JPH07251657A - Power seat driving gear - Google Patents

Abstract

PURPOSE:To provide a power seat driving gear wherein outward appearance after assembly is improved and further external shape of a total unit can be formed into compactness also without damaging a lead screw while reducing a man-hour can be attained. CONSTITUTION:A power seat driving gear 1 comprises ring members 5, 6, 7, 8 mounted on lead screws 3, 4 rotated by a power seat motor 2, stopper members 9, 10, 11, 12 mounted on the ring members 5, 6, 7, 8 on the lead screws 3, 4 and nut members 13, 14 fixed to a seat side also meshed with the lead screws 3, 4 to move on the lead screws 3, 4 during the time before colliding against the stopper members 9, 10, 11, 12.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a power seat drive device used for automatically moving a seat.

[0002]

2. Description of the Related Art As a power seat driving device for automatically moving a seat, when a lead screw is rotated by a power seat motor, a nut member fixed to the seat moves while meshing with teeth provided on the lead screw. It is known to move a seat. Shafts smaller than the diameter of the teeth are provided at both ends of the teeth of the lead screw, and ring-shaped stoppers are screwed into both shafts via washers, so the nut member is The movement stroke of the sheet is defined as the movement of the sheet until the movement is regulated when the tooth travels on the teeth and collides with the stopper. In addition to the above-described power seat drive device, for fixing the washer to the shaft portions provided at both ends of the tooth portion of the lead screw as smaller than the diameter of the tooth portion by welding, the nut member is collided. Some are used as stoppers.

[0003]

In the above power seat drive device, if the stopper is structured to be screwed into the shaft portion of the lead screw, it is necessary to provide the stopper with a female screw for screwing into the shaft portion of the lead screw. At the same time, a male screw for screwing the stopper must be provided on the shaft portion of the lead screw, and the step of screwing the stopper is also required, which increases the man-hours. If the lead screw is screwed in with an appropriate large force, the lead screw may be bent. Also, with the structure in which the washer is fixed to the shaft portion of the lead screw by welding,
It is difficult to set the assembly angle to the lead screw at a right angle and make it uniformly collide with the nut member.If the washer is not installed parallel to the nut member, it is hard to say that it is good in appearance and also the nut member. When the impact force is not dispersed when the is collided and a large stress is partially applied to the washer, there is a problem that the washer may be bent or the washer may come off the lead screw shaft. there were. Further, since the shaft portion of the lead screw in which the nut member is meshed with the tooth portion is connected to the reduction mechanism of the power seat motor, the diameter of the lead screw shaft portion is necessarily limited by the diameter of the tooth portion. The diameter of the tooth is larger than necessary, and the external dimensions of the lead screw and stopper are also large because there is a limit to reducing the diameter of the shaft, because it has to be set smaller than the diameter of the shaft and a male screw must be provided. Therefore, there is a problem that the arrangement in a relatively small space such as the lower side of the seat may be troublesome.

[0004]

SUMMARY OF THE INVENTION The power seat drive device according to the present invention can reduce the number of steps, do not damage the lead screw, have a good appearance after assembly, and have a compact overall outer shape. It is an object of the present invention to provide a power seat drive device that can be used.

[0005]

[Constitution of the invention]

[0006]

A power seat drive device according to claim 1 of the present invention comprises a power seat motor,
A lead screw rotated by a power seat motor, a ring-shaped ring member attached to the lead screw, a stopper member attached to the ring member on the lead screw, fixed to the seat side and meshed with the lead screw, The power seat drive device according to claim 2 of the present invention is characterized in that a tooth member is provided on the lead screw until it collides with the stopper member. And a shaft portion having an outer diameter smaller than that of the tooth portion, a ring-shaped grooved ring member mounting portion is formed on the shaft portion, and the ring member mounting portion is formed in a C shape. The ring member is elastically fitted, and the power seat drive device according to claim 3 of the present invention is The spacer member is formed in a substantially cylindrical shape, and has an inner peripheral side shaft portion insertion hole having an outer diameter larger than the shaft portion of the lead screw and smaller than the tooth portion of the lead screw, from the one end edge to the shaft portion insertion hole. In between, a concave ring member fixing portion fixed to the ring member is formed. The power seat drive device according to claim 4 of the present invention is from the one end edge of the stopper member to the ring member fixing portion. In between, a tapered surface is formed whose inner diameter is set to increase from the ring member fixing portion to one end edge.

