JPH11311303A - Installation structure for gear box - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an installation structure for gear boxes, capable of cost reduction. SOLUTION: This gear box is composed of a shaft (input shaft) 103, a worm 101 attached to the shaft 103, a worm wheel 107 engaging with the worm 101, a screw bar (output shaft) 105 installed to the worm wheel 107, and a case 115 in which the worm 101 and the worm wheel 107 are rotatably provided. In this case, holes 121, 123 through which the screw bar 105 is to be passed, are formed opposite to the faces B, C nearly perpendicular to the screw bar 105 of the case 115, the case 115 is nipped between two brackets 125, 127 installed to a plate (frame) 11, and flange parts 133, 139 which can abut on the outside faces of the respective brackets 125, 127 are formed on the screw bar 105.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an input shaft rotatably driven by a drive source, a worm mounted on the input shaft, a worm wheel meshing with the worm, and an output shaft mounted on the worm wheel. And a case having the worm and the worm wheel therein and rotatably supporting the worm and the worm wheel.

[0002]

2. Description of the Related Art Next, a conventional example will be described with reference to the drawings.
FIG. 2 is a diagram for explaining a mounting structure of a gear box provided on a power seat, and FIG. 3 is a cross-sectional view taken along a cutting line AA in FIG.

In FIG. 2, reference numerals 1 and 3 denote lower rails juxtaposed on the floor side, and reference numerals 5 and 7 denote movably engaging lower rails 1 and 3, and upper rails on which seats are provided. A plate 11 is bridged at the front between the lower rails 1 and 3, and a plate 13 is bridged at the rear.

In the middle part between the upper rails 5 and 7,
Plate 15 is bridged. On the plate 11, a gear box 19 containing a worm and a worm wheel, and a motor 17 for driving the worm of the gear box 19 are provided.

A screw rod 2 is provided between the plate 11 and the plate 13.
The screw rod 21 has a front end connected to a worm wheel in the gear box 19, and a rear end rotatably supported by a bearing 22 provided on the plate 13.

Further, the plate 15 is provided with a nut member 23 screwed to the screw rod 21. Next, the mounting structure of the gear box 19 will be described with reference to FIG.

In FIG. 1, reference numeral 31 denotes a worm which is driven to rotate by the shaft 18 of the motor 17;

The threaded rod 21 is connected to the threaded rod body 21a, a serration 21b formed at the front side of the threaded rod 21 and having a smaller diameter than the threaded rod body 21a, and a serration 21b. And a threaded portion 21c.

When the worm wheel 33 is fitted into the serrated portion 21b of the screw rod 21, rotation of the worm wheel 33 with respect to the screw rod 21 is prohibited, and the nut 61 is screwed into the screw portion 21c of the screw rod 21. so,
The longitudinal movement of the screw rod 21 of the worm wheel 33 is prohibited.

A washer 63 is fitted on the serration portion 21b so as to sandwich the worm wheel 33. The worm 31 and the worm wheel 33 are rotatably supported by a case 39 including a case body 35 and a lid 37.

The holes 41, 43 which face the surfaces B, C of the case 39, which are substantially perpendicular to the screw rod 21, and through which the screw rod 21 is inserted.
Are formed on the case 39.
Are fixed to the plate 11 so that the bolts 4 are inserted through the bracket 45, the case 39, and the bracket 47.
9 and a nut 51 screwed to the bolt 49
9 is attached to the plate 11.

A ring-shaped cushion member 65 made of an elastic material is provided between the inner wall surface of the case 39 and the end surface of the worm wheel 33. Next, the operation of the above configuration will be described.

When the motor 17 is driven to rotate, the rotation of the motor 17 is transmitted to the threaded rod 21 by the mesh between the worm 31 and the worm wheel 33 in the gear box 19.

When the threaded rod 21 rotates, the nut member 23 screwed to the threaded rod 21 moves along the threaded rod 21 because the rotation is prohibited. Due to the movement of the nut member 23, the upper rails 5, 7 move along the lower rails 1, 3.

