JP5936267B2 - PTO gear mounting structure - Google Patents

Description

  The present invention relates to a PTO gear mounting structure that accommodates and mounts a PTO gear coupled to a PTO (Power Take Off) shaft such as a pump drive shaft in a torque converter case mounted on an industrial vehicle such as a forklift.

  Conventionally, as shown in FIG. 6, the axle 100, the transmission 101, and the engine 102 are integrated, and the axle 100 is directly fixed to a frame (not shown), while the engine 102 side is mounted on a rubber mount (not shown). As shown in FIG. 7, the axle 110 and the transmission 111 are connected by a propeller shaft 112, and the transmission 111 and the engine 113 are integrally mounted on a rubber mount (not shown). There is known a floating structure that is directly fixed to an unillustrated).

  The monoblock structure generally has less engine swing, and a loading space for a cargo handling pump 103 (hereinafter simply referred to as “pump”) 103 such as a hydraulic cylinder is installed behind the engine 102. The driving force of the pump 103 was taken out from the crankshaft. The monoblock structure is advantageous in terms of cost because it is a simple structure. However, since the engine 102 and the axle 100 are integrated, the vibration of the engine 102 is transmitted to the operator through the axle 100 directly fixed to the frame. There is a problem that it is easy to communicate.

  On the other hand, the floating structure has an advantage that the vibration of the engine 113 is less likely to be transmitted to the operator due to the intervention of the propeller shaft 112 as compared with the monoblock structure.

  However, in the floating structure, the swing of the engine 113 becomes large and it is difficult to take out the pump power from the crankshaft. In addition, due to the fourth exhaust gas regulation, a device such as a diesel particulate filter is placed near the rear of the engine. In order to secure space for installation, it has become necessary to install a pump in the transmission.

  4 and 5 are developed sectional views of a transmission to which a pump shaft PTO gear is attached in a conventional floating structure. FIG. 5 is a partially enlarged view of FIG.

  The transmission 120 shown in FIG. 4 includes a torque converter 121 and at least one clutch 122 (only one clutch is shown in the figure) that changes the power from the torque converter 121. Is connected to the torque converter case 123 containing the clutch 122 so as to be joined to the joining wall 123a on the front side of the torque converter case 123.

  In addition to the torque converter 121, the torque converter case 123 includes a PTO gear 125 to which a pump shaft (not shown) is spline-coupled, a counter gear 127 that is gear-coupled to the PTO gear 125 and the impeller hub 126 of the torque converter 121. Is housed. The torque converter case 123 is formed such that a PTO gear accommodating portion 128 that accommodates the PTO gear 125 bulges laterally. A flywheel housing 129 is connected to the rear side of the torque converter case 123.

  A drive plate 130 to which a flywheel (not shown) is connected is connected to a driving shaft 131 that receives a rotational driving force from the engine. The driving shaft 131 is connected to the cover shell 132 of the torque converter 121 and rotates the pump impeller 133 engaged with the cover shell 132. A stator shaft 134 (see FIG. 5) is fixed to the torque converter case 123, and a stator 136 is attached to the stator shaft 134 via a one-way clutch 135 so as to be rotatable in one direction. The turbine liner 137 is connected to a driven shaft 138, and the driven shaft 138 extends into the transmission case 124 and is connected to the clutch 122.

  A hub gear 139 is spline-coupled to the impeller hub 126 connected to the cover shell 132, and the counter gear 127 meshes with the hub gear 139.

  The counter gear 127 is rotatably supported on the counter shaft 141 via the bearing 140. The counter shaft 141 includes a flange portion 141a on one end side, and a through hole 143 for inserting the fixing bolt 142 in the axial center portion. The counter shaft 141 is supported by the inner peripheral surface of the through hole 144 formed in the joining wall 123 a of the torque converter case 123, and the peripheral surface of the flange 141 a is extended from the inner surface of the peripheral wall of the torque converter case 123. A fixing bolt 142 is screwed to the portion 123b. An oil seal retainer 146 that holds an oil seal 145 attached to the outer peripheral surface of the impeller hub 126 is also fixed to the extension portion 123 b by a fixing screw 147.

