Abstract: A motor control device controls driving of a motor, which outputs torque to a rack shaft as a load by rotation of a shaft fixed to a rotor. The motor control device has a rotation stress check unit for determining a rotation stress indicating a rotation stress, which is applied inversely from the load to a protection target member such as a shaft, bearing and oil seal related to the rotation of the shaft or torque transmission to the load. The rotation stress check unit determines the rotation stress is excessive based on that an absolute value of a rotation evaluation value exceeds a stress threshold value. The stress threshold value is set to be larger than an absolute value of an upper limit value realized in normal drive control.

Abstract: A rotating electric machine includes a stator core, multi-phase stator coils and a rotor. The stator core has teeth and slots. Each of the multi-phase stator coils is comprised of phase windings received in the slots of the stator core. The rotor radially faces the teeth of the stator core. Between the multi-phase stator coils, there is provided, at a maximum, a phase difference of ?1 in electrical angle. Each of the teeth of the stator core has a radially-extending portion and a distal end portion. The distal end portion has skew-forming portions arranged in an axial direction of the stator core. Each of the skew-forming portions has a distal end surface facing the rotor. Circumferential center positions of the distal end surfaces of the skew-forming portions are circumferentially offset from one another by, at a maximum, ?2 in electrical angle. Moreover, the relationship of ?2<?1 is satisfied.

Abstract: A motor control device controls driving of a motor, which outputs torque to a rack shaft as a load by rotation of a shaft fixed to a rotor. The motor control device has a rotation stress check unit for determining a rotation stress indicating a rotation stress, which is applied inversely from the load to a protection target member such as a shaft, bearing and oil seal related to the rotation of the shaft or torque transmission to the load. The rotation stress check unit determines the rotation stress is excessive based on that an absolute value of a rotation evaluation value exceeds a stress threshold value. The rotation evaluation value is a rotation angular velocity, a rotation angular acceleration or a related value corresponding to the rotation angular velocity or the rotation angular acceleration. The stress threshold value is set to be larger than an absolute value of an upper limit value realized in normal drive control.

Abstract: A case is formed of aluminum. A rotation axis has one end affixed with an input rotor element and is rotational with a rotor. A first bearing is equipped to the case and is located between the input rotor element and the rotor to rotationally support the rotation axis. A second bearing is equipped to the case and is located on an opposite side of the rotor from the first bearing to rotationally support the rotation axis. A multilayered helical wave washer is wound for three rounds or more in a spiral wave form and is located in an axial gap formed between the case and an outer ring of one of the first bearing and the second bearing to apply a spring load to the outer ring in the axial direction.

Abstract: An electric motor is provided which is designed to minimize a risk of corrosion or stress corrosion cracking of parts thereof and reduce mechanical vibration or noise. The electric motor includes an output shaft, a bearing which retains the output shaft, a frame, and a biasing member. The biasing member is made of austenite stainless steel and disposed between the bearing and a bottom wall of a bearing housing to elastically press the output shaft in a lengthwise direction thereof for eliminating mechanical noise arising from vibration of a rotor. The frame has a coating formed on an outer surface thereof for avoiding erosion thereof. The coating is not formed at least on a portion of the frame which faces the biasing member in order to induce sacrificial corrosion of the frame, which decelerates the corrosion of the biasing member to eliminate a risk of the stress corrosion cracking thereof.

Abstract: A drive device includes a shaft rotatably supported by a first bearing and a second bearing. The first bearing is disposed in a shaft hole of an output frame end. The second bearing is disposed in a bearing box of an opposite-to-output frame end. An oil seal is fixed in the shaft hole and is closer to an output end than the first bearing is, and is in sliding contact with an outer circumference of the shaft. A biasing member is housed in the bearing box and biases an outer race of the second bearing toward the output end. Accordingly, a deflection amount and a bend amount of the shaft at the location where the oil seal is disposed may be reduced.

Abstract: A rotating electric machine includes a stator core, multi-phase stator coils and a rotor. The stator core has teeth and slots. Each of the multi-phase stator coils is comprised of phase windings received in the slots of the stator core. The rotor radially faces the teeth of the stator core. Between the multi-phase stator coils, there is provided, at a maximum, a phase difference of ?1 in electrical angle. Each of the teeth of the stator core has a radially-extending portion and a distal end portion. The distal end portion has skew-forming portions arranged in an axial direction of the stator core. Each of the skew-forming portions has a distal end surface facing the rotor. Circumferential center positions of the distal end surfaces of the skew-forming portions are circumferentially offset from one another by, at a maximum, ?2 in electrical angle. Moreover, the relationship of ?2<?1 is satisfied.