[0015]

However, in the above-described structure for mounting the gear box 19, when a load along the axial direction acts on the screw rod 21, the load is applied to the gear box 19 via the washer 63. It is transmitted to the case body 35 or the lid 37 of the case 39.

Therefore, it is necessary to use a high-strength material capable of withstanding a high load as the material of the case 39, and there is a problem that the cost is increased. SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and an object of the present invention is to provide a gear box mounting structure capable of reducing costs.

[0017]

According to the present invention, there is provided an input shaft rotatably driven by a drive source, a worm attached to the input shaft, a worm wheel meshing with the worm, and a worm. An output shaft attached to a wheel, the worm, the worm, the worm, the worm, the worm, a gear box mounting structure comprising a case rotatably supporting the worm wheel, the gear box mounting structure, wherein the case A hole is formed to face the surface substantially orthogonal to the output shaft, through which the output shaft is inserted, and the case is sandwiched by a bracket attached to a frame,
A gear box mounting structure, characterized in that a flange portion is formed on the output shaft so as to be able to contact an outer surface of the bracket.

When an axial load acts on the output shaft, the load is transmitted to the bracket attached to the frame via the collar formed on the output shaft, and is not transmitted to the case.

Therefore, there is no need to use a high-strength material capable of withstanding a high load as the material of the case, and the cost can be reduced.

[0020]

Embodiments of the present invention will now be described with reference to the drawings. FIG. 1 is a sectional view of an embodiment of the present invention. The gear box according to the present embodiment is a gear box provided on a power seat, similarly to the conventional example, and the same parts as those in FIGS.
The same reference numerals are given and detailed description is omitted.

In the figure, reference numeral 101 denotes a motor shaft.
(Input shaft viewed from the gear box) 103 is a worm attached to the worm. The worm 101 is screwed to a worm wheel 107 attached to a screw rod (output shaft as viewed from the gear box) 105.

The worm 101 and the worm wheel 107 are provided in a case 115 including a case body 111 and a lid 113. And warm 1
01 is the case body 111 and the worm wheel 107
Is rotatably supported by the case main body 111 and the lid 113 via a bearing 117 that receives a radial load.

Further, between one end surface of the worm wheel 107 and the inner wall surface of the case body 111, the worm wheel 107 is urged in the direction of the worm 101 so that the teeth of the worm wheel 107 and the teeth of the worm 101 mesh with each other. An annular elastic member 118 is provided to remove backlash. A bearing 1 receiving a load in the thrust direction is provided between the other end surface of the worm wheel 107 and the inner wall surface of the lid 113.
19 are provided.

The screw rod 105 has a screw rod body 105a.
And a serrated portion 105b formed on the front side of the screw rod 105, and a screw portion 105c connected to the serrated portion 105b.

Serration 105b of screw rod 105
The rotation of the worm wheel 107 with respect to the screw rod 105 is prohibited by fitting the worm wheel 107.

The plate 115 has two brackets 125 and 127 facing the surfaces B and C of the case 115 which are substantially perpendicular to the screw rod 105 and having holes 121 and 123 through which the screw rod 105 is inserted. Is fixed so as to sandwich it.

On one side of the worm wheel 107, the main body portion 131 which loosely fits into the screw portion 105 c of the screw rod 105 and loosely fits into the hole 121 of the bracket 125, and has a diameter larger than that of the hole 121 of the bracket 125. A collar 135 is provided which is set and includes a flange portion 133 which can abut on an outer surface of the bracket 125.

The other side of the worm wheel 107 is loosely fitted to the serration portion 105b of the screw rod 105,
Main body portion 137 that loosely fits into hole 123 of bracket 127
And a collar 141 that is set to have a diameter larger than the diameter of the hole 123 of the bracket 127 and that can be brought into contact with the outer surface of the bracket 127.

