The wheel represents authority and dominion, the way things are, and Buddhist teaching. The eight spokes of the wheel refers to the eightfold path, which is elaborated in the precepts. The wheel is dominion, the way things are, and the buddhist teaching.
The first archaeological evidence, mainly of ornamental stone carvings, comes from the time of the Emperor Asoka (273 – 232 BCE), who converted to Buddhism and made it a popular religion in India and beyond.
In Japan, the Nyoirin Kannon is most often depicted as six-armed and holding up a wheel, rinpou 輪宝 with one arm and proffering a “wish-fulfilling jewel” *nyoi houju 如意宝珠 with another arm. These images were largely carved between the Nara Period through Heian Periods.
In very early Buddhist art, to represent Buddha the symbols used were mainly the Eight Spoked Wheel along with the Bodhi Tree, the Buddha’s Footprints, an Empty Throne, a Begging Bowl and a Lion.
The Eight-Spoked Dharma Wheel or ‘Dharmachakra’ (Sanskrit) symbolises the Buddha’s turning the Wheel of Truth or Law (dharma = truth/law, chakra = wheel).
The wheel (on the left and right) refers to the story that shortly after the Buddha achieved enlightenment, Brahma came down from heaven and requested the Buddha to teach by offering him a Dharmachakra. The Buddha is known as the Wheel-Turner: he who sets a new cycle of teachings in motion and in consequence changes the course of destiny.
The Dharmachakra has eight spokes, symbolising the Eight-fold Noble Path. The 3 swirling segments in centre represent the Buddha, Dharma (the teachings) and Sangha (the spiritual community). The wheel can also be divided into three parts, each representing an aspect of Buddhist practice; the hub (discipline), the spokes (wisdom), and the rim (concentration).
Reference Source:
JAPANESE MYTHOLOGY & FOLKLORE 