[0007]

In the power seat drive device according to the first aspect of the present invention, the stopper member is attached to the ring member attached to the lead screw. Therefore, mounting by screwing or welding becomes unnecessary, and the stopper member can be easily mounted even if the diameter of the lead screw is small. In the power seat drive device according to claim 2 of the present invention, the stopper member is the lead. It is mounted on a ring member elastically fitted to a ring member mounting portion formed on the shaft portion of the screw. Therefore, mounting by screwing or welding is unnecessary, and the stopper member can be easily mounted even if the diameter of the lead screw is small. In the power seat drive device according to claim 3 of the present invention, the ring member is replaced by the lead screw. The stopper member is mounted on the ring member by inserting the ring member into the ring member mounting portion so as to cover the shaft portion and mounting it, and then pressingly moving the stopper member arranged on the tooth side toward the ring member side. Therefore, mounting by screwing or welding is unnecessary, and the stopper member can be easily mounted even if the diameter of the lead screw is small.
In the power seat drive device according to the above, when the ring member is covered with the shaft portion of the lead screw so as to be inserted into the ring member mounting portion and attached, and then the stopper member disposed on the tooth side is pressed and moved to the ring member side. The stopper member is mounted on the ring member while being positioned on the ring member by the tapered surface. Therefore, mounting by screwing or welding is unnecessary, and the stopper member can be easily mounted even if the diameter of the lead screw is small.

[0008]

1 to 3 show an embodiment of a power seat driving device according to the present invention. FIG. 1 is a plan view of the power seat driving device, and FIG. 2 is a power seat shown in FIG. FIG. 3 is a vertical cross-sectional side view around the lead screw of the drive unit, and FIG. 3 is a vertical cross-sectional side view illustrating an assembly procedure of the stopper member and the ring member in the power seat drive unit shown in FIG.

The illustrated power seat drive device 1 is mainly composed of a power seat motor 2, a first lead screw 3 as a lead screw 3, a second lead screw 4, a first ring member 5 and a second ring member as a ring member. Ring member 6, third ring member 7, fourth ring member 8,
A first stopper member 9 serving as a stopper member, a second stopper member 10, a third stopper member 11, a fourth stopper member 12, a first nut member 13 serving as a nut member,
It is composed of the second nut member 14.

The power seat motor 2 is provided with a motor shaft, and when the seat slide switch (not shown) is turned on to the forward side, a forward current is supplied to the power seat motor 2 to cause the motor shaft to move. Rotates in the forward direction, and when the power seat switch is turned on to the reverse side to supply a reverse current, the motor shaft rotates in the reverse direction. The motor shaft is coupled to the first reduction gear unit 2a and the second reduction gear unit 2b, respectively, and when the motor shaft rotates in the forward direction, the output unit and the second reduction gear unit 2b provided in the first reduction gear unit 2a.
When the motor shaft rotates in the reverse direction, the output section provided in the first speed reduction section 2a and the output section provided in the second speed reduction section 2b rotate in the reverse direction. The first lead screw 3 is connected to the output portion of the first reduction gear portion 2a, and the second lead screw 4 is connected to the output portion of the second reduction gear portion 2b.

Since the first lead screw 3 and the second lead screw 4 have the same shape, only the first lead screw 3 will be described here.
The first lead screw 3 is provided with a first shaft portion 3a near one end portion and a second shaft portion 3b near the other end portion. , 3
A tooth portion 3c formed by a male screw is provided in the middle of b. The diameter of both shafts 3a and 3b is smaller than that of tooth 3c. Further, as is clear from FIG. 2, the first shaft portion 3a
Since a ring-shaped concave groove-shaped ring member mounting portion 3a1 is formed near the tooth portion 3c, the ring member mounting portion 3
The first ring member 5 is attached to a1. The distance L1 from the ring member mounting portion 3a1 to the tooth portion 3c is set to be slightly larger than the thickness dimension L2 of the first stopper member 9 described later.

The second shaft portion 3b provided on the first lead screw 3 is also formed near the tooth portion 3c as a ring-shaped groove similar to the ring member mounting portion 3a1. A ring member mounting portion is provided, and the second ring member 6 is mounted on the ring member mounting portion provided on the second shaft portion 3b.