The serration portion 1 of the screw rod 105
Groove 1 formed between the screw rod body 05b and the screw rod body 105a
The engagement of the E-ring 153 with the worm wheel 05d prohibits the axial movement (the direction of arrow D) of the worm wheel 107 and the threaded rod 105 of the collar 141, and the nut 151 is screwed into the threaded portion 105c of the threaded rod 105. And color 135
Is pressed against the end face of the worm wheel 107, so that the worm wheel 107 is prohibited from moving in the axial direction of the screw rod 105.

In consideration of the dimensional error of the parts, the nut 1
51 is screwed into the threaded portion 105c of the threaded bar 105, and the E-ring 153 is engaged with the groove 105d of the threaded bar 105, between the collar 133 of the collar 135 and the bracket 125, and the collar of the collar 141. There was a slight gap between 139 and bracket 127.

Next, the operation of the above configuration will be described. When a motor (not shown) is driven to rotate, the rotation of the motor is controlled by the worm 101 and the worm wheel 107 in the gear box.
Is transmitted to the screw rod 105.

When the screw rod 105 rotates, the screw rod 105
Since the rotation of the nut member screwed into the nut is prohibited, the nut member moves along the screw rod 105. Due to the movement of the nut member, the upper rail moves along the lower rail.

According to the above configuration, the screw rod 1 which is the output shaft
When a load in the axial direction is applied to the plate 05, the load is applied to the bracket 125 attached to the plate 11 as a frame via the collar 133 of the collar 135 provided on the screw rod 105 or the collar 139 of the collar 141. Or 127 and not transmitted to the case 115.

Therefore, the material of the case 115 does not need to be made of a high-strength material capable of withstanding a high load, and the cost can be reduced. Note that the present invention is not limited to the above embodiment. In the above embodiment, the E-ring 153 is engaged with the groove 105d formed between the serration portion 105b of the screw rod 105 and the screw rod main body 105a, so that the worm wheel 107 and the screw rod 105 of the collar 141 are engaged. The movement in the axial direction (the direction of arrow D) is prohibited, but instead of the E-ring 153, a flange portion may be integrally formed on the screw rod 105.

Although the two brackets 125 and 127 are provided as the brackets, the gear box may be provided in a bracket having a U-shaped cross section fixed to the plate 11.

Further, in the above-described embodiment, the description has been made with reference to the gear box of the power seat, but the present invention is not limited to this.

[0037]

As described above, according to the present invention, the case is provided with a hole facing the surface substantially perpendicular to the output shaft and through which the output shaft is inserted, and the case is sandwiched by the bracket attached to the frame. In the case where a load in the axial direction is applied to the output shaft by forming the collar portion capable of contacting the outer surface of the bracket on the output shaft, this load is transmitted through the collar portion formed on the output shaft. It is transmitted to the bracket attached to the frame, not to the case.

Therefore, it is not necessary to use a high-strength material capable of withstanding a high load as the material of the case, and the cost can be reduced.

[Brief description of the drawings]

FIG. 1 is a sectional view of an embodiment of the present invention.

FIG. 2 is a diagram illustrating a mounting structure of a gear box provided on a power seat.

FIG. 3 is a cross-sectional view taken along line AA of FIG. 2;

[Explanation of symbols]

 11 Plate (Frame) 101 Worm 103 Shaft (Input Shaft) 105 Screw Rod (Output Shaft) 107 Worm Wheel 115 Case 121,123 Hole 125,127 Bracket 133,139 Collar

Claims (1)

[Claims] An input shaft rotatably driven by a drive source; a worm attached to the input shaft; a worm wheel meshing with the worm; an output shaft attached to the worm wheel; A case having a worm wheel therein, the worm, a case rotatably supporting the worm wheel, and a gear box mounting structure, wherein the gear box faces a surface substantially orthogonal to the output shaft of the case, A gear box, wherein a hole through which an output shaft is inserted is formed, the case is sandwiched between brackets attached to a frame, and a flange portion is formed on the output shaft so as to be able to contact an outer surface of the bracket. Mounting structure.