Abstract: A driving unit includes a stator, a rotor, a shaft, a housing, a protrusion, a small pulley, and a sealing member. The rotor is rotatably disposed relative to the stator. The shaft rotates together with the rotor. The housing houses the stator and the rotor. The protrusion protrudes from an outer surface of the housing toward an outside of the housing. The outer surface is positioned at one side of the housing in an axial direction of the rotor. The small pulley is disposed at an end of the shaft protruding toward the outside of the housing through a hole formed in the protrusion. The small pulley is cylindrical shaped. The sealing member seals a space between an inner surface of the hole of the protrusion and an outer surface of the shaft.

Abstract: The present disclosure provides a driving device including a stator, a rotor, a housing, a controller, and a sealing member. The sealing member includes a base and protrusions. The protrusion includes a cylindrical portion, a cover portion, a first annular protrusion, and a second annular protrusion. The first and second annular protrusions outwardly protrude from the cylindrical portion. The first annular protrusion is fit in a fit region of the lead hole in a compressed state. The second annular protrusion is offset from the fit region toward the controller.

Abstract: An electric motor is provided which is designed to minimize a risk of corrosion or stress corrosion cracking of parts thereof and reduce mechanical vibration or noise. The electric motor includes an output shaft, a bearing which retains the output shaft, a frame, and a biasing member. The biasing member is made of austenite stainless steel and disposed between the bearing and a bottom wall of a bearing housing to elastically press the output shaft in a lengthwise direction thereof for eliminating mechanical noise arising from vibration of a rotor. The frame has a coating formed on an outer surface thereof for avoiding erosion thereof. The coating is not formed at least on a portion of the frame which faces the biasing member in order to induce sacrificial corrosion of the frame, which decelerates the corrosion of the biasing member to eliminate a risk of the stress corrosion cracking thereof.

Abstract: The present disclosure provides a driving device including a stator, a rotor, a housing, a controller, and a sealing member. The sealing member includes a base and protrusions. The protrusion includes a cylindrical portion, a cover portion, a first annular protrusion, and a second annular protrusion. The first and second annular protrusions outwardly protrude from the cylindrical portion. The first annular protrusion is fit in a fit region of the lead hole in a compressed state. The second annular protrusion is offset from the fit region toward the controller.

Abstract: A drive device includes a shaft rotatably supported by a first bearing and a second bearing. The first bearing is disposed in a shaft hole of an output frame end. The second bearing is disposed in a bearing box of an opposite-to-output frame end. An oil seal is fixed in the shaft hole and is closer to an output end than the first bearing is, and is in sliding contact with an outer circumference of the shaft. A biasing member is housed in the bearing box and biases an outer race of the second bearing toward the output end. Accordingly, a deflection amount and a bend amount of the shaft at the location where the oil seal is disposed may be reduced.

Abstract: A driving unit includes a stator, a rotor, a shaft, a housing, a protrusion, a small pulley, and a sealing member. The rotor is rotatably disposed relative to the stator. The shaft rotates together with the rotor. The housing houses the stator and the rotor. The protrusion protrudes from an outer surface of the housing toward an outside of the housing. The outer surface is positioned at one side of the housing in an axial direction of the rotor. The small pulley is disposed at an end of the shaft protruding toward the outside of the housing through a hole formed in the protrusion. The small pulley is cylindrical shaped. The sealing member seals a space between an inner surface of the hole of the protrusion and an outer surface of the shaft.

Abstract: A case is formed of aluminum. A rotation axis has one end affixed with an input rotor element and is rotational with a rotor. A first bearing is equipped to the case and is located between the input rotor element and the rotor to rotationally support the rotation axis. A second bearing is equipped to the case and is located on an opposite side of the rotor from the first bearing to rotationally support the rotation axis. A multilayered helical wave washer is wound for three rounds or more in a spiral wave form and is located in an axial gap formed between the case and an outer ring of one of the first bearing and the second bearing to apply a spring load to the outer ring in the axial direction.

Abstract: A housing (11) including a bearing retainer is formed as one member. One pair of bearings is arranged in the bearing retainer and the shaft is rotatably supported by the pair of bearings. The region for retaining the bearing is reduced in the axis direction and thus the motor is miniaturized by supporting the rotor including the shaft by a so-called cantilever structure.