Similarly to the first lead screw 3, the second lead screw 4 has a first shaft portion 4a and a second shaft portion 4 as well.
b, a tooth portion 4c is provided, and the ring member mounting member (not shown) is formed near the tooth portion 4c of the first shaft portion 4a and has a ring shape similar to the ring member mounting portion 3a1 and has a groove shape. Is provided, and the third ring member 7 is attached to the ring member mounting portion provided on the first shaft portion 4a of the second lead screw 4. Further, a ring member mounting portion (not shown) formed as a ring-shaped groove similar to the ring member mounting portion 3a1 is provided near the tooth portion 4c of the second shaft portion 4b. The fourth ring member 8 is attached to the ring member mounting portion provided on the second shaft portion 4b of the lead screw 4.

The first shaft portion 3 of the first lead screw 3
a is the first speed reducer 2 provided in the power seat motor 2
a is connected to the output portion of the second lead screw 4, and the first shaft portion 4a of the second lead screw 4 is connected to the output portion of the second speed reducer portion 2b provided in the power seat motor 2. When the motor shaft of the seat motor 2 rotates in the forward direction, the first lead screw 3 and the second lead screw 4 respectively rotate in the forward direction, and when the motor shaft rotates in the reverse direction, the first lead screw 3 and the second lead screw 4 rotate. 4 rotates in the opposite direction. The tooth portion 3c of the first lead screw 3 meshes with the first nut member 13, and the tooth portion 4c of the second lead screw 4 meshes with the second nut member 14.

The first nut member 13 and the second nut member 14 are fixed to a seat (not shown), and the seat is slidably attached to the vehicle body through the seat slide mechanism 15, so that the first lead is used. When the screw 3 and the second lead screw 4 rotate in the forward direction, the first nut member 13 and the second nut member 14 move the sheet to the forward side which is the left side in FIG. When the second lead screw 4 rotates in the reverse direction, the first nut member 13 and the second nut member 14 move the seat to the retracted side which is the right side in FIG.

The first ring member 5, the second ring member 6, the third ring member 7, and the fourth ring member 8 are all made of a metal having a slight elasticity, such as steel, and are the same C-shape. The first ring member 5 that is formed into a shape and is attached to the ring member mounting portion 3a1 formed on the first shaft portion 3a of the first lead screw 3 will be described below. As is clear from FIG. 2, the member 5 has an inner diameter slightly smaller than the ring member mounting portion 3a1 and an outer diameter larger than that of the first shaft portion 3a. The first shaft portion 3a is elastically deformed so as to be enlarged, and then inserted into the ring member mounting portion 3a1 so that the ring member mounting portion 3a1 is elastically fitted to the first lead screw 3. separation It is attached to the function. The first ring member 5 attached to the ring member mounting portion 3a1 has an outer edge protruding from the shaft portion 3a, and the first portion is formed on the protruding portion.
The stopper member 9 is attached. The first ring member 5 is attached to a ring member mounting portion 3a1 formed on the shaft portion 3a of the first lead screw 3, and the ring member mounting portion 3a1 is mounted with the C-shaped first ring member 5. Therefore, the depth dimension does not need to be large, so that even if the diameter of the shaft portion 3a of the first lead screw 3 is small, the ring member mounting portion 3a1 is formed.
Are easily formed. In the first lead screw 3, since the diameter of the shaft portion 3a is reduced, the diameter of the tooth portion 3c is also reduced.

Since the first stopper member 9, the second stopper member 10, the third stopper member 11 and the fourth stopper member 12 all have the same shape, only the first stopper member 9 is shown here. To explain, the first stopper member 9 is a stopper member main body 9a formed in a substantially cylindrical shape.
A shaft insertion hole 9b having a round hole shape is provided at the center of the shaft. Since the inner diameter of the shaft portion insertion hole 9b is slightly larger than the first shaft portion 3a of the first lead screw 3 and smaller than the tooth portion 3c of the first lead screw 3,
It is inserted through the first shaft portion 3a of the first lead screw 3 and is not inserted through the tooth portion 3c of the first lead screw 3.

Further, one end edge 9c of the stopper member body 9a opposite to the tooth portion 3c of the first lead screw 3 is formed.
A ring member fixing portion 9d having a ring-shaped groove shape is formed between the above and the shaft portion insertion hole 9b. The inner diameter of the ring member fixing portion 9d is slightly smaller than the outer diameter of the first ring member 5 attached to the ring member mounting portion 3a1 of the first lead screw 3.

