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JP-2026076043-A - Electric wheelchairs and power units for electric wheelchairs

JP2026076043AJP 2026076043 AJP2026076043 AJP 2026076043AJP-2026076043-A

Abstract

[Problem] To provide an electric wheelchair that can reduce the width of the vehicle body when the frame is folded without reducing the battery capacity. [Solution] The electric wheelchair 100 includes an electric motor 21 mounted on the right wheel 10R, an electric motor 21 mounted on the left wheel 10L, a battery 30 for supplying current to the electric motors 21, and a battery holder 40 that houses the battery 30 and is positioned closer to the right wheel 10R than the center of the electric wheelchair 100 in the left-right direction. The battery holder 40 is open inwards, towards the center of the electric wheelchair 100 in the left-right direction, and upwards of the electric wheelchair 100. [Selection Diagram] Figure 4

Inventors

  • 大西 慎太郎

Assignees

  • ヤマハ発動機株式会社

Dates

Publication Date
20260511
Application Date
20241023

Claims (14)

  1. A power unit mounted on an electric wheelchair that has a first wheel, which is one of the right wheel and the left wheel, and a second wheel, which is the other of the right wheel and the left wheel, and is foldable so that the distance between the first wheel and the second wheel is reduced, The first electric motor mounted on the first wheel, The second electric motor mounted on the second wheel, A battery for supplying current to the first electric motor and the second electric motor, The electric wheelchair has a battery holder that houses the battery, which is positioned closer to the first wheel than the center in the left-right direction of the electric wheelchair. The battery holder has openings inward, which is the direction towards the center of the electric wheelchair in the left-right direction, and upward, which are part of the power unit of the electric wheelchair.
  2. The battery has the first side surface that faces inward, A power unit for an electric wheelchair, wherein when the battery is mounted in the battery holder, the entire first side surface is exposed inward from the battery holder.
  3. The battery has a front end facing forward of the electric wheelchair and a rear end facing backward of the electric wheelchair. The battery holder has a front wall portion that runs along the front surface and a rear wall portion that runs along the rear surface. The front wall portion has a first inner surface that is aligned with the front surface of the battery. The rear wall portion has a second inner surface that is aligned with the rear surface of the battery. The power unit for an electric wheelchair according to claim 1, wherein the widths of the first inner surface and the second inner surface in the left-right direction are smaller than the width of the battery in the left-right direction.
  4. When the battery and the battery holder are viewed in the front-rear direction, the center of gravity of the battery coincides with the front wall portion and the rear wall portion, as described in claim 3, for the power unit of an electric wheelchair.
  5. The power unit for an electric wheelchair as described in claim 3, wherein when the battery and the battery holder are viewed in the front-rear direction, the plane passing through the center of the battery in the left-right direction intersects the front wall and the rear wall.
  6. The power unit for an electric wheelchair according to claim 3, wherein the positions of the upper surfaces of the front wall and the rear wall are higher than the center of the battery in the vertical direction.
  7. The battery has a first side facing inward and a second side facing outward, which is in the opposite direction to the inward direction. The battery holder includes a side wall portion that is along the second side surface of the battery, The side wall portion has an inner surface that faces inward, The aforementioned inner surface has a slope at its uppermost part, The power unit for an electric wheelchair according to claim 1, wherein the slope extends diagonally upward and outward from the lower edge of the slope.
  8. The aforementioned battery holder has a guide portion, The aforementioned battery has a guided portion, The power unit for an electric wheelchair according to claim 1, wherein the guide portion and the guided portion allow vertical movement of the battery relative to the battery holder and restrict inward movement of the battery relative to the battery holder.
  9. An electric wheelchair comprising the power unit described in claim 1, the first wheel, and the second wheel.
  10. The electric wheelchair has a stopper portion located closer to the second wheel than the center in the left-right direction of the electric wheelchair, The aforementioned battery holder has a stopper portion, The electric wheelchair according to claim 9, wherein the stopper portion and the portion to be stopped are in contact with each other when the electric wheelchair is folded, and restrict the distance between the first wheel and the second wheel from becoming smaller than a preset value.
  11. The battery holder has the side surface facing inward, The electric wheelchair according to claim 10, wherein the stopper portion is provided on the side surface.
  12. The battery holder has a bottom that supports the lower surface of the battery, The electric wheelchair according to claim 10, wherein the stopper portion is provided at the bottom.
  13. The battery has a front end facing forward of the electric wheelchair and a rear end facing backward of the electric wheelchair. The battery holder has a front wall portion that runs along the front surface and a rear wall portion that runs along the rear surface. When the battery is mounted in the battery holder, it has a portion that is located inward from the inward side surfaces of the front wall and the rear wall, A space is secured in the inward direction of the battery holder where the portion of the battery is to be arranged. The electric wheelchair according to claim 10, wherein when the electric wheelchair is folded with the battery removed from the battery holder, the frame closer to the second wheel is located in front of the space.
  14. The battery has a first side facing inward and a second side facing outward, which is in the opposite direction to the inward direction. The battery holder includes a side wall portion that is along the second side surface of the battery, The side wall portion has an inner surface facing the center in the left-right direction of the electric wheelchair, The aforementioned inner surface has a slope at its uppermost part, and the slope extends diagonally upward and outward from its lower edge. The electric wheelchair according to claim 9, wherein the battery holder is supported away from the first wheel in the inward direction.

