A bearing assembly, comprising: a retainer assembly ; a bearing stationary ring ; and a bearing rotary ring , the retainer assembly being disposed between the bearing stationary ring and the bearing rotary ring, a lubrication passage being provided in an end face of the bearing rotary ring ; wherein the lubrication passage comprises: a first lubrication passage provided in the end face of the bearing rotary ring ; wherein, the first lubrication passage extends along a circumferential direction of the bearing rotary ring ; wherein the lubrication passage further comprises: a second lubrication passage provided in the end face of the bearing rotary ring ; wherein, the second lubrication passage is communicated with the first lubrication passage ; wherein the second lubrication passage is provided with an oil inlet and an oil outlet , the oil inlet intersects with a circumferential outer surface of the bearing rotary ring , and the oil outlet is communicated with the first lubrication passage ; characterized in that the second lubrication passage is an expansion groove, and the second lubrication passage gradually expands from the oil outlet to the oil inlet. a retainer assembly ; a bearing stationary ring ; and a bearing rotary ring , the retainer assembly being disposed between the bearing stationary ring and the bearing rotary ring, a lubrication passage being provided in an end face of the bearing rotary ring ; wherein the lubrication passage comprises: a first lubrication passage provided in the end face of the bearing rotary ring ; wherein, the first lubrication passage extends along a circumferential direction of the bearing rotary ring ; wherein the lubrication passage further comprises: a second lubrication passage provided in the end face of the bearing rotary ring ; wherein, the second lubrication passage is communicated with the first lubrication passage ; wherein the second lubrication passage is provided with an oil inlet and an oil outlet , the oil inlet intersects with a circumferential outer surface of the bearing rotary ring , and the oil outlet is communicated with the first lubrication passage ; characterized in that the second lubrication passage is an expansion groove, and the second lubrication passage gradually expands from the oil outlet to the oil inlet. a first lubrication passage provided in the end face of the bearing rotary ring ; wherein, the first lubrication passage extends along a circumferential direction of the bearing rotary ring ; wherein the lubrication passage further comprises: a second lubrication passage provided in the end face of the bearing rotary ring ; wherein, the second lubrication passage is communicated with the first lubrication passage ; wherein the second lubrication passage is provided with an oil inlet and an oil outlet , the oil inlet intersects with a circumferential outer surface of the bearing rotary ring , and the oil outlet is communicated with the first lubrication passage ; characterized in that the second lubrication passage is an expansion groove, and the second lubrication passage gradually expands from the oil outlet to the oil inlet. a second lubrication passage provided in the end face of the bearing rotary ring ; wherein, the second lubrication passage is communicated with the first lubrication passage ; wherein the second lubrication passage is provided with an oil inlet and an oil outlet , the oil inlet intersects with a circumferential outer surface of the bearing rotary ring , and the oil outlet is communicated with the first lubrication passage ; characterized in that the second lubrication passage is an expansion groove, and the second lubrication passage gradually expands from the oil outlet to the oil inlet. <EOS>