Between the ring member fixing portion 9d and the one end edge 9c, there is formed a tapered surface 9e whose inner diameter is set to increase from the ring member fixing portion 9d to the one end edge 9c. Tapered surface 9e is one edge 9c
The inner diameter on the side is larger than the outer diameter of the first ring member 5, and the inner diameter on the ring member fixing portion 9d side is slightly smaller than the outer diameter of the first ring member 5. ing.

Similarly to the first stopper member 9, the second stopper member 10, the third stopper member 11, and the fourth stopper member 12 also have a stopper member main body, a shaft portion insertion hole, one end edge, and a ring member fixed. It has a portion, a tapered surface, and the other edge.

Here, as is clear from FIG. 3, the first
The other end edge 9f of the stopper member 9 is directed toward the tooth portion 3c of the first lead screw 3 and the shaft portion insertion hole 9b is formed in the shaft portion of the first lead screw 3 until the other end edge 9f contacts the tooth portion 3c. As the thickness dimension L2 of the first stopper member 9 is smaller than the distance L1 from the ring member mounting portion 3a1 to the tooth portion 3c when the first stopper member 9 is inserted into the ring member mounting portion 3a1. It is located at a position slightly passing through.

In this state, the first ring member 5 is put on the first shaft portion 3a of the first lead screw 3 so as to be inserted into the ring member mounting portion 3a1 to be attached, and then the first ring member 5 is arranged on the tooth portion 3c side. The first stopper member 9 is moved to the first ring member 5 side, the tapered surface 9e of the first stopper member 9 is aligned with the first ring member 5, and the first stopper member 9 is moved to the first By further pressing and moving the ring member 5 side, the ring member fixing portion 9d of the first stopper member 9 is press-fitted into the first ring member 5 as shown in FIG. 1 lead screw 3
Fixed on top. At this time, since the first stopper member 9 is aligned with the first ring member 5 by the taper surface 9e, the first stopper member 9 is easily press-fitted to the first ring member 5 while being positioned.

The first lead screw 3 is the first shaft portion 3
Even if the diameter of a is small, the ring member mounting portion 3a1 is easily formed, and by setting the diameter of the first shaft portion 3a of the first lead screw 3 to be small, the outer shape of the first stopper member 9 is Does not grow.

The second shaft portion 3 of the first lead screw 3
The second ring member 6 is also attached to the ring member mounting portion (not shown) provided in b in the same manner as described above, and the second stopper member 10 is attached to this second ring member by press fitting. The third ring member 7 is attached to the ring member mounting portion (not shown) provided on the first shaft portion 4a of the second lead screw 4 in the same manner as described above, and the third ring member 7 is provided with the third ring member 7. The stopper member 11 is attached by press fitting. The fourth ring member 8 is attached to the ring member mounting portion (not shown) provided on the second shaft portion 4b of the second lead screw 4 in the same manner as described above, and the fourth ring member 8 has a fourth ring member 8a. The stopper member 12 is attached by press fitting.

The first stopper member 9 and the second stopper member 10 are arranged at the ends of the tooth portions 3c of the first lead screw 3, respectively, and the third stopper member 11 and the fourth stopper member 12 are the Since the first nut member 13 collides with the first stopper member 9 and the second stopper member 10 because they are respectively arranged at the ends of the two lead screws 4,
The second nut member 14 is the third stopper member 11, the fourth
The movement stroke of the sheet is set until the collision with the stopper member 12.

In the power seat drive device 1 having such a structure, the first nut member 13 is meshed with the tooth portion 3c of the first lead screw 3, and the first stopper member 9 is fixed to the first lead screw. The first ring member 5 is attached to the ring member mounting portion 3a1 of the first lead screw 3 after passing through the first shaft portion 3a of No. 3 and arranged on the tooth portion 3c side of the first lead screw 3. To press the ring member fixing portion 9d of the first stopper member 9 into the first ring member 5 to attach the first stopper member 9 to the first lead screw 3 and to attach the second stopper member 9 to the first stopper member 9. The second ring member 6 is attached to the other ring member of the first lead screw 3 after passing through the second shaft part 3b of the lead screw 3 and arranging it on the tooth part 3c side of the first lead screw 3. Take part A first lead screw 3 only by then press-fitting the ring member fixing portion 10d of the second stopper member 10 to the second ring member 6 and the second stopper member 10
Install.