Description

This disclosure relates to an electric wheelchair and a power unit for an electric wheelchair. Patent Document 1 discloses an electric wheelchair. The electric wheelchair has electric motors located on the left and right wheels, and a battery for supplying power to the electric motors. Furthermore, the electric wheelchair disclosed in Patent Document 1 is foldable so that the distance between the left and right wheels is reduced. In this electric wheelchair, the battery pack housing the battery is located on the back of the backrest. Unlike the electric wheelchair described in Patent Document 1, electric wheelchairs with battery holders positioned along the wheels are also in use. In this type of electric wheelchair, the battery holder is a box-shaped structure opening upwards and has four walls surrounding the left, front, right, and rear sides of the battery. Japanese Patent Publication No. 2015-198814 This is a perspective view of an electric wheelchair from the diagonal left rear.This is a perspective view of an electric wheelchair from the rear right.This is a rear view of the battery holder, battery, and right wheel.This is a perspective view of the battery holder.This is a plan view of the battery holder.This is a left side view of the battery.This is a perspective view of the battery.This is a rear view showing the frame in its folded state. The following describes the electric wheelchair and power unit proposed in this disclosure. As an example of the electric wheelchair and power unit proposed in this disclosure, the electric wheelchair 100 and power unit U shown in Figure 1, etc., will be described. The power unit U includes left and right electric motors 21, a battery 30, and a battery holder 40 as its components. In the following explanation, the Z1 and Z2 directions shown in Figure 1 will be referred to as upward and downward, respectively. Similarly, the Y1 and Y2 directions shown in Figure 1 will be referred to as forward and backward, respectively, and the X1 and X2 directions shown in Figure 1 will be referred to as right and left, respectively. As shown in Figure 1, the electric wheelchair 100 has wheels 10R and 10L positioned on the right and left sides of the vehicle body, respectively. Each wheel 10R and 10L has a hub 11 and an electric motor 21 located inside the hub 11. The electric motor 21 has a motor housing 23 (see Figure 2), a rotor housed in the motor housing 23, and a stator. The rotation of the rotor is transmitted to the hub 11 via a reduction mechanism located inside the hub 11. As shown in Figure 1, the electric wheelchair 100 has a battery 30 that stores power supplied to the electric motor 21, and a battery holder 40 that holds the battery 30. The battery 30 is electrically connected to the electric motors 21 mounted on the left and right wheels 10L and 10R via cables. As shown in Figure 6A, the battery 30 has a battery body 31 that houses multiple battery cells, and a handle 32 provided on the top of the battery body 31. As shown in Figure 1, the electric wheelchair 100 has casters 66 positioned in front of the wheels 10R and 10L, foot supports 61 for the user's feet, a seat 62 for the user to sit on, a back support 63 for supporting the user's back, and arm supports 64 for the user's arms. An operating unit (not shown) that receives input from the user is positioned in front of the arm supports 64. Through this operating unit, the user can input instructions regarding the wheelchair 100's direction of travel and speed into the control unit. As shown in Figure 1, the electric wheelchair 100 has a frame 50. The frame 50 has a right frame section 51R, which forms the right side of the vehicle body, and a left frame section 51L, which forms the left side of the vehicle body. Each of the right frame section 51R and the left frame section 51L has a rear frame section 52, a seat frame section 53, a lower frame section 54, etc. The rear frame section 52 extends vertically and supports the right and left sides of the back support 63. The seat frame section 53 extends forward from the rear frame section 52 and supports the right and left sides of the seat 62, and also supports the left and right arm supports 64. The lower frame section 54 extends forward from the rear frame section 52 and supports the casters 66, etc. The left wheel 10L and the right wheel 10R are supported by the left frame portion 51L and the right frame portion 51R, respectively. As shown in Figure 2, for example, a support portion 52a protruding rearward is formed at the lower part of the rear frame portion 52. The axles of the wheels 10L and 10R are supported by this support portion 52a. For example, the axles are inserted into through holes formed in the support portion 52a. The frame 50 can be folded so that the distance between the left and right wheels 10L and 10R is reduced (see Figure 7). For example, as shown in Figure 2, frame 50 has movable arms 55a and 55b that connect the left and right frame sec