  The oil seal retainer 146 is arranged as close to the cover shell 132 as possible to reduce the size in the front-rear direction (left-right direction in FIGS. 4 and 5). In addition, the vicinity of the mounting portion of the fixing screw 147 of the oil seal retainer 146 is bent along the curved surface of the cover shell 132, and the extending portion 123b is extended into the space generated by the bending, and the fixing bolt 142 is screwed. By forming the female screw hole to be reduced, the size is reduced in the front-rear direction (left-right direction in FIGS. 4 and 5).

Komatsu Forklift Co., Ltd., engine-type forklift LEO, shop manual (book number BEC10J1-02CB), page 5, published by Komatsu Utility Co., Ltd. on September 30, 2008

  However, although the conventional PTO mounting structure shown in FIGS. 4 and 5 is reduced in size in the front-rear direction, the size in the width direction or the height direction is not sufficient. It may not be possible to load a cargo handling vehicle with a rated load of 5 tons or less.

  Therefore, a main object of the present invention is to provide a PTO mounting structure capable of reducing the size in the width direction or the height direction.

  In order to achieve the above object, a PTO mounting structure according to the present invention includes a torque converter, a counter gear geared to an impeller hub of the torque converter, a PTO gear meshing with the counter gear, the torque converter, and the counter. A torque converter case having a joint wall for joining a gear and the transmission case containing the PTO gear and containing a clutch; an oil seal mounted on an outer peripheral surface of the impeller hub of the torque converter; and the counter gear And an oil seal retainer that holds the oil seal, and is inserted into a shaft hole of the counter gear, and is fixed to the inner surface of the joining wall of the torque converter case. Counter shaft and the counter shaft A bearing inserted between the counter gear and having one end surface in the axial direction supported by the flange portion and the other end surface in the axial direction supported by the inner wall surface of the joining wall; and an inner peripheral surface of the torque converter case A plate-like bracket that extends in a gap between the counter gear and the oil seal retainer and that has a through hole that supports a collar side surface of the counter shaft, and the counter shaft includes the counter shaft. A screw with a hexagonal hole inserted into a bolt hole with a deep counterbore formed in the shaft center portion of the torque converter case is screwed into a screw hole formed on the inner surface of the joining wall of the torque converter case, thereby the torque converter It is fixed to the inner surface of the joint wall of the case.

  It is preferable that the counter gear includes a boss portion only on a surface opposite to the bracket.

  The counter gear further includes a pair of snap rings that are attached to the outer peripheral surface of the bearing and fix the counter gear from both sides, and the counter gear has a depth of a recessed step portion into which the snap ring on the bracket side is fitted. It is preferable that it is formed larger than the thickness of the snap ring.

  The side surface of the counter gear on the bracket side and the end surface of the bearing on the bracket side are preferably at the same level.

  It is preferable that the thickness of the bracket is equal to or less than the thickness of the flange portion.

  According to the present invention, the screw hole is formed in the inner wall surface of the joining wall of the torque converter case, and the counter shaft is fixed with the bolt from the inside of the joining wall. The joining wall is formed thick in order to ensure rigidity, and since the screw thread allowance of the bolt can be sufficiently secured, it can be firmly fixed. Since the bracket only supports the periphery of the end portion of the countershaft, it can be formed into a thin plate shape. The fixing bolt is a hexagon socket head bolt, and the counter shaft shaft hole is used as a counterbore so that the head of the bolt does not protrude from the counter shaft. As a result, the bracket can be extended deeply into a narrow gap between the cover shell and the counter gear, and the counter shaft can be brought close to the impeller hub, so that the diameter of the counter gear can be reduced accordingly. If the diameter of the counter gear is reduced, the PTO gear approaches the impeller hub, so the size of the torque converter case in the width direction or height direction can be reduced.