Further, the second nut member 14 is engaged with the tooth portion 4c of the second lead screw 4, and the third stopper member 11 is passed through the first shaft portion 4a of the second lead screw 4. After arranging on the tooth part 4c side of the second lead screw 4, the third ring member 7 is attached to the ring member mounting part of the second lead screw 4, and the ring member fixing part 11d of the third stopper member 11 is attached. Is press-fitted into the third ring member 7 to attach the third stopper member 11 to the second lead screw 4, and the fourth stopper member 12 is passed through the second shaft portion 4b of the second lead screw 4. It is arranged on the tooth portion 4c side of the second lead screw 4, the fourth ring member 8 is attached to the other ring member mounting portion of the second lead screw 4, and the ring member fixing portion of the fourth stopper member 12 is attached. 12d The press-fitted into the fourth ring member 82
The fourth stopper member 12 is attached to the lead screw 4 of FIG.

Therefore, the second shaft portion 3b of the first lead screw 3 in which the first nut member 13, the first stopper member 9 and the second stopper member 10 are assembled is attached to the seat slide mechanism 15. While supporting it rotatably,
The first shaft portion 3a of the first lead screw 3 is connected to the output portion of the first reduction gear portion 2a included in the power seat motor 2. The first shaft portion 3a of the first lead screw 3 and the first reduction gear portion 2a are connected to each other by spline connection.

Further, the second shaft portion 4b of the second lead screw 4 in which the second nut member 14, the third stopper member 11 and the fourth stopper member 12 are assembled is attached to the seat slide mechanism 15. While supporting it rotatably,
The first shaft portion 4a of the second lead screw 4 is connected to the output portion of the second reduction gear portion 2b included in the power seat motor 2. The first shaft portion 4a of the second lead screw 4 and the second reduction gear portion 2b are also connected by spline connection of both.

Then, the power seat motor 2 in which the first lead screw 3 is connected to the first speed reducer 2a and the second lead screw 4 is connected to the second speed reducer 2b is attached to the seat slide mechanism. The first nut member 13 and the second nut member 14 are fixed to the seat, and the seat slide mechanism is attached to the vehicle body.

In this state, when the seat slide switch (not shown) is turned on by the occupant to the forward side, the power seat motor operates to rotate the first lead screw 3 and the second lead screw 4 forward, The seat is moved forward by the first nut member 13 and the second nut member 14. When the first nut member 13 moves on the first lead screw 3 and reaches the end of the tooth portion 3c, the first nut member 13 collides with the first stopper member 9 and is prevented from moving, so that the tooth of the first lead screw 3 is prevented. While stopping at the end of the portion 3c, the second nut member 14 moves on the second lead screw 4 and, when reaching the end of the tooth portion 4c, collides with the third stopper member 11 to prevent movement. Then, the sheet is stopped at the end of the tooth portion 4c of the second lead screw 4, so that the sheet is stopped at the stroke end on the forward side.

When the seat slide switch is turned on by the occupant in the backward direction, the power seat motor operates to rotate the first lead screw 3 and the second lead screw 4 in the reverse direction. Member 1
3 and the second nut member 14 moves the seat backward, and the first nut member 13 moves on the first lead screw 3 to reach the end of the tooth portion 3c. Is blocked from moving because it collides with
When the second nut member 14 moves on the second lead screw 4 and reaches the end portion of the tooth portion 4c while stopping at the end portion of the tooth portion 3c of the lead screw 3 of FIG. Since the collision causes the movement, the movement is blocked and the sheet is stopped at the end of the tooth portion 4c of the second lead screw 4, so that the sheet is stopped at the stroke end on the backward side.

