the axial direction.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Engine (power source), 2 ... Crankshaft (output shaft), 8 ... Forward / reverse switching mechanism, 10 ... Belt type continuously variable transmission (transmission), 11 ... Input shaft (transmission input shaft), 25 ... Primary shaft (drive shaft), 26 ... Secondary shaft (driven shaft), 39 ... Drive shaft (transmission output shaft), 101 ... Hub, 104 ... Forward hub, 105 ... Reverse hub, 106 ... Forward gear pair, 107: reverse gear pair, 109: counter gear, 110: switching sleeve.

Claims (6)

Forward drive shaft is driven parallel to or nearly parallel to the drive shaft, and the output torque of the power source input to the transmission input shaft is transmitted to the transmission output shaft without reversing the rotation direction. A forward / reverse switching mechanism that selectively sets a state, a reverse state in which the rotation direction is reversed and transmitted to the transmission output shaft, and a neutral state in which the output torque is not transmitted to the transmission output shaft. In the transmission,
The forward / reverse switching mechanism is disposed between the drive shaft and the driven shaft, and the transmission input shaft is an axis on the same axis as the output shaft of the power source and is different from the drive shaft. A transmission characterized by being provided as follows.   The forward / reverse switching mechanism sets the forward state by transmitting the output torque to the drive shaft via a forward gear pair, and sets the output torque to the driven shaft via a reverse gear pair and a counter gear. The transmission according to claim 1, wherein the reverse state is set by transmitting directly to the transmission.   The transmission according to claim 2, wherein the forward gear pair is configured to amplify the output torque, decelerate and reverse the rotation thereof, and transmit the rotation to the drive shaft.   The transmission according to claim 2 or 3, wherein a power transmission path constituted by the reverse gear pair and the counter gear is disposed between the drive shaft and the driven shaft.   5. The forward / reverse switching mechanism is constituted by a meshing clutch that selectively connects and disconnects the transmission input shaft and the forward gear pair or the reverse gear pair. A transmission according to any one of the above.   The forward / reverse switching mechanism has an intermediate shaft on which one of the gears of the reverse gear pair is attached to a power transmission path between the transmission input shaft and the driven shaft. The transmission according to any one of claims 2 to 5.

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