It is an expanded sectional view showing one embodiment of the PTO attachment structure concerning the present invention. It is a partially expanded sectional view of FIG. It is a partially expanded sectional view of FIG. It is an expanded sectional view showing the conventional PTO attachment structure. It is sectional drawing which expands and shows a part of FIG. It is a side view which shows the monoblock structure with which the conventional transaxle and the engine were integrated. It is a side view which shows the floating structure with which the conventional axle and the transmission were connected with the propeller shaft.

  An embodiment of a PTO mounting structure according to the present invention will be described below with reference to FIGS. In the following description, the same or similar components as those in the conventional example shown in FIGS. 4 and 5 may be denoted by the same reference numerals and redundant description may be omitted.

  As shown in FIG. 1, the torque converter case 1, the counter gear 2, and the PTO gear 3 are accommodated in the torque converter case 1. A transmission case 124 in which the clutch 122 is accommodated is joined and connected to the joining wall 1a of the torque converter case 1.

  As shown in FIG. 2, an oil seal 145 is attached to the outer peripheral surface of the impeller hub 126 of the torque converter 121, and the oil seal retainer 4 disposed between the counter gear 2 and the cover shell 132 of the torque converter 121 A seal 145 is held.

  A counter shaft 6 is inserted into the shaft hole 2 a of the counter gear 2 via a bearing 5, and the counter gear 2 is fixed to the inner surface of the joining wall 1 a of the torque converter case 1.

  As shown in FIG. 3, a bracket 7 extending inward from the inner peripheral surface of the torque converter case 1 extends into a gap between the counter gear 2 and the oil seal retainer 4, and a through hole 7 a formed in the bracket 7. Is supporting the peripheral side surface of the collar part 6a formed in the edge part of the axial direction one side (right side of FIG. 3) of the countershaft 6. As shown in FIG. The bracket 7 is formed in a thin plate shape that enters the gap between the counter gear 2 and the oil seal retainer 4, and has a thickness equal to or less than the thickness of the flange portion 6a. The flange portion 6 a supports one end surface of the bearing 5 in the axial direction. The other axial end surface of the bearing 5 is supported by the end surface of the short cylindrical portion 8 formed on the inner surface of the joining wall 1a. The other end of the counter shaft 6 in the axial direction (left side in FIG. 3) is fitted into and supported by the cylindrical portion 8.

  The counter shaft 6 is formed with a bolt hole 6b with a counterbore formed in the shaft center portion, and a hexagon socket head bolt 9 is inserted into the bolt hole 6b, and the hexagon socket head bolt 9 is joined to the torque converter case 1. By screwing into a screw hole 10 formed on the inner surface of the wall 1a, the inner surface of the joining wall 1a of the torque converter case 1 is fixed. The counterbore depth of the counterbore of the bolt hole 6b is equal to or greater than the height of the head of the bolt 9, so that the head of the bolt 9 sinks into the countershaft 6 and is completely buried. To do.

  By adopting the configuration as described above, the axis of the counter gear 2 can be brought close to the driven shaft 138 of the torque converter 121, thereby reducing the diameter of the counter gear 6 and the axis of the PTO gear 3. Since the distance L1 (FIG. 1) from the axis of the driven shaft 138 can be reduced, the size of the torque converter case 1 in the width direction or height direction (vertical direction in FIG. 1) can be reduced.

  Since the joining wall 1a is formed thick in order to ensure rigidity for connecting to the mission case 124, the depth of the screw hole 10 of the bolt 9 can be sufficiently secured. In general, it is necessary to secure the screw allowance depth of the screw hole 10 at least 1.5 times the diameter of the bolt 9. On the other hand, the bracket 7 need only support the peripheral surface of the flange portion 6a of the countershaft 6, and can be formed thin. Accordingly, it is possible to reduce the size in the width direction or the height direction (up and down direction in FIG. 1) while firmly supporting the counter gear 2 and reducing the size in the front and rear direction (left and right direction in FIG. 1).