[0033]

As described above, according to the power seat drive device of the first aspect of the present invention, since the stopper member is mounted on the ring member mounted on the lead screw, mounting by screwing or welding is performed. Unnecessary and
Even if the diameter of the lead screw is small, the stopper member can be easily attached, reducing the number of steps and avoiding damage to the lead screw, and improving the appearance after assembly. Even if the diameter of the stopper is reduced, the stopper member can be easily attached, and as a result, the outer shape of the entire device can be made compact. In the power seat drive device according to claim 2 of the present invention, the stopper member Since it is mounted on the ring member that is elastically fitted to the ring member mounting part formed on the shaft of the lead screw, mounting by screwing or welding is unnecessary, and even if the diameter of the lead screw is small, the stopper member can be mounted. Since it can be done easily, the number of steps can be reduced and the lead screw is not damaged. Therefore, the appearance after assembly can be improved, and even if the diameter of the lead screw is reduced, the stopper member can be easily attached, and as a result, the external shape of the entire device can be made compact. In the power seat drive device according to the third aspect of the present invention, the ring member is put on the shaft portion of the lead screw so as to be inserted into the ring member mounting portion and mounted, and then the stopper member arranged on the tooth side is attached. Since the stopper member is attached to the ring member by pushing and moving it toward the ring member side, there is no need to install it by screwing or welding, and even if the diameter of the lead screw is small, it is easy to install the stopper member. The lead screw is not damaged and the appearance after assembly can be improved. Also, even if the diameter of the lead screw is reduced, the stopper member can be easily attached, and as a result, the outer shape of the entire device can be made compact. The power seat drive device according to claim 4 of the present invention In the above, the ring member is covered with the shaft portion of the lead screw, inserted into the ring member mounting portion and attached, and then the stopper member arranged on the tooth side is pressed and moved to the ring member side, whereby the stopper is formed by the tapered surface. Since the member is mounted on the ring member while being positioned on the ring member, there is no need to install it by screwing or welding, and even if the diameter of the lead screw is small, the stopper member can be easily installed, reducing man-hours. The lead screw is not damaged and the appearance after assembly can be improved. However, even if the diameter of the lead screw is reduced, the stopper member can be easily attached, and as a result, the outer shape of the entire apparatus can be made compact, which is an excellent effect.

[Brief description of drawings]

FIG. 1 is a plan view of an embodiment of a power seat drive device according to the present invention.

FIG. 2 is a vertical sectional side view around a lead screw of the power seat drive device shown in FIG.

FIG. 3 is a vertical cross-sectional side view for explaining an assembling procedure of a stopper member and a ring member in the power seat drive device shown in FIG.

[Explanation of symbols]

 1 power seat drive device 2 power seat motor 3 lead screw (first lead screw) 3a shaft portion (first shaft portion) 3a1 ring member mounting portion 3b shaft portion (second shaft portion) 3c tooth portion 4 lead screw (2nd lead screw) 4a Shaft part (1st shaft part) 4b Shaft part (2nd shaft part) 4c Tooth part 5 Ring member (1st ring member) 6 Ring member (2nd ring member) 7 Ring Member (Third Ring Member) 8 Ring Member (4th Ring Member) 9 Stopper Member (First Stopper Member) 9b Shaft Insertion Hole 9d Ring Member Fixing Part 9e Tapered Surface 10 Stopper Member (Second Ring Member) Stopper member) 11 Stopper member (third stopper member) 12 Stopper member (fourth stopper member) 13 Nut member (first nut member) 14 Nut member (second stopper member) Nut member)

Claims (4)

[Claims] 1. A power seat motor, a lead screw rotated by the power seat motor, a ring member formed in a ring shape and attached to the lead screw, and a stopper member attached to the ring member on the lead screw. The power seat drive device is characterized in that it is fixed to the seat side, meshed with the lead screw, and provided with a nut member that moves on the lead screw until it collides with the stopper member. 2. The lead screw is provided with a tooth portion and a shaft portion having an outer diameter smaller than that of the tooth portion, and a ring-shaped groove member mounting portion is formed on the shaft portion. The power seat driving device according to claim 1, wherein a C-shaped ring member is elastically fitted to the ring member mounting portion. 3. The stopper member is formed in a substantially cylindrical shape, and is provided with a shaft portion insertion hole having an outer diameter larger than a shaft portion of the lead screw and smaller than a tooth portion of the lead screw on an inner peripheral side from one end edge. The power seat drive device according to claim 2, wherein a concave ring member fixing portion fixed to the ring member is formed between the shaft portion insertion hole and the shaft member insertion hole. 4. The tapered surface having an inner diameter set to be larger between the one end edge of the stopper member and the ring member fixing portion is formed from the ring member fixing portion to the one end edge. Power seat drive.