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EP-4737764-A1 - SPEED REDUCER AND METHOD OF ASSEMBLING SPEED REDUCER

EP4737764A1EP 4737764 A1EP4737764 A1EP 4737764A1EP-4737764-A1

Abstract

A speed reducer includes a case, a carrier that is at least partly disposed in the case, a main bearing disposed between the case and the carrier, and a sealing member that seals between the carrier and the case. At least one of the carrier or the case includes a main body portion and a flange portion. The main bearing is pressed in an axial direction between the main body portion of the carrier and the case. The sealing member is pressed in the axial direction between the flange portion of the carrier and the case. Alternatively, the main bearing is pressed in the axial direction between the main body portion of the case and the carrier. The sealing member is pressed in the axial direction between a flange portion of the case and the carrier.

Inventors

  • WANAKA, Yuta
  • HASEGAWA, NORIAKI

Assignees

  • Nabtesco Corporation

Dates

Publication Date
20260506
Application Date
20251013

Claims (7)

  1. A speed reducer comprising: a case; a carrier at least partly disposed in the case; a main bearing disposed between the case and the carrier; and a sealing member sealing between the carrier and the case, wherein one of the carrier or the case is configured to rotate relative to the other of the carrier or the case about a rotational axis, wherein the one of the carrier or the case includes a main body portion and a flange portion connected to the main body portion, wherein the main bearing is pressed in an axial direction parallel to the rotational axis between the main body portion and the other of the carrier or the case, and wherein the sealing member is pressed in the axial direction between the flange portion and the other of the carrier or the case.
  2. The speed reducer of claim 1, wherein the other of the carrier or the case includes a second main body portion and a second flange portion connected to the second main body portion, wherein the main bearing is pressed in the axial direction between the main body portion and the second main body portion, and wherein the sealing member is pressed in the axial direction between the flange portion and the second flange portion.
  3. The speed reducer of claim 1 or 2, wherein the main bearing includes an inner race, an outer race, and a plurality of rolling elements disposed between the inner race and the outer race, and wherein the sealing member overlaps with the inner race in the axial direction.
  4. The speed reducer of any one of claims 1 to 3, wherein a connection surface between the flange portion and the main body portion is situated on a same side in the axial direction as the sealing member with respect to the main bearing.
  5. The speed reducer of any one of claims 1 to 4, wherein the other of the carrier or the case includes a connecting portion connecting the main body portion and the flange portion, and wherein the connecting portion is positioned inward relative to the sealing member in a radial direction orthogonal to the rotational axis.
  6. The speed reducer of any one of claims 1 to 5, wherein the flange portion includes a restricting portion restricting movement of the sealing member in the axial direction.
  7. A method of assembling a speed reducer, the speed reducer including: a case that includes a case body and a case flange connected to the case body; a carrier that includes a carrier body and a carrier flange connected to the carrier body, the carrier being disposed at least partly in the case; a main bearing disposed between the case and the carrier; and a sealing member sealing between the carrier and the case, the method comprising: pressing the main bearing disposed between the carrier body and the case body; connecting the case flange to the case body and connecting the carrier flange to the carrier body; and pressing the sealing member disposed between the carrier flange and the case flange.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS This application is based on and claims the benefit of priority from Japanese Patent Application Serial No. 2024-190943 (filed on October 30, 2024), the contents of which are hereby incorporated by reference in its entirety. TECHNICAL FIELD The present disclosure relates to a speed reducer and a method of assembling a speed reducer. BACKGROUND For example, as disclosed in Japanese Patent Application Publication No. 2000-120846 ("the '846 Publication"), a speed reducer is known that includes a case, a carrier at least partly disposed in the case, a main bearing disposed between the case and the carrier, and a sealing member sealing between the carrier and the case. In the speed reducer, one of the carrier or the case rotates relative to the other about a rotational axis. The main bearing and the sealing member are pressed in an axial direction, parallel to the rotational axis, between the carrier and the case. The pressure required for proper operation of the main bearing differs from that required for proper operation of the sealing member. As for the carrier disclosed in the '846 Publication, a portion of the carrier that presses the main bearing and a portion of the carrier that presses the sealing member move in conjunction with each other relative to the case. As for the case disclosed in the '846 Publication, a portion of the case that presses the main bearing and a portion of the case that presses the sealing member move in conjunction with each other relative to the carrier. Therefore, in the speed reducer of the '846 Publication, the pressure applied to the main bearing in the axial direction and the pressure applied to the sealing member in the axial direction cannot be adjusted independently from each other. Therefore, in the speed reducer of the '846 Publication, it is difficult to ensure stable operation of both the main bearing and the sealing member. One object of the present disclosure is to ensure stable operation of the main bearing and the sealing member in the speed reducer. SUMMARY One aspect of the disclosure provides a speed reducer that includes: a carrier; a main bearing held on the carrier; a case held on the main bearing; a sealing member sealing between the carrier and the case, wherein one of the carrier or the case is configured to rotate relative to the other of the carrier or the case about a rotational axis, wherein the one of the carrier or the case includes a main body portion and a flange portion connected to the main body portion, wherein the main bearing is pressed in an axial direction parallel to the rotational axis between the main body portion and the other of the carrier or the case, and wherein the sealing member is pressed in the axial direction between the flange portion and the other of the carrier or the case. Another aspect of the disclosure provides a method of assembling a speed reducer. The speed reducer includes: a carrier that includes a carrier body and a carrier flange connected to the carrier body; a main bearing held on the carrier; a case that includes a case body and a case flange connected to the case body, the case being held on the main bearing; and a sealing member sealing between the carrier and the case. The method includes: pressing the main bearing disposed between the carrier body and the case body; connecting the case flange to the case body; connecting the carrier flange to the carrier body; and pressing the sealing member disposed between the carrier flange and the case flange. ADVANTAGEOUS EFFECTS According to the aspects of the disclosure, the operation of the main bearing and the sealing member in the speed reducer can be stabilized. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a sectional view of a speed reducer for describing an embodiment of the disclosure.Fig. 2 is a sectional view taken along the line II-II in Fig. 1.Fig. 3 is an enlarged view of the portion A of Fig. 1.Fig. 4 illustrates a method of adjusting the pressure applied to a sealing member of a carrier flange.Fig. 5 illustrates a method of adjusting the pressure applied to a sealing member of a case flange. DESCRIPTION OF THE EMBODIMENTS An embodiment of the disclosure relates to the following items (1) to (7). (1) A speed reducer including: a case; a carrier at least partly located in the case; a main bearing located between the case and the carrier; and a sealing member for sealing between the carrier and the case, wherein one of the carrier or the case is configured to rotate relative to the other of the carrier or the case about a rotational axis, wherein the one of the carrier or the case includes a main body portion and a flange portion connected to the main body portion, wherein the main bearing is pressed in an axial direction parallel to the rotational axis between the main body portion and the other of the carrier or the case, and wherein the sealing member is pressed in the axial direction between the flange portion and