  The counter gear 2 can be configured to include the boss portion 2 b only on the surface opposite to the bracket 7. Thus, by omitting the boss portion on the bracket side of the counter gear 2, a space for the bracket 7 is secured without increasing the size in the front-rear direction (left-right direction in the figure), and the size in the width direction or the height direction is reduced. Can be achieved.

  A pair of snap rings 11, 12 are attached to the outer peripheral surface of the bearing 5, and the counter gear 2 is sandwiched and held by these snap rings 11, 12 from both sides. The snap rings 11 and 12 are fitted into recessed step portions 13 and 14 formed at both ends of the shaft hole 2a of the counter gear 2.

  In the counter gear 2, the depth t (FIG. 3) of the concave step portion 13 into which the snap ring 12 on the bracket 7 side is fitted is formed larger than the thickness of the snap ring 11 (preferably twice or more). Thereby, the side surface 2c on the bracket 7 side of the counter gear 2 and the end surface 5c on the bracket 7 side of the bearing 5 can be at the same level, that is, substantially flush with each other. It is possible to secure a space for the bracket 7 and reduce the size in the width direction or the height direction without increasing the size in the direction) or while further reducing the size in the front-rear direction.

  The present invention is not limited to the above embodiment, and various modifications can be made without departing from the spirit of the present invention.

DESCRIPTION OF SYMBOLS 1 Torque converter case 1a Joint wall 2 Counter gear 2a Shaft hole 2b Boss part 3 PTO gear 4 Oil seal retainer 5 Bearing 6 Counter shaft 6b Bolt hole with counterbore 7 Bracket 9 Hexagon socket head bolt 10 Screw hole 11, 12 Snap ring 13 recessed step 121 the torque converter 126 impeller hub 122 clutch 124 transmission case 145 oil seal 132 cover shell

Claims (4)

A torque converter;
A counter gear geared to the impeller hub of the torque converter;
A PTO gear meshing with the counter gear;
A torque converter case having a joint wall for housing the torque converter, the counter gear, and the PTO gear, and joining a transmission case in which a clutch is housed;
An oil seal mounted on the outer peripheral surface of the impeller hub of the torque converter;
An oil seal retainer disposed between the counter gear and a cover shell of the torque converter, and holding the oil seal;
A countershaft inserted into the shaft hole of the counter gear, fixed to the inner surface of the joining wall of the torque converter case, and having a flange formed at one end in the axial direction;
A bearing inserted between the counter shaft and the counter gear, wherein one end surface in the axial direction is supported by the flange portion and the other end surface in the axial direction is supported by the inner wall surface of the joining wall;
A plate-like bracket provided with a through hole extending from the inner peripheral surface of the torque converter case to the gap between the counter gear and the oil seal retainer, and supporting the flange peripheral surface of the counter shaft;
With
The counter shaft has a hexagon socket head cap screw inserted into a bolt hole with a counterbore formed in the axial center of the counter shaft, and is screwed into a screw hole formed in the inner surface of the joint wall of the torque converter case. Is fixed to the inner surface of the joint wall of the torque converter case ,
A pair of snap rings that are attached to the outer peripheral surface of the bearing and fix the counter gear from both sides;
The counter gear is a PTO gear mounting structure characterized in that a depth of a recessed step portion into which the snap ring on the bracket side is fitted is larger than a thickness of the snap ring .   The PTO gear mounting structure according to claim 1, wherein the counter gear includes a boss portion only on a surface opposite to the bracket. PTO gear mounting structure according to claim 1 or 2, characterized in that said bracket side end face of the bracket-side side surface and the bearing of the counter gear is equal level. PTO gear mounting structure according to any one of claims 1 to 3, the thickness of the bracket, wherein said at most the thickness of the flange portion.

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